Phase contrast CMR in the descending aorta as a supportive reference for severe aortic regurgitation

Abstract

Abstract Accurate grading of aortic regurgitation (AR) severity is crucial for treatment decisions. This study aimed to determine whether phase contrast cardiac magnetic resonance (PC-CMR) in the descending aorta can be used as a supporting reference for grading of the AR severity in patients with chronic AR. PC-CMR was performed both in the ascending and descending aorta of 191 AR-patients. Regurgitation thresholds in the descending aorta for hemodynamically significant AR [regurgitation volume (RVol) DA and fraction (RF) DA ] were determined in 41 well-controlled patients and then validated in a cohort surveyed for AR in our clinic. Myerson’s outcome-based thresholds (RVol > 42 mL, RF > 33%) served as reference. For comparison, holodiastolic flow reversal (HFR) was determined. Regurgitation measurements in the descending and ascending aorta were strongly correlated (RVol: R  ≥ 0.92; RF: R  ≥ 0.85; p  < 0.001). Diagnostic performance of RVol DA >17 mL and RF DA >23% was high (sensitivity: 92%, 83%; specificity: 95%, 93%) and more patients with significant AR were identified using these PC-MRI based thresholds [RVol DA >17mL (13%) and RF DA >23% (15%)] than with HFR alone. PC-CMR in the descending aorta has the potential to reliably grade AR severity in patients with chronic AR and thereby may serve as a supportive reference in the decision-making regarding optimal timing of intervention.