Real-Time Fluoroscopic Assessment of Underexpansion Predicts Hemodynamic Valve Deterioration Following TAVR With Balloon-Expandable Device.

BACKGROUND

The clinical sequelae of transcatheter heart valve (THV) underexpansion following transcatheter aortic valve replacement (TAVR) with balloon-expandable devices remain incompletely understood.

OBJECTIVES

The aim of this study was to investigate the impact of THV underexpansion on clinical outcomes among patients treated with balloon-expandable TAVR.

METHODS

Consecutive patients undergoing transfemoral TAVR with the SAPIEN 3 and SAPIEN 3 Ultra systems in the prospective Bern TAVI registry were retrospectively evaluated. THV underexpansion was assessed on postimplantation fluoroscopic images and quantified using the validated commissural post height method. Significant THV underexpansion was defined as a reduction in stent frame midportion diameter ≥20% compared with the nominal diameter, using an optimal cutoff value determined by maximizing the log-rank statistic. The outcomes of interest were moderate or severe hemodynamic valve deterioration (HVD) according to the Valve Academic Research Consortium 3 and all-cause and cardiovascular mortality at 5-year follow-up.

RESULTS

Among 1,043 patients (median age 81 years; Q1-Q3: 76-85 years; 34.6% women) undergoing TAVR with SAPIEN 3 or SAPIEN 3 Ultra valves between 2014 and 2022, 57 (5.4%) exhibited THV underexpansion. THV underexpansion ≥ 20% was associated with an increased risk for HVD at 5-year follow-up (subdistribution HR: 4.88; 95% CI: 2.18-10.97). The risk for HVD gradually increased with increasing degree of underexpansion (subdistribution HR: 1.94 per 5% increase; 95% CI: 1.42-2.79), with consistent findings across all valve sizes. Total aortic valve calcium volume, bicuspid anatomy, and valve iteration were significant predictors of THV underexpansion. At 862-day follow-up (Q1-Q3: 366-1,812 days), underexpansion was not associated with mortality.

CONCLUSIONS

Underexpansion of balloon-expandable THVs is associated with an increased risk for HVD at mid-term follow-up.