Heart Researchers Study Cardiac Device That 'Hugs' Heart to Improve Cardiac Function

Murray, UT (12/14/2007) — Even the heart needs a "hug" sometimes.

Heart researchers at Intermountain Medical Center are studying a novel cardiac support device that is wrapped around the heart via a minimally invasive procedure that appears to improve cardiovascular function and exercise capacity in patients with an advanced stage of heart failure called dilated cardiomyopathy.

The HeartNet Ventricular Support System is a super-elastic Nitinol mesh that is designed to wrap around and reinforce the walls of the heart. It provides permanent, gentle support that is designed to help slow or stop the heart enlargement process so that the heart can work more efficiently, ultimately decreasing the debilitating symptoms of heart failure.

Intermountain Medical Center is one of just 30 medical centers in the nation to participate in a phase III randomized multi-center clinical trial to evaluate the effectiveness and efficacy of the HeartNet device.

Initial studies show that patients may begin to feel better and may be able to more comfortably perform their day-to-day activities with the HeartNet device. When coupled with other heart failure therapies like proper medication, the HeartNet therapy may help return patients to their desired lifestyle. The most recent clinical study demonstrated both safety and efficacy, showing the therapy was associated with notable improvement in patients' functional status (six minute walk, peak volume oxygen consumption) and perceived quality of life. Placement of the HeartNet device elevated global myocardial function in patients, improving left ventricular wall thickening with improvement in cardiac synchrony. Researchers will determine if similar results can be achieved in the larger multi-center study now underway across the country.

The HeartNet procedure is performed using a "mini-thoracotomy" approach that avoids open-chest surgery. The HeartNet is placed over the failing heart by stretching the elastic device over the heart's ventricles. When the HeartNet is "released" it tries to return to its original size, which creates a gentle "squeeze" around the heart.

By augmenting the heart's pumping chambers, or ventricles, the device has shown the potential to help the heart work more efficiently and decrease the debilitating symptoms of heart failure, according to John R. Doty, M.D., a cardiothoracic surgeon at Intermountain Medical Center and co-principal investigator of the study at the center.

It's estimated that more than 5 million Americans suffer from heart failure, including 10% of those over the age of 65. Heart failure is the leading cause of hospital admissions in the nation and one of the leading cause of cardiovascular disability. Each year, more than 300,000 people die from the disease. Dilated cardiomyopathy is a condition in which the heart becomes weakened and enlarged, reducing its ability to pump blood efficiently. Diminished heart function adversely affects the viability of other critical organs and body systems as well, including the lungs and liver. Once diagnosed with the disease, less than 50% of patients live for five years.

Because each patient is physically different, the HeartNet device comes in various sizes. Based on results from a non-invasive echocardiogram, which shows the size of the heart itself, the appropriate size device is chosen for each patient. Patients enrolled in the study are randomized meaning that some patients will receive the HeartNet device while others will be given the optimal medical treatment.

"We're excited to see if this less invasive technology is a viable option for patients with severe heart failure," says Dr. Doty. "It would be a wonderful advancement If it proves successful in halting and reversing progressive deterioration in heart function for these patients and decreases the need for more invasive end-stage therapies."