Discussion

Coronary involvement is a rare but recognised complication of neurofibromatosis type 1. This is the first report of ST elevation acute coronary syndrome, in a patient of this age. This case has some clinical and pathophysiological hints.

The specific pathophysiologic mechanism involved in this case was purely acute thrombosis in an aneurysmatic vessel with apparently smooth contour. The pathogenesis of vascular involvement and, in particular, aneurysm development is still incompletely understood. Cases of post-mortem examination have reported some common findings characterised by intimal and medial proliferation and/or dysplasia.^{Reference Kanter, Graham, Fairbrother and Smith4} Our patient was elected to undergo thromboaspiration avoiding the implant of any stent. There is no consensus about the most appropriate acute management of patients with coronary aneurysms and acute coronary syndromes, and several interventional strategies (including thromboaspiration and stent implantation) and antithrombotic regimens have been proposed.^{Reference Ruggieri, D’Arrigo, Abbate, Distefano and Upadhyaya5,Reference Cereda, Tiberti, Pera, Cantù, Ferri, Savonitto and Piatti7} A 68-year-old woman with neurofibromatosis type 1 and recurrent acute coronary syndrome associated with coronary aneurysms was successfully chronically treated with anti-platelets and anticoagulation, with no further events after 14 months follow-up.^{Reference Molina-Martin de Nicolas, Jurado, Rubio and Garcia6}

The rationale of long-term treatment may also depend on the presence of associated stenosis, the size and extension of the aneurysm. Since the most obvious mechanism of coronary occlusion was intra-aneurysm thrombotic occlusion, our patient was initially treated with aspirin and warfarin after mechanical coronary recanalisation.

The coronary CT performed at follow-up confirmed aneurysms involving the circumflex and the right coronary arteries without evidence of residual thrombus and/or any wall irregularities; therefore, we decided to maintain full antithrombotic regimen, including aspirin and warfarin. It is worth underscoring that, differently from other reports of older patients, in our case coronary disease was very segmental and characterised purely by aneurysms without evidence of pathology involving the vessel wall, neither inside the dilated segment nor at the entry and exit edges where the parietal stress is allegedly higher.^{Reference Ruggieri, D’Arrigo, Abbate, Distefano and Upadhyaya5}

This case report highlights that cardiac ischaemic complication, although rare, should not be overlooked even in very young patients with neurofibromatosis type 1. In this regard, new generation coronary CT scans may play a role in active surveillance of selected cases. A possible alternative explanation of coronary aneurysm formation is Kawasaki disease sequele. However, the particular angiographic presentation of this case, characterised by multiple “cobblestone like” dilatations, further supports the etiopathogenetic link with neurofibromatosis type 1.^{Reference Kawakubo, Uehara, Minatsuki, Amiya and Komuro8} Furthermore, as expected, acute thrombosis in absence of arterial wall pathology is the most relevant mechanism; therefore, long-term single anti-platelet associated with low intensity anticoagulation therapy appears to be a reasonable option to minimise the risk of ischaemic recurrences.