Time and cause of death in patients after acute coronary syndrome

Abstract Background Acute coronary syndrome (ACS) remains a substantial mortality burden despite enormous progress achieved in treatment and prevention in recent decades, yet systematic investigation of detailed causes of death among ACS patients remains limited. Objective This study aimed to describe the association between time and cause of death in patients after ACS using data from a large, multicenter, contemporary cohort. Methods Patients’ data from the China Chest Pain Database between 2015 and 2021 were linked to the China National Death Registration System Database using unique national IDs to obtain accurate vital status. Patients with documented death records were extracted into a merged database, which encompassed all deaths that occurred in the hospital and post-discharge out-of-hospital. Patients were enrolled with a discharge diagnosis of ACS. Cardiovascular (CV) mortality was defined as a death certificate with a CV diagnosis using the ICD-10 classification listed as the primary cause of death. A trend chi-square test was performed to assess the causes of death at different times after ACS. Results Among the 126,704 eligible patients, the mean age at baseline was 74 (66, 81) years old, 39.3% were women. Of these patients, 16,546 (13.1%) died during hospitalisation, 53,980 (42.6%) within the first six months after discharge, 19,664 (15.5%) from 6 to12 months after discharge, and 36,514 (28.8%) beyond 12 months after discharge. The most common cause of CV death was ischemic heart disease (70.1%), followed by ischemic stroke (7.1%) and hemorrhagic stroke (6.8%). The main causes of non-CV death were malignant tumours (37.1%) and respiratory disease (21.5%). For death in-hospital, within the first six months, from 6 to 12 months post-discharge, and beyond 12 months, the proportion of CV causes was 86.3%, 78.3%, 70.7%, and 67.9%, respectively (P<0.001). The proportion of deaths due to haemorrhagic stroke and aortic aneurysm/dissection increased progressively with time to death increasing (P<0.001). Meanwhile, the proportion of non-CV deaths continuously increased, reaching 13.7%, 21.7%, 29.3%, and 32.1%, respectively. Conclusion Despite cardiovascular diseases being the primary cause of death in patients after ACS, the causes of death vary among patients with different times of death, highlighting the importance of categorising patients into distinct population groups according to time after ACS for targeted cause-specific preventive strategies.