New York-Presbyterian/Weill Cornell researchers said as many as 1-in-5 people over age 55 suffers the problem that occurs when the heart contracts to send blood around the body and some backward leakage occurs across the heart's mitral valve. When sufficiently severe, mitral regurgitation causes buildup of blood in the lungs, leading to congestive heart failure or heart arrhythmias.

The researchers found monitoring the capacity of such patients to exercise on a treadmill might be useful in predicting the condition's progression and deciding whether the patient needs surgery.

"Mitral regurgitation can be very benign, going unnoticed for many years, or can be severe, impeding the heart's proper function and leading to complications, even death," said Dr. Jeffrey Borer, study co-author. "Our study shows that exercise tolerance testing … is an excellent tool for predicting if the patient is deteriorating and needs surgery."

The research is reported in the American Journal of Cardiology.