Real world outcomes of aspirin monotherapy compared with aspirin plus clopidogrel in a south Indian cohort with cardiovascular and cerebrovascular disease

Abstract Cardiovascular and cerebrovascular diseases remain leading causes of global morbidity and mortality, with platelet activation playing a central pathogenic role. Aspirin is the cornerstone of antiplatelet therapy, while dual antiplatelet therapy (DAPT) with aspirin and clopidogrel offers enhanced platelet inhibition in selected clinical settings. However, real-world comparative data on aspirin monotherapy versus DAPT in South Asian populations characterized by distinct genetic and vascular risk profiles are limited. This prospective observational study conducted at a tertiary care hospital in South India enrolled 84 adults with cardiovascular or cerebrovascular disease receiving aspirin monotherapy (n = 31) or DAPT (n = 53). Patients were followed for nine months for a composite outcome of death, hospitalization, or recurrent ischemic events. Baseline bleeding risk was estimated using the HAS-BLED framework; observed bleeding events were not ascertained. Quality of life (QoL) was evaluated using domains from the SF-36 and EQ-5D instruments. Composite event rates were lower in the DAPT group than in the aspirin group at first (13.2% vs. 38.7%; p = 0.03) and second follow-up (15.1% vs. 54.8%; p < 0.001), although the groups differed at baseline in index diagnosis, smoking, and alcohol use, and treatment was allocated by the treating physician rather than at random. Individual outcomes favoured DAPT but did not reach statistical significance. Estimated baseline bleeding risk, characterised using the HAS-BLED framework, was moderate to high in 66.7% of patients and was similarly distributed across groups; actual bleeding events were not collected. Pain and discomfort scores were higher in the DAPT group, while physical functioning was similar between groups. Because of the observational design, baseline imbalance, and small number of events, these findings are exploratory and hypothesis-generating; they describe an association rather than establish that DAPT is superior to aspirin and require confirmation in adjusted or randomised studies before informing antiplatelet selection in South Asian populations.