REDUCED CORONARY FLOW RESERVE IN HYPERCHOLESTEROLEMIC PATIENTS WITHOUT OVERT CORONARY STENOSIS

Background Reduced coronary how reserve (CFR) in hypercholesterolemic patients without evidence of ischemia has been reported. However, it r emains uncertain whether this abnormality occurs without overt coronar y atherosclerosis. This study aimed to clarify whether CFR is impaired even in anatomically normal coronary arteries in hypercholesterolemic patients and to compare CFR between Familial hypercholesterolemic (FH ) patients and secondary hypercholesterolemic (SH) patients. Methods a nd Results Twenty-two patients with hypercholesterolemia (11 FH, 11 SH ) and 11 control subjects were studied. Baseline myocardial blood how (MBF) and MBF during dipyridamole loading were measured in segments pe rfused by angiographically normal coronary arteries with the use of po sitron emission tomography and N-13-ammonia, and CFR was calculated. B aseline MBF (mL/min per 100 g heart wt) in FH (81.3+/-31.4) and SH (70 .0+/-20.7) patients was not different from that in control subjects (7 5.0+/-34.9). However, MBF during dipyridamole loading was significantl y lower in FH patients (129+/-19.1) than in control subjects (322+/-17 4, P<.01) and SH patients (210+/-71.2, P<.01). CFR in FH patients (1.5 9+/-0.41) was also significantly lower compared with both control subj ects (4.22+/-1.42, P<.01) and SH patients (3.00+/-0.96, P<.01). CFR in SH patients was also significantly lower than that in control subject s (P<.05). CFR correlated significantly with both plasma total cholest erol (r=.67, P<.01) and LDL cholesterol concentrations (r=.69, P<.01). Conclusions CFR was decreased even in anatomically normal coronary ar teries in hypercholesterolemic patients. This abnormality was more pro minent in FH patients.