Multimodality Quantitative Assessment of Aortic Regurgitation: A Systematic Review

We performed a systematic review on the agreement and reproducibility of 3 advanced imaging methods, 3-dimensional echocardiography (3DE), cardiac computed tomography (CCT), and cardiac magnetic resonance (CMR), for quantifying aortic regurgitation (AR) severity. Medline, Embase, and Cochrane databases were systematically searched using the PICO model from inception to February 4, 2022, for publications that quantified AR severity with 3DE, CCT, or CMR. Measurement agreement and intraobserver and interobserver reproducibility results were extracted from each study. Study quality was assessed using the QUADAS-2 tool. Forty-two publications with 2176 patients with AR were identified. For 3DE, vena contracta (VC) width, VC area, and effective regurgitant orifice area had higher correlations with AR volume than the 2-dimensional echocardiography (2DE)-derived VC width. CCT-derived regurgitant volume had moderate-to-good correlations with 2DE. CMR regurgitant volume measurements had lower intraobserver and interobserver variabilities because of improved endocardial definition, fewer geometric assumptions, and less angle dependence for flow measurements when compared with 2DE. 3DE color flow convergence methods used to quantify AR severity were superior to 2DE methods and could be used in patients with adequate echocardiographic windows. CCT methods also demonstrated improvements over 2DE methods. Although this method is limited due to the radiation exposure, it could play a role in patients with poor echocardiographic windows unable to tolerate CMR. CMR demonstrated the smallest intraobserver and interobserver variability in evaluating AR severity and is a reasonable option for those where the echocardiographic results are mixed and for clinical trials.