Clinical & Experimental Cardiology
Open Access

Abstract

Influence of Enalapril Therapy Schedule on the Progression of the Disease in Dilated Cardiomyopathic Syrian Hamsters (Bio TO-2 strain)

Sonia Goineau, Pierre Lacroix and Patrício Soares-da-Silva

The influence of enalapril therapy schedule on the progression of the disease in terms of hemodynamics, cardiac remodeling and survival was assessed in cardiomyopathic Syrian hamsters (CMHs). CMHs (Bio TO-2 dilated strain) were treated orally with enalapril at 20 mg/kg/day from 60 to 200 (early treatment), from 120 to 200 (late treatment) or 120 to 250 (prolonged treatment) days of age. In survival studies, CMHs were treated until 90% of controls are death. Early, late and prolonged treatments significantly decreased mean arterial blood pressure (-23%, -27% and -22%, respectively), but had no effects on cardiac output and stroke volume. Late and prolonged treatments significantly decreased total peripheral resistance (-38% and -24%, respectively), but not early treatment. Only, prolonged treatment significantly decreased left ventricle (LV) end diastolic blood pressure (-60%). Early, late and prolonged treatments significantly decreased LV collagen density (-44%, -31% and -54%, respectively) and LV cavity area (-26%, -21% and -29%, respectively). Survival was significantly improved when enalapril was administered from 120 days of age, but not significantly when administered earlier. In conclusion, enalapril exerted beneficial effects (improvement of cardiac function and prolonged survival) more marked when the treatment was begun late in the evolution of congestive heart failure.