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
Cp. Cannon et al., 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, Journal of the American College of Cardiology, 30(1), 1997, pp. 133-140
Objectives. We sought to determine the prognostic value of the admissi
on electrocardiogram (ECG) in patients with unstable angina and non-Q
wave myocardial infarction (MI). Background Although the ECG is the mo
st widely used test for evaluating patients with unstable angina and n
on-Q wave MI, little prospective information is available on ib value
in predicting outcome in the current era of aggressive medical and int
erventional therapy. Methods. ECGs dth the qualifying episode of pain
were analyzed in patients enrolled in the Thrombolysis in Myocardial I
schemia (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 greater than or equal to 1 mm was present in 143% 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 greater than or equal to 1 mm ST segm
ent deviation compared with 6.8% of patients with new, isolated T wave
inversion and 82% of those with no ECG changes (p < 0.001 when compar
ing ST with no ST segment deviation). live other high risk groups were
identified: those with only 0.5-mm ST segment deviation and those wit
h LBBB, whose rates of death or MI by 1 year were 163% and 22.9%, resp
ectively. On multivariate analysis, ST segment deviation of either gre
ater than or equal to 1 mm or greater than or equal to 0.5 mm remained
independent predictors of death or MI by 1 year. Conclusions. The adm
ission ECG is very useful in risk stratifying patients with non-Q wave
MI. The new criteria of not only greater than or equal to 1-mm ST seg
ment deviation hut also greater than or equal to 0.5-mm ST segment dev
iation or LBBB identify high risk patients, whereas T wave inversion d
oes not add to the clinical history in predicting outcome. (C) 1997 by
the American College of Cardiology.