A new study in the April 11 issue of JAMA shows that both minor and major electro-cardiographic abnormalities are linked to a higher risk of incidents involving coronary heart disease (CHD) in elderly people without pre-existing cardiovascular disease and that these abnormalities were better in predicting CHD events like heart attacks outside common cardiovascular risk factors.

Background information in the articles states:

“In populations of older adults, prediction of CHD through traditional risk factors is less accurate than among middle-aged adults.”

Electrocardiographic (ECG) abnormalities are common in older adults. However, performing routine ECG among asymptomatic adults is not supported by current evidence. Considering the higher prevalence of both cardiovascular disease (CVD) and ECG abnormalities in older adults, risk prediction incorporating ECG might be more useful in this group. To date, few studies have examined the improvement of CVD risk prediction using ECG abnormalities in a population of older adults, and none could adequately adjust the analyses for presence of previous CVD and traditional cardiovascular risk factors (CVRFs). In a study to determine whether minor and major ECG abnormalities at the start of the research, as well as developing new ECG abnormalities and persistent ECG abnormalities during follow-up, were linked to new events of CHD, independent of traditional cardiovascular risk factors, Reto Auer, M.D., of the University of Lausanne in Switzerland, and the University of California in San Francisco, and his team recruited 2,192 white and black adults, aged between 70 to 79 years, who had no known cardiovascular disease.

Over 8 years, from 1997/98 to 2006/07, the authors noted adjudicated CHD events and categorized ECG abnormalities that occurred at the start of the study and at 4-years. To predict CHD events, they examined ECG abnormalities that occurred in addition to the traditional risk factors.

The study findings demonstrated that 506 or 23% of the 2,192 participants had major ECG abnormalities, whilst 276 or 13% had minor ones.

At the average follow up of 8.2 years, the researchers found that from all the 351 participants who had CHD events, 96 died, 101 had an acute heart attack, and 154 were hospitalized for angina or coronary revascularizations. The total death toll at the average follow up was 602 participants, although 96 of those deaths were linked to CHD.

After evaluating the data, the results confirmed that major and minor ECG abnormalities at the start of the study were both linked to a higher CHD risk. The figures after adjusting for various cardiovascular risk factors, such as age, sex, total and high-density lipoprotein cholesterol, systolic blood pressure, smoking, and diabetes showed that participants with minor ECG abnormalities at the start of the study had a 35% higher risk of CHD events, and those with major ECG abnormalities had a 51% higher risk, compared to those who had no ECG abnormalities at the start of the study.

An analysis by race revealed comparable findings between white and black participants.

The researchers declare:

“The addition of ECG abnormalities to the model adjusted for traditional CVRFs resulted in reclassification of 13.6 percent of intermediate-risk participants and 7.1 percent in the overall sample. When ECG abnormality was added to the model adjusted for traditional CVRFs, 176 intermediate-risk participants (8 percent) were reclassified as high risk, of whom 27 (15.2 percent) experienced events. Conversely, 136 participants (6.2 percent) were reclassified as low risk, of whom 7 (5.2 percent) experienced events.”

The study showed that 65% of the overall population would fall into either the highest- or lowest-CHD risk category when measured by ECG abnormality with adjustment for CVRFs, compared to 49% with traditional risk factors alone.

At 4 years, the researchers noted that 208 participants developed new and 416 participants had persistent abnormalities. When adjusting for CVRFs, both new and persistent ECG abnormalities at 4 years were linked to a higher risk of subsequent CHD events.

The researchers state:

“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. 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.”

Written By Petra Rattue