Predictors and prognosis of spontaneous reperfusion in acute myocardial infarction

Abstract

ST elevation myocardial infarction (STEMI) remains one of the most frequent emergencies, requiring an as early as possible reperfusion that may result, in some cases, from physiological fibrinolysis. We aimed to analyze the clinical characteristics of patients presenting with clinical markers of spontaneous reperfusion (SR) during acute myocardial infarction, and to evaluate its effect on hospital prognosis. We retrospectively reviewed data for 1785 patients admitted for STEMI. The patients were divided into SR group (spontaneous relief of chest pain less than 5 on a scale from 0 to 10, and ST segment elevation resolution of more than 50% from baseline) and non-SR group (the remaining population). The clinical and prognostic features of the patients were analyzed. The incidence of SR in our population was 10.4% of patients ( N = 187). SR patients were younger (57.6 vs. 61.1 years; P = 0.002) and had a higher prevalence of current smoking (77.9% vs. 65.9%; P = 0.003) and less myocardial damage as indicated by lower peak creatine kinase (1158 vs. 2022 UI/l; P < 0.001). In hospital mortality (3.2% vs. 10%; P = 0.013), heart failure (8.4% vs. 19.7%; P = 0.001), atrial fibrillation (0.6% vs. 7.3%; P = 0.002) and acute pericarditis (0% vs. 4%; P = 0.011) were significantly lower for SR patients. Multivariate analysis found smoking as the only predictor factor of SR (OR = 1.82, 95% CI [1.2–2.7]; P = 0.003). Our data shows that SR decreased infarction size, improved heart function and reduced mortality. The subgroup of STEMI with SR carries a more favorable prognosis.