Systolic–diastolic energy loss imbalance and adverse outcomes in patients with worsening aortic regurgitation after TAVR
S Sasaki, T Nagai, K Kamiya, T Hamaya, S Tsuneta, K Tamano, T Tamura, A Takahashi, Y Mori, Y Yasui, S Takenaka, S Ishizaka, Y Kobayashi, T AnzaiAbstract
Background
Worsening aortic regurgitation (AR) after transcatheter aortic valve replacement (TAVR) is associated with adverse clinical outcomes; however, the underlying hemodynamic mechanisms remain poorly understood. Energy loss (EL), a marker of hemodynamic inefficiency, is known to be elevated in AR. Given the distinct physiological roles of systolic and diastolic flow, we hypothesized that an imbalance favoring systolic over diastolic EL after TAVR may identify high-risk patients with worsening AR.
Purpose
To investigate peri-procedural changes in EL in patients with worsening AR after TAVR and to evaluate their prognostic and mechanistic implications.
Methods
We examined 205 consecutive patients who underwent TAVR between May 2018 and August 2025 and completed pre- and post-procedural four-dimensional flow magnetic resonance imaging (4D flow MRI). Systolic and diastolic EL were quantified in the ascending aorta (AAo) and left ventricle (LV). Based on echocardiography, patients were classified into worsening AR (AR-w, n=55) and non-worsening AR (AR-nw, n=150), defined as an increase of at least one grade on a five-grade scale. Patients were further stratified according to the post procedural systolic to diastolic EL ratio (S/D) into higher (>1) and lower (<1) groups. The primary outcome was a composite of all-cause death and heart failure hospitalization.
Results
The median age was 83 years and 71 patients were male. Baseline characteristics and valve type were comparable between groups. During a median follow-up of 620 days (IQR 253 to 1123), AR-w patients had a higher incidence of the primary outcome compared with AR-nw patients (P=0.030). Systolic EL in the AAo decreased in all groups, although the reduction was smaller in AR-w (P<0.001) after TAVR. In contrast, left ventricular systolic EL increased significantly in AR-w (P=0.008) but remained unchanged in AR-nw (P=0.60). Diastolic EL in both the AAo and LV decreased in AR-nw, whereas no significant changes were observed in AR-w. When stratified by post-procedural S/D ratio, patients with AR-w and a higher S/D ratio demonstrated the highest cumulative incidence of adverse outcomes (Figure 1). In multivariable analysis, AR-w with a higher S/D ratio remained independently associated with adverse outcomes (HR 3.78 95%CI 1.43-0.99). Detailed flow analysis in this high-risk group demonstrated reduced physiologic vortex formation in the LV, more frequent jet inflow collision at larger angles, and a higher prevalence of posteriorly directed wall hugging jets (Figure 2).
Conclusion
Worsening AR after TAVR is associated with adverse outcomes, particularly when accompanied by a predominance of systolic over diastolic EL. Hemodynamic inefficiency characterized by jet inflow collision and impaired vortex formation may underlie this association. Quantification of EL using 4D flow MRI may provide incremental risk stratification and insights into procedural optimization.