Noninvasive Evaluation of Coronary Flow Velocity Reserve in Homozygous Familial Hypercholesterolemia by Transthoracic Doppler Echocardiography

Abstract

To evaluate the value of transthoracic Doppler echocardiography (TTDE) of the left anterior descending coronary for the detection of early abnormalities of coronary arteries in asymptomatic patients with homozygous familial hypercholesterolemia (HoFH). Seventeen asymptomatic patients with HoFH and 10 controls had plasma total cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides measured and underwent TTDE of their left coronary descending artery to determine peak and mean flow velocities under basal conditions and under hyperemia induced by adenosine infusion. Coronary flow velocity reserve (CFVR) was calculated from the mean flow velocities. The presence of aortic supravalvular stenosis was also determined from supravalvular flow velocity and aortic valve thickening values. HoFH patients had similar basal but significantly lower hyperemic flow velocities and CFVR than control patients. Eight of the 17 HoFH patients had supravalvular aortic stenosis, and these patients had significantly higher LDL cholesterol and lower CFVR than those without this stenosis. Treatment with lipid-lowering drugs lowered lipid levels and increased CFVR values, but neither of these parameters reached normal values. TTDE is a suitable noninvasive technique to detect early abnormalities of coronary arteries and to monitor the clinical efficacy of lipid-lowering treatment in asymptomatic HoFH patients.