Dual antiplatelets therapy prescription trends and mortality outcomes among senior citizens with acute coronary syndrome: insights from the Malaysian National Cardiovascular Disease Database

OBJECTIVES: To examine 5-year trends and variations in dual antiplatelet therapy (DAPT) prescription among multiethnic Malaysian patients aged 60 years and older.

METHODS: Using the Malaysian National Cardiovascular Disease-Acute Coronary Syndrome (NCVD-ACS) registry, DAPT 5-year temporal trends prescribing patterns at discharge were examined. Multivariate logistic regression was used to calculate the adjusted odds ratio (aOR) of DAPT prescription. The 1-year all-cause mortality by Cox proportional hazard regression model (adjusted hazard ratio, aHR) using inverse proportional weighting covariates adjustment was performed to assess DAPT prognostic impacts.

RESULTS: Data of patients aged 60 years and older were extracted from 2013 to 2017 (n = 3718, mean age: 68 ± 6.74 years, men: 72%, and Malay ethnicity: 43%). The majority of patients were diagnosed with non-ST-segment elevation acute coronary syndrome (63%), predisposed hypertension (76%) and were overweight (74%), while only 35% of patients underwent percutaneous coronary intervention. Over the five years, there was a significant increasing trend in DAPT prescriptions (P < 0.001), with the aspirin-clopidogrel combination being the most common. Aspirin-ticagrelor prescriptions have also increased over the years. Variations in DAPT prescriptions were observed based on patient characteristics. Patients who underwent percutaneous coronary intervention were more likely to be prescribed DAPT in general (aOR = 2.53, 95% CI: 1.95-3.28, P < 0.001) and aspirin-ticagrelor specifically (aOR = 7.76, 95% CI: 5.65-10.68, P < 0.001). Patients with chronic lung disease (aOR = 0.62, 95% CI: 0.42-0.92, P = 0.02) and a history of angina within two weeks (aOR = 0.69, 95% CI: 0.56-0.85, P < 0.001) were approximately 30% less likely to be prescribed DAPT. Approximately 15% of 1-year all-cause mortality were reported. Older patients prescribed DAPT showed significantly higher survival rates than those who were not (aHR < 1.0, P < 0.001). Aspirin-ticagrelor was associated with higher survival rates than aspirin-clopidogrel (aHR = 0.21, 95% CI: 0.11-0.40, P < 0.001).

CONCLUSIONS: Despite the optimal prescription rate and variation of DAPT in the older Malaysian population, there is room for investigation and improvement in the prescription of newer DAPT combinations that have been suggested to improve patient survival.