Introduction
Pulmonary valve stenosis is a common CHD and accounts for approximately 8–10% of congenital cardiac anomalies. Reference van der Linde, Konings and Slager1–Reference Cuypers, Witsenburg, van der Linde and Roos-Hesselink3 It is characterised by narrowing of the pulmonary valve, primarily due to two well-defined anatomical mechanisms. The first, known as a dome-shaped valve, results from commissural fusion or absence of pulmonary valve commissures, creating a small central orifice. The second mechanism corresponds to a dysplastic valve, characterised by thickened and rigid leaflets with limited mobility of the free edges. Both mechanisms produce significant obstruction to right ventricular outflow into the pulmonary artery. Reference Feltes, Bacha and Beekman III4
This condition presents a broad clinical spectrum, ranging from mild and asymptomatic forms to severe and critical presentations. In particular, pulmonary stenosis may manifest in its critical form during the neonatal period, characterised by severe right ventricular outflow tract obstruction leading to ductal-dependent pulmonary circulation, desaturation, and cyanosis secondary to right-to-left shunting through a patent foramen ovale. Reference Feltes, Bacha and Beekman III4,Reference Latson5
Since 1982, when Kan et al. Reference Kan, White, Mitchell and Gardner6 performed the first successful percutaneous balloon pulmonary valvuloplasty, this technique has become the treatment of choice over surgical valvotomy in patients with pulmonary stenosis, regardless of patient age or valve morphology, given that it is a minimally invasive percutaneous procedure with high immediate success rates.
Pulmonary stenosis severity is established by transthoracic echocardiography using Doppler-derived peak transvalvular velocity and classified as mild, moderate, or severe according to current international guidelines. Reference Stout, Daniels and Aboulhosn7,Reference Baumgartner, Hung and Bermejo8
In paediatric population, although the same echocardiographic parameters are used for severity stratification, cardiac catheterisation guidelines consider a peak instantaneous Doppler gradient ≥40 mmHg a reasonable threshold for intervention, particularly in infants and young children. This cut-off is especially relevant in symptomatic patients and in neonates with critical pulmonary stenosis. Reference Feltes, Bacha and Beekman III9–Reference Otto, Nishimura and Bonow11
Despite balloon pulmonary valvuloplasty being the treatment of choice, restenosis or pulmonary regurgitation may occur during follow-up in a relevant proportion of patients, potentially requiring repeat percutaneous or surgical interventions. The occurrence and severity of these outcomes have been associated with various clinical, anatomical, and haemodynamic factors. Reference Tabatabaei, Boutin, Nykanen, Freedom and Benson12–Reference Abu-Tair, Willershausen and Friedmann17
Internationally, data from large cohorts systematically evaluating risk factors associated with residual stenosis during long-term follow-up, as well as the incidence and progression of clinically significant pulmonary regurgitation, remain limited. This gap is particularly relevant in infants, who exhibit distinct anatomical and pathophysiological characteristics compared with older children and adolescents.
In Colombia, available evidence regarding mid- and long-term outcomes after balloon pulmonary valvuloplasty in patients with critical or severe pulmonary stenosis is scarce and largely limited to immediate or short-term results. Data evaluating long-term clinically relevant outcomes in infants and young children remain limited, particularly regarding freedom from restenosis, pulmonary regurgitation, and reintervention over extended follow-up. Furthermore, there are few reports from Latin American referral centres describing long-term outcomes in children ≤24 months after balloon pulmonary valvuloplasty. Reference Sánchez-Escobar, Lince-Varela, Díaz-Medina and Restrepo18
In this context, the primary objective of this study was to evaluate the short- and long-term clinical outcomes of balloon pulmonary valvuloplasty in children ≤24 months with critical or haemodynamically significant pulmonary stenosis treated at Clínica Cardio VID between January 2004 and July 2024. Secondary objectives were to assess immediate procedural success, estimate freedom from significant restenosis, moderate-or-greater pulmonary regurgitation, pulmonary valve reintervention, and surgical reintervention using Kaplan–Meier analysis, evaluate predictors of significant restenosis and moderate-or-greater pulmonary regurgitation using Cox proportional hazards regression, and describe longitudinal changes in tricuspid regurgitation following relief of pulmonary valvuloplasty obstruction.
Methods
Study design
An analytical retrospective cohort study was conducted at Clínica Cardio VID, a tertiary cardiovascular referral centre in Medellín, Colombia. The institutional paediatric cardiac catheterisation registry was reviewed to identify all consecutive patients ≤24 months who underwent balloon pulmonary valvuloplasty for critical or haemodynamically significant pulmonary stenosis between January 2004 and July 2024. Clinical records, catheterisation reports, and echocardiographic data were reviewed to evaluate immediate procedural results and long-term clinical outcomes.
Study population
The study population was identified from the institutional catheterisation laboratory database and included all consecutive patients ≤24 months of age who underwent balloon pulmonary valvuloplasty for congenital pulmonary stenosis between January 2004 and July 2024. Patients with complex CHD requiring palliative balloon pulmonary valvuloplasty, including pulmonary atresia with intact ventricular septum, and those who had undergone previous surgical pulmonary valve intervention or pulmonary blood flow augmentation procedures before the initial balloon pulmonary valvuloplasty were excluded.
After application of these predefined exclusion criteria, 148 patients remained eligible for the study. Clinical records, catheterisation reports, and echocardiographic studies were subsequently reviewed to obtain baseline clinical characteristics, procedural data, and longitudinal follow-up information.
Nineteen patients were excluded from the final longitudinal analysis. Three patients died within the first 10 days after balloon pulmonary valvuloplasty from causes unrelated to the procedure (one due to respiratory failure secondary to severe respiratory infection and two due to septic shock). The remaining sixteen patients were excluded because essential baseline clinical, echocardiographic, and invasive haemodynamic data required to assess procedural efficacy and longitudinal outcomes were unavailable in the medical records. Consequently, baseline characteristics and longitudinal outcomes could not be reliably assessed in these patients, precluding their inclusion in the analytical cohort.
The final study cohort consisted of 129 patients (Figure 1).
Patient selection and study cohort.
Inclusion and exclusion criteria
Patients were included if they had critical pulmonary stenosis or haemodynamically significant pulmonary stenosis requiring balloon pulmonary valvuloplasty.
Critical pulmonary stenosis was defined as severe congenital valvar pulmonary stenosis presenting in the neonatal period with ductal-dependent pulmonary blood flow, such that adequate pulmonary perfusion required maintenance of ductal patency with prostaglandin infusion. These patients typically presented with cyanosis and hypoxaemia due to right-to-left shunting across a patent foramen ovale secondary to severe right ventricular outflow tract obstruction and systemic or near-systemic right ventricular pressure. Reference Jacob, Levy and Sen19
Haemodynamically significant valvar pulmonary stenosis was defined as a peak instantaneous Doppler gradient ≥40 mmHg across the pulmonary valve on transthoracic echocardiography, or clinically significant valvar obstruction associated with right ventricle dysfunction or right ventricle pressures approaching systemic levels. These indications are consistent with the American Heart Association Scientific Statement on Indications for Cardiac catheterisation and Intervention in Pediatric Cardiac Disease, which recommends balloon pulmonary valvuloplasty for patients with a peak instantaneous Doppler gradient >40 mmHg or clinically significant obstruction associated with right ventricle dysfunction or systemic right ventricle pressure. Reference Feltes, Bacha and Beekman III9
Patients with minor associated cardiac lesions not requiring surgical intervention, including atrial septal defect, patent ductus arteriosus, or small ventricular septal defect, were included.
Patients were excluded from the longitudinal analysis if they had previous surgical pulmonary valve intervention, complex CHD in which balloon pulmonary valvuloplasty was performed with palliative intent, unavailable baseline pre-intervention clinical, echocardiographic, or invasive haemodynamic data required for outcome assessment, absence of follow-up echocardiographic evaluation, or early in-hospital death unrelated to the procedure.
Procedure
Balloon pulmonary valvuloplasty was performed using a standard institutional technique by the paediatric interventional cardiology team. All procedures were performed under general anaesthesia with endotracheal intubation, including neonates and critically ill infants. Anaesthetic management was provided by a dedicated paediatric anaesthesia team with continuous haemodynamic and ventilatory monitoring throughout the procedure. The anaesthetic approach remained consistent throughout the 20-year study period.
The following parameters were recorded: peak-to-peak right ventricle/pulmonary artery gradient, right ventricle systolic pressure before and after dilation, right ventricle/systemic pressure ratio, maximum balloon diameter used, balloon-to-annulus ratio, and requirement for predilation.
The balloon-to-annulus ratio was calculated based on the maximum balloon diameter and the pulmonary valve annulus diameter measured by angiography in the lateral projection.
Data collection and variables
A retrospective review of medical records, catheterisation reports, and written echocardiographic reports was performed. Demographic data, including age, sex, weight, height, and body surface area, as well as pre-intervention clinical characteristics, baseline echocardiographic parameters, intraprocedural haemodynamic variables, and follow-up outcomes were collected.
Baseline echocardiographic parameters included peak and mean transvalvular pulmonary gradients measured by spectral Doppler. In the presence tricuspid regurgitation, right ventricle pressure was estimated using the modified Bernoulli equation. Pulmonary and tricuspid annular Z-scores were calculated according to the Pediatric Heart Network model described by Lopez et al. Reference Lopez, Colan and Stylianou20 Tricuspid valve dysplasia and qualitative severity of tricuspid regurgitation were also recorded.
Follow-up variables included peak echocardiographic pulmonary valve gradient, severity of pulmonary regurgitation and tricuspid regurgitation, occurrence of significant restenosis, moderate-or-greater pulmonary regurgitation, pulmonary valve reintervention, surgical reintervention, type of reintervention, and time to each event. Given the variability in follow-up duration, longitudinal outcomes were analysed as time-to-event variables. Echocardiographic data were also summarised at two predefined time points: within the first 6 months after the procedure and at the last available echocardiogram obtained beyond 6 months.
All echocardiographic variables were extracted from written clinical reports without systematic re-review of the original imaging studies.
Operational definitions
A pulmonary annular Z-score ≤ −2 was categorised as hypoplastic.
Predilation was defined as a stepwise dilation strategy performed during the same catheterisation procedure, consisting of one or more preliminary inflations using a balloon smaller than the definitive therapeutic balloon before final balloon pulmonary valvuloplasty. This technique was selectively applied in cases of critically stenotic or markedly restrictive valve orifices to facilitate valve crossing, achieve partial commissural separation, and allow controlled delivery and expansion of the definitive balloon. Predilation was not performed as a staged procedure, and all patients underwent definitive balloon pulmonary valvuloplasty during the same intervention.
Immediate procedural success was defined as a reduction of the peak-to-peak invasive transvalvular pressure gradient between the right ventricle and pulmonary artery to ≤25 mmHg at the end of the procedure. This definition was based on invasive haemodynamic measurements obtained during cardiac catheterisation and is consistent with previously reported haemodynamic targets after successful balloon pulmonary valvuloplasty. Although some studies have defined procedural success as a reduction of at least 50% in the baseline transvalvular gradient, we selected an absolute residual peak-to-peak right ventricle–pulmonary artery gradient ≤25 mmHg because it reflects the residual haemodynamic obstruction immediately after intervention. Reference McCrindle13,Reference Liu, Gao, Butera, Chessa, Eicken and Thomson21–Reference Merino-Ingelmo, Santos-de Soto, Coserria-Sánchez, Descalzo-Señoran and Valverde-Pérez23 Because invasive peak-to-peak catheterisation gradients and peak instantaneous Doppler echocardiographic gradients are physiologically different measurements, they should not be used interchangeably.
Residual pulmonary stenosis was defined as a peak echocardiographic gradient ≥20 mmHg on follow-up echocardiography. Significant restenosis was defined as a peak instantaneous Doppler gradient ≥36 mmHg across the pulmonary valve during follow-up echocardiography. Because no universally accepted paediatric definition of restenosis after balloon pulmonary valvuloplasty exists, this threshold was selected based on echocardiographic severity criteria for pulmonary stenosis, in which a peak gradient <36 mmHg corresponds to mild obstruction, while gradients ≥36 mmHg indicate at least moderate obstruction This definition was used to identify recurrent moderate-or-greater obstruction on follow-up echocardiography as an imaging outcome. Reintervention was analysed as a separate time-to-event clinical endpoint and was based on the overall clinical context, including symptoms, right ventricle function, progression of obstruction, and invasive haemodynamic assessment, rather than on Doppler gradient alone. Reference McCrindle13,Reference Liu, Gao, Butera, Chessa, Eicken and Thomson21–Reference El Tahlawi, Morsy, Elawady, Abdelaziz and Eldamanhory25
Pulmonary regurgitation and tricuspid regurgitation were classified qualitatively according to the echocardiographic report.
Persistent tricuspid regurgitation was defined as any residual tricuspid regurgitation greater than trivial (mild, moderate, or severe) after the 6-month follow-up echocardiographic evaluation.
Reintervention was defined as any subsequent percutaneous or surgical procedure performed on the pulmonary valve.
Time to reintervention was calculated in months from the date of balloon pulmonary valvuloplasty to the subsequent procedure.
Follow-up duration was defined as the interval from the date of balloon pulmonary valvuloplasty to the last available institutional echocardiogram or to the echocardiogram preceding surgical valve intervention, if applicable, and was expressed in years.
Statistical analysis
Statistical analyses were performed using standard methods for observational clinical studies. Categorical variables are presented as frequencies and percentages. Continuous variables were tested for normality using the Kolmogorov–Smirnov test and are reported as mean ± standard deviation or median and interquartile range, as appropriate.
Paired continuous variables before and after balloon pulmonary valvuloplasty were compared using the Wilcoxon signed-rank test. Changes in tricuspid regurgitation severity between baseline and the 6-month follow-up were also assessed using the Wilcoxon signed-rank test after grading tricuspid regurgitation as an ordinal variable (none/trivial, mild, moderate, and severe). Improvement in tricuspid regurgitation was defined as any reduction in tricuspid regurgitation severity, whereas persistent tricuspid regurgitation was defined as residual tricuspid regurgitation greater than trivial at 6-month follow-up. Correlations between improvement in tricuspid regurgitation and reductions in right ventricular pressure or pulmonary valve gradient were evaluated using Spearman’s rank correlation coefficient. Comparisons according to tricuspid valve morphology were performed using the χ2 test. Associations between persistent tricuspid regurgitation and continuous variables were evaluated using the Mann–Whitney U test, whereas categorical outcomes were compared using the χ2 test or Fisher’s exact test, as appropriate.
Time-to-event outcomes were analysed using Kaplan–Meier methods. The outcomes evaluated were freedom from significant pulmonary stenosis, moderate-or-greater pulmonary regurgitation, pulmonary valve reintervention, and surgical reintervention. Patients without an event were censored at the last available follow-up, and Kaplan–Meier estimates were reported at 1, 3, 5, and 10 years. Univariable Cox proportional hazards regression was used to evaluate predictors of each outcome, and hazard ratios with 95% confidence intervals were reported. Continuous predictors were scaled to improve clinical interpretability (balloon-to-annulus ratio per 0.1-unit increase, baseline right ventricle–pulmonary artery gradient per 10-mmHg increase, and RV/systemic pressure ratio per 0.1-unit increase). Because of the limited number of events for several outcomes, multivariable Cox regression was not performed to avoid model overfitting.
All analyses were performed using SPSS version 27.0 (IBM Corp., Armonk, NY, USA). A two-sided p value < 0.05 was considered statistically significant.
Results
Baseline characteristics
A total of 129 patients were included. Median age at balloon pulmonary valvuloplasty was 1.5 months (interquartile range 0.2–6.3), 48.7% were male, median weight was 4.0 kg (interquartile range 3.3–6.0), median height was 54 cm (interquartile range 49–61), and median body surface area was 0.24 m2 (interquartile range 0.20–0.32) (Table 1).
Demographic, clinical, echocardiographic, and haemodynamic characteristics
Table 1. Long description
A table with 18 rows and 2 columns. The first column lists variables, and the second column provides corresponding values. Row 1: Variable N, 129. Row 2: Demographic and clinical characteristics Age (months), median (IQR), 1.5 (0.2-6.3). Row 3: Male sex, n (%), 60 (48.7). Row 4: Weight (kg), median (IQR), 4.0 (3.3-6.0). Row 5: Height (cm), median (IQR), 54 (49-61). Row 6: Body surface area (m^2), median (IQR), 0.24 (0.20-0.32). Row 7: Critical pulmonary stenosis, n (%), 48 (37.2). Row 8: Comorbidities, n (%), 6 (4.6). Row 9: Noonan syndrome, 5 (3.8). Row 10: Down syndrome, 1 (0.77). Row 11: Prostaglandin E1 dependent, n (%), 45 (34.8). Row 12: Echocardiographic variables Peak doppler pulmonary valve gradient (mmHg), median (IQR), 75 (65-100). Row 13: Pulmonary annulus diameter (mm), median (IQR), 7.5 (6.7-9). Row 14: Pulmonary valve Z-score, n (%), <= -2, 54 (41.8); -2 a 0, 71 (55); >0, 4 (3.2). Row 15: Tricuspid valve Z-score, n (%), < -2, 0; -2 a 2, 49 (38); >2, 80 (62). Row 16: Patent ductus arteriosus (PDA), n (%), 63 (48.8). Row 17: Atrial septal defect (ASD), n (%), 19 (14.7). Row 18: Patent foramen ovale (PFO), n (%), 82 (63.5). Row 19: Ventricular septal defect (VSD), n (%), 5 (3.8). Row 20: Dysplastic tricuspid valve, n (%), 32 (24.8). Row 21: Catheterisation variables Procedure time (minutes), median (IQR), 38 (25-50). Row 22: RV-to-systemic pressure ratio, median (IQR), 1.1 (0.9-1.5). Row 23: Balloon-to-annulus ratio, median (IQR), 1.28 (1.25-1.33). Row 24: Balloon diameter (mm), median (IQR), 10 (9-12). Row 25: Predilation balloon valvuloplasty, n (%), 22 (17.1). Row 26: Balloon type, n (%), Z-Med (NuMED), 3 (2.3); Mini-Tyshak /Tyshak, 126 (97.7). Row 27: Follow-up duration (years), median (IQR), 7 (3-10); range 0.2-19 years.
Notes: Data are presented as median (interquartile range) or n (%).
IQR = interquartile range; WHO = World Health Organization; RV = right ventricle.
Critical pulmonary stenosis was present in 48 patients (37.2%). Comorbidities were identified in six patients (4.6%), predominantly Noonan syndrome (n = 5, 3.8%). Forty-five patients (34.8%) required prostaglandin E1 infusion before balloon pulmonary valvuloplasty because of ductal-dependent pulmonary blood flow. On baseline echocardiography, the median peak Doppler pulmonary valve gradient was 75 mmHg (interquartile range 65–100). Pulmonary annular hypoplasia (Z-score ≤ −2) was present in 41.8% of patients, whereas tricuspid annular enlargement (Z-score > 2) was observed in 62%. Dysplastic tricuspid valves were identified in 24.8% (Table 1).
During the procedure, median catheterisation time was 38 minutes (interquartile range 25–50), and the median Median procedure time was 38 minutes (interquartile range 25–50). Median right ventricle/systemic pressure ratio was 1.1 (interquartile range 0.9–1.5), median balloon-to-annulus ratio was 1.28 (interquartile range 1.25–1.33), and median balloon diameter was 10 mm (interquartile range 9–12). Predilation was performed in 22 patients (17.1%). Median follow-up duration was 7 years (interquartile range 3–10).
No procedure-related complications or deaths occurred.
Immediate haemodynamic results
Immediate procedural success, defined as a peak-to-peak right ventricle–pulmonary artery gradient ≤ 25 mmHg at the end of the procedure, was achieved in 122 patients (94.5%). Balloon pulmonary valvuloplasty resulted in a significant reduction in the median peak right ventricle–pulmonary artery catheter gradient from 44 mmHg (interquartile range 41–58.5) to 7 mmHg (interquartile range 3.5–12), accompanied by a decrease in median right ventricle systolic pressure from 70 mmHg (interquartile range 62–85) to 36 mmHg (interquartile range 28–46) (both p < 0.01) (Table 2).
Immediate invasive haemodynamic results before and after balloon pulmonary valvuloplasty
Table 2. Long description
A table with two rows and four columns comparing hemodynamic parameters before and after balloon pulmonary valvuloplasty. The columns are labeled ‘Haemodynamic parameters’, ‘Pre-BPV’, ‘Post-BPV’, and ‘p Value’. The first row compares the peak right ventricle-pulmonary artery catheter gradient in mmHg, with median values of 44 (interquartile range 41-58.5) pre-BPV and 7 (interquartile range 3.5-12) post-BPV, with a p value of less than 0.01. The second row compares the right ventricle pressure in mmHg, with median values of 70 (interquartile range 62-85) pre-BPV and 36 (interquartile range 28-46) post-BPV, also with a p value of less than 0.01.
Notes: Data are presented as median (IQR). Pre-BPV and post-BPV values correspond to invasive haemodynamic measurements obtained immediately before and after the procedure. Comparisons between pre- and post-procedural invasive haemodynamic measurements were performed using the Wilcoxon signed-rank test.
IQR = interquartile range; RV = right ventricle; PA = pulmonary artery; BPV = balloon pulmonary valvulopasty.
Among the seven patients who did not meet the predefined criterion for immediate procedural success, five had concomitant supravalvular pulmonary stenosis, three of whom also had Noonan syndrome. Four underwent early surgical intervention because of persistent right ventricular outflow tract obstruction within 4–25 days after balloon pulmonary valvuloplasty. Surgical procedures included pulmonary valve replacement with a homograft (n = 2), surgical commissurotomy with pulmonary valvuloplasty (n = 1), and right ventricular outflow tract reconstruction using an autologous pericardial patch with creation of a monocusp pulmonary valve (n= 1). The remaining three patients demonstrated progressive haemodynamic improvement during follow-up, with reduction of the peak Doppler gradient to <36 mmHg within 6 months, without requiring additional catheter-based or surgical intervention.
Immediate post-procedural pulmonary and tricuspid regurgitation were not systematically documented throughout the study period and therefore were not included in the immediate haemodynamic analysis. These variables were instead evaluated using standardised follow-up echocardiographic assessments.
Echocardiographic follow-up
Estimated right ventricle pressure decreased from a median of 100 mmHg (interquartile range 89–121) before balloon pulmonary valvuloplasty to 40 mmHg (interquartile range 35–50) within the first 6 months and to 35 mmHg (interquartile range 32–40) thereafter. Similarly, the median peak Doppler pulmonary valve gradient decreased from 75 mmHg (interquartile range 65–100) to 22 mmHg (interquartile range 15–30) at 6 months and to 16 mmHg (interquartile range 12–35) beyond 6 months (Table 3).
Ppulmonary regurgitation became more frequent during follow-up, increasing from 100 patients (77.5%) within the first 6 months after V to 122 patients (94.6%) at the last follow-up evaluation. Despite this increase, pulmonary regurgitation remained predominantly trivial to mild at both time points, whereas moderate and severe pulmonary regurgitation were observed in 21 (16.3%) and 4 (3.1%) patients, respectively, at the last follow-up (Table 3).
Echocardiographic findings at baseline and during follow-up after balloon pulmonary valvuloplasty
Table 3. Long description
A table comparing echocardiographic parameters before and after balloon pulmonary valvuloplasty. The table has 4 rows and 3 columns. Column headers are: Echocardiographic parameters, Pre-BPV, First 6 months, After 6 months. Row 1: Estimated RV pressure (mmHg), median (IQR); Pre-BPV: 100 (89-121), First 6 months: 40 (35-50), After 6 months: 35 (32-40). Row 2: Peak Doppler pulmonary valve gradient (mmHg), median (IQR); Pre-BPV: 75 (65-100), First 6 months: 22 (15-30), After 6 months: 16 (12-35). Row 3: Pulmonary regurgitation severity, n (%); No pulmonary regurgitation; Pre-BPV: 0, First 6 months: 29 (22.5), After 6 months: 7 (5.4). Row 4: Trivial to mild; Pre-BPV: 0, First 6 months: 82 (63.5), After 6 months: 97 (75.2). Row 5: Moderate; Pre-BPV: 0, First 6 months: 17 (13.2), After 6 months: 21 (16.3). Row 6: Severe; Pre-BPV: 1 (0.8), First 6 months: 0, After 6 months: 4 (3.1).
Notes: Continuous variables are presented as median (IQR). Categorical variables are expressed as n (%). Pulmonary regurgitation severity was assessed qualitatively using transthoracic echocardiography at each follow-up time point.
IQR = interquartile range; RV = right ventricle; BPV = balloon pulmonary valvulopasty.
Tricuspid regurgitation after balloon pulmonary valvuloplasty
At baseline, tricuspid regurgitation was absent or trivial in 52 patients (40.3%), mild in 37 (28.7%), moderate in 22 (17.1%), and severe in 18 (14.0%). At 6-month follow-up, absent or trivial tricuspid regurgitation increased to 80 patients (62.0%), whereas severe tricuspid regurgitation decreased from 14.0% to 1.6%. Overall, tricuspid regurgitation severity improved significantly following balloon pulmonary valvuloplasty (Wilcoxon signed-rank test, p < 0.001). Tricuspid regurgitation improved in 59 patients (45.7%), remained unchanged in 59 (45.7%), and worsened in 11 (8.5%) (Table 4).
Changes in tricuspid regurgitation after balloon pulmonary valvuloplasty and its association with haemodynamic and clinical outcomes
Table 4. Long description
A table comparing tricuspid regurgitation (TR) severity at baseline and after 6 months, along with its correlation with haemodynamic improvement. The table has 12 rows and 2 columns. Column headers are Variable N = 129 and Finding. Row labels include Baseline TR severity, TR after 6 months, Wilcoxon signed-rank test, Correlation with haemodynamic improvement, Patients with dysplastic tricuspid valve, and Persistent TR (> trivial after 6 months). Row 1: Baseline TR severity, None/trivial, 52 (40.3 percent). Row 2: Baseline TR severity, Mild, 37 (28.7 percent). Row 3: Baseline TR severity, Moderate, 22 (17.1 percent). Row 4: Baseline TR severity, Severe, 18 (14.0 percent). Row 5: TR after 6 months, None/trivial, 80 (62.0 percent). Row 6: TR after 6 months, Mild, 32 (24.8 percent). Row 7: TR after 6 months, Moderate, 15 (11.6 percent). Row 8: TR after 6 months, Severe, 2 (1.6 percent). Row 9: Wilcoxon signed-rank test, p<0.001. Row 10: Correlation with haemodynamic improvement, TR improvement vs RV pressure reduction, ρ = 0.180; p = 0.041. Row 11: Correlation with haemodynamic improvement, TR improvement vs pulmonary gradient reduction, ρ = 0.019; p = 0.83. Row 12: Patients with dysplastic tricuspid valve, Baseline TR severity, More severe baseline TR than non-dysplastic valves (p<0.001). Row 13: Patients with dysplastic tricuspid valve, TR improvement, 74.2 percent vs 36.7 percent; p < 0.001. Row 14: Persistent TR (> trivial after 6 months), Residual RV pressure, p = 0.029. Row 15: Persistent TR (> trivial after 6 months), Residual pulmonary gradient, p = 0.618. Row 16: Persistent TR (> trivial after 6 months), Restenosis, p = 0.135. Row 17: Persistent TR (> trivial after 6 months), Reintervention, p = 0.249.
Notes: Values are presented as n (%) unless otherwise specified. TR severity was graded as none/trivial (0), mild (1), moderate (2), or severe (3). Improvement in TR was defined as any reduction in TR severity between baseline and 6-month follow-up. Persistent TR was defined as any residual TR greater than trivial after 6 months. p values were calculated using the Wilcoxon signed-rank test, Spearman’s rank correlation, Mann–Whitney U test, χ2 test, or Fisher’s exact test, as appropriate.
TR = tricuspid regurgitation; RV = right ventricle; TV = tricuspid valve.
Improvement in tricuspid regurgitation showed a weak but statistically significant correlation with reduction in right ventricle pressure (Spearman’s ρ = 0.180, p = 0.041), whereas no significant correlation was observed with reduction in the pulmonary valve gradient (ρ = 0.019, p = 0.831). Patients with dysplastic tricuspid valves had significantly more severe baseline tricuspid regurgitation and demonstrated a higher frequency of tricuspid regurgitation improvement following intervention (74.2% vs. 36.7%, p < 0.001), This finding likely reflects the greater baseline severity of tricuspid regurgitation in this subgroup rather than an intrinsically greater response to intervention.
Persistent tricuspid regurgitation (>trivial after 6 months) was associated with higher residual right ventricle pressure (p = 0.029), but not with residual pulmonary valve gradient (p = 0.618), restenosis (p = 0.135), or reintervention (p = 0.249). Additional analyses evaluating these associations are provided in Supplementary Table S1. Similarly, detailed subgroup analyses according to tricuspid valve morphology are presented in Supplementary Tables S2 and S3.
Follow-up and reinterventions
Median follow-up duration was 7 years (interquartile range 3–10; range 0.2–19 years). Sixty-nine patients had <5 years of follow-up, 33 had 5–10 years, and 27 had >10 years, including four with 19 years of follow-up.
Post-stenotic dilation was observed in 40 patients (31%). Overall, 24 patients (17.8%) underwent pulmonary valve reintervention after a median of 13.1 months (interquartile range 2.4–29.1). Repeat balloon pulmonary valvuloplasty was the most common first reintervention, followed by surgical pulmonary valve replacement with a bioprosthesis, pulmonary homograft implantation, right ventricular outflow tract reconstruction, and surgical commissurotomy (Table 5).
Clinical follow-up and pulmonary valve reinterventions
Table 5. Long description
A table with 7 rows and 2 columns. The columns are labeled ‘Variable’ and ‘Value’. The table summarizes clinical follow-up and pulmonary valve reinterventions. Row 1: Post-stenotic dilation, n (percent): 40 (31). Row 2: Reintervention on the pulmonary valve, n (percent): 24 (17.8). Row 3: Time to reintervention (months), median (interquartile range): 13.1 (2.4 - 29.1). Row 4: Type of reintervention, n (percent): Repeat balloon pulmonary valvuloplasty, 14 (58.3). Row 5: Surgical bioprosthetic pulmonary valve implantation, 4 (16.7). Row 6: Pulmonary homograft implantation, 3 (12.5). Row 7: RVOT reconstruction with autologous pericardial patch and monocusp valve creation, 2 (8.3). Row 8: Surgical commissurotomy with pulmonary valvuloplasty, 1 (4.2).
Notes: Continuous variables are presented as median (IQR). Categorical variables are expressed as n (%).
IQR = interquartile range; RVOT = right ventricular outflow tract.
Among the 14 patients undergoing repeat balloon pulmonary valvuloplasty, six subsequently required surgical intervention: three underwent pulmonary homograft implantation, two underwent right ventricular outflow tract reconstruction with transannular patch and monocusp valve creation, and one underwent surgical commissurotomy with pulmonary valvuloplasty. One of these patients later underwent percutaneous Melody valve implantation.
Four patients with severe pulmonary regurgitation underwent surgical bioprosthetic pulmonary valve replacement, two of whom subsequently underwent Melody transcatheter pulmonary valve implantation 12, 13, and 15 years after the index balloon pulmonary valvuloplasty procedure (Table 5, Figure 2).
Longitudinal clinical outcomes after balloon pulmonary valvuloplasty in the final analytical cohort.
Notes: The diagram summarises the occurrence of pulmonary regurgitation, residual pulmonary stenosis, and subsequent catheter-based or surgical reinterventions during follow-up. Percentages are calculated using the corresponding subgroup denominator. PR = pulmonary regurgitation; PVS = pulmonary valve stenosis; BPV = balloon pulmonary valvuloplasty.
Long-term time-to-event outcomes
Long-term clinical outcomes were evaluated using Kaplan–Meier time-to-event analysis (Table 6). During a median follow-up of 7 years (interquartile range, 3–10 years), significant pulmonary restenosis occurred in 33 patients (25.6%), moderate-or-greater pulmonary regurgitation in 25 (19.4%), pulmonary valve reintervention in 24 (18.6%), and surgical reintervention in 16 (12.4%).
Kaplan–Meier estimates of freedom from time-to-event outcomes
Table 6. Long description
A table with four rows and five columns comparing long-term clinical outcomes over 1 year, 3 years, 5 years, and 10 years. The outcomes measured are freedom from significant pulmonary restenosis, freedom from moderate-or-greater pulmonary regurgitation, freedom from pulmonary valve reintervention, and freedom from surgical reintervention. Row 1: Freedom from significant pulmonary restenosis, 80.6 percent, 77.1 percent, 73.3 percent, 71.9 percent. Row 2: Freedom from moderate-or-greater pulmonary regurgitation, 94.4 percent, 90.6 percent, 82.6 percent, 74.5 percent. Row 3: Freedom from pulmonary valve reintervention, 91.4 percent, 85.6 percent, 84.6 percent, 77.9 percent. Row 4: Freedom from surgical reintervention, 96.1 percent, 92.8 percent, 88.4 percent, 84.2 percent.
Notes: Values represent Kaplan–Meier estimates of freedom from event. Patients without the event were censored at the time of last follow-up.
Kaplan–Meier estimates of freedom from significant pulmonary restenosis were 80.6%, 77.1%, 73.3%, and 71.9% at 1, 3, 5, and 10 years, respectively (Figure 3A). Freedom from moderate-or-greater pulmonary regurgitation was 94.4%, 90.6%, 82.6%, and 74.5%, respectively (Figure 3B). Freedom from pulmonary valve reintervention was 91.4%, 85.6%, 84.6%, and 77.9% (Figure 3C), whereas freedom from surgical reintervention remained 96.1%, 92.8%, 88.4%, and 84.2% at 1, 3, 5, and 10 years, respectively (Figure 3D).
Kaplan–Meier estimates of freedom from time-to-event outcomes.
Notes: Kaplan–Meier estimates of freedom from significant pulmonary restenosis (A), moderate-or-greater pulmonary regurgitation (B), pulmonary valve reintervention (C), and surgical reintervention (D) following balloon pulmonary valvuloplasty. Shaded areas represent 95% confidence intervals; tick marks indicate censored observations. The table below each panel displays the number of patients at risk at each time point.
Predictors of long-term time-to-event outcomes
Univariable Cox proportional hazards regression was performed to identify predictors of long-term outcomes (Table 7). Predilation was consistently associated with an increased hazard of significant pulmonary restenosis (hazard ratio 2.21, 95% confidence interval 1.05–4.65; p = 0.036), moderate-or-greater pulmonary regurgitation (hazard ratio 3.10, 95% confidence interval 1.32–7.29; p = 0.009), pulmonary valve reintervention (hazard ratio 3.21, 95% confidence interval 1.37–7.52; p = 0.007), and surgical reintervention (hazard ratio 5.22, 95% confidence interval 1.93–14.15; p = 0.001).
Univariable Cox proportional hazards analysis for predictors of time-to-event outcomes
Table 7. Long description
A table with 6 rows and 10 columns comparing predictors of time-to-event outcomes using Cox proportional hazards analysis. The columns are labeled as Variable, Restenosis HR (95% CI), p, Moderate/severe PR HR (95% CI), p, Reintervention HR (95% CI), p, Surgery HR (95% CI), and p. The rows list different variables such as Age at BPV, per month, Balloon/annulus ratio, per 0.1 increase, Baseline RV-PA gradient, per 10 mm Hg, RV/systemic pressure ratio, per 0.1 increase, Predilation, yes versus no, and Pulmonary annulus Z-score, per 1-unit increase. Each row provides hazard ratios (HR) with 95% confidence intervals (CI) and p-values for different outcomes: Restenosis, Moderate/severe PR, Reintervention, and Surgery.
Note: Hazard ratios were estimated using univariable Cox proportional hazards models. Balloon/annulus ratio was analysed per 0.1-unit increase, baseline RV-PA gradient per 10-mmHg increase, and RV/systemic pressure ratio per 0.1-unit increase.
BPV = balloon pulmonary valvuloplasty; CI = confidence interval; HR = hazard ratio; PR = pulmonary regurgitation; RV = right ventricle; RV-PA = right ventricular-to-pulmonary artery.
A higher balloon-to-annulus ratio was also associated with an increased hazard of significant pulmonary restenosis (hazard ratio 1.39 per 0.1-unit increase, 95% confidence interval 1.06–1.84; p = 0.018), moderate-or-greater pulmonary regurgitation (hazard ratio 1.39, 95% confidence interval 1.02–1.90; p = 0.037), and pulmonary valve reintervention (hazard ratio 1.49, 95% confidence interval 1.13–1.96; p = 0.005). Conversely, a larger pulmonary annulus Z-score was associated with a lower hazard of significant pulmonary restenosis (hazard ratio 0.78, 95% confidence interval 0.61–0.98; p = 0.037). Age at balloon pulmonary valvuloplasty, baseline right ventricle–pulmonary artery gradient, and right ventricle/systemic pressure ratio were not significantly associated with any time-to-event outcome.
Because of the limited number of events, particularly for surgical reintervention, multivariable Cox regression analysis was not performed to avoid model overfitting.
Discussion
The present study adds to the existing literature by providing a 20-year institutional experience with balloon pulmonary valvuloplasty in children ≤ 24 months from a high-volume Latin American cardiovascular referral centre. Although the efficacy and safety of balloon pulmonary valvuloplasty are well established, long-term data focusing specifically on infants and young children remain limited, particularly from Latin America. In addition to confirming sustained haemodynamic improvement, our study provides long-term time-to-event estimates of clinically relevant restenosis, pulmonary regurgitation, and reintervention, together with an evaluation of predictors of adverse outcomes in this high-risk population.
Our cohort included a substantial proportion of patients with critical pulmonary stenosis and prostaglandin E1 dependence, reflecting a clinically complex population. Despite this, no procedure-related complications or intervention-related mortality were observed, consistent with previously reported complication rates of 0–10% and mortality rates of 0–4%. Reference Voet, Rega and de Bruaene26–Reference Samardhi, Luis and Lee28 The three in-hospital deaths were attributable to non-procedural causes, further supporting the safety profile of balloon pulmonary valvuloplasty even in critically ill infants.
Immediate procedural outcomes demonstrated marked haemodynamic improvement, with significant reductions in the right ventricle–pulmonary artery gradient and right ventricle systolic pressure, consistent with previous paediatric series. Reference Merino-Ingelmo, Santos-de Soto, Coserria-Sánchez, Descalzo-Señoran and Valverde-Pérez23,Reference Holzer, Gauvreau and Kreutzer29–Reference Casa, Dolensky, Spinner, Veledar, Lerakis and Yoganathan32 The procedural success rate of 94.5% was comparable to contemporary paediatric registries Reference Hansen, Naimi and Wang16,Reference Holzer, Gauvreau and Kreutzer29,Reference Gerçek and Rudolph33 and slightly higher than that reported in older studies, Reference Lopez, Colan and Stylianou20,Reference Liu, Gao, Butera, Chessa, Eicken and Thomson21 confirming the high effectiveness of balloon pulmonary valvuloplasty when current procedural techniques and patient selection criteria are applied. Among the small subgroup of patients who did not achieve immediate procedural success, most had associated supravalvular pulmonary stenosis, and three also had Noonan syndrome, consistent with previous reports demonstrating reduced responsiveness to balloon dilation in patients with dysplastic or complex right ventricular outflow tract anatomy. Reference Hansen, Naimi and Wang16
The relatively high proportion of infants with critical pulmonary stenosis in our cohort also underscores the importance of early recognition of ductal-dependent right ventricular outflow tract obstruction. Timely diagnosis allows prompt initiation of prostaglandin infusion and referral for balloon pulmonary valvuloplasty before progressive hypoxaemia or haemodynamic deterioration occurs. Recently, El Tahlawi et al. Reference Eltahlawi, Elghamrawy and Elsayed34 demonstrated the feasibility and effectiveness of pulse oximetry screening for the early detection of critical congenital heart disease in a multicentre study, reinforcing the value of neonatal screening programmes to facilitate timely identification and referral of newborns with critical pulmonary stenosis requiring urgent evaluation and intervention.
An additional finding of our study was the favourable evolution of tricuspid regurgitation following balloon pulmonary valvuloplasty. Nearly half of the patients experienced an improvement in tricuspid regurgitation severity, with a significant overall reduction in regurgitation grade after relief of pulmonary stenosis. Improvement in tricuspid regurgitation demonstrated a weak but statistically significant correlation with the reduction in right ventricle pressure, supporting the concept that functional tricuspid regurgitation in infants with severe pulmonary stenosis is, at least in part, a consequence of chronic right ventricle pressure overload. Reference Casa, Dolensky, Spinner, Veledar, Lerakis and Yoganathan32,Reference Gerçek and Rudolph33 In contrast, no significant association was observed between tricuspid regurgitation improvement and reduction in the pulmonary valve gradient. Furthermore, persistent tricuspid regurgitation at follow-up was associated with higher residual right ventricle pressure, but not with residual pulmonary valve gradient, restenosis, or reintervention, suggesting that persistent right ventricle pressure overload may contribute more to ongoing tricuspid valve dysfunction than residual valvular obstruction itself.
Consistent with previous paediatric studies, pulmonary valve gradients remained durably reduced throughout medium- and long-term follow-up, supporting the sustained effectiveness of balloon pulmonary valvuloplasty. Reference Liu, Gao, Butera, Chessa, Eicken and Thomson21,Reference Parent, Ross, Bendaly and Breinholt35–Reference Devanagondi, Peck and Sagi38 Although residual or recurrent obstruction was common, only a subset of patients developed significant restenosis, defined as moderate-or-greater recurrent obstruction on follow-up echocardiography. Importantly, significant restenosis was intentionally defined as an imaging outcome rather than a clinical indication for repeat intervention. Consequently, not all patients meeting the echocardiographic threshold required reintervention, highlighting the distinction between Doppler-based severity assessment and clinical decision-making. This distinction is further supported by the separate time-to-event analyses for restenosis and reintervention, which demonstrated different long-term event rates. These findings are consistent with previous studies reporting persistent residual gradients after balloon pulmonary valvuloplasty, although only a proportion of patients ultimately progress to clinically significant recurrent obstruction requiring additional treatment. Reference Yin, Wu and Xiang14,Reference Hansen, Naimi and Wang16 Similarly, El Tahlawi et al. Reference El Tahlawi, Morsy, Elawady, Abdelaziz and Eldamanhory25 reported that patients who developed restenosis after balloon pulmonary valvuloplasty had recurrent elevation of serum troponin I and worsening right ventricular function during follow-up, suggesting that biomarkers may complement echocardiographic follow-up in identifying patients at risk of recurrent obstruction.
Time-to-event analysis provides a more robust assessment of long-term outcomes after balloon pulmonary valvuloplasty than cumulative event proportions because it accounts for differences in follow-up duration and censoring. Kaplan–Meier analysis demonstrated sustained freedom from clinically relevant events throughout follow-up, with more than 70% of patients remaining free from significant restenosis and pulmonary valve reintervention at 10 years, and more than 80% remaining free from surgical reintervention. These findings further support the long-term durability of balloon pulmonary valvuloplasty as definitive treatment for congenital PS in infants and young children.
In univariable Cox regression analysis, predilation and a higher balloon-to-annulus ratio were associated with an increased hazard of significant restenosis, whereas a larger pulmonary annulus Z-score was associated with a lower hazard of recurrent obstruction. Older age was not associated with restenosis in the present time-to-event analysis, differing from our previous binary analysis. Predilation has not previously been reported as a predictor of restenosis; however, in our cohort, it was primarily used in patients with extremely restrictive valve orifices and therefore most likely represents a marker of anatomical complexity and baseline disease severity rather than a direct procedural cause. Reference Yin, Wu and Xiang14,Reference Hansen, Naimi and Wang16,Reference Rao37
Pulmonary regurgitation increased during follow-up but remained predominantly trivial or mild, consistent with long-term studies demonstrating that some degree of pulmonary regurgitation is almost universal after balloon pulmonary valvuloplasty but is generally well tolerated clinically. Reference Yin, Wu and Xiang14,Reference Hansen, Naimi and Wang16,Reference Hatem, Castro and Haertel Jé22,Reference Parent, Ross, Bendaly and Breinholt35 Severe pulmonary regurgitation remained uncommon in our cohort. Kaplan–Meier analysis further demonstrated that freedom from moderate-or-greater pulmonary regurgitation remained above 80% at 5 years and approximately 75% at 10 years, indicating that clinically relevant pulmonary regurgitation develops gradually in only a minority of patients.
Predilation and a higher balloon-to-annulus ratio were associated with an increased hazard of developing moderate-or-greater pulmonary regurgitation. Similar to the findings for restenosis, predilation most likely reflects greater baseline anatomical complexity and more severe valvular obstruction rather than a direct adverse effect of the procedure itself. Likewise, although larger balloon-to-annulus ratios have previously been associated with pulmonary regurgitation in some series, Reference Voet, Rega and de Bruaene26,Reference Loureiro, Cardoso, Gomes Iês, Martins Jé and Pinto Fátima39–Reference Garty, Veldtman, Lee and Benson41 our time-to-event analysis suggests that this variable may identify patients at increased long-term risk rather than represent an independent causal mechanism. Because operators are more likely to select larger balloons in anatomically complex valves, residual confounding by disease severity cannot be excluded. Nevertheless, these findings support careful long-term surveillance in patients requiring more aggressive balloon dilation despite adherence to currently recommended BAR. Reference McCrindle13,Reference Talukder, Hongxin, Fei and Khashru15,Reference Qian, Qian, Zhou and Yang40–Reference Roushdy, Eldin and Ezz Eldin43
Pulmonary valve reintervention was required in a minority of patients, with repeat balloon pulmonary valvuloplasty representing the most frequent initial strategy, followed by surgical intervention, consistent with previously reported reintervention rates of approximately 10–20%. Reference Yin, Wu and Xiang14,Reference Hansen, Naimi and Wang16,Reference Devanagondi, Peck and Sagi38–Reference Poon and Menahem46 Kaplan–Meier analysis demonstrated durable freedom from pulmonary valve reintervention throughout long-term follow-up, further supporting balloon pulmonary valvuloplasty as an effective first-line therapy for congenital pulmonary stenosis. Among patients requiring additional treatment, repeat balloon pulmonary valvuloplasty successfully postponed or avoided surgery in several cases, whereas surgical intervention was reserved primarily for persistent or recurrent obstruction or progressive valve dysfunction.
Three patients subsequently underwent transcatheter pulmonary valve implantation using the Melody valve, reflecting the expanding role of transcatheter pulmonary valve replacement in the long-term management of right ventricular outflow tract dysfunction. Although the number of patients was small, these cases illustrate how contemporary transcatheter therapies may complement surgical management and provide additional treatment options for selected patients requiring late pulmonary valve replacement.
Overall, our findings support the long-term efficacy and safety of balloon pulmonary valvuloplasty as first-line therapy for congenital pulmonary stenosis in infants and young children. This 20-year institutional experience adds to the limited long-term evidence available for children ≤ 24 months, particularly from Latin American cardiovascular referral centres, and demonstrates sustained haemodynamic improvement, durable freedom from clinically important adverse events, and low rates of reintervention. Continued long-term echocardiographic surveillance remains essential to identify patients at risk of recurrent obstruction or progressive pulmonary regurgitation and to guide timely reintervention.
Limitations
This study has several limitations. First, despite the 20-year study period, the cohort size remained relatively small because congenital pulmonary valve stenosis requiring balloon pulmonary valvuloplasty in children ≤24 months is an uncommon condition and our study was intentionally restricted to this specific age group. Consequently, the relatively limited sample size may have reduced statistical power, particularly for less frequent outcomes, and may limit the generalisability of the findings. Furthermore, the retrospective single-centre design introduces the potential for information bias and reflects the case mix and referral patterns of a tertiary cardiovascular referral centre.
Approximately 13% of otherwise eligible patients were excluded because essential baseline clinical, echocardiographic, or invasive haemodynamic data were unavailable. Although these exclusions were necessary to ensure reliable longitudinal analyses, they may have introduced selection bias and could have affected the generalisability of the results.
Second, echocardiographic data were obtained from written clinical reports without systematic re-evaluation of the original imaging studies. Consequently, assessment of pulmonary and tricuspid regurgitation severity, pulmonary and tricuspid valve morphology, and features of valve dysplasia relied on the original clinical interpretation rather than standardised image re-analysis. This approach may have introduced interobserver variability, subjective interpretation, and measurement bias and may also have been influenced by changes in echocardiographic reporting practices over the 20-year study period. In addition, echocardiographic measurements were performed as part of routine clinical practice rather than according to a prospective research protocol, which may have introduced variability in the timing of follow-up examinations.
Third, the 20-year inclusion period may have introduced temporal heterogeneity in interventional techniques, operator experience, balloon technology, peri-procedural management, and follow-up protocols, although it also reflects real-world clinical practice and contemporary evolution in patient care.
Finally, although the cohort is relatively large for a study restricted to children ≤24 months, the number of events for several time-dependent outcomes limited statistical power and precluded multivariable Cox proportional hazards regression. Consequently, the reported associations should be interpreted as exploratory and require confirmation in larger prospective multicentre studies. Although Kaplan–Meier methods appropriately accounted for variable follow-up duration and censoring, differences in follow-up length may still have influenced the precision of long-term estimates, particularly at later time points where fewer patients remained at risk.
Prospective multicentre studies with standardised echocardiographic assessment and longer longitudinal follow-up are warranted to validate these findings and further refine long-term risk stratification after balloon pulmonary valvuloplasty in infants and young children.
Conclusion
In children ≤24 months with critical or haemodynamically significant pulmonary stenosis, balloon pulmonary valvuloplasty is a safe and highly effective first-line therapy that provides sustained haemodynamic improvement, favourable reverse remodelling of tricuspid regurgitation, and durable long-term freedom from clinically important adverse outcomes. Although pulmonary regurgitation became more frequent during follow-up, it remained predominantly trivial or mild. Patients requiring predilation, larger balloon-to-annulus ratio, or smaller pulmonary annulus Z-scores were more likely to develop adverse valve-related outcomes during follow-up. These findings support the role of balloon pulmonary valvuloplasty as the preferred first-line treatment in this population and emphasise the importance of structured long-term echocardiographic surveillance to identify patients at increased risk and optimise the timing of reintervention.
Supplementary material
The supplementary material for this article can be found at https://doi.org/10.1017/S1047951126124421
Data availability statement
The datasets generated and/or analysed during the current study are not publicly available due to institutional data protection policies but are available from the corresponding author on reasonable request.
Acknowledgements
The authors thank the Pediatric Cardiac catheterisation team, the Department of Epidemiology at Clínica Cardio VID and Universidad Pontificia Bolivariana for their support in data acquisition and institutional coordination.
Author contributions
Andrea Dávila Ruales: Conceptualisation; Methodology; Data curation; Formal analysis; Investigation; Writing – original draft; Writing – review & editing.
Sergio González Butrón: Conceptualisation; Methodology; Formal analysis; Writing – review & editing.
Eliana Mabel Cañas Arenas: Methodology; Formal analysis; Validation; Writing – review & editing.
Guillermo José Aristizábal Villa: Investigation; Data curation; Supervision; Writing – review & editing.
Rafael Lince Varela: Investigation; Data curation; Supervision; Writing – review & editing.
All authors approved the final version of the manuscript and agree to be accountable for all aspects of the work.
Financial support
The authors did not receive any financial support for the research, authorship, and/or publication of this article.
Competing interests
The authors declare no conflicts of interest related to this study.
Ethical standard
This study was conducted in accordance with the ethical guidelines of the Declaration of Helsinki. The work was approved by the Research and Ethics Committee of the Universidad Pontificia Bolivariana and the Clínica Cardio VID, Medellín Colombia (document number: FM-CIE-0086-25).
Patient consent statement
Given the retrospective cohort design based on medical record and institutional registry review, without additional intervention or direct patient contact, the Ethics Committee granted a waiver of individual informed consent.
Confidentiality was ensured through data anonymisation and exclusive use for academic and scientific purposes.
