Health professionals have known for years that exercise testing on a treadmill is useful for measuring how a person’s heart performs under stress. Now researchers have determined that such testing can be used to predict the risk of cardiac-related death and may ultimately rule out the need for aggressive treatment for cardiovascular disease in some cases.
Reporting in the September 3 issue of the Journal of the American College of Cardiology, researchers at the Cleveland Clinic Foundation found that people whose heart rates remain elevated after a stress test are more than twice as likely to die within 6 years as those whose rates are normal. (Heart rate recovery was considered abnormal if it dropped by only 12 beats per minute [bpm] or less during the first minute after exercise, or by 18 bpm or less in subjects who underwent an immediate ultrasound exam without a cool-down period.) This finding may cause physicians to use exercise stress testing as a frontline approach for identifying high-risk candidates, sparing them unnecessary and more invasive treatments.
However, in a press release issued by the American College of Cardiology, one of the researchers warned exercisers not to try to interpret their own heart rate recovery risk after a workout.
“The problems with people taking their own heart rates are, one, we use a standard protocol, which is . . . very different from what people do in the gym,” said Michael S. Lauer, MD. “Two, we measure heart rates very accurately using an electrocardiogram machine. Hence, we can’t simply extrapolate our findings to casual heart rate measurements in people doing typical exercise.”