Characteristics and outcome following transcatheter aortic valve replacement in patients with severe aortic stenosis with low flow.

Aims: Only a few studies have examined the respective impact of low flow (LF), low gradient (LG) and low ejection fraction (LEF) on outcomes following transcatheter aortic valve replacement (TAVR). The purpose of this study was to assess the impact of preprocedural stroke volume index, aortic valve gradient, left ventricular ejection fraction (LVEF) and different flow/gradient/LVEF patterns on the clinical outcomes of patients with severe aortic stenosis (AS) who undergo TAVR.
Methods and Results: We analysed the clinical, echocardiographic, and outcome data collected in 770 patients with AS who underwent TAVR. Overall, 357 patients had normal flow (NF) AS and 413 had LF AS. Patients with NF had similar one-year mortality (12.0% vs. 15.0%, p=0.23) compared with those in the LF group. Overall, patients with NF and/or HG had lower one-year mortality rates (11.7 to 13%) compared to those with paradoxical LF-LG with NEF (19%) and those with classical LF-LG with LEF (27.3%). Low mean gradient was an independent predictor of all-cause mortality (hazard ratio: 1.14, per 10 mmHg decrease, p=0.02). Despite significant association in univariable analyses, LF and LEF were not found to be predictors of outcomes in multivariable analyses.
Conclusions: Patients with HG and those with NF-LG have low one-year mortality rates following TAVR, whereas those with classical LF-LG and LEF and those with paradoxical LF-LG and NEF have high and intermediate risk of mortality, respectively. In contradiction to previous reports, LG but not LF or LEF is an independent predictor of late mortality in high-risk patients with severe AS undergoing TAVR.