Body mass index in acute heart failure: association with clinical profile, therapeutic management and in-hospital outcome.

Background: Increased body mass index (BMI) is a risk factor for heart failure, but evidence regarding BMI in acute heart failure (AHF) remains inconclusive. We sought to compare the clinical profile, treatment and in-hospital outcome across BMI categories in a large international AHF cohort.
Methods: The Acute Heart Failure Global Survey of Standard Treatment (ALARM-HF) is a retrospective survey on 4953 patients admitted for AHF from nine countries in Europe, Latin America, and Australia. Patients with unavailable BMI data or BMI <18.5 kg/m(2) were excluded. Clinical data and in-hospital mortality were compared among the following BMI categories: 18.5-24.9 kg/m(2) (normal weight), 25-29.9 kg/m(2) (overweight) and ≥30 kg/m(2) (obese).
Results: Overweight/obese patients represented 75.7% of patients and had worse New York Heart Association class (P < 0.001) and higher admission systolic blood pressure (P < 0.001). The prevalence of comorbidities increased in parallel with BMI and included arterial hypertension, diabetes mellitus, dyslipidaemia (all P < 0.001), chronic obstructive pulmonary disease (P = 0.041) and chronic kidney disease (P = 0.056). Use of guideline-recommended medications also increased in parallel with BMI (angiotensin converting enzyme inhibitors/angiotensin II receptor blockers, P < 0.001; β-blockers P < 0.001; mineralocorticoid receptors antagonist, P = 0.002). In-hospital mortality had a U-shaped relationship with BMI, with overweight patients having significantly lower rate (log-rank P = 0.027); this relationship vanished after adjustment for confounders.
Conclusions: Overweight/obese patients represented the vast majority of AHF cases, had a higher prevalence of non-cardiovascular comorbidities and were more likely to receive guideline-recommended medications. The U-shaped relationship between in-hospital mortality and BMI may be explained by differences in clinical profile and treatment and not by an effect of body composition per se.
(© 2016 The Authors European Journal of Heart Failure © 2016 European Society of Cardiology.)