title: Prognostic value of electrocardiographic detection of unrecognized myocardial infarction in persons with stable coronary artery disease: data from the Heart and Soul Study.
abstract: Unrecognized myocardial infarction (MI) carries a poor prognosis in the general population, but its prognostic value is less clear in high-risk patients. We sought to determine whether Q waves on electrocardiogram (ECG), suggestive of unrecognized MI, predict cardiovascular events in patients with stable coronary artery disease (CAD), but without a prior history of MI. We studied 462 patients enrolled in the Heart and Soul Study with stable CAD but without a prior history of MI. All patients had baseline ECGs. The baseline prevalence of unrecognized myocardial infarction was 36%. After a mean of 6.3 years of follow-up, there were a total of 141 cardiovascular events. The presence of Q waves in any ECG lead territory predicted cardiovascular events before (unadjusted HR 1.41, 95% CI 1.01-1.97) and after adjustment for demographics, medical history, diastolic function, and ejection fraction (HR 1.55, 95% CI 1.06-2.26). This association was partly attenuated after adjustment for the presence of inducible ischemia at baseline (HR 1.43, 95% CI 0.96-2.12). When specific territories were analyzed separately, Q waves in anterior leads were predictive of cardiovascular events in both unadjusted and adjusted models (adjusted HR 1.85, 95% CI 1.14-3.00), and this association was partly attenuated after adjustment for inducible ischemia. In conclusion, in patients with CAD but no history of prior MI, the presence of any Q waves or anterior Q waves alone is independently predictive of adverse cardiovascular events.
authors.affiliation: Department of Medicine, University of California-San Diego, CA, USA.
authors.forename: Devin W
authors.initials: DW
authors.lastname: Kehl
authors.forename: Ramin
authors.initials: R
authors.lastname: Farzaneh-Far
authors.forename: Beeya
authors.initials: B
authors.lastname: Na
authors.forename: Mary A
authors.initials: MA
authors.lastname: Whooley
mesh_terms: D000368:Aged; D015331:Cohort Studies; D003324:Coronary Artery Disease / Q000175:diagnosis*; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis*; D015995:Prevalence; D011379:Prognosis; D011446:Prospective Studies