Washington, Sept. 28 (Reuters): A treadmill stress test can predict heart attacks or other serious heart disease even in men without symptoms, US researchers reported yesterday.

The findings, published in the journal Circulation, suggest exercise tests may be able to help predict which men who already appear to have a moderate to high risk of heart disease really need to take care.

One of the two studies showed exercise tests may be used to judge who would receive an implanted pacemaker-like device called a defibrillator, researchers said.

In one study two measurements ? a change in electrocardiogram or ECG tracing called ST-segment depression and an inability to reach a target heart rate ? more than doubled the 10-year risk of coronary events such as heart attacks.

Men who did well on the stress test had a lower-than-expected rate of heart attack and serious heart disease in the 10 years following.

?Our results suggest that exercise testing may be of benefit in asymptomatic men with intermediate to high risk,? said Dr. Gary Balady, a professor of medicine at Boston University School of Medicine.

His team tested women, too, but so few women developed heart attacks or serious heart disease that they could not decide if the test was a good predictor for women.

The 1,431 men and 1,612 women were taking part in a bigger study called the Framingham Heart Study. They were 45 years old at the start on average and had been followed for more than 18 years.

The volunteers got a battery of tests when they began the study that included the stress test. In the 10 years following 224 men, or 15.7 per cent, had chest pain, a heart attack or died from coronary heart disease. Overall, there was a 9.6 per cent risk of heart attack, chest pain or other serious heart disease for the 3,000 people in the study over 10 years.

Men who had the highest predicted risk, based on cholesterol levels, high blood pressure, family history and other factors, were the most likely to have serious heart disease if they also did poorly on the stress tests, researchers found.