Myocardial blood flow in patients with hypertrophic cardiomyopathy receiving perindopril (CARAPaCE): a pilot study.

Aims: 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.
Methods: 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.
Results: 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.
Conclusion: 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.
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