Stress test abnormalities may predict both noncardiovascular and cardiovascular mortality

USA: Exercise test abnormalities, such as low functional aerobic capacity, predicted non-cardiovascular causes of death such as cancer in addition to cardiovascular-related deaths, according to a new study from Mayo Clinic published in Mayo Clinic Proceedings.

The treadmill exercise test with electrocardiogram (ECG), also known as an exercise stress test, is one of the most familiar tests in medicine.  Exercise testing typically is focused on diagnosing coronary artery disease. 

The exercise stress test is noninvasive, easily available and provides important diagnostic information. In addition to the ECG itself, the test produces data on functional aerobic capacity, heart rate recovery and chronotropic index, the standardized measure of heart rate during exercise that reflects age, resting heart rate and fitness.

"In our exercise testing cohort, non-cardiovascular deaths were more frequently observed than cardiovascular deaths," says Thomas Allison, Ph.D., M.P.H., director of Mayo Clinic's Integrated Stress Testing Center and the study's senior author. "Though this was a cardiac stress test, we found that cancer was the leading cause of death, at 38%, whereas only 19% of deaths were cardiovascular. Exercise test results including low exercise capacity, low peak heart rate, and a slow recovery of the heart rate after exercise test were associated with increased mortality."