Association of COVID-19 Infection with Acute Coronary Syndrome: A Case–Control Study

Background: The coronavirus disease 2019 (COVID-19) pandemic has had profound cardiovascular implications, with emerging evidence linking it to acute coronary syndrome (ACS). However, data from low- and middle-income countries, particularly India, remain limited. Objective: To investigate the association between prior COVID-19 infection and the occurrence of ACS in patients admitted to a tertiary care hospital in Kerala, India. Methods: This hospital-based case–control study was conducted in the Department of Internal Medicine, Government Medical College, Thiruvananthapuram, over one year. Fifty cases with ACS (ST-elevation myocardial infarction, non-ST-elevation myocardial infarction, or unstable angina) were matched 1:1 by age and sex with 50 controls without ACS. Data on demographics, comorbidities, lifestyle factors, COVID-19 infection and vaccination history, and laboratory parameters were collected using a structured proforma. Statistical analysis included chi-square test, Student’s t-test, and odds ratios (OR) with 95% confidence intervals (CI). Results: The mean age of cases (50.9 ± 15.4 years) and controls (51.9 ± 16.2 years) did not differ significantly (p = 0.738). Dyslipidemia (48% vs. 18%, p = 0.001) and family history of coronary artery disease (44% vs. 24%, p = 0.035) were significantly more common among cases. Diabetes mellitus (56% vs. 38%, p = 0.071) and hypertension (46% vs. 32%, p = 0.151) were more frequent in cases but not statistically significant. Prior COVID-19 infection was reported in 36% of cases and 22% of controls (p = 0.123). Vaccination status did not differ significantly between groups (68% vs. 64%, p = 0.673). Conclusion: Although prior COVID-19 infection was not significantly associated with ACS, a higher prevalence among cases suggests a possible contributory role. Dyslipidemia and family history of coronary artery disease were significant risk factors for ACS in this cohort. These findings highlight the importance of traditional cardiovascular risk factors in the post-COVID era and the need for larger multicentric studies to clarify the causal relationship between COVID-19 and ACS.