The relationship between body weight, body condition, and survival in cats with heart failure

Background: Obese people with heart failure have improved survival compared with their normal or underweight counterparts. The purpose of this study was to determine if there is a relationship between body weight or body condition and survival in cats with heart failure.

Hypothesis: Body weight and body condition score (BCS) are predictors of survival in cats with heart failure.

Animals: One-hundred and one cats with heart failure (International Small Animal Cardiac Health Council Classes II, IIIa, or IIIb) evaluated between March 2007 and June 2009.

Methods: Data regarding initial body weight and BCS, subsequent changes in body weight, and treatment were collected from records and compared with survival times.

Results: Median initial body weight was 5.1 kg (range, 2.2-9.5 kg). Median BCS was 5 (range, 3-9). Of the 68 cats that were discharged from the hospital, median body weight change was 0.0 kg (range, -2.6 to +2.3 kg). Survival time for all 101 cats was 93 days (0-811 days). Survival could be predicted using a model combining initial body weight (P=.02), body weight squared (P=.02), and survival to discharge (P<.001) with a resulting global P value for this model of P<.0001.

Conclusions and clinical importance: Cats with the lowest and highest body weights had reduced survival times compared with those with body weights in the intermediate ranges, suggesting a U-shaped relationship between body weight and survival. Additional research into the effects of body composition could help to determine optimal management of cats with heart failure.