Clinical Impact of the 'Delta-Aortic Valve Gradient', the Reduction in the Mean Aortic Valve Pressure Gradient After Transcatheter Aortic Valve Implantation, on Left Ventricular Ejection Fraction Improvement and Long-Term Mortality in Patients With Severe Aortic Stenosis and Left Ventricular Dysfunction.

Background: The relationship between the reduction in aortic valve pressure gradient (AVG) after transcatheter aortic valve implantation (TAVI) and improvements in left ventricular ejection fraction (LVEF) or long-term survival remains unclear. Methods and Results: We retrospectively analyzed 121 patients with aortic stenosis (AS) and LVEF <50% who underwent TAVI. Transthoracic echocardiography (TTE) was performed before and after TAVI, and the difference in mean AVG was defined as delta-AVG. LVEF improvement was defined as a ≥10% increase from baseline at 1 year. Among 82 patients with 1-year TTE evaluation, LVEF improvement was observed in 37 (45.1%) patients. A higher delta-AVG was identified as an independent predictor of LVEF improvement (odds ratio 1.04; 95% confidence interval [CI] 1.01-1.07; P=0.002), and receiver operating characteristic analysis indicated the optimal cut-off was 20.5 mmHg (sensitivity 48.9%; specificity 89.2%; area under curve 0.723; P=0.002). During a mean follow up of 1,042.6±577.5 days, 5 cardiac deaths occurred. Cox proportional hazards analysis revealed that a low delta-AVG was identified as an independent predictor of cardiac death (hazard ratio 0.91; 95% CI 0.7-0.99; P=0.023). Additionally, a greater delta-AVG was significantly associated with a larger increase in delta-stroke volume between post-TAVI to 1 year (r=0.255; P=0.021). Conclusions: In patients with severe AS and reduced LVEF, delta-AVG could be a novel predictor of 1-year LVEF improvement and long-term survival after TAVI.