Is cardiac stress testing appropriate in asymptomatic adults at low risk?
POSSIBLE HARM ASSOCIATED WITH CARDIAC STRESS TESTING
The overall risk of sudden cardiac death or an event that requires hospitalization during exercise electrocardiography is very small, estimated to be 1 per 10,000 tests, and the risk is probably even less in patients at low risk.5 But the risk of potential downstream harm from additional testing or interventions may be greater than direct harm. Still, no study has yet assessed harm associated with follow-up testing or interventions after screening with exercise electrocardiography.
On the basis of large, population-based registries that include symptomatic persons, the risk of any serious adverse event as a result of angiography is about 1.7%; this includes a 0.1% risk of death, a 0.05% risk of myocardial infarction, a 0.07% risk of stroke, and a 0.4% risk of arrhythmia.6 In addition, coronary angiography is associated with an average effective radiation dose of 7 mSv and myocardial perfusion imaging with a dose of 15.6 mSv.7 These are approximately two times and five times the amount of radiation an average person in the United States receives per year from exposure to ambient radiation (3 mSv).
Several studies that included symptomatic and asymptomatic patients who had undergone angiography reported that between 39% and 85% of patients had no coronary artery disease. This means that many patients were subjected to the risks of invasive testing and treatment without the possibility of benefit. Patients who receive lipid-lowering therapy or aspirin because of an abnormal exercise electrocardiogram are also exposed to the risks related to those interventions.
THE CLINICAL BOTTOM LINE
On the basis of current data, the insurance executive should not get a stress test because the results of the test are unlikely to have an impact on his medical management, are unlikely to improve his clinical outcome, and carry a small risk of harm. Low-risk, asymptomatic people with a positive stress test have the same mortality rate as those who have a negative stress test, and its usefulness beyond traditional risk-factor assessment in motivating patients and guiding therapy has not been established.8 In addition, the rate of false-positive results with exercise stress testing is as high as 71%.9 Although the risk of an adverse event from the initial stress test is low, ie, 1 serious event in 10,000 tests, the risk of subsequent cardiac catheterization after a positive test is significantly higher, ie, 170 serious events in 10,000 tests. For these reasons, the potential harm of exercise electrocardiography outweighs the benefits in this patient.
