Does the electrocardiographic presence of Q waves influence the survival of patients with acute myocardial infarction?

Aims To compare the outcome of short- and long-term survival of patients wi th Q wave vs non-Q wave myocardial infarction. Methods A total of 6676 patients with acute myocardial infarction were enro lled on the TRAndolapril Cardiac Evaluation (TRACE) register between 1990 a nd 1992. Medical history, electrocardiographic diagnosis of Q wave and non- Q wave myocardial infarction, echocardiographic estimation of left ventricu lar systolic function determined as wall motion index, infarct complication s, and survival were documented. The factors influencing the postmyocardial infarction outcome of these patients were studied after 30 days and after 8 years of follow-up, respectively. Results Cox proportional-hazard models demonstrated that the electrocardiog raphic Q waves had significant influence on survival during the first 30 da ys [risk ratio 1.4 (95% confidence limits 1.2-1.7)] but no influence therea fter [1.0 (0.9 1.1)]. The result was the same in univariate and multivariat e analyses. Subgroup analysis defined by age, sex, wall motion index, prese nce of congestive heart failure, diabetes mellitus, arterial hypertension, subsequent myocardial infarctions and use of thrombolytic therapy did not d isclose importance of Q waves on mortality. Conclusion The electrocardiographic presence of Q waves is associated with increased mortality during the initial 30 days after a myocardial infarctio n, but has no influence thereafter. (C) 2001 The European Society of Cardio logy.