EKG Can Help Predict Heart Attacks in Healthy Elderly People

Can a simple diagnostic test used to measure a heart’s electrical activity help predict heart attacks? And can that knowledge help doctors reroute their patients away from coronary heart disease?

These are the questions researchers at UCSF asked in a comprehensive eight-year study focused on senior citizens in the United States. Researchers found a higher risk of heart attack when abnormalities showed up on electrocardiogram (EKG) results of healthy elderly people.

“We did not include them if they reported a previous heart attack,” said lead author Reto Auer, MD, a research fellow at UCSF’s Department of Epidemiology and Biostatistics. "So we looked at people who lived independently - not in assisted living facilities - with no history of heart attacks or coronary heart disease."

The findings, scheduled to be published tomorrow in the Journal of the American Medical Association (JAMA) (http://jama.ama-assn.org/), help answer the question of whether or not EKGs can be used to detect heart disease earlier in patients who don't have chest pain or other symptoms.

"This research is taking the information from an EKG and adding it to other traditional risk factors to better predict who is going to have a heart attack," said second author Douglas Bauer, MD, director of the UCSF Division of General Internal Medicine Research Program.

FOCUS ON HEALTHY SENIOR CITIZENS

Researchers studied 2,192 healthy adults aged 70 and older for eight years in Memphis, Tenn., and Pittsburgh. Those with EKG abnormalities had more heart attacks. The results were consistent even when researchers took into account known risk factors for heart attacks, such as smoking, high cholesterol, high blood pressure and diabetes.

At baseline, 276 (13%) participants had minor and 506 (23%) major EKG abnormalities. During follow-up, 351 participants (16%) had coronary heart disease (CHD) events (96 heart-related deaths, 101 heart attacks, 154 hospitalizations for chest pain or a procedure to restore blood flow to the heart). Both baseline minor and major EKG abnormalities were associated with an increased risk of heart disease after adjusting for traditional risk factors.

Each abnormality was categorized in terms of the level of experienced risk. High risk markers included left bundle branch block, a cardiac condition in which the left ventricle contracts later than the right ventricle, as well as major ST-T wave changes in an EKG, among others. Low risk markers included subtle ST-T wave changes and T-wave abnormalities.

"There was a trend towards increased coronary heart disease (CHD) risk from no abnormality to minor, and from minor up to major abnormality," Auer said. "But both minor and major EKG changes were significantly associated with an increased risk of CHD."

GENDER AND RACIAL VARIATIONS?