Incidence and natural history of coronary artery aneurysm developing after drug-eluting stent implantation

Aims: There is a growing concern about the occurrence of coronary artery aneurysms (CAAs) after drug-eluting stent (DES) implantation and their long-term course. We assessed the occurrence and the factors affecting the long-term outcome of DES-associated CAA. Methods and Results: We analyzed 3,612 consecutive patients (4,419 lesions) who underwent follow-up angiography after DES implantation. All 34 CAAs (0.76% per lesion) in 29 patients (0.8% per patient) were detected at follow-up, and the mean elapsed time from DES implantation to CAA diagnosis was 414 ± 213 days. Angiographically, CAAs developed almost exclusively in complex (type B2/C) de novo lesions (30 [88.2%] of 34 lesions), and lesion length was significantly greater in patients with CAA than without CAA (26.9 ± 9.03 vs 23.1 ± 7.14 mm; P = .004). Myocardial infarction with stent thrombosis occurred in 5 patients with CAA (17.2%), 4 of whom were on aspirin only without clopidogrel. Conclusion: Although CAAs rarely develop after DES implantation and show mostly favorable clinical courses, long-term maintenance of clopidogrel therapy might be required to minimize occurrence of adverse clinical events resulting from stent thrombosis.