Feasibility and Diagnostic Utility of Echocardiographic Distal Abdominal Aortic Diastolic Flow Reversal for Assessing Aortic Regurgitation

Aims Although abdominal aortic holo-diastolic flow reversal (HDFR) is a useful marker for aortic regurgitation (AR), guidelines do not specify the optimal measurement site. We compared the feasibility of proximal versus distal abdominal aortic diastolic flow reversal (DFR) measurements, evaluated the diagnostic accuracy of distal HDFR for severe AR, and assessed its consistency with cardiac magnetic resonance (CMR). Methods and Results We evaluated 103 patients with moderate (n = 81) or severe (n = 22) chronic AR. DFR feasibility was significantly higher in the distal than in the proximal segment (94% vs. 54%, P < 0.01). In the overall clinical diagnostic yield analysis (n = 103), distal DFR demonstrated a significantly higher diagnostic yield for AR severity grading compared with proximal DFR (82% vs. 50%, P < 0.01). In an exploratory paired analysis of patients with feasible DFR at both sites (n = 56), distal and proximal HDFR demonstrated no statistically significant differences in diagnostic performance for severe AR: sensitivity (92% vs. 85%, P = 1.00), specificity (86% vs. 93%, P = 0.38), and accuracy (88% vs. 91%, P = 0.73). Inter- and intra-observer reproducibility was excellent. Furthermore, echo-derived distal HDFR showed descriptive consistency with CMR-derived HDFR in a small exploratory subgroup (n = 12; 92% agreement, κ = 0.82). Conclusions Distal abdominal aortic DFR is a simple and highly feasible method for assessing AR severity, potentially overcoming the limitations of proximal DFR assessment in routine clinical practice.