OBESICA study: relationship between BMI and acute heart failure outcome.

OBJECTIVE

The objective of this study was to investigate the relationship between BMI and outcome of acute heart failure (AHF).

METHODS

We carried out a secondary analysis of the Epidemiology of Acute Heart Failure in Emergency department Registry (prospective, multicenter registry following a cohort of AHF patients from 34 Spanish emergency departments). Follow-up was at 3 months and 1 year after enrolment over the telephone and included medical history review. We analyzed revisits to the emergency department and death in relation to BMI. Significant differences were analyzed using proportional risk models including data on demographic variables, basal status, the acute episode, and patient outcome.

RESULTS

We included 1562 patients: low weight 1.3%, normal weight 26.1%, overweight 45.3%, obese 24.3%, and morbidly obese 3.1%. BMI was inversely associated with mortality (P<0.001) but not with revisit (P=0.70). Compared with patients with normal weight, the proportional risk of death among patients with low weight was increased [hazard ratio (HR) 1.75, 95% confidence interval (CI) 0.95-3.23], being reduced in overweight, obese and morbidly obese patients (HR 0.72, 95% CI 0.59-0.89; HR 0.75, 95% CI 0.58-0.96; and HR 0.42, 95% CI 0.20-0.85, respectively). These differences disappeared after adjusting the model for confounding factors and other predictive variables of mortality.

CONCLUSION

BMI seems to be related to AHF and death, although this relationship disappeared on considering other prognostic factors and confounding variables. This finding limits the use of BMI by emergency physicians when estimating the risk of emergency department reconsultation or death in AHF patients.