Abstract
Aims: No studies have evaluated the influence of management strategies in different health insurance environments on atrial fibrillation (AF). This observational study compared the incidence of and treatment strategies for postoperative AF after primary coronary bypass surgery. Methods and results: One insurance and one public funded location was compared: University of Michigan Health Center (USA, n=272) and Tampere University Hospital (Finland, n=314). USA patients had more co-morbidities and were treated more aggressively after acute myocardial infarction. More Finns were on β-blockers both preoperatively (93 vs. 68%, P<0.001) and postoperatively (97 vs. 66%, P<0.001). However, AF was more frequent among Finns (38 vs. 29%, P=0.037) and present on 4.6% of cases when transferred postoperatively. No USA patients had AF at time of discharge. Mean length of stay was 8.6 days at USA, and not affected by AF. The incidence of in-hospital death, strokes and multiorgan failures was similar. Multivariable analysis, adjusted for site and selection biases (propensity analysis) revealed increasing age [OR=1.063 (1.042, 1.084), P<0.0001] and use of radial arteries [OR=2.175 (1.071, 4.417), P=0.032) to be independent predictors to the incidence of postoperative AF. Conclusions: We found several major differences in patient selection and treatment strategies among primary coronary bypass patients managed in the two institutions. Despite the marked practice variation, the incidence of postoperative AF was rather similar. Despite routine use of β-blockers, AF occurred in 29-38% of patients. However, the length of stay was not particularly affected by postoperative AF.