Objectives: The aim of this study was to investigate the independent prognostic value of ischemic electrocardiographic (ECG) findings for cardiovascular mortality and to evaluate a possible sex-differential in this regard.
Background: In previous reports, ST segment and T wave changes on the resting ECG were described as independent risk factors for development of coronary heart disease. Although more prevalent in women, they are often given less clinical importance than in men.
Methods: Ten-year follow-up data from the Belgian Interuniversity Research on Nutrition and Health study were used. The results presented here are based on ECGs of the 4,797 men and 4,320 women, aged 25 to 74 years, who were free of angina pectoris at the start of follow-up, had no history of myocardial infarction (MI) and showed no Q wave evidence of an old MI on their ECG.
Results: At baseline, the age-standardized prevalence of an "ischemic ECG" (Minnesota codes I3, IV1-3, V1-3 or VII1) was 8.4% in men and 10.6% in women. Cardiovascular mortality rates in men and women with an ischemic ECG were respectively 7.7 and 2.6 per 1,000 person-years, compared with 2.3 and 1.0 in those with no such ECG findings. After correction for the potential confounding effects of established cardiovascular disease (CVD) risk factors, the multivariately adjusted risk ratios were 2.45 (95% confidence interval [CI]: 1.70 to 3.53) for men and 2.16 (95% CI: 1.30 to 3.58) for women. Testing the interaction between an ischemic ECG and sex on CVD mortality revealed that the risk ratios were not significantly changed (p=0.95). The etiologic fraction of CVD deaths attributable to an ischemic ECG was estimated as 19.3% for men and 22.4% for women. Both men and women with major ischemic findings in their baseline electrocardiogram (Minnesota codes IV1,2, V1,2 or VII1) had a fourfold increased risk of CVD death.
Conclusion: These results support the hypothesis that women with ischemic ECG findings are at the same increased risk for CVD mortality as men.