Post-Dilatation in Balloon-Expandable TAVI Prostheses (DUOTAP)

Effects of Post-Dilatation on THV Expansion, Hemodynamics, Durability, and Outcomes in Balloon-Expandable TAVI Prostheses

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.

Study Overview

• Status: Recruiting
• Conditions: Aortic Valve Stenosis
• Intervention / Treatment: Other: Post-dilatation

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Estimated): 146
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Christian Nitsche, MD, PhD; Phone Number: +43-1-40400-48590; Email: christian.nitsche@meduniwien.ac.at
• Study Contact Backup: Name: Philipp E Bartko, MD, PhD; Phone Number: +43-1-40400-48590; Email: philippemanuel.bartko@meduniwien.ac.at

Study Locations

• Austria
  • State of Vienna
    • Vienna, State of Vienna, Austria, 1090
      • Recruiting
      • Medical University of Vienna
      • Contact: Christian Nitsche, MD, PhD; Phone Number: +43-1-40400-48590; Email: christian.nitsche@meduniwien.ac.at
      • Contact: Philipp E Bartko, MD, PhD; Phone Number: +43-1-40400-48590; Email: philippemanuel.bartko@meduniwien.ac.at
      • Principal Investigator: Christian Nitsche, MD, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Severe AS
• AS treatment by transfemoral TAVI as determined by an interdisciplinary heart team board
• Anatomical feasibility to receive a balloon-expandable THV
• Age 65 years or older
• Informed consent

Exclusion Criteria:

• Active endocarditis or active rheumatic heart disease or leaflets degenerated from rheumatic disease (i.e., non compliant, perforated)
• Bicuspid aortic valve anatomy
• Valve-in-valve procedure
• Severe calcification of the aortic annulus protruding into the left ventricular outflow tract and predisposing for annular rupture
• Significant stenosis of the left main or proximal left anterior descending artery with substantial risk of hemodynamic instability during rapid ventricular pacing

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: No post-dilatation after THV deployment
Experimental: Nominal post-dilatation using the original delivery balloon	Other: Post-dilatation; Nominal post-dilatation using the original delivery balloon

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
THV-asymmetry index	The THV-asymmetry index will be calculated from freeze-frame fluoroscopic images as: [(longer THV height/shorter THV height) - 1] × 100. Minimum value: 0 Maximum value: NA Higher values indicate more asymmetry.	Peri-procedural

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
THV diameters at inflow, midframe and outflow and THV heights at the inner and outer curve	THV diameters will be measured on freeze-frame fluoroscopic images. Minimum value: 0 Maximum value: NA Measured in millimeter. Higher values indicate better THV expansion. THV heights will be measured on freeze-frame fluoroscopic images. Minimum value: 0 Maximum value: NA Measured in millimeter. Lower values indicate better THV expansion.	Peri-procedural
THV asymmetry index from pre- to post-dilatation in the treatment group	The THV-asymmetry index will be calculated from freeze-frame fluoroscopic images as: [(longer THV height/shorter THV height) - 1] × 100; Minimum value: 0 Maximum value: NA; Higher values indicate more asymmetry.	Peri-procedural
THV diameters at inflow, midframe and outflow and THV heights at the inner and outer curve from pre- to post-dilatation in the treatment group.	THV diameters will be measured on freeze-frame fluoroscopic images. Minimum value: 0 Maximum value: NA Measured in millimeter. Higher values indicate better THV expansion. THV heights will be measured on freeze-frame fluoroscopic images. Minimum value: 0 Maximum value: NA Measured in millimeter. Lower values indicate better THV expansion.	Peri-procedural
Residual trans-prosthetic gradient	Residual trans-prosthetic gradient on transthoracic echocardiography; Minimum value: 0 Maximum value: NA; Measured in mmHg; Lower values indicate better THV hemodynamics.	One day, one year and five years
Doppler Velocity Index	Doppler Velocity Index assessed on transthoracic echocardiography; Minimum value: 0 Maximum value: 1; Higher values indicate better THV hemodynamics.	One day, one year and five years
Paravalvular Regurgitation	≥mild paravalvular regurgitation on transthoracic echocardiography	One day, one year and five years
Cross-sectional THV area	Cross-sectional THV area on cardiac CT scans; Minimum value: 0 Maximum value: NA; Measured in millimeter²; Higher values indicate better THV expansion	Three months
Bioprosthetic valve dysfunction	Bioprosthetic valve dysfunction including assessment of structural and non structural valve deterioration (i.e., leaflet thrombosis, endocarditis) on transthoracic echocardiography. Bioprosthetic valve dysfunction will be defined according to the Valve Academic Research Consortium 3 criteria.	One year and five years
Composite of aortic valve re-intervention, cardiovascular hospitalization and all-cause mortality	Time-to-first-event of either aortic valve re-intervention, unplanned cardiovascular hospitalization and all-cause mortality	One year and five years
Aortic valve re-intervention	Time to first aortic valve reintervention	One year and five years
Cardiovascular hospitalization	Time to first unplanned cardiovascular hospitalization	One year and five years
All-cause mortality	Time to all-cause mortality	One year and five years
Major periprocedural complications	Assessment of: periprocedural death;; any type of stroke;; procedure- or valve related hospitalization;; type ≥2 bleeding;; major vascular complication;; new conduction system disorders requiring pacemaker implantation;; major cardiac structural complication;; other acute procedural and technical valve related complications (conversion to open surgery, unplanned use of mechanical circulatory support, implantation of multiple THV valves during the index hospitalization, valve malposition). All defined according to the Valve Academic Research Consortium 3 criteria	30 days

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from baseline in NT-proBNP		One year and five years
Change from baseline in Kansas City Cardiomyopathy Questionnaire Overall Score	Kansas City Cardiomyopathy Questionnaire Overall Score: Minimum score: 0 Maximum score: 100 Higher scores indicate better cardiovascular health.	One year and five years

Collaborators and Investigators

• Sponsor: Medical University of Vienna

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2025
• Primary Completion (Estimated): May 1, 2026
• Study Completion (Estimated): May 1, 2031

Study Registration Dates

• First Submitted: March 3, 2026
• First Submitted That Met QC Criteria: March 12, 2026
• First Posted (Actual): March 17, 2026

Study Record Updates

• Last Update Posted (Actual): May 12, 2026
• Last Update Submitted That Met QC Criteria: May 7, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Computed tomography; Balloon-expandable TAVI prostheses; Fluoroscopic imaging; Post-Dilatation; Double-Tap
• Additional Relevant MeSH Terms: Aortic Valve Disease; Cardiovascular Diseases; Heart Diseases; Heart Valve Diseases; Ventricular Outflow Obstruction; Aortic Valve Stenosis
• Other Study ID Numbers: 2329/2024

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No