Abstract 11126: Longitudinal MRI-Based Superficial Femoral Artery Velocity Measurements in Peripheral Artery Disease: An Analysis of the Effect of Lipid Modification on Peripheral Artery Disease After Endovascular Intervention Trial (ELIMIT)

Abstract

Introduction: Peripheral artery disease (PAD) causes lower extremity dysfunction and is associated with an increased risk of cardiovascular mortality and morbidity. We analyzed longitudinal associations of non-invasive 2-dimensional-phase-contrast magnetic resonance imaging (2D-PC-MRI) velocity markers of the distal superficial femoral artery (SFA) with characteristics of PAD. Hypothesis: Longitudinal changes in MRI-based measures of SFA velocity are associated with changes in SFA lumen volumes in PAD. Methods: A total of 33 (11 diabetic, 22 non-diabetic) PAD patients, who completed baseline and 2-year follow-up MRI were included in this secondary analysis of ELIMIT. Electrocardiographically-gated 2D-PC-MRI was performed at a proximal and a distal imaging location of the distal SFA territory. SFA lumen, wall, and total vessel volumes were averaged over all distal SFA MRI slices. Results: Baseline characteristics did not differ between diabetic and non-diabetic PAD patients (Table). Proximal and distal SFA velocity measures did not differ between baseline and 2-years (41.98: IQR (23.58, 72.6) cm/s; vs. 40.31: IQR (26.69, 61.29) cm/s; p=0.30, for maximum SFA velocity). The velocity amplitude (defined as the difference between the SFA minimum and maximum velocity) was significantly lower in the distal compared to the proximal SFA location at both baseline and at the 2-year visit (p=0.003, p<0.001). In a pooled analysis of all 33 PAD patients, the 2-year change of the average SFA velocity was significantly associated with the 2-year change in the averaged SFA lumen volume (beta: 0.00011, r 2 : 0.175, p=0.017). In a subgroup analysis, a similar pattern was observed in diabetic patients (beta: 0.00006, r 2 : 0.714, p=0.001), but not in non-diabetics (beta: -0.000019, r 2 : 0.0095, p=0.68). Conclusion: Longitudinal 2D-PC-MRI SFA velocity changes are associated with 2-year SFA lumen changes. 2D-PC-MRI velocity measures may be of interest in assessing PAD.