Effect of Obesity and Being Overweight on Long-Term Mortality in Congestive Heart Failure: Influence of Left Ventricular Systolic Function

prognostic risk factors in the present study, including left ventricular ejection fraction and serum lipid levels. Perspective: Though all the usual limitations of observational studies apply, it is noteworthy that statin users were more likely than nonusers to have prior diabetes, hypertension, peripheral vascular disease and myocardial infarction, yet they still had lower subsequent mortality. The absence of an effect on nonfatal myocardial infarction or stroke may have been due to inadequate statistical power, but might also reflect a specific effect of statins on heart failure or sudden death unrelated to coronary occlusion. The researchers cite animal studies suggesting favorable statin effects on postinfarction remodeling and adrenergic and baroreceptor dysfunction in heart failure. KA

obese. Compared with normal weight, and adjusted for gender and age, risk ratios (RR) and 95% confidence limits were: underweight 1.56 (1.33–1.84), overweight 0.90 (0.83– 0.97), obese 0.77 (0.70 – 0.86). Being underweight conferred a greater risk in HF patients with normal systolic function (RR 1.66 [1.29 –2.14], compared with normal weight) than in patients with reduced systolic function (RR 1.11 [0.87–1.42], p for interaction⫽0.03). In patients with systolic dysfunction, obesity was associated with increased risk compared with normal weight (RR 1.21 [1.01–1.45]). Conclusions. Increasing BMI in HF is associated with a lower mortality, but the influence is complex and depends on LV systolic function. Hence, in patients with systolic dysfunction, obesity may indicate an increased risk. Perspective: Previous studies have suggested that a high BMI is associated with an improved outcome in HF, but the studies have not evaluated whether this relationship differs in systolic vs. nonsystolic HF. Though the lack of a protective effect of obesity in systolic HF in this study reinforces the prejudices of this reviewer, there is still the quandary as to how obesity improves survival in nonsystolic HF. Given the difficulty in defining this entity, the frequency of fatigue, weakness and exertional dyspnea as presenting symptoms in a variety of chronic illnesses, and the fact that COPD and smoking were more common in underweight patients, one is tempted to attribute serious comorbidities to the excess mortality in the underweight nonsystolic HF patients. However, the stepwise decrease in risk with each increasing weight category in nonsystolic HF suggests something more profound, and as yet, unexplained. KA

Effect of Obesity and Being Overweight on LongTerm Mortality in Congestive Heart Failure: Influence of Left Ventricular Systolic Function Gustafsson F, Kragelund CB, Torp-Pedersen C, et al. for the DIAMOND Study Group. Eur Heart J 2005;26:58 – 64. Study Question: Is the association between obesity and mortality in heart failure patients influenced by left ventricular (LV) systolic function? Methods: The researchers performed a retrospective analysis of baseline and survival data for 4700 hospitalized heart failure (HF) patients for whom BMI was available. The LV systolic function was available for 95% of the patients. Follow-up time ranged from 5 to 8 years. Results: In the total population, the risk of death decreased steadily with increasing BMI from the underweight to the

ACC CURRENT JOURNAL REVIEW May 2005

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