The electrocardiogram predicts one-year outcome of patients with unstable angina and non-Q wave myocardial infarction: results of the TIMI III Registry ECG Ancillary Study. Thrombolysis in Myocardial Ischemia

J Am Coll Cardiol. 1997 Jul;30(1):133-40. doi: 10.1016/s0735-1097(97)00160-5.


Objectives: We sought to determine the prognostic value of the admission electrocardiogram (ECG) in patients with unstable angina and non-Q wave myocardial infarction (MI).

Background: Although the ECG is the most widely used test for evaluating patients with unstable angina and non-Q wave MI, little prospective information is available on its value in predicting outcome in the current era of aggressive medical and interventional therapy.

Methods: ECGs with the qualifying episode of pain were analyzed in patients enrolled in the Thrombolysis in Myocardial Ischemia (TIMI) III Registry, a prospective study of patients admitted to the hospital with unstable angina or non-Q wave MI.

Results: New ST segment deviation > or = 1 mm was present in 14.3% of 1,416 enrolled patients, isolated T wave inversion in 21.9% and left bundle branch block (LBBB) in 9.0%. By 1-year follow-up, death or MI occurred in 11% of patients with > or = 1 mm ST segment deviation compared with 6.8% of patients with new, isolated T wave inversion and 8.2% of those with no ECG changes (p < 0.001 when comparing ST with no ST segment deviation). Two other high risk groups were identified: those with only 0.5-mm ST segment deviation and those with LBBB, whose rates of death or MI by 1 year were 16.3% and 22.9%, respectively. On multivariate analysis, ST segment deviation of either > or = 1 mm or > or = 0.5 mm remained independent predictors of death or MI by 1 year.

Conclusions: The admission ECG is very useful in risk stratifying patients with non-Q wave MI. The new criteria of not only > or = 1-mm ST segment deviation but also > or = 0.5-mm ST segment deviation or LBBB identify high risk patients, whereas T wave inversion does not add to the clinical history in predicting outcome.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aged
  • Angina, Unstable / physiopathology*
  • Angioplasty, Balloon, Coronary
  • Confounding Factors, Epidemiologic
  • Coronary Artery Bypass
  • Electrocardiography*
  • Female
  • Heart Conduction System*
  • Humans
  • Male
  • Multivariate Analysis
  • Myocardial Infarction / drug therapy
  • Myocardial Infarction / physiopathology*
  • Myocardial Infarction / surgery
  • Myocardial Infarction / therapy*
  • Predictive Value of Tests
  • Proportional Hazards Models
  • Prospective Studies
  • Registries
  • Risk
  • Thrombolytic Therapy*
  • Treatment Outcome