April 10th, 2012
Baseline ECG Abnormalities in Older Patients Tied to Increased CHD Risk
Although routine ECG screening in asymptomatic people is not recommended by guidelines, a new study raises the possibility that ECGs in an elderly population can provide a modest improvement in risk classification.
In the Health, Aging, and Body Composition Study, published in JAMA, Reto Auer and colleagues followed 2192 adults 70 to 79 years of age without known cardiovascular disease. People with any ECG abnormality at baseline had a significant increase in risk for CHD after adjustment for other risk factors:
- HR 1.35, CI 1.02-1.8 (17.2 per 1000 person-years for those with no ECG abnormalities compared with 30.8 per 1000 person-years for those who had an ECG abnormality)
The investigators report that by adding the ECG test to a model containing traditional risk factors, 7.1% of the overall population, and 13.6% of the intermediate-risk population, were reclassified. Eight percent of the intermediate-risk group were reclassified as high risk, and this group had an event rate of 15.2%. By contrast, 6.2% were reclassified as low risk, and this group had an event rate of 5.2%.
The authors conclude that because of “the safety, the low cost, and the wide availability of ECG, ECG data might be useful to improve CHD risk prediction in older adults.” But they stated that before the ECG becomes a routine screening test, it “should be evaluated in randomized controlled trials.”
In an accompanying editorial, Philip Greenland points out that a sufficiently largely clinical trial would be prohibitively expensive and would have little likelihood of demonstrating substantial benefit. He advises that “in the absence of clear evidence of benefit and no clear implications for costs, the best advice is not to perform ECGs in asymptomatic patients, regardless of age.”