Prognostic importance of weight loss in patients with coronary heart disease regardless of initial body mass index

BACKGROUND: Recently, mild elevations in body mass index (BMI) have been related to better outcomes in patients with coronary heart disease. Our aim was to determine whether patients with coronary heart disease who are participating in cardiac rehabilitation would have improved outcomes if they lost weight and whether this would depend on initial BMI. METHODS: This is a prospective cohort study of 377 consecutive patients enrolled at a cardiac rehabilitation program, aged 30-85 years with a mean follow-up of 6.4+/-1.8 years. We measured total mortality, acute cardiovascular events (fatal and nonfatal myocardial infarction, fatal and nonfatal stroke, emergent revascularization in the setting of unstable angina, and hospitalization for congestive heart failure) and a composite outcome (mortality+acute cardiovascular events). Statistical testing used Cox Proportional Hazards Regression. RESULTS: On average, the weight loss group (n=220) lost 3.6+/-4.1 kg, and the nonweight loss group (n=157) gained 1.5+/-1.4 kg (P<0.0001). The rate of the composite outcome was 24% (53/220) in those who did lose weight versus 37% (58/157) in those who did not lose weight. Weight loss was significantly associated with lower rate of the composite outcome after adjustment for age, sex, smoking, dyslipidemia, diabetes, hypertension, myocardial infarction, and obese status [hazard ratio (HR)=0.62; P=0.018]. Subgroup analysis showed that patients who lost weight had favorable outcomes both in patients with BMI<25 (HR=0.32; P=0.035) and those with BMI>or=25 kg/m (HR=0.64; P=0.032). CONCLUSIONS: Weight loss in cardiac rehabilitation is a marker for favorable long-term outcomes, regardless of initial BMI.