English abstract
Background: Acute coronary syndrome (ACS) is a leading global cause of morbidity and
mortality. Current guidelines suggest prescribing five evidence-based medications (EBMs) for
ACS patients after revascularization. This combination has been scantly evaluated in real-life
settings, and given the variation in prescribing rates worldwide, it is unknown yet whether these
medications are ideally prescribed at discharge at Sultan Qaboos University Hospital (SQUH).
Aim: To assess the prevalence and impact of prescribing EBM combination on major adverse
cardiovascular events (MACE) in ACS patients after revascularization at SQUH, Muscat, Oman.
Methods: This is a retrospective cohort study of 268 patients admitted to SQUH with ACS who
had undergone revascularization between January 2016 and September 2021. Patients were then
followed-up through medical records until March 2022.
Results: The five EBM combination was prescribed to 70% of the patients. However, after taking
into account the presence of contraindications, the actual adherence to guidelines was in fact 95%.
Patients who received the full EBM combination concurrently had lower mean age (58 versus 62
years; p = 0.03) and associated with lower rates of chronic kidney disease (11% versus 41%; p <
0.001) and heart failure (9% versus 20%; p = 0.012). The EBM group was associated with lower
MACE rates. However, after multivariate adjustment using logistic regression, the apparent
differences in morbidity and mortality rates were no longer significant (adjusted odds ratio 0.79;
95% CI: 0.41-1.53; p = 0.492). Surprisingly, bleeding rates were significantly higher in the group
without full EBM combination.
Conclusion: In line with the current guidelines' recommendations, EBM utilization was high at
SQUH, predominantly in younger and less comorbid patients. The EBM group was associated
with lower MACE rates. However, the differences were no longer apparent in the multivariate
logistic regression. The multivariate non-significant findings should be interpreted with caution
due to the inherent study design and low study power. Further research employing larger, more
representative sizes are required to derive better statistical inference and generalizability.
