Routine 'Double Tap' During TAVR Cuts Valve Asymmetry by 70 Percent, DUOTAP Trial Finds

A simple intraprocedural adjustment during transcatheter aortic valve replacement can drastically improve the structural geometry of the new implant. Results from the DUOTAP randomized clinical trial, presented at the 2026 Transcatheter Cardiovascular Therapeutics conference, demonstrate that routine postdilation cuts valve asymmetry by 70 percent. The findings offer a straightforward method to optimize hemodynamics in patients with severe aortic stenosis.[1][3]

Transcatheter aortic valve replacement, or TAVR, has become the standard of care for many patients suffering from severe aortic stenosis. During the procedure, operators deploy a replacement valve inside the diseased native valve using a balloon-expandable platform. The structural integrity of that newly deployed transcatheter heart valve dictates its long-term performance and durability.

Historically, operators have accepted the final shape of the deployed valve as a passive consequence of the patient's native anatomy. If the native valve is heavily calcified, the new transcatheter heart valve often expands asymmetrically. This uneven expansion can lead to residual gradients, impaired leaflet motion, and early bioprosthetic valve dysfunction.[2]

To combat this, some interventional cardiologists have utilized a technique known as postdilation, colloquially referred to as the "double tap." After the initial deployment, the operator reinflates the delivery balloon a second time inside the newly placed valve. In theory, this extra inflation forces the valve frame into a more circular, optimal geometry.[1]

Despite its theoretical benefits, routine postdilation has remained controversial in clinical practice due to safety concerns. Operators have historically worried that a second balloon inflation might trigger annulus rupture, dislodge the valve, or damage the heart's electrical conduction system. Until now, the strategy lacked rigorous randomized data to justify its universal application.[1]

The DUOTAP Trial Design

To provide definitive evidence, researchers at the Medical University of Vienna launched the DUOTAP randomized clinical trial. The single-center, single-blinded study enrolled 148 patients with severe aortic stenosis who were scheduled for transfemoral TAVR. All participants received a Sapien balloon-expandable transcatheter heart valve, manufactured by Edwards Lifesciences.[2][3][4]

The trial specifically excluded patients with high-risk anatomical features on preprocedural computed tomography, such as bicuspid aortic valves or severe calcification predisposing them to annular rupture. Investigators randomized the 148 participants in a one-to-one ratio. Half received routine postdilation using the original delivery balloon at nominal volume, while the control group received standard deployment.[2][4]

The patient cohort reflected a typical contemporary TAVR population, ensuring the results would be broadly applicable to daily practice. The median age of the participants was 81 years, and 47 percent of the enrolled patients were female. Their median EuroSCORE-II, a standard metric for predicting operative mortality, sat at a relatively low 2.3 percent.[1][3]

The primary endpoint of the DUOTAP trial focused on the transcatheter heart valve asymmetry index, measured via fluoroscopy immediately after the procedure. Secondary endpoints included echocardiographic assessments of paravalvular leak prior to discharge. Researchers also utilized cardiac computed tomography at three months to evaluate hypo-attenuated leaflet thickening, a marker of subclinical valve thrombosis.[2][3]

Dramatic Improvements in Valve Geometry

The intervention delivered striking improvements in the structural deployment of the transcatheter valves. Routine postdilation yielded a 70 percent lower asymmetry index compared to the control group. The median asymmetry index dropped to just 1.2 percent in the postdilation cohort, compared to 2.8 percent in patients who received standard deployment without the second tap.[3]

Fluoroscopic analysis revealed exactly how the second balloon inflation corrected the structural imbalances. Postdilation actively reduced the valve height on the outer curve of the device, forcing the frame into a more symmetrical cylinder. This geometric optimization resulted in significantly larger valve areas at the inflow, midframe, and outflow levels on follow-up imaging.[1]

Better geometry immediately translated into superior hemodynamic performance for the patients. Echocardiography performed before hospital discharge showed a 67 percent reduction in more-than-mild paravalvular leak among the postdilation group. Paravalvular leak occurs when blood flows backward around the edges of the new valve, a complication that forces the heart to work harder.[1]

The benefits extended beyond the immediate hospital stay, as evidenced by the three-month computed tomography scans. Patients assigned to routine postdilation experienced a 63 percent reduction in hypo-attenuated leaflet thickening. This thickening is often a precursor to reduced leaflet mobility and early valve failure, making its prevention a major priority for interventional cardiologists.[1][2]

Addressing Safety Concerns

Given the historical fears surrounding the "double tap" technique, the safety outcomes of the DUOTAP trial were heavily scrutinized. Reassuringly, the data showed no significant increase in procedure-related adverse events between the two groups. At 30 days, procedural or early clinical adverse events occurred in 24.3 percent of the postdilation group versus 31.1 percent of controls.[1][3]

The risk of damaging the heart's electrical system, a primary concern with aggressive balloon expansion, did not materialize. A new conduction system disorder requiring a permanent pacemaker implantation was logged in 20.3 percent of the postdilation patients. This rate was statistically indistinguishable from the 21.6 percent observed in the standard deployment control group.[1]

The geometric benefits of the second inflation proved remarkably consistent across various patient demographics and anatomical variations. Subgroup analyses confirmed that postdilation corrected asymmetry regardless of the patient's sex or the specific size of the transcatheter heart valve used. It also remained effective across varying degrees of native aortic valve calcification.[1]

Shifting the Clinical Paradigm

The results of the DUOTAP trial, simultaneously published in JAMA Cardiology in November 2026, challenge long-held assumptions in structural heart disease. Maximilian Autherith, MD, the study's lead author, emphasized that the data fundamentally changes how operators should view valve deployment. The shape of the valve is no longer something cardiologists must simply accept.[1][3]

"By providing randomized evidence that THV asymmetry is modifiable intraprocedurally, the DUOTAP trial challenges the concept of THV geometry as a passive consequence of valve deployment," Autherith stated during the presentation. He added that the findings support "geometry optimization as an actionable therapeutic target during contemporary TAVI procedures."

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The broader cardiology community has responded positively to the robust randomized data. In an editorial comment accompanying the publication, John G. Webb, MD, FACC, noted that the findings confirm earlier observational signals. He highlighted that the trial demonstrates favorable structural, functional, and clinical outcomes for patients undergoing the optimized procedure.

Webb and his co-authors concluded that the evidence justifies a shift in standard operating protocols for transcatheter valve replacements. They suggested that "double tap postdilation seems a reasonable strategy which should be adopted more widely—if not routinely, then at least more often," providing a strong endorsement for the technique's integration into daily practice.

Long-Term Durability Questions

While the immediate geometric and hemodynamic improvements are clear, the ultimate test of routine postdilation will be its impact on long-term patient survival. The DUOTAP trial has proven that the "double tap" creates a better-functioning valve at three months. However, researchers acknowledge that extended follow-up is necessary to confirm lasting clinical benefits.[1][5]

"Whether these mechanistic and hemodynamic benefits translate into improved valve durability and long-term clinical outcomes remains to be assessed," Autherith cautioned. The trial investigators plan to track the cohort over the next five years to monitor for structural valve deterioration, heart failure hospitalizations, and overall mortality rates.[1]

The question of valve durability is becoming increasingly urgent as TAVR expands into new patient populations. Recent trials have begun testing transcatheter valves in younger patients and those with only moderate aortic stenosis. If these younger patients are to avoid repeat procedures, their initial implants must function flawlessly for a decade or more.[5]

By proving that a simple, low-cost intraprocedural step can drastically improve the initial geometry of the valve, the DUOTAP trial offers a tangible path toward that longevity. Correcting asymmetry before the patient ever leaves the catheterization laboratory minimizes the mechanical stress on the prosthetic leaflets, theoretically extending the lifespan of the device.[5]

As interventional cardiology continues to refine its techniques, the "double tap" may soon transition from a controversial maneuver to a mandatory quality-control step. For the thousands of patients undergoing TAVR each year, this optimized approach promises a safer, more durable solution to severe aortic stenosis, ensuring their new valves perform at their absolute best.[5]