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Resting electrocardiogram and risk of coronary heart disease in middle-aged British men
P H Whincup1, G Wannamethee, P W Macfarlane
1Department of Primary Care and Population Sciences, Royal Free Hospital School of Medicine, London, UK.
Insights
Resting electrocardiogram (ECG) abnormalities like myocardial infarction and ischemia significantly predict coronary heart disease (CHD) risk, especially in men with symptomatic CHD. However, ECGs are not effective screening tools for middle-aged men without symptoms.
Area of Science:
- Cardiology
- Preventive Medicine
- Diagnostic Electrocardiography
Background:
- Resting electrocardiogram (ECG) abnormalities are potential indicators of cardiovascular risk.
- Identifying individuals at high risk for coronary heart disease (CHD) is crucial for preventive strategies.
Purpose of the Study:
- To investigate the association between resting electrocardiographic (ECG) abnormalities and the risk of developing coronary heart disease (CHD).
Main Methods:
- A prospective study involving 7735 middle-aged men (40-59 years) from the British Regional Heart Study.
- Baseline assessments included a chest-pain questionnaire, medical history, and a three-lead orthogonal electrocardiogram.
- Follow-up for major CHD events (fatal and non-fatal myocardial infarction) occurred over 9.5 years.
Main Results:
- Definite myocardial infarction and ischemia on ECG were strongly associated with increased major CHD event risk (RR 2.5 and 1.9, respectively).
- Other significant predictors included left ventricular hypertrophy, left axis deviation, and ectopic beats.
- ECG abnormalities, particularly definite myocardial infarction, were most predictive of future CHD events in men with symptomatic CHD.
Conclusions:
- The prognostic value of ECG abnormalities for CHD risk is significantly enhanced by the presence of symptomatic CHD.
- Resting ECG can identify high-risk individuals among those with symptomatic CHD who may benefit from intervention.
- ECG screening has limited utility for predicting CHD events in asymptomatic middle-aged men.
Objective:
To examine the relation between resting electrocardiographic (ECG) abnormalities and risk of coronary heart disease (CHD).
Design And Setting:
This was a prospective study of 7735 middle-aged men aged 40-59 years at entry (British Regional Heart Study). At baseline assessment each man completed a modified World Health Organization (WHO) (Rose) chest-pain questionnaire, gave details of his medical history and had a three-lead orthogonal electrocardiogram recorded. "Symptomatic CHD' refers to a history of anginal chest pain and/or a prolonged episode of central chest pain on WHO questionnaire and/or recall of a doctor diagnosis of CHD (angina or myocardial infarction).
Main Outcome Measures:
These were the first major CHD events, i.e. fatal CHD and non-fatal myocardial infarction, occurring during 9.5 years of follow-up.
Results:
Of 611 first major CHD events during follow-up, 243 (40%) were fatal. After adjustment for age, other ECG abnormalities and symptomatic CHD, the ECG abnormalities most strongly associated with risk of a major CHD event were definite myocardial infarction (relative risk 2.5; 95% confidence interval 1.8-7.5) and definite myocardial ischaemia (1.9; 1.1-2.9). Other ECG abnormalities independently associated with a statistically significant increase in risk were left ventricular hypertrophy (2.2; 1.5-3.3), left axis deviation (1.3; 1.1-1.6) and ectopic beats, particularly if these were ventricular (1.6; 1.1-2.4). Three ECG abnormalities associated with a marked increase in CHD case-fatality rate were pre-existing myocardial infarction (67%), major conduction defect (71%) and arrhythmia (67%); the rate in men with none of these abnormalities was 32%. The relative risks associated with each ECG abnormality were similar in men with and without symptomatic CHD. The increase in risk in the presence of symptomatic CHD (2.4-fold) and ECG evidence of definite myocardial infarction (2.5-fold) was similar; the presence of both factors increased risk more than six-fold. The most serious ECG abnormalities-definite myocardial infarction and ischaemia-were useful predictors of future major CHD events only in men with symptomatic CHD.
Conclusion:
The prognostic importance of major ECG abnormalities is strongly influenced by the presence of symptomatic CHD. In men with symptomatic CHD the resting electrocardiogram may help to define a group at high risk who may benefit from intervention. However, it has little or no value as a screening tool in middle-aged men without symptomatic CHD.