DurAVR Biomimetic Transcatheter Heart Valve: Early Feasibility Study (EFS) Update | SCAI

Why is the study important, and what is different about this study?

The DurAVR is a unique biomimetic valve, which is a single-piece native-shaped valve designed to function like a native healthy aortic valve. It is unlike the traditional mechanical or bioprosthetic valve used in valve replacements and is made of contiguous bovine pericardium folded into a single frame instead of having leaflets sutured together. It uses the ADAPT anti-calcification technology on a balloon expandable platform. Prior hydrodynamic bench studies have shown better hemodynamics with better effective orifice area compared to presently above commercial valves.

Should I change my practice because of these findings? 

This is an early feasibility study small in caliber, including 15 patients at 7 US sites, which limits its broader application. 

What question was the study supposed to answer? 

The study has been designed to study the safety and feasibility of the DurAVT transcatheter heart valve delivery system. 

What did the study show? 

This prospective non-randomized single-arm early feasibility study enrolled 15 patients with severe symptomatic aortic stenosis. The follow up period is up to ten years with echocardiogram, CT, or optional CMR. Baseline characteristics of the enrolled subjects included older age (81 yo), predominantly female (67%), Society of Thoracic Surgeons (STS) score 5.8% with an area derived annulus 22.2mm and NYHA Class II- III symptoms. Some of the main risk factors observed in the patients included underlying conduction disturbance (47%) and coronary artery disease (53%). 

Good safety profile was demonstrated in the study with 0% incidence of 30-day primary safety endpoint of all-cause mortality or disabling stroke. The secondary safety endpoints included cause mortality (0), disabling stroke (0), Valve Academic Research Consortium VARC-3 type 2-4 bleeding (0), major vascular or structural heart complications (0), acute kidney injury stage 3,4 (0), moderate or severe aortic regurgitation (0) and no need for device-related surgery or intervention/re-intervention (0). 1 patient (6.7%) needed a pacemaker due to procedure-related conduction abnormality, the patient did have a pre-existing conduction abnormality. 

30-day hemodynamic results report a starting mean gradient of 41 mm Hg that were reduced to 7.8mm Hg on discharge and were sustained at 7.5mm Hg at 30 days. The starting effective orifice area was reported as 0.8 cm2 at index procedure and reported to be 2.4 cm2 at discharge and maintained at 2.2 cm2 at 30 days. No paravalvuar leak was reported at 30 days. 

How good was the approach/methodology? 

Given that this is a limited clinical investigation designed to gain early insights into this innovative bioengineering technology, larger-scaled clinical trials will be needed to validate findings reported in this study.  

30 Day Events N = 15
Primary Safety Endpoints  
All-cause mortality or disabling stroke  0 (0)
Secondary Safety Endpoints  
All-cause mortality  0 (0) 
Disabling stroke  0 (0)
VARC-3 type 2-4 bleeding  0 (0)
Major vascular or structural heart complications  0 (0)
Acute Kidney Injury (AKI) Stage 3 or 4  0 (0)
Moderate or severe aortic regurgitation  
New permanent pacemaker due to procedure-related conduction abnormalities* 1 (6.7)
Surgery or intervention related to the device, including aortic valve reintervention  0 (0) 

Values are n (%)