Post-Dilatation in Balloon-Expandable TAVI Prostheses

Overview

Asymmetrical and inadequate expansion of transcatheter heart valves (THVs) have been described as a key predictor of impaired valve hemodynamic performance predisposing patients for bioprosthetic valve dysfunction (BVD) and death. Post-dilatation using the original delivery system balloon at the identical filling volume after deployment of balloon-expandable THVs represents an invasive strategy to potentially optimize expansion and reduce asymmetry of balloon-expandable THVs. Currently, the efficacy and safety of routine post-dilatation has never been assessed in a randomized controlled fashion. The present randomized controlled DUOTAP trial aims to assess efficacy and safety of routine post-dilatation on THV expansion, hemodynamics, durability, and associated clinical outcomes in patients with severe aortic stenosis.

This study is a randomized controlled trial investigating the effect of routine post-dilatation, using the original delivery balloon at nominal volume, in patients scheduled for and receiving a balloon-expandable THV at the Medical University of Vienna. Consecutive adult patients with severe degenerative AS scheduled for a balloon expandable THV will be prospectively enrolled at a university-affiliated tertiary center in Austria. Eligibility and decision for TAVI will be determined by a multidisciplinary Heart Team. All patients who are willing to participate will then be randomly assigned in a 1:1 ratio to undergo a) routine post-dilatation using the original delivery balloon at nominal volumes or b) no post-dilatation after THV deployment. Methods: The DUOTAP trial is an investigator-driven, prospective, single-blinded, randomized, controlled trial performed at the Medical University of Vienna. In patients assigned to the intervention group post-dilatation will be performed right after deployment of the THV. The balloon will be re-inserted into the deployed THV and after initiation of rapid ventricular pacing the balloon will be inflated at the level of the deployed TAVI prosthesis and then will be immediately deflated again. The duration of rapid ventricular pacing and additional balloon deployment is in the range of a few seconds. Pre-specified study visits: V0 (Pre-TAVI): Medical history and physical evaluation (concomitant diseases, risk factors, medication, EuroSCORE-II, height, weight, age, sex, blood pressure, heart rate, ECG, symptoms), Routine blood and urine analysis (serum creatinine, NT-proBNP, electrolytes, full blood count, etc.), Echocardiography, KCCQ overall score; V1 (TAVI): Fluoroscopic assessment of THV asymmetry, diameters and heights; V2 (Pre-discharge): Routine blood and urine analysis, Echocardiography; V3 (1 month Post-TAVI): Assessment of safety endpoints via phone follow-up; V4 (3 months Post-TAVI): Assessment of cross-sectional THV area on computed tomography (CT); V5 (1 year Post-TAVI): Medical history and physical evaluation (concomitant diseases, risk factors, medication, EuroSCORE-II, height, weight, age, sex, blood pressure, heart rate, ECG, symptoms), Routine blood and urine analysis (Serum creatinine, NT-proBNP, electrolytes, full blood count, etc.), Echocardiography, KCCQ overall score; V6 (5 years Post-TAVI): Medical history and physical evaluation (concomitant diseases, risk factors, medication, EuroSCORE-II, height, weight, age, sex, blood pressure, heart rate, ECG, symptoms), Routine blood and urine analysis (Serum creatinine, NT-proBNP, electrolytes, full blood count, etc.), Echocardiography, KCCQ overall score Outcome: Outcomes (see below) will be assessed peri-procedural, at 1 month, at 3 months, at 1 year and at 5 years post TAVI.