LVAD eyed as long-term option in severe CHF. (Cardiovascular Medicine: No longer just bridge to transplant).
ANAHEIM, CALIF. -- Left ventricular assist devices are a long-term option for patients with end-stage congestive heart failure, Dr. Eric A. Rose said at the annual scientific sessions of the American Heart Association.Left ventricular assist devices (LVADs) are not likely to replace cardiac transplants any time soon. But given that less than 3,000 hearts are available worldwide, and 550,000 new cases of CHF are diagnosed each year, the odds of a transplant are nil for most of those in need. Advanced CHF carries a 1-year mortality rate exceeding 50%.
Data from the Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure (REMATCH) trial show that for patients in whom transplantation is not an option, a new, fully implantable LVAD can reduce mortality and improve quality of life, compared with combination drug therapy alone.
The Thoratec HeartMate device, roughly the size of a portable compact disc player, is implanted into the peritoneal cavity or into a preperitoneal pouch. An intake tube, attached to the failing left ventricle, draws blood from the ventricle into the implanted pump, which then forces the blood out into the aorta. A short drive line extends from the device through a small incision in the abdominal wall and connects to a beeper-sized electronic system controller box and a videotape-sized battery pack that the patient wears externally in a shoulder holster.
The device allows patients to ambulate freely, without the limits imposed by large control systems that hindered the practicality of earlier-generation LVADs. The Thoratec device has specially textured surfaces designed to reduce thrombus formation even in the absence of systemic anticoagulants, said Dr. Rose, chairman of surgery, Columbia-Presbyterian Medical Center, New York, on presenting the REMATCH data, published in the New England Journal of Medicine (345[20]:1435-43, 2001).
REMATCH randomized 129 terminally ill patients with class IV heart failure to either the HeartMate LVAD or continuation of state-of-the-art medical therapy with a combination of digoxin, ACE inhibitors, diuretics, [beta]-blockers, inotropics, and other appropriate medications. All patients were ineligible for transplantation owing to age, diabetes or other comorbidities; 68 patients got the LVADs, and 61 remained on medication alone. The groups were comparable, with a mean age of 68 years.
Dr. Rose and his colleagues observed a 48% reduction in all-cause mortality over the 2-year follow-up. By the close of the first year, 52% of the LVAD group and 25% of the medication-only group were alive. By the second year, 23% of LVAD patients and 8% of those on medication alone were still alive.
He estimated that for every 1,000 end-stage heart failure patients treated with HeartMate devices, 270 deaths could be prevented annually. This is four times greater than the expected impact of [beta]-blockers or ACE inhibitors, which give an estimated reduction of about 70 deaths per 1,000 patients treated.
Quality of life, as measured by the Medical Outcomes Study short form (SF-36) questionnaire, the Beck Depression Inventory, the New York Heart Association classification system, and the Minnesota Living with Heart Failure questionnaire, all showed significant or near-significant improvements in physical function and emotional well being in the LVAD group vs. the controls.
But the LVAD patients paid a price for these benefits in the form of complications. There was a 2.4-fold greater incidence of complications--primarily bleeding and infections along the drive line--in those receiving the devices. There was also a considerably greater incidence of malnutrition, which may be due to a chronic low-grade inflammatory state associated with all such implants. "We're just beginning to look into that," Dr. Rose said.
Health care financing systems could pay a hefty price, too, if LVADs catch on. Dr. Rose hesitated to quote an exact cost for the HeartMate, but estimated that it will probably be close to the $160,000 average price tag for heart transplantation. Since LVADs can be mass-produced but transplantable hearts are rare, the devices have a far broader market potential, meaning the net cost of end-stage CHF care could rise considerably.
The Medicare and Medicaid programs, not to mention private insurers, have yet to determine if they will cover the HeartMate, once it is approved for use. Dr. Rose expects that the Food and Drug Administration will approve it as a long-term "destination" therapy in the next several months. Currently, LVADs are only approved as short-term "bridges" to transplantation.
Although a head-to-head comparison between the HeartMate and transplantation remains to be done, Dr. Rose said that it is unlikely that this or any LVAD will beat the 80% 1-year survival and the 50% 10-year survival seen in published transplantation trials.
The relationship between LVADs and heart transplants will ultimately mirror that of hemodialysis and kidney transplants. The one will not substitute for the other, but given the shortage of transplantable organs, mechanical devices will be the only options for most patients.
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| Title Annotation: | left-ventricular assist devices; congestive heart failure |
|---|---|
| Author: | Goldman, Erik L. |
| Publication: | Internal Medicine News |
| Article Type: | Brief Article |
| Geographic Code: | 1USA |
| Date: | Apr 1, 2002 |
| Words: | 807 |
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