Influence of Body Mass Index on Long-Term Survival After Cardiac Catheterization

We examined 18,654 patients who underwent cardiac catheterization in a single center to clarify the association between catheterization indication, body mass index (BMI), and long-term survival over a mean follow-up of 81 months. Patients were grouped by indication for catheterization: (a) acute coronary syndromes (ACS), 7,426 patients; (b) coronary artery disease (CAD) evaluation in stable clinical presentation, 6,911 patients; and (c) primarily non-CAD cardiac evaluations, 4,317 patients. Compared with normal weight, overweight and obesity (but not morbid obesity) was associated with lower risk of long-term mortality. Underweight patients had the greatest risk of mortality. After multivariate adjustment, survival benefit of the overweight and obese was retained in the ACS group [hazard ratio 0.86, 95% confidence interval (0.77-0.96), p = 0.006 and 0.79, (0.68-0.91), p = 0.001, respectively] and in overweight patients in the stable presentation CAD group [0.83, (0.72-0.94), p = 0.005], whereas there was no survival benefit in any of the BMI categories in those catheterized primarily for non-CAD indications. Further analysis of matched cohorts showed similar patterns of survival benefit of the overweight/obese. In conclusion, among patients who underwent cardiac catheterization, an inverse association between BMI and long-term mortality was observed, with the lowest risk noted in the overweight and obese population; the obesity paradox was principally demonstrated in patients with ACS, and was eliminated after covariate adjustment in those catheterized primarily for non-CAD indications.