April 12, 2000 (Tampa) -- Whatever causes your heart muscle to weaken and fail also predicts how long you will live, according to a recent study. And if doctors can predict who will live longer, they will be better able to determine who among those waiting for a heart transplant needs a heart the most.
"For years, patients with unexplained heart failure have been lumped together with the nonspecific diagnosis of 'cardiomyopathy,'" researcher Ralph H. Hruban, MD, professor of pathology at Johns Hopkins University in Baltimore, tells WebMD. But patients with this diagnosis had widely varying survival rates.
A study of more than 1,000 patients at Johns Hopkins Hospital found that the underlying cause of heart muscle disease causing failure helps predict how long patients will live. The study was reported in the April 13 issue of The New England Journal of Medicine.
"This study helps us ... to make end-of-life decisions, and to determine the need to transplant and when," researcher Edward K. Kasper, MD, tells WebMD. He is associate professor of medicine and director of the cardiomyopathy and heart transplant service at Johns Hopkins. "If the patient has a type of cardiomyopathy associated with [poor survival], I would counsel them to get their affairs in order, and [they] might also be more likely candidates for transplant."
The study showed that five years after diagnosis, three-quarters of these patients with heart failure caused by unknown reasons were still alive, as were three-quarters of patients with heart failure caused by lack of oxygen to the heart muscle. The majority of patients with heart failure related to pregnancy were still alive five years after diagnosis.
Patients with poor survival rates included those who had heart failure as a result of HIV, heart infections, or undergoing chemotherapy. Less than half of these patients were still alive after five years.
"This exciting study [shows] that a heart biopsy, which is safe at specialized centers such as Johns Hopkins, can help classify patients with cardiomyopathy into clinically important groups," Hruban tells WebMD. Even after biopsy, or surgical removal and microscopic examination of a small piece of heart muscle, no definite diagnosis could be made in half the patients.
The study did not examine the effect of heart function when the patient was first seen, nor of drugs or other treatments given, so "we can't conclude definitively that it was diagnosis [alone] that determined survival," Michael M. Givertz, MD, tells WebMD when asked to review the study. He is clinical director of the cardiomyopathy program at Boston University.
The researchers looked at survival between 1982 and1997 and found no significant improvement with time. "If you look at this study, as well as at community-based [studies such as from the] Mayo Clinic, we have not seen improvement in survival with time," says Givertz. Medications called "ACE-inhibitors and other medical therapies have been available for more than 10 years, and heart transplant for more than 30 years, yet this has not translated into improved survival.
"We have good therapies, but they tend to be underutilized in the community," says Givertz. "There is a need for education among primary care physicians as well as cardiologists. We could all be more aggressive in the vigorous evaluation, treatment, and follow-up of heart failure, including medical and nonmedical therapies such as diet and exercise. ... These nonmedical therapies may be especially important in ... improving quality of life."
Suggestions for improving your diet and developing an exercise program to decrease the risk of heart disease and improve quality of life in heart failure can be found at the American Heart Association's web site.
- Heart failure occurs when the heart muscle doesn't pump as well as it should, and all cases are often lumped together and diagnosed as cardiomyopathy.
- New research shows, however, that the underlying cause of cardiomyopathy can be important because it helps predict how long a person with the disease will live.
- A biopsy of the heart can help determine the cause of cardiomyopathy, but in some patients no definite diagnosis can ever be made.