Objective: We examined the effect of body mass index on the association between revascularization strategy and survival in patients with coronary artery disease.
Methods: Using the Duke Database for Cardiovascular Disease, we selected 22,877 patients who underwent cardiac catheterization from January 1986 to August 2004 and were found to have significant coronary artery disease. Patients were categorized into three coronary disease management groups: no revascularization, percutaneous coronary intervention, and coronary artery bypass surgery. Propensity scoring was used to control for coronary artery revascularization strategy. The relationship between body mass index, coronary disease treatment, and survival was assessed via Cox multivariable models adjusting for baseline demographic, clinical, and angiographic characteristics.
Results: The median body mass index was 27.2 kg/m(2) (24.4-30.4) in the overall cohort, 27.1 kg/m(2) (24.1-30.3) in the no revacularization group, 27.4 kg/m(2) (24.8-30.9) in the percutaneous intervention group, and 26.9 kg/m(2) (24.4-30.1) in the coronary bypass group. Body mass index was a significant, but weak, predictor of revascularization, with higher indexes predicting lower rates of coronary bypass. Thirty-day survival did not differ across body mass indexes among treatment groups, but survival curves appeared to separate over longer-term follow-up. An inverted U-shaped survival function was noted across all time points after 30 days, with the lowest risk of death at a body mass index of approximately 26 kg/m(2) (independent of revascularization strategy). Coronary bypass was associated with the highest survival at all later time points, whereas no revascularization was associated with the lowest.
Conclusions: Extremes of body mass index are associated with lower long-term survival in patients with significant coronary disease. Revascularization, particularly with coronary bypass, is consistently associated with the best survival across the spectrum of body mass indexes.