Long-Term (>10 Years) Clinical Outcomes of First-In-Man Biodegradable Poly-l-lactic Acid Coronary Stents: Igaki-Tamai Stents

Background —The purpose of this study was to evaluate the long-term safety of the Igaki-Tamai stent, the first-in-man fully biodegradable coronary stent made of poly- l -lactic acid. Methods and Results —Between September 1998 and April 2000, 50 patients with 63 lesions were treated electively with 84 Igaki-Tamai stents. Overall clinical follow-up (>10 years) of major adverse cardiac events (MACE) and rates of scaffold thrombosis were analyzed together with the results of angiography and intravascular ultrasound (IVUS). MACE included all-cause death, nonfatal myocardial infarction (MI) and target lesion revascularization / target vessel revascularization (TLR/TVR). During the overall clinical follow-up period (121±17 months), 2 patients were lost to follow-up. There was 1 cardiac death, 6 non-cardiac deaths and 4 MIs. Survival rates free of all-cause death, cardiac death and MACE at 10 years were 87%, 98% and 50%, respectively. The cumulative rates of TLR (TVR) were 16% (16%) at 1 year, 18% (22%) at 5 years and 28% (38%) at 10 years. Two definite scaffold thromboses (1 subacute, 1 very late) were recorded. The latter case was related to a sirolimus-eluting stent, which was implanted for a lesion proximal to an Igaki-Tamai stent. From the analysis of IVUS data, the stent struts mostly disappeared within 3 years. The external elastic membrane area and the stent area did not change. Conclusions —Acceptable MACE and scaffold thrombosis rates without stent recoil and vessel remodeling suggested the long-term safety of the Igaki-Tamai stent.