Effects of enalapril maleate on survival of dogs with naturally acquired heart failure. The Long-Term Investigation of Veterinary Enalapril (LIVE) Study Group.

OBJECTIVE: To test the long-term effect of enalapril maleate treatment on progression of clinical signs of heart disease in dogs with moderate or severe naturally acquired heart failure associated with chronic degenerative mitral valvular disease (mitral regurgitation [MR]) or dilated cardiomyopathy (DCM). DESIGN: Prospective multicenter study. ANIMALS: 110 dogs enrolled at 15 locations in the United States. PROCEDURE: All dogs enrolled in this study were maintained on their randomly allocated treatment regimen until death, treatment failure (deterioration of condition requiring additional medication), or termination of the study. All dogs entered in the study received standard heart failure treatment (furosemide with or without digoxin). Statistical analysis (log-rank test) was performed to compare the distribution of number of days in the study between dogs that received placebo tablets and dogs that received enalapril tablets. RESULTS: When dogs with MR and DCM were grouped together, mean number of days until treatment failure was significantly different between those receiving enalapril and those given placebo tablets (157.5 and 77.0 days, respectively). For dogs with MR, mean number of days until treatment failure was significantly different between those receiving enalapril and placebo tablets (159.5 and 86.6 days, respectively). Mean number of days until treatment failure among dogs with DCM receiving enalapril and placebo tablets was 142.8 and 56.5, respectively. CLINICAL IMPLICATIONS: Use of enalapril in combination with standard treatment (diuretics with or without digoxin) appears to be beneficial over an extended period, compared with standard treatment alone.