Abstract 12251: Increased Vertebral Artery Tortuosity Index Evaluated by Magnetic Resonance Angiography is Associated with Adverse Cardiovascular Outcomes in Connective Tissue Disorder Patients
Background: Although arterial tortuosity (AT) has been commonly described in Loeys-Dietz Syndrome (LDS), there is no accepted definition or measure of AT in patients with connective tissue disorders (CTD). We hypothesized that vertebral artery AT can be reliably measured using an MRI-based index and that increased AT in CTD patients is associated with adverse cardiovascular outcomes.
Methods: Patients ≤ 50 y with Marfan Syndrome (MS), LDS, Ehlers-Danlos Syndrome, or non-specific CTD (NSCTD) who underwent thoracic contrast-enhanced MR angiography were included. Controls underwent MRI to exclude arrhythmogenic right ventricular dysplasia. Right and left vertebral artery distance factor (DF = (actual / straight line distance-1)*100) were calculated from a volume-rendered angiogram by a single blinded examiner. Maximum DF in each patient was designated “Vertebral Tortuosity Index” (VTI). VTI was compared among groups and the relationship between VTI and root size, dissection, cardiac surgery, and death were examined.
Results: Median age was 19.6 y (range 0.2-50.1 y). VTI interrater reliability was ICC=.987, p<.001. VTI in controls (n=28, med 5, IQ 3-6.5) and NSCTD (n=18, med 4, IQ 3-5) was lower than in MS (n=56, med 25, IQ 10-48) and LDS (n=13, med 58, IQ 18-92; p<.001 for all). VTI and maximum BSA-adjusted aortic root diameter were strongly correlated (R=.645, p<.001). Abnormal VTI (>10) was associated with higher rate of dissection compared to normal VTI (p=.02). When stratified into VTI ≤10, 11-49, and ≥ 50, each successive group had increased rate of surgery and earlier median age at surgery (Figure), even when controlling for maximum root size (adj. p <.001). VTI ≥50 was associated with mortality compared to VTI <50 (p<.001), with median VTI in patients who died 144 (IQ 126-175). There was no difference in surgery, dissection, or death in MS v. LDS.
Conclusions: In this cohort, AT measured by MR angiography is a reproducible marker of adverse cardiovascular events in CTD.
- © 2010 by American Heart Association, Inc.