Support for a weak heart

The concept is deceptively simple -- use a fiber jacket to support a damaged heart -- but it may give thousands of ailing organs a second chance.

That’s the idea behind the Acorn CorCap, an experimental device that doctors hope will slow, or even reverse, the ravages of progressive heart failure.

“If it does work, it could be a huge breakthrough,” says Dr. Douglas L. Mann, a cardiologist at the Veterans Affairs Medical Center in Houston who has studied the device. The CorCap, which is currently being tested on 300 patients at 30 hospitals in North America, may help people with moderate to severe heart failure who don’t qualify for a transplant but have few other treatment options.

Heart failure is the steadily declining ability of the heart muscle to pump blood, either from sudden damage caused by heart attacks or from gradual deterioration in muscle function from high blood pressure, leaky heart valves, viral infections or other factors. The heart offsets this loss by contracting more forcefully. “But this sets up a vicious cycle that perpetuates further weakening of the heart muscle,” says Dr. Randall C. Starling, a cardiologist at the Cleveland Clinic Foundation in Ohio.

This prolonged overcompensation enlarges the heart muscle, which diminishes its ability to pump blood efficiently and causes heart valves to lose their proper fit.

With less blood leaving the heart, blood returning to the heart backs up, triggering fluid accumulation in the legs, ankles and lungs, making it difficult to breathe. Muscles and other tissues receive less oxygen and nutrition, both of which are carried in the blood.

“Medications can only do so much, and some patients don’t respond,” says Dr. Kathy E. Magliato, a heart surgeon at Cedars-Sinai Medical Center who has implanted the CorCap device into several patients. “It’s a very debilitating way to die.”

Made of a polyester fiber, the sock-like device is fitted around the heart and stitched into place in a 30-minute surgical procedure. It is designed to work like a brace and to encourage the heart to revert to its natural shape. “The device’s simplicity is so important with patients who are critically ill,” says Magliato. “They spend less time in the operating room, under anesthetic, and they don’t have to be put on a heart-lung machine.”

Experiments in animals and with different surgical procedures in the last decade suggested that coaxing the heart back to its original shape could improve function and prevent it from getting bigger. “This gave birth to the concept that this passive support would allow the heart to heal itself,” says Mann.

Preliminary tests conducted on 47 patients in Germany and Australia demonstrated that the device prevents progressive enlargement of the heart, preserves or improves the pumping function and eliminates the back flow of blood through one of the heart valves. While the CorCap won’t make hearts perform like new, it may buy patients some quality time.

Since the company must do a 12-month follow-up on patients with the experimental device, it probably won’t be on the market until 2005. “But this could be a unique weapon for patients who have exhausted conventional therapy and are still doing only marginally well,” says Starling.

*

(BEGIN TEXT OF INFOBOX)

Two heart splints in development

The CorCap is not the only device designed to reduce stress on the heart. The Myocore Myosplint system, which is being tested in Europe and the United States, does its job by changing the size and shape of the heart’s main pumping chamber, the left ventricle.

It consists of two pads connected by a tension bar. The bar is placed down the length of the left ventricle and threaded through the opposing walls of the chamber, where it is anchored on each end by a pad. This allows the chamber’s opposing walls to be drawn together, which should reduce its size and improve cardiac function. The device is not as far along in development as the CorCap, but has been implanted in 25 patients, including six at the Cleveland Clinic. The manufacturer plans to enroll up to 25 more patients to determine whether it works.