IMPROVEMENT OF ATHEROSCLEROSIS AND STIFFNESS OF THE THORACIC DESCENDING AORTA WITH CHOLESTEROL-LOWERING THERAPIES IN FAMILIAL HYPERCHOLESTEROLEMIA

The thoracic aorta is frequently involved in atherosclerotic lesions a ssociated with familial hypercholesterolemia (FH). Transesophageal ech ocardiography (TEE) allows quantitative evaluation of the wall propert ies of the thoracic aorta. Using TEE, we tested whether atherosclerosi s of the thoracic aorta in FH could be improved by cholesterol-lowerin g therapies. The subjects investigated were 22 FH patients and 22 age- matched normal subjects. The descending aorta (DA) was divided into fo ur longitudinal portions of equal length. Atheromatous lesions of each portion of the DA were scored by character and extension of lesions b y biplane two-dimensional TEE. The scores of atheromatous lesions from all four portions of the DA were added together to give the total ath eromatous score (TAS). We also measured instantaneous dimensional chan ges of the DA in a cardiac cycle by M-mode TEE and blood pressure by a cuff method and calculated the stiffness parameter beta (ln[SBP/DBP]/ [Dmax-Dmin]/Dmin), where SEP is the systolic arterial blood pressure, DBP is the diastolic arterial blood pressure, Dmax is the maximum aort ic dimension during the ejection period, and Dmin is the minimum aorti c dimension during the preejection period. TAS was higher in FH (3.70/-1.32) than normal (0.62+/-0.54, P<.0001) subjects. beta in FH (10.35 +/-4.87) was greater than in normal (5.10+/-1.25, P<.0001) subjects, b ut there were no significant differences of DA dimensions between the groups. In both normal subjects and FH patients, beta correlated with age (r=.52, P<.02 and r=.59, P<.005, respectively). In FH patients, be ta and TAS correlated well with pretreatment total cholesterol levels (r=.43, P<.05 and r=.60, P<.005, respectively). In 12 of 22 FH patient s, strict cholesterol-lowering therapies with diet and cholesterol-low ering drugs (pravastatin and probucol) were undertaken for 13 months. Cholesterol levels were significantly decreased from 333+/-45 to 219+/ -39 mg/dL (P<.0001); this was associated with significant decreases in beta and TAS (from 9.88+/-5.03 to 7.88+/-3.92, P<.005, and from 3.61/-1.50 to 2.94+/-1.22, P<.0005, respectively). In FH patients, the inc idence and severity of morphological and physiological atherosclerosis of the DA were significantly higher than in age-matched normal subjec ts. A significant regression of atherosclerosis was achieved by strict cholesterol-lowering therapies in relatively young FH patients.