Comparative Study of Aspirin Monotherapy versus Dual Antiplatelet Therapy in Stable Coronary Artery Disease

Abstract

Introduction: Stable coronary artery disease (CAD) remains one of the leading causes of morbidity and mortality worldwide. Antiplatelet therapy is the cornerstone of secondary prevention, with aspirin recommended as standard therapy, whereas Dual Antiplatelet Therapy (DAPT) may provide additional protection against ischemic events at the expense of an increased bleeding risk. This study aimed to compare the effectiveness and safety of Aspirin Monotherapy and DAPT in patients with stable CAD.

Methodology: A retrospective cohort study was conducted at the Department of Cardiology, Ayub Teaching Hospital, Abbottabad, Pakistan, from June 2025 to May 2026. A total of 200 adult patients with stable CAD were included, comprising 100 patients receiving Aspirin Monotherapy and 100 receiving DAPT (predominantly aspirin plus clopidogrel). Clinical data were obtained from medical records. The primary efficacy outcome was major adverse cardiovascular events (MACE), defined as the composite of myocardial infarction, ischemic stroke, and cardiovascular death. Secondary outcomes included cardiovascular hospitalization and bleeding events classified as major or minor according to standard clinical criteria. Baseline characteristics were compared using the independent-samples t-test, Chi-square test, or Fisher's exact test, while multivariable logistic regression analysis was performed to identify independent predictors of MACE and bleeding.

Results: Baseline demographic and clinical characteristics were comparable between the two treatment groups. Patients receiving DAPT experienced lower rates of myocardial infarction (6.0% vs. 12.0%), ischemic stroke (3.0% vs. 8.0%), cardiovascular hospitalization (9.0% vs. 18.0%; p = 0.047), and cardiovascular mortality (4.0% vs. 7.0%) than those receiving Aspirin Monotherapy. However, overall bleeding events were significantly more frequent in the DAPT group (32.0% vs. 12.0%; p = 0.001), including both major (11.0% vs. 3.0%; p = 0.027) and minor bleeding (21.0% vs. 9.0%; p = 0.017). Multivariable logistic regression demonstrated that DAPT was independently associated with a lower risk of MACE (adjusted odds ratio [AOR] = 0.54; 95% CI: 0.29–0.98; p = 0.042) but a higher risk of bleeding complications (AOR = 3.41; 95% CI: 1.74–6.68; p < 0.001).

Conclusion: Dual Antiplatelet Therapy was associated with a reduced risk of composite major adverse cardiovascular events but a significantly increased risk of bleeding compared with Aspirin Monotherapy in patients with stable coronary artery disease. Treatment decisions should be individualized by carefully balancing the expected ischemic benefits against the potential bleeding risks. Further multicenter prospective studies are warranted to validate these findings.