Effect of Extended Dual Antiplatelet Therapy on the Prognosis of Patients With ST Segment Elevation Myocardial Infarction Undergoing Percutaneous Coronary Intervention: A Retrospective Cohort Study

ABSTRACT Background and Aims To inquire the effect of extending the duration of dual antiplatelet therapy (DAPT) to 18–24 months on the prognosis of patients with ST segment elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI). Methods A retrospective investigation were conducted on 757 patients with STEMI from a single center from September 2016 to August 2020. Based on the duration of postoperative DAPT, patients were divided into a standard group ( n = 326) and an extended group ( n = 431). Those in the standard group received aspirin 100 mg + ticagrelor 90 mg or clopidogrel 75 mg for 12 months, after which the drug regimen was changed to aspirin 100 mg, once per day. Those in the extended group received aspirin 100 mg + ticagrelor 90 mg or clopidogrel 75 mg that was continued for 18–24 months. The duration of DAPT in all patients was ≥ 12 months, and the follow‐up time was 12 months, 18 months, and 24 months after PCI. The primary end point was major adverse cardiovascular and cerebrovascular events (MACCEs) during the follow‐up period, including composite end points of cardiac death, myocardial infarction, ischemia‐driven revascularization, and stroke. The major safety endpoint was bleeding events. Results The results showed that during follow‐up, the difference in the incidence of MACCEs between the two groups (4.6% vs. 3.9%, χ ² = 0.198, p = 0.66) was not statistically significant, but the incidence of bleeding events in the standard group was significantly lower than that in the extended group (5.2% vs. 10.7%, χ ² = 7.242, p = 0.007). Conclusion For patients with STEMI undergoing PCI, continuing DAPT to 18–24 months did not reduce ischemic events but increased the incidence of bleeding events, especially minor bleeding events.