Trends in optimal medical therapy at discharge and clinical outcomes in patients with acute coronary syndrome in Thailand

Abstract

Background: Optimal medical therapy (OMT) is recommended for patients with acute coronary syndrome (ACS) at discharge. This study aimed to assess temporal trends of OMT prescription as a five-drug regimen at discharge and its association with clinical outcomes in patients with ACS in Thailand.

Methods: A retrospective cohort study was conducted in a tertiary-care medical center in Thailand. Data were collected from an electronic medical database. Patients were categorized into OMT or non-OMT groups based on their discharge medications. OMT was defined as a combination of aspirin and P2Y12 inhibitors, statins, beta-blockers, and angiotensin-converting enzyme inhibitors, or angiotensin receptor blockers. The primary outcome was 1-year all-cause mortality. The secondary outcome was major adverse cardiac events (MACE) which was defined as a composite of non-fatal myocardial infarction, non-fatal stroke, and all-cause mortality. The prescription trends were also estimated. A multivariate Cox's proportional hazard model was used to assess the association of OMT prescriptions at discharge with all-cause mortality and MACE.

Results: A total of 3531 patients discharged with ACS [mean age, 69.5 (SD 12.4) years; 58.3% male] were identified. Only 42.6% were discharged with OMT. The rates of OMT prescriptions did not change over time. However, the prescription of OMT with high-intensity statin was significantly increased from 5.0% in 2013 to 38.3% in 2018 (p for trend <0.001). Multivariable analyses indicated that OMT significantly reduced all-cause mortality (adjusted HR: 0.77; 95%CI: 0.63-0.95; p=0.012) and MACE (adjusted HR 0.84; 95%CI: 0.71-0.99; p = 0.044). Subgroup analysis indicated that patients receiving OMT with high-intensity statins exhibited survival benefits (adjusted HR: 0.72; 95%CI: 0.56-0.92; p=0.008).

Conclusions: The five-drugs comprising OMT were associated with a reduction in all-cause mortality and MACE in patients with ACS. Nevertheless, OMT prescribing remains underused and could be enhanced in the real-world setting.

Keywords: Acute coronary syndrome; Major adverse cardiac events; Mortality; Optimal medical therapy; Predictor; Trend.