Selected hematological, biochemical, and echocardiographic variables as predictors of survival in canine patients with myxomatous mitral valve disease and congestive heart failure

We investigated the association of breed, age, weight, duration of therapy, and selected blood and echocardiographic variables with the survival of dogs with congestive heart failure (CHF) due to myxomatous mitral valve disease. We also sought to identify differences in selected echocardiographic and routine blood variables between dogs with stable and unstable CHF and between hospitalized and non-hospitalized patients. This retrospective study included dogs with a complete cardiovascular workup. Blood analysis and the initial and final echocardiographic results were included. Covariates were analyzed using Cox proportional hazards models. One hundred sixty-five dogs with myxomatous mitral valve disease were evaluated in this study: 96 stable patients and 69 unstable CHF patients. In total, 107 dogs (64.8%) died, and 58 (35.2%) were censored. The median survival time of the dogs that died was 11.5 months (range 11 days to 4.3 years). Unstable CHF patients had significantly higher neutrophils and lower potassium concentrations than stable CHF patients, and hospitalized patients had higher white blood cell, neutrophil, and monocyte counts and urea and creatinine concentrations than non-hospitalized patients. Variables negatively associated with survival were older age, unstable CHF, duration of therapy, white blood cell count, urea concentration, and left atrium to aorta ratio. Chihuahuas had a lower risk of death. Selected blood and echocardiographic variables distinguish dogs with stable and unstable CHF and predict survival.