Abstract 2128: Assessment Of Carotid Compliance Using Real Time Vascular Ultrasound Image Analysis In Marfan Syndrome
Background: The functional abnormalities in aortic root and ascending aorta in patients with Marfan syndrome (MFS) reflect reduced content of fibrillin-1 (FBN1), dysregulated cytokine transforming growth factor-β and increased collagen deposition related to FBN-1 gene mutations. Carotid arteries in MFS possibly have similar alterations which could predispose to impaired carotid compliance (CC). The aim of this study was to detect any CC abnormalities in MFS using the vascular image analysis system (VIA).
Methods: Thirty-one unoperated MFS patients, 20 men and 11 women (mean age 34.3 ± 12.2 years) and 29 normal controls matched for age, sex and body surface area (BSA) were recruited. The entire length of each carotid system was initially scanned longitudinally using a 14 MHz linear transducer. A stereotactic clamp was used to hold the transducer in contact with the carotid artery 2cm below the level of the carotid bulb. Changes in the arterial size during the cardiac cycle were continually recorded for 1 min from the right (RCCA) and left common carotid arteries (LCCA) seperately using the VIA system.
Results: CC measurements obtained from the RCCA and LCCA showed statistically significant differences between MFS patients and normal controls (RCCC: 0.126 ± 0.008 mm^2.mmHg^−1 vs 0.173 ± 0.007 mm^2.mmHg^−1, p =< 0.001 and LCCC: 0.132 ± 0.007 mm^2.mmHg^−1 vs 0.158 ± 0.007 mm^2.mmHg^−1, p = 0.007). RCCA and LCCA intima-media thickness did not differ between patients and normal controls (RCCA: 0.050 cm ± 0.001 vs 0.050 cm ± 0.001, p > 0.05 and LCCA: 0.050 cm ± 0.001 vs 0.047 cm ± 0.001, p > 0.05). In a multivariate regression analysis after adjusting for age, sex, BSA, β-blockade and systolic blood pressure (SBP), the presence of MFS associated with reduced CC, (RCCC: beta = −0.036, p < 0.001 & LCCC: beta = −0.021, p = 0.019). Sex, BSA and β-blockade showed no effect on CC, whereas age was negatively associated with CC (RCCC: beta = −0.0016, p=0.001 & LCCC: beta = −0.0015, p=0.001). SBP measurements did not differ between the two groups (119 ± 2.09 mmHg vs 114 ± 1.37 mmHg, p > 0.05).
Conclusion: Our findings suggest that despite normal intimal thickness, MFS patients have abnormal carotid compliance. This could be attributed to alterations in elastic properties related to FBN1 deficiency.