Impact of Diabetes on Coronary Angiographic Findings in ST-Elevation Myocardial Infarction Patients: A Comparative Study

INTRODUCTION: Differences in the angiographic profile of diabetic versus non-diabetic patients with ST-elevation myocardial infarction (STEMI) may influence treatment strategies and outcomes. This study aimed to compare angiographic severity and lesion characteristics between these groups. METHODS: In this prospective comparative cross-sectional study, 150 consecutively enrolled STEMI patients (75 diabetics, 75 non-diabetics) were recruited at Hayatabad Medical Complex (HMC) over 12 months (July 2022-June 2023). Diabetes mellitus (DM) was defined according to American Diabetes Association (ADA) criteria or documented use of glucose-lowering therapy. Inclusion criteria were adults aged 30-80 years presenting with STEMI (per European Society of Cardiology (ESC) guidelines) undergoing primary or early invasive angiography. Exclusion criteria included prior percutaneous coronary intervention (PCI)/coronary artery bypass grafting (CABG), stage IV/V chronic kidney disease, or inadequate angiographic data. Two independent interventional cardiologists, blinded to diabetes status, assessed angiograms for vessel involvement, calcification, diffuse disease, and severity using the Modified Gensini Score. Interobserver agreement was evaluated (κ = 0.87). Statistical analyses included chi-square test and t-test with reporting of 95% confidence intervals (CIs), and logistic regression was used to adjust for confounders (age, hypertension, dyslipidemia, smoking). A priori sample size of 150 was determined to provide 80% power to detect a 15% difference in triple-vessel disease (TVD) prevalence between groups (α = 0.05). RESULTS: Diabetic patients had a higher prevalence of TVD (30, 40.0% vs. 18, 24.0%; p = 0.031, 95% CI: 1.05-3.81), diffuse disease (41, 54.7% vs. 23, 30.7%; p = 0.003, 95% CI: 1.36-4.87), and significant calcification (29, 38.7% vs. 14, 18.7%; p = 0.007, 95% CI: 1.22-4.56). The mean Gensini score was significantly higher in diabetics (42.6 ± 9.4) than non-diabetics (35.8 ± 8.7; mean difference 6.8, 95% CI: 3.4-10.2, p < 0.001). Adjusted analyses confirmed diabetes as an independent predictor of more severe and complex coronary artery disease (CAD). No significant differences were observed in culprit vessel distribution or thrombolysis in myocardial infarction (TIMI) 3 flow post PCI. At six-month follow-up, diabetics had higher rates of recurrent angina (11, 14.7% vs. 5, 6.7%), though mortality differences were not statistically significant. CONCLUSION: STEMI patients with diabetes demonstrate more severe, diffuse, and calcified CAD compared to non-diabetics, even after adjusting for confounders. These findings underscore the need for early, aggressive cardiovascular risk management and tailored interventional strategies in diabetic STEMI populations. Ethical approval was obtained (Ref: 757/CD/HMC/2022), and all patients provided informed consent.