The most seriously ill congestive heart failure patients live longer and have a better quality of life if implanted with a heart pump, researchers report in Circulation: Journal of the American Heart Association.
End-stage heart failure occurs when the heart is so weak, it can no longer pump enough blood and nutrients to the body’s organs. Standard treatment includes lifestyle modification, and medications that strengthen the heart’s pumping ability, ease the heart’s work by relaxing blood vessels, and help the body eliminate excess fluid. If symptoms are life-threatening despite optimal drug treatment, a heart transplant is considered. However, there are fewer than 2,500 hearts transplanted each year in the United States, and 500,000 to 800,000 patients have advanced heart failure.
The left ventricular assist device (LVAD) is a newer treatment option. This mechanical pump helps maintain the pumping ability of a heart that can’t work effectively on its own. LVADs were originally conceived as a “bridge to transplant” – a temporary device to use while patients waited for a heart transplant. Now they are now being investigated as permanent “destination therapy” for patients ineligible for transplant instead of as a temporary measure.
In this study, a sub-analysis of the Randomized Evaluation of Mechanical Assistance of the Treatment of Congestive Heart Failure (REMATCH) trial, researchers investigated the outcomes of the sickest 129 patients enrolled in REMATCH (average age 68). Of these people, 91 were ill enough to receive ongoing intravenous infusions of medications to boost the heart’s pumping strength (inotropic therapy). Inotropic therapy is sometimes used as a temporary bridge to transplantation; in this case it was used to relieve symptoms in patients with end-stage heart failure. Sixty-eight patients received an LVAD and 61 patients were placed on optimal medical management.
“This is the sickest group of heart failure patients to ever enter a clinical trial. Most had frequent and oppressive breathing difficulties and lived a bed-bound or bed-to-chair existence,” says Lynne W. Stevenson, M.D., co-director of the cardiomyopathy and heart failure program at the Brigham and Women’s Hospital in Boston and associate professor of medicine at Harvard Medical School.
One year after the study began, 49 percent of those sickest patients who received an LVAD were alive, compared with 24 percent of those receiving optimal medical treatment. After two years, 28 percent of the LVAD recipients were alive, compared with only 11 percent of those on medical care alone. In contrast, of the 38 REMATCH patients not on inotropic therapy, 57 percent of those who received LVAD were alive after one year, as were 40 percent of those who continued on optimal medical treatment.
Survivors who received LVADs had significant improvements in their quality of life, becoming ambulatory and experiencing moderate rather than severe symptoms, according to Stevenson.
“The benefit of LVAD was most dramatic in the sickest people, those who will have the worst outcome without the device. But the overall outcome is best for less-ill patients who have not yet tipped over to certain mortality,” Stevenson said. “Our challenge is to find the patients who are sick enough to expect a large benefit, but to identify them before that tipping point, so they are treated early enough to have an optimal outcome.”
Previously, the REMATCH trial found that patients too ill to undergo heart transplant fared better if they received a pumping device rather than optimal treatment with medications. The LVAD was already used as temporary “bridge” therapy for patients anticipating transplant within a few months. REMATCH was the first test of their value for the permanent treatment of patients who are not eligible for transplantation because they were too old or too sick.
“Although this subset analysis of patients on inotropic therapy in REMATCH is the only data we currently have available, it is limited by the small numbers and it must be considered exploratory but not definitive,” Stevenson said. “Furthermore, this study highlighted the limits of current knowledge about what is optimal medical management for very sick patients who do not receive LVAD.” To obtain further data on the outcome of patients receiving mechanical circulatory support, the National Heart, Lung, and Blood Institute (NHLBI) is spearheading efforts to create an LVAD registry.