Trial Tests Heart Valve Replacement Without Opening Chest

(Yale School of Medicine/Wikimedia Commons)

A clinical trial at several medical centers in the U.S., including Rush University Medical Center in Chicago, is testing a new approach  for implanting an aortic heart valve without open-heart surgery. This technology is designed for patients with conditions such as severe aortic stenosis — constriction of the left heart ventricle — who are considered not suitable for open heart valve replacement surgery.

Aortic stenosis occurs when the aortic valve becomes more narrow and pressure increases inside the left heart ventricle. This causes the left heart ventricle to become thicker, which decreases blood flow and can lead to chest pain. As the pressure continues to rise, blood may back up into the lungs, which can lead to shortness of breath. Severe forms of aortic stenosis prevent enough blood from reaching the brain and rest of the body, which can cause light-headedness and fainting.

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

The trial tests the SAPIEN XT valve, which is made of bovine heart tissue sewn on a metal frame. Also part of the trial is the 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. Both devices are made by Edwards Lifesciences in Irvine, California.

The 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 to restore normal blood flow. Transcatheter valve procedures are performed on a beating heart, without the need for a cardiopulmonary bypass. These procedures take about 90 minutes, compared with four to six hours for open-heart surgery.

The phase 2 trial is called the PARTNER II — Placement of AoRTic traNscathetER valves — trial. It is now enrolling some 600 patients and test the SAPIEN XT with either the NovaFlex delivery system or the Edwards’s current transfemoral delivery system that will serve as the control.

Read more: New Balloon Catheter Reduces Cardiac Surgery Invasiveness

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