New heart valve replacement option

(Image: Wikimedia Commons)

An innovative approach for implanting a new aortic heart valve without open-heart surgery is being offered at Rush University Medical Centre to patients with severe aortic stenosis who are at high-risk or not suitable candidates for open heart valve replacement surgery.

"This breakthrough technology could save the lives of thousands of patients with heart valve disease who have no other therapeutic options," says Dr. Ziyad Hijazi, director of the Rush Centre for Congenital and Structural Heart Disease and interventional cardiologist of the Rush Valve Clinic. The treatment is offered through a multi-centre, phase IIb cohort study called the PARTNER II (Placement of AoRTic traNscathetER valves) trial.

Aortic valve stenosis (AS) is a type of valvular heart disease characterised by an abnormal narrowing of the aortic valve opening. It is a condition that affects nearly 1.5 million Americans. It causes hardening or thickening of the aortic valve leaflets, which limits leaflet motion and obstructs oxygen-rich blood flow from the heart to the rest of the body. Patients with severe AS may have symptoms of chest pain, fatigue, shortness of breath, light-headedness or fainting. Although AS typically progresses slowly without symptoms, once symptoms occur, treatment is required. 50% of patients may not survive beyond one to three years.

Some considered inoperable

Traditionally, patients with symptomatic AS undergo aortic valve replacement during an open-heart surgery to alleviate symptoms, improve survival and improve quality of life. However, many patients who are at very high risk for surgery, such as elderly, frail individuals with multiple health concerns, are considered inoperable.

The PARTNER II trial will compare a pioneering technology called the Edwards SAPIEN XT valve, which is made of bovine pericardial tissue leaflets hand-sewn onto a metal frame, and a new catheter delivery system called the Edwards NovaFlex delivery system, which navigates the heart from a small incision to the femoral artery in a patient's leg or through a small incision between the ribs and snaked up into the left ventricle. The Edwards NovaFlex delivery system positions the catheter inside the patient's original, collapsed valve, using a balloon to deploy the frame, which holds the artificial valve in place in order to restore normal blood flow. Both procedures are performed on a beating heart, without the need for open, cardiopulmonary bypass and its associated risks.

'Transcatheter valve replacement is a safe and effective alternative to open surgery'

Annually, some 200 000 people in the US need a new heart valve, but nearly half of them do not receive a new valve for a variety of reasons.

"Past study results show conclusively that transcatheter valve replacement is a safe and effective alternative to open surgery, which remains the 'gold standard' for most patients," says Hijazi.

Results from the first phase of the PARTNER trial showed that the rate of death from any cause at one year was 50.7% in the patients who received standard therapy, as compared to 30.7% of patients treated with transcatheter aortic valve replacement (TAVR).

The transcatheter valve procedures take about 90 minutes, compared with four to six hours for open-heart surgery. In open-heart surgery, the surgeon cuts through the breastbone, stops the heart, removes the valve and replaces it. Open-heart surgery can require a two- to three-month recovery period, compared to only a few days for the transcatheter approach.

The next generation Edwards SAPIEN XT valve in The PARTNER II trial was engineered to provide a better valve patterned after surgical heart valves and potentially decrease treatment complications.

The PARTNER trial is the world's first randomised, controlled trial of a transcatheter aortic heart valve. In this clinical phase IIb cohort, patients are randomised to receive either the new Edwards Sapien XT valve using the NovaFlex delivery system or the Edwards SAPIEN Transcatheter Heart Valve.

"The primary objective of the trial is to reduce death, major stroke and repeat hospitalisation in these patients," says Hijazi. "Additionally, we hope to improve quality-of-life indicators."

The PARTNER II trial is one of the three latest, nationwide clinical trials for minimally invasive heart valve replacement being offered through the Rush Valve Clinic, where a team of cardiac surgical and interventional experts address diseases of the aortic, mitral and pulmonary valves.

The three clinical trials include:

PARTNER II trial for patients with aortic stenosis
COMPASSION trial for patients with a dysfunctional conduit - A phase II clinical trial using the SAPIEN Transcatheter Heart Valve in patients who have a dysfunctional conduit between the right ventricle and the pulmonary artery
EVEREST II trial for patients with mitral regurgitation - A continued access trial using the eValve MitraClip to treat a mitral valve leak.

Source: Rush University Medical Centre