Patients with severe aortic stenosis, a potentially fatal heart condition, who are not suitable for surgery might benefit from an experimental treatment that avoids open heart surgery to replace the aortic valve, according to a trial reported in the New England Journal of Medicine (NEJM).

Aortic stenosis is the stenosis (narrowing) of the heart valve between the left heart ventricle and the aorta, resulting in impeded blood delivery through the aorta to the body. It is estimated that approximately 1.5 million Americans have aortic stenosis.

The NEJM article reports on the Cohort B of The PARTNER Trial, which studied the Edwards SAPIEN transcatheter heart valve for severe aortic stenosis treatment. Edwards Lifesciences Corporation, the creators of the heart valve, say the results of the trial successfully met the primary endpoints of all-cause mortality and mortality plus repeat hospitalization.

The authors wrote:

In patients with severe aortic stenosis who were not suitable candidates for surgery, TAVI [transcatheter aortic valve implantation], as compared with standard therapy, significantly reduced the rates of death from any cause, the composite end point of death from any cause or repeat hospitalization, and cardiac symptoms, despite the higher incidence of major strokes and major vascular events.

On the basis of a rate of death from any cause at one year that was 20 percentage points lower with TAVI than with standard therapy, balloon-expandable TAVI should be the new standard of care for patients with aortic stenosis who are not suitable candidates for surgery.”

In this new procedure, a new aortic valve is implanted in the heart without the need for major surgery. The surgeon attaches the replacement valve to a catheter. The catheter is then passed through blood vessels until it reaches the heart and the valve is placed.

The researchers monitored 358 patients whose average age was 83 years. Half of them were randomly selected to have valves implanted with the new catheter-delivery procedure, while the other half received other therapies, such as balloon aortic valvuloplasty – they did not receive replacement valves. This was done in 21 centers, 17 of which were in the USA. They were followed-up regularly.

After a 1-year follow-up the researchers revealed that 30.7% of those who received the replacement valve had died, compared to 50.7% of those who didn’t.

At 30 days there was a higher incidence of stroke among those who had received a replacement valve compared with those who didn’t.

After one year there was no deterioration in the functioning of the heart valve, the authors wrote.

The researchers explained:

Aortic stenosis is an insidious disease with a long latency period followed by rapid progression after the appearance of symptoms, resulting in a high rate of death. Standard medical therapy… did not alter the natural history of severe aortic stenosis.

Michael A. Mussallem, CEO of Edwards Lifesciences, said:

The commitment and partnership demonstrated by the interventional cardiologists, surgeons and their heart teams during this very rigorous trial was inspiring as they diligently seek new treatment options for their patients.

The authors concluded that implanting the heart valve in patients with severe aortic stenosis who were not suitable candidates for surgery had a lower risk of death, repeat hospitalizations and cardiac symptoms, compared to those who had other therapies; despite a higher risk of stroke after 30 days.

The trial was funded by Edwards Lifesciences Corporation.

Source: NEJM, Edwards Lifesciences Corporation.

“Transcatheter Aortic-Valve Implantation for Aortic Stenosis in Patients Who Cannot Undergo Surgery”
Martin B. Leon, M.D., Craig R. Smith, M.D., Michael Mack, M.D., D. Craig Miller, M.D., Jeffrey W. Moses, M.D., Lars G. Svensson, M.D., Ph.D., E. Murat Tuzcu, M.D., John G. Webb, M.D., Gregory P. Fontana, M.D., Raj R. Makkar, M.D., David L. Brown, M.D., Peter C. Block, M.D., Robert A. Guyton, M.D., Augusto D. Pichard, M.D., Joseph E. Bavaria, M.D., Howard C. Herrmann, M.D., Pamela C. Douglas, M.D., John L. Petersen, M.D., Jodi J. Akin, M.S., William N. Anderson, Ph.D., Duolao Wang, Ph.D., and Stuart Pocock, Ph.D. for the PARTNER Trial Investigators
NEJM September 22, 2010 (10.1056/NEJMoa1008232)

Written by Christian Nordqvist