Shelley Wood

May 27, 2014

PARIS, FRANCE — Promising early results from a novel, polymer-frame percutaneous aortic valve that has no metallic components suggest that this fully repositionable and retrievable device may one day shake up a field dominated by metal-stent–based valves.

New study results released at EuroPCR 2014 last week indicated that the Direct Flow transcatheter valve, considered first in class because of its unique design, is safe and associated with very low rates of mortality and stroke, plus minimal aortic regurgitation.

The Direct Flow device received CE Mark in Europe in January 2013[1]; the US FDA announced last week that it had granted Direct Flow Medical investigational device exemption (IDE), enabling the company to move forward with its US pivotal trial, dubbed SALUS [2].

Dr Murat Tuzcu (Cleveland Clinic, OH) presented the 30-day results from the feasibility phase of SALUS at last week's meeting. Designed to enroll 30 patients at six US sites, SALUS tested two valve sizes, 25 mm and 27 mm, although the pivotal phase of the trial will also include 23-mm and 29-mm devices, all delivered via an 18F catheter.

The SALUS feasibility study also used the new EuroSCORE II risk score, rather than the logistic EuroSCORE used in earlier studies: patients in SALUS Feasibility had a mean EuroSCORE II of 6 and a mean STS score of 8, with 93% of patients having NYHA 3 or 4 heart failure.

As Tuzcu announced last week, at 30 days, 97% of patients were alive and stroke-free and 89% of patients had no or trace aortic regurgitation.

"Transcatheter aortic-valve replacement with the Direct Flow Medical System is safe and feasible," he concluded.

DISCOVER 12-Month Results

Direct Flow aortic valve [Source: Direct Flow Medical]

Elsewhere at the meeting, Dr Joaquim Schofer (Medical Care Center, Hamburg, Germany) presented 12-month outcomes from DISCOVER , the single-arm study that enrolled 100 "extreme high-risk" patients at nine sites in Europe. DISCOVER formed the basis for European clearance of Direct Flow last year.

In DISCOVER, "extreme high risk" was defined as a logistic EuroSCORE >20 or comorbidities such as severe chronic obstructive pulmonary disease (COPD), porcelain aorta, or previous thorax radiation, with both the interventional cardiologist and surgeon agreeing that a transfemoral approach was warranted.

At one year, 86% of patients were alive and stroke-free, the primary end point of this study. Survival was 90%, and there was zero moderate or severe paravalvular aortic regurgitation, with 23% of patients having mild regurgitation by core lab echo.

"The 12-month DISCOVER results are unprecedented for a [transcatheter aortic-valve implantation] TAVI device," Schofer commented in a press release. "The Direct Flow Medical system has demonstrated that it successfully treats aortic stenosis with low mortality, while addressing the very serious issue of aortic regurgitation in a clinically meaningful way in order to significantly improve patient outcomes."

The pivotal phase for SALUS will also be a nonrandomized trial and will expand to 30 US sites using the same primary end point as DISCOVER: freedom from death or stroke at 12 months. The company has not announced how many patients the study intends to enroll.

A wide range of transcatheter aortic valves hold CE Mark approval. In the US, the Edwards Sapien valves and Medtronic's CoreValve are the only FDA-approved devices.

Tuzcu had no conflicts of interest. Schofer disclosed being a consultant ($<25 000) to Boston Scientific.


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