Reperfusion Therapy and Predictors of 30-Day Mortality after ST-Segment Elevation Myocardial Infarction in a University Medical Center in Western Iran

Abstract

Background: Considerable variability in survival rate after ST-segment elevation myocardial infarction (STEMI) is present and outcomes remain suboptimal, especially in low- and middle-income contraries. This study aimed to investigate predictors of 30- day mortality after STEMI, including reperfusion therapy, in a tertiary hospital in western Iran. Methods: In this registry-based cohort study (2016–2019), we investigated reperfusion therapies – primary percutaneous coronary intervention (PPCI), pharmaco-invasive (thrombolysis followed by angiography/percutaneous coronary intervention), and thrombolysis alone – used in Imam-Ali hospital, the only hospital with a PPCI capability in the Kermanshah Province. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs), using Cox proportional-hazard models, to investigate the potential predictors of 30-day mortality including reperfusion therapy, admission types (direct admission/referral from non-PPCI-capable hospitals), demographic variables, coronary risk factors, vital signs on admission, medical history, and laboratory tests. Results: Data of 2428 STEMI patients (mean age: 60.73; 22.9% female) were available. Reperfusion therapy was performed in 84% of patients (58% PPCI, 10% pharmaco-invasive, 16% thrombolysis alone). Only 17% of the referred patients had received thrombolysis at non-PPCI-capable hospitals. Among patients with thrombolysis, only 38.2% underwent coronary angiography/ percutaneous coronary intervention. The independent predictors of mortality were: no reperfusion therapy (HR: 2.01, 95% CI: 1.36–2.97), referral from non-PPCI-capable hospitals (1.73, 1.22–2.46), age (1.03, 1.01–1.04), glomerular filtration rate (0.97, 0.96–0.97), heart rate>100 bpm (1.94, 1.22–3.08), and systolic blood pressure<100 mm Hg (4.92, 3.43–7.04). Mortality was lower with the pharmaco-invasive approach, although statistically non-significant, than other reperfusion therapies. Conclusion: Reperfusion therapy, admission types, age, glomerular filtration rate, heart rate, and blood pressure were independently associated with 30-day mortality. Using a comprehensive STEMI network to increase reperfusion therapy, especially pharmaco-invasive therapy, is recommended.