Association of major and minor ECG abnormalities with coronary heart disease events
Reto Auer1, Douglas C Bauer, Pedro Marques-Vidal
1Department of Ambulatory Care and Community Medicine, University of Lausanne, Lausanne, Switzerland. reto.auer@ucsf.edu
Insights
Electrocardiogram (ECG) abnormalities in older adults predict coronary heart disease (CHD) events. Both baseline and new/persistent ECG changes increase CHD risk, improving prediction beyond traditional factors.
Area of Science:
- Cardiology
- Geriatric Medicine
- Preventive Cardiology
Background:
- Traditional risk factors for coronary heart disease (CHD) are less accurate in predicting events in older adults.
- Electrocardiogram (ECG) abnormalities are common in this demographic and may offer additional predictive value.
- The Health, Aging, and Body Composition (Health ABC) Study provides a robust dataset for investigating this association.
Purpose of the Study:
- To assess if baseline ECG abnormalities are linked to increased CHD events in older adults.
- To determine if the development of new or persistent ECG abnormalities over time predicts future CHD events.
- To evaluate the added value of ECG abnormalities in CHD risk prediction models.
Main Methods:
- A population-based cohort of 2192 older adults (70-79 years) without prior cardiovascular disease was studied.
- Baseline and 4-year ECGs were analyzed for major and minor abnormalities using the Minnesota Code.
- Cox proportional hazards regression models were used to assess the association between ECG abnormalities and adjudicated CHD events over 8 years.
Main Results:
- At baseline, 13% had minor and 23% had major ECG abnormalities. Both were associated with increased CHD risk (HR 1.35 and 1.51, respectively).
- New and persistent ECG abnormalities after 4 years also significantly predicted subsequent CHD events (HR 2.01 and 1.66, respectively).
- Adding ECG abnormalities to traditional risk factors improved CHD risk reclassification in intermediate-risk individuals.
Conclusions:
- Both baseline and evolving ECG abnormalities are significant predictors of CHD events in older adults.
- ECG analysis provides valuable information for refining CHD risk prediction beyond established risk factors in this population.
- These findings support the routine use of ECGs in assessing cardiovascular risk in older individuals.
Context:
In populations of older adults, prediction of coronary heart disease (CHD) events through traditional risk factors is less accurate than in middle-aged adults. Electrocardiographic (ECG) abnormalities are common in older adults and might be of value for CHD prediction.
Objective:
To determine whether baseline ECG abnormalities or development of new and persistent ECG abnormalities are associated with increased CHD events.
Design, Setting, And Participants:
A population-based study of 2192 white and black older adults aged 70 to 79 years from the Health, Aging, and Body Composition Study (Health ABC Study) without known cardiovascular disease. Adjudicated CHD events were collected over 8 years between 1997-1998 and 2006-2007. Baseline and 4-year ECG abnormalities were classified according to the Minnesota Code as major and minor. Using Cox proportional hazards regression models, the addition of ECG abnormalities to traditional risk factors were examined to predict CHD events.
Main Outcome Measure:
Adjudicated CHD events (acute myocardial infarction [MI], CHD death, and hospitalization for angina or coronary revascularization).
Results:
At baseline, 276 participants (13%) had minor and 506 (23%) had major ECG abnormalities. During follow-up, 351 participants had CHD events (96 CHD deaths, 101 acute MIs, and 154 hospitalizations for angina or coronary revascularizations). Both baseline minor and major ECG abnormalities were associated with an increased risk of CHD after adjustment for traditional risk factors (17.2 per 1000 person-years among those with no abnormalities; 29.3 per 1000 person-years; hazard ratio [HR], 1.35; 95% CI, 1.02-1.81; for minor abnormalities; and 31.6 per 1000 person-years; HR, 1.51; 95% CI, 1.20-1.90; for major abnormalities). When ECG abnormalities were added to a model containing traditional risk factors alone, 13.6% of intermediate-risk participants with both major and minor ECG abnormalities were correctly reclassified (overall net reclassification improvement [NRI], 7.4%; 95% CI, 3.1%-19.0%; integrated discrimination improvement, 0.99%; 95% CI, 0.32%-2.15%). After 4 years, 208 participants had new and 416 had persistent abnormalities. Both new and persistent ECG abnormalities were associated with an increased risk of subsequent CHD events (HR, 2.01; 95% CI, 1.33-3.02; and HR, 1.66; 95% CI, 1.18-2.34; respectively). When added to the Framingham Risk Score, the NRI was not significant (5.7%; 95% CI, -0.4% to 11.8%).
Conclusions:
Major and minor ECG abnormalities among older adults were associated with an increased risk of CHD events. Depending on the model, adding ECG abnormalities was associated with improved risk prediction beyond traditional risk factors.
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