Ramipril treatment for 1 year did not significantly change left ventricular mass (P=0.85), improve diastolic function, or alter myocardial fibrosis compared with placebo in cats with HCM without CHF.
RCT (n=26)
Blinded
Matched for LV mass index
Does ramipril reduce LV mass, improve diastolic function, and reduce myocardial fibrosis in Maine Coon cats with familial HCM without CHF?
In a feline model of familial HCM without heart failure, 1 year of ramipril therapy did not improve structural, functional, or neurohormonal markers of disease.
p-value: p=0.85
BACKGROUND: Hypertrophic cardiomyopathy (HCM) is the most common heart disease of cats, resulting in left ventricular (LV) hypertrophy, myocardial fibrosis, and diastolic dysfunction. HYPOTHESIS: Ramipril will reduce LV mass, improve diastolic function, and reduce myocardial fibrosis in cats with HCM without congestive heart failure (CHF). ANIMALS: This prospective, blinded, placebo-controlled study included 26 Maine Coon and Maine Coon cross-bred cats with familial HCM but without CHF. METHODS: Cats were matched for LV mass index (LVMI) and were randomized to receive ramipril (0.5 mg/kg) or placebo q24h for 1 year, with investigators blinded. Plasma brain natriuretic peptide (BNP) concentration, plasma aldosterone concentration, Doppler tissue imaging (DTI), and systolic blood pressure were measured at baseline and every 3 months for 1 year. Cardiac magnetic resonance imaging (cMRI) was performed to quantify LV mass and myocardial fibrosis by delayed enhancement (DE) cMRI at baseline and 6 and 12 months. Plasma angiotensin-converting enzyme (ACE) activity was measured on 16 cats 1 hour after PO administration. RESULTS: Plasma ACE activity was adequately suppressed (97%) in cats treated with ramipril. LV mass, LVMI, DTI, DE, blood pressure, plasma BNP, and plasma aldosterone were not different in cats treated with ramipril compared with placebo (P = .85, P = .94, P = .91, P = .89, P = .28, P = .18, and P = .25, respectively). CONCLUSION: Treatment of Maine Coon cats with HCM without CHF with ramipril did not change LV mass, improve diastolic function, alter DE, or alter plasma BNP or aldosterone concentrations in a relevant manner.
MacDonald et al. (Sun,) conducted a rct in Familial hypertrophic cardiomyopathy without congestive heart failure (n=26). Ramipril vs. Placebo was evaluated on Left ventricular mass (p=0.85). Ramipril treatment for 1 year did not significantly change left ventricular mass (P=0.85), improve diastolic function, or alter myocardial fibrosis compared with placebo in cats with HCM without CHF.