Impact of nutritional status on heart failure mortality: a retrospective cohort study.

Background: Chronic heart failure (CHF) is one of the most common causes of mortality in industrialized countries despite regular therapeutic advances. Numerous factors influence mortality in CHF patients, including nutritional status. It is known that malnutrition is a risk factor for mortality, whereas obesity may play a protective role, a phenomenon dubbed the "obesity paradox". However, the effect of the obesity-malnutrition association on mortality has not been previously studied for CHF. Our aim was to study the effect of nutritional status on overall mortality in CHF patients.

Methods: This retrospective, multicenter study was based on a French nationwide database (PMSI). We included all CHF patients aged ≥18 years admitted to all public and private hospitals between 2012 and 2016 and performed a survival analysis over 1 to 4 years of follow-up.

Results: Malnutrition led to a significant decrease in life expectancy in CHF patients when compared with normal nutritional status (aHR=1.16 [1.14-1.18] at one year and aHR=1.04 [1.004-1.08] at four years), obese, and obese-malnutrition groups. In contrast, obesity led to a significant increase in life expectancy compared with normal nutritional status (aHR=0.75 [0.73-0.78] at one year and aHR=0.85 [0.81-0.90] at four years), malnutrition, and obese-malnutrition groups. The mortality rate was similar in patients presenting both malnutrition and obesity and patients with normal nutritional status.

Conclusions: Our results indicate that the protective effect on mortality observed in obese CHF patients seems to be linked to fat massincrease. Furthermore, malnourished obese and normal nutritional status patients had similar mortality rates. Further studies should be conducted to confirm our results and to explore the physiopathological mechanisms behind these effects.