Asymmetrical Expansion of Balloon-Expandable Transcatheter Aortic Valve Prostheses: Implications for Valve Hemodynamic and Clinical Outcomes.

Background Asymmetrical expansion of transcatheter heart valves (THVs), manifesting as stent frame deformation, is an occasional fluoroscopic finding in transcatheter aortic valve replacement (TAVR).Objectives The aim of this study was to investigate the impact of asymmetrical expansion of balloon-expandable THVs on hemodynamic valve performance and clinical outcomes.Methods In a prospective registry, TAVR asymmetry index was measured using freeze-frame fluoroscopic images and was defined as the ratio of THV heights: [(longer height/shorter height) - 1] × 100. THV hemodynamic performance was measured using echocardiography before hospital discharge. Impaired hemodynamic valve performance was defined as a mean residual THV gradient ≥20 mm Hg and/or moderate or greater paravalvular regurgitation.Results Among 1,216 patients undergoing transfemoral TAVR for native severe aortic valve stenosis with contemporary balloon-expandable THVs between February 2014 and June 2022, asymmetry index was an excellent predictor of impaired hemodynamic valve performance (area under the receiver-operating characteristic curve: 0.88; 95% CI: 0.84-0.92; P < 0.001). The optimal asymmetry index threshold for predicting impaired THV performance was >5.5% (sensitivity 77%, specificity 86%) and occurred in 17% of patients. Higher asymmetry index, as a continuous variable, was associated with impaired hemodynamic valve performance independent of total aortic valve calcium, bicuspid anatomy, balloon-expandable valve prosthesis type or size, and Society of Thoracic Surgeons Predicted Risk of Mortality score (OR: 1.37; 95% CI: 1.29-1.46; P < 0.001). High TAVR asymmetry index was not associated with all-cause mortality during a median of 376 days of follow-up (HR: 1.00; 95% CI: 0.71-1.41; P = 0.989).Conclusions Asymmetrical expansion of balloon-expandable THVs was associated with impaired hemodynamic valve performance but not with clinical outcomes.