Coronary microvascular dysfunction (CMD) represents a powerful independent predictor of adverse outcome in hypertrophic cardiomyopathy (HCM). No treatment for CMD exists. The angiotensin-converting enzyme (ACE)-inhibitor perindopril improves myocardial blood flow (MBF) in animal models of cardiac hypertrophy and in hypertensive patients. Whether HCM patients with CMD may benefit is unknown.
Fourteen HCM patients aged 18–60 years with CMD [MBF post 0.56 mg/kg dipyridamole (Dip) infusion <2.1 ml/min∗g] were included. Presence of left ventricular outflow obstruction, hypertension and coronary artery disease were exclusion criteria. Perindopril was administered after the initial Dip 13N-NH3 PET study at 10 mg for 6 months. After wash-out, a second PET was performed. MBF before and after treatment was compared.
No relevant associations were found between baseline MBF values and sex, genetics, history of angina, type of HCM (apical/classic), maximum left ventricular thickness and left ventricular mass. No significant improvement in Dip-MBF was observed with treatment (1.79 ± 0.30 vs.1.76 ± 0.26 ml/min∗g at baseline; P = 0.59). A limited but significant improvement in Dip-MBF was seen only in the subset without evidence of fibrosis at cardiac MRI (n = 4; 28%; 2.03 ± 0.13 vs.1.77 ± 0.26 ml/min∗g at baseline; P = 0.014). The drug was generally well tolerated: only one patient temporarily stopped the drug, because of cough.
A 6-month perindopril treatment course in HCM patients with CMD was not associated with significant improvement in Dip-MBF. A limited but significant improvement was observed only in the subset of patients without myocardial fibrosis, suggesting potential utility in early disease stages.