Cardiovascular status of carriers of the apolipoprotein A-I-Milano mutant - The Limone sul Garda study

Background-Carriers of the apolipoprotein A-I-Milano (apoA-I-M) mutant pres ent with very low plasma HDL cholesterol and moderate hypertriglyceridemia, apparently not leading to premature coronary heart disease. The objective of this study was to establish whether this high-risk lipid/lipoprotein pro file is associated with structural changes in the carotid arteries and hear t, indicative of preclinical atherosclerosis. Methods and Results-Twenty-one A-I-M carriers were compared with age- and s ex-matched control subjects from the same kindred and with 2 series of matc hed subjects with primary hypoalphalipoproteinemia (HA). Structural changes in the carotid arteries were defined as the intima-media thickness (IMT) m easured by B-mode ultrasound. HA subjects, both recruited among patients at tending our Lipid Clinic and blood donors, showed significant thickening of the carotids (average IMT, 0.86 +/-0.25 and 0.88 +/-0.29 mm, respectively) compared with control subjects (average IMT, 0.64 +/-0.12 mm); the apoA-I- M carriers instead showed normal arterial thickness (average IMT, 0.63 +/-0 .10 mm). Moreover, a significantly higher prevalence of atherosclerotic pla ques was found in patients and blood donors with HA (both 57%) compared wit h apoA-I-M carriers (33%) and control subjects (21%). Echocardiographic fin dings and maximal treadmill ECG did not differ significantly between apoA-I -M carriers and control subjects, apart from a slight increase in left vent ricular end-diastolic dimension in the carriers, Conclusions-Despite severe HA, carriers of the apoA-I-M mutant do not show structural changes in the arteries and heart, in contrast to HA subjects, w ho are characterized by a marked increase in carotid IMT and increased prev alence of atherosclerotic plaques.