Benazepril added to standard care in canine heart failure (BENCH) — LIKELY

In dogs with congestive heart failure from myxomatous mitral valve disease or dilated cardiomyopathy, does benazepril added to standard care vs standard care alone prolong survival and delay clinical deterioration?

Shelf #204 · gate-verified and approved by the developer

LIKELY: Benazepril added to diuretic-based standard care prolongs the useful life of dogs in ISACHC class II–III heart failure. In the single claim-carrying trial — BENCH, a multicenter, prospective, randomized, double-blinded, placebo-controlled trial of 162 dogs — mean survival time (to death or withdrawal for worsening heart failure) was 428 days on benazepril versus 158 days on placebo (2.7 times longer; 44% relative reduction in risk, P < 0.05), and the one-year survival rate was 49% versus 20%, an absolute difference of 29 percentage points. The benefit was statistically significant in the chronic valvular disease subgroup (n = 125) but not in the small dilated cardiomyopathy subgroup (n = 37), so the claim is strongest for valvular disease. The endpoint is not mortality alone — it counts withdrawal for worsening heart failure as an event — and this is one trial, not a replicated body of evidence, which is why the stamp is LIKELY and not PROBABLE. Drafted Nov 10, 2026 (VetMed build, topic #204); all figures from abstracts fetched and verified at drafting.

BENCH 1999: survival time 428 vs 158 days on benazepril vs placebo in dogs with class II–III heart failure

Multicenter, prospective, randomized, double-blinded, placebo-controlled, long-term clinical trial (record's own title wording)

Who: Dogs: 162 dogs with ISACHC class II and III heart failure caused by chronic valvular disease (n = 125) or dilated cardiomyopathy (n = 37), enrolled at 16 centers in France, Italy, Switzerland and the UK. Benazepril (minimum dosage 0.25 mg/kg) or placebo was given orally once daily for up to 34 months, either alone or as add-on therapy to standard therapy (diuretics and/or digoxin and/or anti-arrhythmic drugs).

Result: The mean survival time (to death or withdrawal from the study due to worsening of heart failure) was 2.7 times longer in the benazepril group (428 days) than in the placebo group (158 days); the difference reached statistical significance (P < 0.05, Cox proportional hazards model; 44% relative reduction in risk). The survival rate after one year was 49% with benazepril and 20% with placebo (absolute difference 29 percentage points). Benazepril produced a statistically significant (P < 0.05) 46% relative reduction in the risk of worsening of heart failure (to ISACHC class III) when therapy was initiated early (in ISACHC class II). In subgroup analyses, a statistically significant (P < 0.05) benefit of benazepril was reached for both survival and worsening endpoints for dogs with chronic valvular disease (n = 125), but not for the small sample of dogs with dilated cardiomyopathy (n = 37). Benazepril also improved exercise tolerance and global clinical condition at day 28 (P < 0.05). Dogs treated with benazepril had the same frequency of undesirable clinical events as the placebo group and fewer biochemical disturbances (less frequent increases in plasma urea or creatinine and decreases in plasma potassium).

Watch out: The survival endpoint is a composite of death or withdrawal due to worsening heart failure, not mortality alone. The dilated cardiomyopathy subgroup was small (n = 37) and showed no significant benefit — do not extend the claim to DCM on this trial. This is a single trial, and its record carries no MeSH terms and is indexed only as Journal Article; the randomised, double-blinded, placebo-controlled design is established by the article title and abstract. Note: the mined topic draft cited this trial as J Vet Intern Med 1999; the verified record is the Journal of Veterinary Cardiology 1999.

BENCH (BENazepril in Canine Heart disease) Study Group. The effect of benazepril on survival times and clinical signs of dogs with congestive heart failure: Results of a multicenter, prospective, randomized, double-blinded, placebo-controlled, long-term clinical trial. J Vet Cardiol. 1999;1(1):7-18. PMID: 19081317. Registry ID: none in the record. MeSH: none in the record

Synthesis: one blinded trial, a large survival-time gain, strongest for valvular disease

Synthesis

Who: Synthesis of the card above: BENCH Study Group 1999 (multicenter, prospective, randomized, double-blinded, placebo-controlled trial; 162 dogs with ISACHC class II–III heart failure from chronic valvular disease or dilated cardiomyopathy, 16 European centers).

Result: A 2.7-fold longer mean survival time (428 vs 158 days) with a 44% relative reduction in the risk of death or withdrawal for worsening, and a 29-percentage-point absolute gain in one-year survival (49% vs 20%), is a large, clinically material effect from a properly blinded placebo-controlled trial — enough for LIKELY on a survival claim. It does not reach PROBABLE: it is a single trial, its endpoint mixes death with withdrawal for worsening, and the dilated cardiomyopathy subgroup (n = 37) showed no significant benefit, so the confident claim belongs to dogs with valvular-disease heart failure on standard care.

Watch out: Trial dogs received protocol follow-up for up to 34 months; benazepril's tolerability in the trial (no excess of undesirable clinical events, fewer biochemical disturbances than placebo) was under trial monitoring conditions.

Synthesis of BENCH (BENazepril in Canine Heart disease) Study Group. PMID: 19081317. Registry ID as on the individual card.

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