Edwards Lifesciences’ new Sapien transcatheter heart valve, an experimental device designed to be inserted through an artery without the need for open heart surgery, appears to have impressed US federal health reviewers, who said in documents released on Monday that the valve “demonstrated superiority” in trials. But they also expressed concerns about safety, saying it put patients at higher risk for stroke and other neurological effects.

A panel of independent experts that advises the US Food and Drug Administration (FDA) is due to meet and consider the trial data on the Sapien heart valve, on Wednesday. Then they will vote on whether to recommend that the FDA approve the device for market. The FDA does not always follow the recommendations of its advisory panels, but it usually does.

As part of their deliberations, the independent advisors, in this case the “Circulatory System Devices Panel of the Medical Devices Advisory Committee”, will also review the comments of the FDA’s in-house reviewers, who have specifically asked that the panel weigh up carefully the benefits and the risks.

The testing data they will review is from the PARTNER (Placement of AoRTic traNscatheterER valves) trial, that evaluated the new heart valve in patients with severe calcific aortic stenosis who were considered to be too sick or high-risk for conventional open-heart valve replacement surgery.

Aortic stenosis is where the valve to the aorta, the main artery that carries blood from the heart, does not open and close properly.

The trial compared the new heart valve procedure with surgical replacement in 699 high risk patients.

Results from the trial were published in the New England Journal of Medicine last month, June 2011. The study concluded that in “high-risk patients with severe aortic stenosis, transcatheter and surgical procedures for aortic-valve replacement were associated with similar rates of survival at 1 year, although there were important differences in periprocedural risks”.

For example, the results showed that rates of major stroke were 3.8% in the transcatheter group and 2.1% in the surgical group at 30 days, and 5.1% and 2.4%, respectively, 1 year after insertion. The rates of major vascular complications were also “significantly more frequent with transcatheter replacement”. Adverse events that were more frequent in the surgical replacement group included major bleeding and new-onset atrial fibrillation.

If approved, the Sapien heart valve with be the first transcatheter aortic heart valve to be marketed in the US. Edwards have been marketing such a valve in Europe since 2007, reports Reuters news agency.

Investment analysts suggest there will only be one contentious issue when the panel meets on Wednesday, and that is the higher risk of stroke and other neurovascular events, which occurred 3.1 times more often in the patients with the new valve than those who underwent surgical replacement.

The Sapien valve can be inserted in two minimally invasive ways: “transfemoral” insertion uses the RetroFlex 3 Transfemoral Delivery System, and “transapical” insertion used the Ascendra Transapical Delivery System.

The transfemoral insertion occurs via the femoral artery through a small cut made in the patient’s groin. A thin wire delivers the device up the artery to the site of the patient’s diseased valve.

The transapical insertion occurs via an incision between the patient’s ribs into the apex of the left ventricle of the heart.

Sources: Edwards Lifesciences, FDA, Reuters, AP, NEJM.

Written by: Catharine Paddock, PhD