Efficacy of Enalapril for Prevention of Congestive Heart Failure in Dogs with Myxomatous Valve Disease and Asymptomatic Mitral Regurgitation

Abstract

We evaluated the long-term effect of early angiotensin-converting enzyme (ACE) inhibition (enalapril maleate) as monotherapy to postpone or prevent congestive heart failure (CHF) in asymptomatic dogs with mitral regurgitation (MR) attributable to myxomatous valvular disease (MVD) in a prospective, randomized, double-blinded, placebo-controlled multicenter trial involving 14 centers in Scandinavia. Two hundred twenty-nine Cavalier King Charles (CKC) Spaniels with MR attributable to MVD but no signs of CHF were randomly allocated to treatment with enalapril 0.25-0.5 mg daily (n 116) or to placebo groups (n 113). Each dog was evaluated by physical examination, electrocardiography, and thoracic radiography at entry and every 12 months (30 days). The number of dogs developing heart failure was similar in the treatment and placebo groups (n 50 [43%] and n 48 [42%], respectively; P .99). The estimated means, adjusted for censored observations, for the period from initiation of therapy to heart failure were 1,150 50 days for dogs in the treatment group and 1,130 50 days for dogs in the placebo group (P .85). When absence or presence of cardiomegaly at the entrance of the trial was considered, there were still no differences between the treatment and placebo groups (P .98 and .51, respectively). Multivariate analysis showed that enalapril had no significant effect on the time from initiation of therapy to heart failure (P .86). Long-term treatment with enalapril in asymptomatic dogs with MVD and MR did not delay the onset of heart failure regardless of whether or not cardiomegaly was present at initiation of the study.

Long‐term Outcome of Irish Wolfhound Dogs with Preclinical Cardiomyopathy, Atrial Fibrillation, or Both Treated with Pimobendan, Benazepril Hydrochloride, or Methyldigoxin Monotherapy

“…Several studies have reported efficacy of ACEI drugs in the management of dogs with heart disease associated with MMVD. Two clinical trials designed to determine whether treatment with enalapril would prevent or delay onset of CHF in small breed dogs with MMVD reported limited12 benefit or lack of clinical effect 13. Benazepril used alone or as an add‐on to standard treatment in MMVD or DCM dogs with CHF extended life span compared to dogs that did not receive benazepril 34.…”

“…Clinical trial data are limited in dogs, and the majority of studies have focused on treatment to manage chronic myxomatous valvular disease (MMVD). Trials using enalapril and conducted largely in populations of dogs with advanced heart disease but not heart failure have reported limited benefit or no benefit in these populations 12, 13. Digitalis traditionally has been used to manage supraventricular tachyarrhythmias14 and dilated cardiomyopathy in dogs,14, 15, 16 but evidence for clinical efficacy is sparse.…”

Assessment of Left Ventricular Function Using Pulsed Tissue Doppler Imaging in Healthy Dogs and Dogs with Spontaneous Mitral Regurgitation

“…In the remaining 39 dogs, MR attributable to chronic mitral valve disease was identified by the same examinations. The dogs with MR were divided into 4 categories-Group I (n=12), Group II (n=12), Group III (n=9), and Group IV (n=6) based on the modified New York Heart Association functional classification for heart failure (NYHA class) [21]. In addition, Groups I and II were categorized as compensated congestive heart failure (CHF) [CHF (-), n=24], and Groups III and IV were categorized as decompensated CHF [CHF (+), n=15].…”

Relation of Vitamin D Status to Congestive Heart Failure and Cardiovascular Events in Dogs

“…Because AVD is characterized by chronic progression, to date, there is little an owner or veterinarian can do to alter the disease process. Evidence suggests that benazepril might be beneficial in dogs with asymptomatic heart disease,22 but 2 trials23, 24 were not able to demonstrate a significant effect of enalapril on time to develop CHF. DCM is characterized by a slowly progressive presymptomatic phase during which ventricular premature contractions occur along with progressive left ventricular dysfunction and, usually, progressively more severe ventricular tachyarrhythmias 25, 26, 27.…”