Doctors at the University of Maryland Medical Center say that contrary to conventional thinking, a kidney transplant can significantly improve the heart function of people on dialysis with a serious form of heart failure.
In a study published in the April 5, 2005 issue of the Journal of the American College of Cardiology, the researchers found that a majority of patients who had systolic heart failure, in which the heart's left ventricle was weak and not pumping blood efficiently, had a dramatic recovery after their kidney transplant.
"These findings are contrary to conventional thinking that a kidney transplant may put additional strain on the hearts of patients with systolic heart failure," says the lead author of the study, Ravinder K. Wali, M.D., a nephrologist at the University of Maryland Medical Center and assistant professor of medicine at the University of Maryland School of Medicine. "We were surprised to find that, in fact, many of those people with severe heart failure had striking improvement in terms of cardiac function after a kidney transplant."
Dr. Wali adds, "Our study also found that systolic heart failure was more likely to be reversed if patients received a transplant soon after they began dialysis to treat their kidney failure."
The study followed 103 patients between June 1998 and November 2002. Prior to their transplant, all of the patients had congestive heart failure with a left ventricular ejection fraction of 40 percent or less. The ejection fraction is a measure of the ability of the heart to pump blood. In the normal ejection fraction, the heart is capable of pumping more than 55 percent of the blood volume in the ventricle. The researchers assessed the heart's pumping ability of the patients at six and 12 months and at a later follow-up visit after successful transplantation.
Overall, after a kidney transplant, the heart's pumping ability improved in more than 86 percent of the patients. For 70 percent of the patients, pumping ability returned to normal or close to normal following the transplant. Even more dramatic, the majority of the patients with the worst heart failure (about 20 percent of those studied) regained significant cardiac function following the transplant, according to Dr. Wali.
The investigators also observed major recovery in patients whose heart failure included blocked or narrowed heart arteries, a condition known as ischemic heart failure. "We showed that the ejection fraction went up even among those who had undergone coronary artery bypass surgery," says Dr. Wali.
The most important factor that directly affected recovery of the heart function was the length of time the patient was on dialysis. The study was not large enough to determine how long a person can remain on dialysis and still receive a cardiac benefit from a kidney transplant.