In a group of older adults without preexisting CVD, researchers found major and minor electrocardiographic abnormalities were associated with an increased risk for CHD events. ECG abnormalities also significantly improved the prediction of CHD beyond traditional CV risk factors, researchers said.
Findings come from a population-based study that included white and black adults aged 70 to 79 years. Reto Auer, MD, of the University of Lausanne, Switzerland, and University of California, San Francisco, and colleagues analyzed baseline major and minor ECG abnormalities, the development of new ECG abnormalities and persistent ECG abnormalities during follow-up. The researchers then examined how abnormalities were related to new CHD events, independent of traditional CV risk factors, in 2,192 study participants. All participants were without known CVD at baseline.
Researchers collected information on adjudicated CHD events during a median follow-up of 8.2 years between 1997 to 1998 and 2006 to 2007. ECG abnormalities were classified as either major or minor.
At baseline, 23% of all participants had major ECG abnormalities and 13% had minor. During the median 8.2-year follow-up, 351 participants had CHD events (96 CHD deaths, 101 acute MIs, and 154 hospitalizations for angina or coronary revascularizations).
Of 1,670 adults with a second ECG at 4 years, 208 had new ECG abnormalities and 416 had persistent abnormalities. During a median follow-up of 6.4 years, 185 of these patients had CHD events and 57 died from CHD. Both baseline minor and major ECG abnormalities and new and persistent abnormalities at 4 years were associated with an increased risk for CHD events. After adjusting for other CV risk factors, participants with minor ECG abnormalities at baseline had a 35% increased risk for CHD events, compared with participants with no abnormalities at baseline. Participants with major abnormalities had a 51% increased risk, compared with participants with no abnormalities. Similar findings were reported for both black and white participants. In addition, when ECG abnormalities were added to the model adjusted for traditional CV risk factors, 176 intermediate-risk participants (8%) were reclassified as high risk. Of those, 15.2% experienced CHD events. Also, 136 participants (6.2%) were reclassified as low risk. Of those, 5.2% experienced CHD events.
“In conclusion, we found that major and minor ECG abnormalities are associated with future CHD events and provide modestly improved risk reclassification beyond traditional risk factors,” the researchers wrote in the study. “Risk prediction with traditional risk factors is less accurate in older persons compared with middle-aged adults. Given the safety, the low cost and the wide availability of ECG, ECG data might be useful to improve CHD risk prediction in older adults. Whether ECG should be incorporated in routine screening of older adults should be evaluated in randomized controlled trials.”
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Disclosure: Dr. Auer reports grant support from the Swiss National Science Foundation and the Swiss Heart Foundation. See the full study for disclosures from the other researchers.