Abstract Body (Do not enter title and authors here): Introduction: Patients with acute coronary syndrome (ACS) face significant risks of recurrent cardiovascular (CV) events and bleeding complications. These bleeding risks are particularly pronounced in Asian populations, who may have a higher predisposition to bleeding complications due to genetic and physiological factors. This study aims to compare the long-term outcomes and characteristics of ACS patients who experienced only a single ACS event with those who had multiple CV events.
Methods: Utilizing Taiwan's National Health Insurance Research Database, this retrospective cohort study categorized patients into single-event and multiple-event groups based on the occurrence of major adverse cardiovascular events within two years after index ACS. In this cohort study, 28,535 patients were considered. After 1:2 matching by age, sex, and interval between the first and second CV events, the final cohorts included 8,720 patients in the multiple-event group and 17,368 in the single-event group.
Results: The multiple-event group had higher rates of comorbidities, including hypertension, prior coronary artery disease, heart failure, stroke, atrial fibrillation, peripheral vascular disease, and chronic kidney disease. Over a 5-year period, the multiple-event group exhibited higher all-cause mortality (34.1% vs. 24.6%, p < 0.0001) and CV mortality (11.4% vs. 6.2%, p < 0.0001) compared to the single-event group. Non-CV deaths (22.7% vs. 18.3%, p < 0.0001) and major bleeding events (7.8% vs. 1.6%, p < 0.0001) were also more frequent in the multiple-event group, as were minor bleeding events (34.4% vs. 7.2%, p < 0.0001). Additionally, we found that compared to the single-event group, which showed a significant decrease in major bleeding events after one month from the index ACS, the multiple-event group continued to have a higher rate of major bleeding events within three months following the index ACS. A previous major bleeding event in the multiple-event group was linked to earlier subsequent CV events, with each day preceding of the major bleeding advancing the CV event onset by 1.0044 days.
Conclusion: ACS patients with multiple CV events have higher rates of all-cause mortality, CV mortality, and major bleeding compared to the single-event group. However, major bleeding events may be associated with subsequent CV events, highlighting the importance of implementing a tailored antiplatelet strategy in Asian populations.