Characteristics and outcomes among patients undergoing coronary artery bypass grafting in western Sweden and Minneapolis–St Paul, Minnesota

Background The purpose of this study was to compare patient selection, operative factors, and survival for coronary artery bypass grafting (CABG) for coronary heart disease in Minneapolis–St Paul (MSP), Minnesota, and Western Sweden (WS). Methods and Results All patients from WS between 1988 and 1991 (n = 2365) and a 17% random sample of MSP patients between 1985 and 1990 (n = 1659) who underwent CABG surgery were studied. CABG was 3 times greater in MSP. MSP patients had significantly more obesity, cigarette smoking, prior CABG, and prior coronary angioplasty. WS patients had more and longer angina pectoris, better left ventricular function, and waited longer from previous acute MI until CABG. WS patients had more internal mammary artery graphs and a shorter aortic cross-clamp time. At discharge, WS patients received more β-blockers and antiplatelet agents, whereas MSP patients received more calcium channel blockers and digitalis. Age-adjusted mortality rate at 28 days was significantly higher in MSP but not at 3 years. Adjustment for patient characteristics and treatment factors reduced or eliminated these differences. Conclusions Although coronary heart disease rates were higher in WS, age-adjusted CABG rates were 3-fold higher in MSP. Better survival among WS patients was associated with differences in patient selection and clinical and treatment characteristics because MSP patients were more severely ill and at increased risk. Health system characteristics and practice may account for these differences. (Am Heart J 2001;142:1080-7.)