DALLAS, Dec. 1 -- A mechanical heart device has allowed individuals with congestive heart failure to recover lost pumping function and avoid a heart transplant, according to a new study in today's Circulation: Journal of the American Heart Association.
This implantable mechanical heart, called the left ventricular assist device, or LVAD, has been used for the past 40 years to take over the pumping function of the heart for patients with severe heart failure awaiting transplantation surgery.
Researchers from the Columbia-Presbyterian campus of New York Presbyterian Hospital in New York City found that the LVAD can serve not only as a "bridge" to transplantation, but also as a "road to recovery" for some individuals with severe or end-stage congestive heart failure.
Donna Mancini, M.D., associate professor in the department of medicine at Columbia-Presbyterian and medical director of the cardiac transplant program, says, "Significant recovery occurred in patients on LVAD therapy. The study illustrates that patients at the end stages of heart failure still possess heart tissue that can be restored to normal or near-normal function."
About 4.9 million Americans suffer from heart failure, the only form of heart disease that is increasing significantly in the population. Because in CHF the heart pumps less blood than the amount needed by the body, people with the disease have fluid retention, fatigue and difficulty breathing. Heart failure often involves worsening symptoms with gradual deterioration of heart function leading to death.
Current therapies for heart failure include drugs -- which reduce the heart's workload to slow the progression of the disease -- and heart transplantation. For patients with advanced heart failure, heart transplantation is the only lifesaving therapy. However, due to the shortage of donor organs for transplants, relatively few people receive the surgery.
Researchers studied 111 patients who received the LVAD while waiting for heart transplantation. When it came time for the patient to receive a new heart, researchers found that five patients could be weaned from the device and did not need a transplant. Various methods were used to determine if patients could be taken off the LVAD, including direct visualization of the heart at the time of removing the device, or an echocardiogram. The average age of the 89 men and 22 women in the study was 50 years old. Congestive heart failure was caused by coronary artery disease in 60 individuals and 51 had dilated cardiomyopathy in which the heart is enlarged. The LVADs were implanted for an average of 100 days.
"Despite the small number of patients from whom the device could be successfully removed, the results of the study are strikingly important," says Mancini. "All of the patients had presumably irreversible end-stage heart failure. Yet these patients demonstrated that their heart function could be dramatically modified and almost return to normal for short periods."
Mancini also says that few patients recover with the LVAD because people with coronary artery disease who have sustained a large myocardial infarction are unlikely to reverse their dysfunction. However, researchers found the LVADs were helpful for individuals who had cardiomyopathy and whose exercise capacity was high, as measured by peak oxygen consumption. Mancini says the mechanism underlying this improvement is unclear and needs to be the focus of future studies.
In an accompanying editorial, Douglas Mann, M.D., of the Veterans Administration Medical Center and Baylor College of Medicine, Houston, says the study brings both good and bad news.
The bad news is that a reversal in heart failure occurred in only a few patients.
"The good news is that individuals could be weaned from the device and that researchers were able to use exercise testing to identify patients in which LVAD support may provide a stable bridge to heart recovery. Thus, overall, the report by Mancini and colleagues should be viewed as favorable for patients with heart failure," says Mann.
This research builds on a previous report on LVADs that appeared in the June 16 issue of Circulation: Journal of the American Heart Association by Kenneth B. Margulies, M.D., associate professor of medicine and physiology at Temple University Cardiac Transplant Center, Philadelphia. This study found that the LVAD reduced the workload of the failing left side of the heart (the left ventricle) to such an extent that some heart muscle cells -- called myocytes -- recovered their ability to contract and relax.
Further studies are needed to identify the best candidates for LVAD therapy and, more importantly, whether the improvements in myocytes are lasting or transient, say researchers.
If improvement persists, the research suggests that LVADs may not just be a "bridge" to transplantation, but also a "bridge" to recovery, says Mancini. "In the future, some types of cardiomyopathy may be curable."
Co-authors of the study are Ainat Beniaminovitz, M.D.; Howard Levin, M.D.; Katharine Catanes, R.N.; Margaret Flannery, R.N.; Marco DiTullio, M.D.; Sergey Savin, B.S.; Marie Elena Cordisco, R.N.; Eric Rose, M.D.; and Mehmet Oz, M.D.
Co-author of the editorial is James Willerson, M.D.
The above story is based on materials provided by American Heart Association. Note: Materials may be edited for content and length.
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