Study finds obese patients fair better than lean patients when hospitalized for acute heart failure

FINDINGS: Researchers report that for patients hospitalized with acute heart failure, a higher body mass index (BMI) was associated with a substantially lower in-hospital mortality rate. For every 5-unit increase in body mass, the odds of risk-adjusted mortality fell 10 percent. The finding held when adjusted for age, sex, blood urea nitrogen, blood pressure, and additional prognostic factors.

IMPACT: The finding offers more insight into an observed phenomenon in chronic heart failure called the 'obesity paradox.' This is the first study to document that this inverse relationship with BMI holds in the setting of acute hospitalization for heart failure. Further study is required but the finding suggests that nutritional/metabolic support may have therapeutic benefit in specific patients hospitalized with heart failure.

BACKGROUND: The study found that by weight category, in-hospital mortality rate was 6.3 percent for underweight, 4.6 percent for healthy weight, 3.4 percent for overweight and 2.4 percent for obese patients. "The study suggests that overweight and obese patients may have a greater metabolic reserve to call upon during an acute heart failure episode, which may lessen in-hospital mortality risk," said Fonarow. Obesity is a known risk factor for developing heart disease and heart failure and every effort should be made to avoid it, but once heart failure has manifested, this paradox seems to occur. Researchers utilized data on over 100,000 acute heart failure patient episodes, taken from the Acute Decompensated Heart Failure National Registry (ADHERE). The study and ADHERE is funded by Scios, Inc. The authors have received research grants and served as consultants for Scios.

AUTHORS: Dr. Gregg C. Fonarow, The Eliot Corday Chair in Cardiovascular Medicine and Science, first author and director, Ahmanson-UCLA Cardiomyopathy Center, David Geffen School of Medicine at UCLA, is available for interviews.

JOURNAL: The research appears in the January 2007 edition of the peer reviewed American Heart Journal. A PDF of the full study is available.