A drug often used to treat chronic heart failure may not ease symptoms in people with one form of the disease, a new study suggests.
Spironolactone failed to improve symptoms or quality of life among 422 patients with diastolic heart failure — a form of the disease that affects about half of all people with heart failure.
The drug did, however, benefit the structure and function of patients’ hearts. And experts said it’s too early to know what to make of the results, which appear in the Feb. 27 issue of the Journal of the American Medical Association.
“It would be premature to say this is not beneficial,” said Dr. Sanjiv Shah, a cardiologist at Northwestern University Feinberg School of Medicine, in Chicago, who was not involved in the study.
Shah is involved in an ongoing study of spironolactone’s effects in people with diastolic heart failure. And that trial is focusing on the big questions: Can the drug prevent or delay hospitalizations, or prolong people’s lives?
Spironolactone is in a class of drugs called aldosterone receptor antagonists. They cause the kidneys to eliminate excess water and sodium from the body, so they can lower blood pressure and get rid of fluid build-up in some people with heart failure.
Studies have shown that spironolactone can extend the lives of some heart failure patients — namely, those with a low “ejection fraction.
The problem is that heart failure is a “syndrome” – or a collection of signs and symptoms – rather than a disease. So a treatment that works for some patients may not work as well for others.
In systolic heart failure, the heart’s left ventricle (the main pumping chamber) cannot contract strongly enough, and many people with this form of heart failure have a reduced ejection fraction.
In the diastolic form, the left ventricle doesn’t relax enough between contractions, which means it cannot fill up with as much blood as it should. But the heart’s ejection fraction is actually normal.
Diastolic heart failure is trickier to diagnose, and doctors know less about how to best treat it, said Dr. John Cleland, a cardiologist at Hull York Medical School in Kingston-upon-Hull who co-wrote an editorial published with the study.
He agreed that it’s too soon to draw conclusions from the current findings, and that doctors will know more when Shah’s study results are in.