Proposal criteria of paradoxical low-flow low-gradient aortic stenosis for predicting prognosis in patients undergoing transcatheter aortic valve implantation

Abstract

Background Paradoxical low-flow, low-gradient (PLF-LG) aortic stenosis (AS) is associated with poor prognosis in patients undergoing transcatheter aortic valve implantation (TAVI). This study aimed to verify the conventional criteria of PLF-LG AS (left ventricular ejection fraction [LVEF]>50%, mean aortic valve pressure gradient [AVPG]<40 mm Hg and stroke volume index [SVI]<35 ml/m² by measuring Doppler method) compatible for predicting prognosis in patients undergoing TAVI.
Materials and methods A total of 128 consecutive patients who underwent TAVI for AS with LVEF>50% were enrolled. The primary endpoint was the hospital readmission due to heart failure (HRHF) and the secondary endpoint was all-cause mortality after hospital discharge. The patients were classified by both the conventional criteria of PLF-LG AS and the proposal criteria of PLF-LG AS if mean aortic valve pressure gradient (AVPG)<40 mmHg and SVI by measuring Simpson’s method<cut off value based on the ROC curve for predicting HRHF.
Results According to the conventional criteria, only 6 patients were diagnosed with PLF-LG AS. However, according to the proposal criteria, 16 patients were diagnosed with PLF-LG AS. Fourteen patients developed HRHF during the follow-up period after TAVI. Based on the ROC curves, SVI by measuring Simpson’s method (cut off value=25 ml/m²) had higher sensitivity and specificity for predicting HRHF (AUC=0.74, p=0.0013) than SVI by measuring Doppler method (AUC=0.63, p=0.045). The multivariate analysis revealed that PLF-LG AS defined by the proposal criteria (HR: 5.25; 95% CI: 1.60-17.16; p=0.0073) but not by the conventional criteria was independently associated with HRHF. PLF-LG AS defined by the conventional criteria and the proposal criteria were not associated with all-cause mortality in the univariate analysis.
Conclusions Our results demonstrated that new criteria of PLF-LG AS defined as SVI<25 ml/m² measured by Simpson’s method could predict HRHF in patients with severe AS who underwent TAVI.