Abstract 14369: The Prognostic Importance of Weight Loss in Coronary Artery Disease: A Systematic Review and Meta-Analysis
BACKGROUND: Although obesity is a risk factor for coronary artery disease (CAD), several studies suggest that weight loss among patients with established CAD may lead to adverse long-term outcomes. These controversial findings cast significant doubt on American Heart Association guidelines which recommend weight loss for all overweight and obese patients with CAD.
METHODS: We performed a systematic review and meta-analysis of the prognostic effects of weight loss in patients with CAD on all-cause death, cardiovascular death, myocardial infarction, and other major adverse cardiac events. We searched PubMed, EMBASE, Web of Science, and bibliographies of selected articles through February 2013. Studies were divided according to weight loss intention. We considered weight loss “presumably intentional” when it occurred in the presence of programmed therapeutic lifestyle changes (TLC), and “observational” when no such intervention was specified. We excluded studies of heart failure, cardiac cachexia, bariatric surgery, or of populations composed only of diabetes, peripheral vascular disease, or stroke.
RESULTS: We searched 1,185 abstracts of which 12 studies with 15 cohorts met inclusion criteria. A total of 35,211 patients (age 64 years old, 70% male, BMI 30, primarily USA and Europe, 2.9 years of follow-up) were included. When all cohorts were combined, weight loss was associated with worse long-term outcomes, RR (95% CI), 1.28 (1.06 to 1.55), p = 0.01. However, heterogeneity was high, I2 = 76%, and was primarily explained by weight loss intention (p < 0.001.) While observational weight loss (n = 11) worsened outcomes (RR 1.49 [1.26 to 1.77], p <0.001,) presumed intentional weight loss (n = 4) improved outcomes (RR of 0.65 [0.48 to 0.87], p = 0.004.) There was marked variability in study populations, outcomes, representativeness, and weight loss definitions.
CONCLUSIONS: Observational weight loss in patients with CAD is associated with long term adverse cardiovascular events, but presumed intentional weight loss in the setting of TLC is associated with lower event rates. These results suggest that the underlying mechanism of weight loss (i.e., intentional or unintentional) may affect its impact on mortality risk in persons with known CAD.
- © 2013 by American Heart Association, Inc.