Which Factors are Associated With the Application of Reperfusion Therapy in ST-Elevation Acute Coronary Syndromes? Lessons from the Euro Heart Survey on Acute Coronary Syndromes I: Nieuwlaat R, Lenzen M, Crijns HJ, et al. Cardiology 2006;106:137–46

Abstract

This study from the Netherlands examines data from the Euro Heart Survey on Acute Coronary Syndrome I to try to elucidate which factors might be associated with the clinical decision to use reperfusion therapy in these patients. The original study, as well as several others cited in the article’s introduction, was to examine how many ST-segment elevation myocardial infarction (STEMI)-eligible patients received reperfusion therapy as recommended by the European Society of Cardiology (ESC) and the American College of Cardiology/American Heart Association. The original data showed that of all 4260 eligible STEMI patients, 35% received fibrinolysis and 21% underwent percutaneous coronary intervention (PCI). Thirty-three variables reflecting baseline characteristics of the patient and hospital were examined (and missing data imputed using mean values for continuous variables, median values for skewed variables, and mode for nominal variables). Univariate analyses were performed on the original dataset without data imputation, and multivariate analyses were performed on the dataset after data imputation. Variables significantly (p < 0.05) associated with reperfusion therapy were maintained in a final regression model. The authors state that variables most strongly associated with reperfusion therapy were significant ST-segment elevation (>3 mm), short prehospital delay (<90 minutes), PCI facilities available, and participation in a clinical trial. Still significant, but less clearly, variables that made reperfusion less likely were increasing age, prior angina or myocardial infarction (MI), atypical symptoms, heart failure, and female gender. Variables including anterior MI on electrocardiogram, prior coronary bypass surgery, admission after daytime, and diabetes did not predict associated with the whether patients received reperfusion therapy. The authors postulate possible explanations for their results, including that PCI centers may have opinion leaders and specialized nurses who promote guideline adherence and implementation, that patients in clinical trials may reflect healthier and younger populations (who were more likely to get reperfusion, due to possible fear of perceived hazards of reperfusion in patients with more severe disease), and that doctors may be deterred by data suggesting the effectiveness of fibrinolysis rapidly declines beyond 3 hours.