Impairment of myocardial blood flow reserve in patients with asymptomatic left ventricular dysfunction: Effects of ACE-inhibition with perindopril

Myocardial blood flow (MBF) reserve is impaired in patients with symptomati c chronic heart failure. Whether this is already present in asymptomatic le ft ventricular (LV) dysfunction, and whether it is affected by angiotensin converting enzyme (ACE) inhibition, is unknown. We examined MBF in 20 patie nts with asymptomatic LV dysfunction and compared them to healthy volunteer s. MBF (reserve) was assessed with positron emission tomography (PET) and N -13 ammonia at rest, during dipyridamole stress test (DST) and during cold pressor test (CPT). Further, in the LV-dysfunction group, we studied the ef fects of 3 months treatment with ACE inhibition with a second PET study. Pa tients were randomized double-blind to perindopril 4 mg daily or placebo. M BF at rest was similar in controls and patients. DST-induced MBF reserve, h owever, was decreased in patients vs. controls (1.71 +/- 0.2 vs. 2.62 +/- 0 .5, respectively p < 0.05). Also CPT-induced MBF was lower in patients (1.1 4 +/- 0.06 vs. 1.23 +/- 0.03, p < 0.05). After 3 months double-blind treatm ent, CPT-induced MBF decreased in the placebo group (from 1.12 +/- 0.02 to 0.93 +/- 0.06), but was preserved in the perindopril group (from 1.16 +/- 0 .08 to 1.14 +/- 0.08 shifts from baseline: -0.19 +/- 0.05 vs. -0.02 +/- 0.0 7 respectively p = 0.07). This was compatible with a trend to a smaller inc rease in coronary vascular resistance during CPT (1.23 +/- 0.08 vs. 1.03 +/ - 0.06, placebo vs. perindopril, p = 0.06). In patients with asymptomatic L V dysfunction, MBF, both after vasodilation and after CPT, is already impai red. ACE inhibition with perindopril during this short-term treatment had n o significant effects.