#3 Continuous-Flow Ventricular Assist Devices
Approximately 2,200 Americans undergo heart transplants every year. While nearly 3,000 people with damaged hearts are placed on waiting lists to receive new donor hearts, up to 20% die without getting a second chance at life because of the shortage of available hearts. All of that could change now that the newest versions of continuous-flow ventricular assist devices are revolutionizing the transplant process.
“Continuous flow heart pumps are going to be the wave of the future for treating hearts irreversibly damaged by long-lasting heart failure, viral infection, heart muscle disease, and multiple heart attacks,” says James Young, MD, Chair, Endocrinology and Metabolism Institute, Cleveland Clinic.
“For patients whose hearts are unable to effectively pump blood due to severe heart problems, this remarkable device can help them improve their heart function as they await a heart transplant. And for those patients with advanced heart failure who don’t qualify for heart transplantation due to debilitating health, destination therapy with the device is now being studied.” Approval for this indication by the U.S. Food and Drug Administration is expected in 2010.
Heart-assisting technology has improved dramatically since 1984, when the first successful heart-assist device was used. The tiny titanium and plastic continuous-flow ventricular assist devices have come under intense focus over the years as researchers have looked for ways to decrease pump size and boost efficiency. Today’s latest pump, a 3-ounce device, is attached alongside the native heart and runs on rechargeable batteries connectedthrough the abdomen. The device quietly and effectively takes over the pumping ability of the heart’s left ventricle and provides continuous blood flow through the circulatory system using only one moving part—a rotary pumping mechanism. The advantages of the latest generation of continuous flow devices include greatly decreased risk of infection, greater reliability, and smaller size to enhance their use with smaller adults and children.
The new pumps, which can generate up to 10 liters of blood flow per minute, have the potential of providing up to 10 years of circulatory support, although the life-saving devices are used mainly to bridge the interim between end-stage heart failure and a cardiac transplant. Before implantation of the device, most patients are rated class four on the New York Heart Association scale. They are fatigued and short of breath even at rest. Six months after implantation of their pump, many only have minimal or mild symptoms. Finally able to rehabilitate themselves, their overall fitness, quality of life, and heart function improves, which makes them better candidates for heart transplantation.
Another possibility with this latest technology: No longer would someone have to depend on the generosity of a person dying in making his or her heart available to a heart-sick patient. With the number of people donating hearts limited and the number of people needing heart transplants growing exponentially, doctors expect that one day these continuous-flow assist devices may be used as a long-term support or destination therapy for end-stage heart failure patients. Permanently implanted, it alone will support or replace the failing heart.
