Two-Year Follow-Up of Vascular Events in Peripheral Arterial Disease Treated With Antiplatelet Agents: A Prospective Observational Multicenter Cohort Study (SEASON)

The present analysis was intended to evaluate the real-world management of peripheral arterial disease (PAD) in Asia, and to explore cardiovascular events in patients with PAD undergoing antiplatelet therapy over 2 years of follow-up. The Surveillance of cardiovascular Events in Antiplatelet-treated arteriosclerosis Obliterans patients in JapaN (SEASON) registry is a prospective observational multicenter study of cardiovascular events in antiplatelet-treated patients with PAD in Japan. The SEASON registry included 11,375 patients who were scheduled to receive treatment for PAD. Two analysis populations were defined: a real-world population (RWP; n = 10,322) and a definite PAD population (DPP; n = 3992) who had ankle-brachial pressure index (ABPI) <0.9 and intermittent claudication, or a history of lower limb revascularization. The primary outcome measure was the rate of the composite of cerebrovascular, cardiovascular, and peripheral vascular events. The composite event rates (95% confidence interval) were 3.28 (3.00–3.57) and 5.71 (5.13–6.34) events per 100 patient-years in the RWP and DPP groups, respectively. Fontaine IV classification and ABPI <0.4 at baseline were both identified as strong risk factors for vascular events. These findings contribute to understanding the situation for real-world patients with PAD receiving antiplatelet therapy.