REDUCED CORONARY FLOW RESERVE IN FAMILIAL HYPERCHOLESTEROLEMIA

Familial hypercholesterolemia (FH) presents the highest risk for coron ary artery disease (CAD) among patients with hyperlipidemia. Therefore , early detection of coronary arterial atherosclerosis is important fo r the treatment of FH patients. The aim of this study was to detect ea rly coronary arterial abnormalities that may relate to future atherosc lerosis in asymptomatic FH patients by measuring coronary Row reserve (CFR) using PET and N-13-ammonia. Methods: Twenty-five patients with F H (14 men, 11 women) without a history of myocardial ischemia and 14 c ontrol subjects (9 men, 5 women) were studied. Total serum cholesterol (mmole/liter) was 5.33 +/- 0.66 in control subjects and 7.90 +/- 0.77 in FH patients (p < 0.01 versus control subjects). Results: Myocardia l blood Row (MBF) at rest and during dipyridamole loading was measured using PET, and CFR was calculated. MBF (ml/min/100 g weight heart) at rest in the FH group (79.0 +/- 20.0) was comparable to that in contro l subjects (70.0 +/- 17.0). However, MBF during dipyridamole loading w as significantly lower in FH patients (163.0 +/- 67.0) than in control subjects (286.0 +/- 120.0, p < 0.01). CFR in FH patients (2.09 +/- 0. 62) was also significantly lower than that in control subjects (4.13 /- 1.38, p < 0.01). CFR showed a gender-specific variance in FH patien ts (1.85 +/- 0.40 in men versus 2.55 +/- 0.74 in women p < 0.05) but n ot in control subjects. Significant inverse correlations between CFR a nd the total plasma cholesterol level as well as plasma LDL cholestero l were observed. Conclusion: The CFR was reduced in patients with FH. This abnormality was more prominent in men than in women patients. Non invasive assessment of CFR by N-13-ammonia PET was useful to detect ea rly abnormalities of the coronary arteries in asymptomatic patients wi th FH.