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Aortic stiffness in young patients with heterozygous familial hypercholesterolemia
C Pitsavos1, K Toutouzas, J Dernellis
1Cardiology Department, Hippokration Hospital, University of Athens, Greece.
Insights
Dyslipidemia impairs aortic elastic properties, reducing aortic distensibility and increasing aortic stiffness. These changes occur before clinical signs of atherosclerosis manifest, highlighting early vascular effects.
Area of Science:
- Cardiovascular Medicine
- Vascular Biology
- Biophysics
Background:
- Dyslipidemia is a major risk factor for atherosclerosis.
- Aortic distensibility impacts cardiac function and coronary blood flow.
- Alterations in aortic elasticity in dyslipidemia are not well-understood.
Purpose of the Study:
- To investigate the effect of dyslipidemia on aortic elastic properties.
- To compare aortic distensibility and stiffness in patients with familial hypercholesterolemia and healthy siblings.
Main Methods:
- Studied 60 patients with familial hypercholesterolemia and 20 normolipidemic siblings.
- Measured aortic distensibility and stiffness index using echocardiography and sphygmomanometry.
- Calculated indexes based on aortic dimensions and blood pressure measurements.
Main Results:
- No significant difference in mean aortic diameter between groups.
- Aortic distensibility was significantly reduced in familial hypercholesterolemia patients (p < 0.02).
- Aortic stiffness index was doubled in patients with familial hypercholesterolemia compared to controls.
Conclusions:
- Severe dyslipidemia affects aortic elastic properties.
- Impaired aortic elasticity occurs before clinical atherosclerosis.
- Aortic dimensions are not overtly influenced by severe dyslipidemia.
Background:
Dyslipidemia is a primary risk factor for the development of atherosclerosis. Aortic distensibility is an important determinant of left ventricular function and coronary blood flow whose possible alterations in patients with dyslipidemia have not been fully investigated.
Methods:
To assess the effect of dyslipidemia on the elastic properties of the aorta, we studied 60 patients (mean age 37+/-11 years) with heterozygous familial hypercholesterolemia and no manifest arterial disease and compared them with 20 of their normolipidemic siblings (mean age 34+/-10 years). Two indexes of the aortic elastic properties were measured: aortic distensibility was calculated by use of the formula: 2 x (AoS-AoD)/PP x AoD, and aortic stiffness index was calculated by use of the formula: In (SBP/DBP)/(AoS-AoD)/AoD, where AoS and AoD are aortic root end-systolic and end-diastolic diameters, respectively, SBP and DBP are systolic and diastolic arterial pressure, respectively, and PP is pulse pressure. Internal aortic root diameters were measured at 3 cm above the aortic valve by use of two-dimensional guided M-mode transthoracic echocardiography, and arterial pressure was measured simultaneously at the brachial artery by sphygmomanometry.
Results:
The mean aortic systolic and diastolic diameter index did not differ significantly between the two groups. In contrast, aortic distensibility was found to be significantly reduced in subjects with isolated familial hypercholesterolemia compared with that in the control group (2.15+/-1.72 cm2.dynes(-1).10(-6) vs 3.18+/-1.58 cm2.dynes(-1).10(-6), p < 0.02). In addition, the mean aortic stiffness index was double in patients with familial hypercholesterolemia compared with that in normolipidemic subjects.
Conclusions:
Severe dyslipidemia does not overtly influence aortic dimensions but leads to impairment of aortic elastic properties before the occurrence of clinical manifestations of atherosclerotic disease.