Exercise-electrocardiography and/or pharmacological stress echocardiography for non-invasive risk stratification early after uncomplicated myocardial infarction. A prospective international large scale multicentre study

Abstract

Aims: The aim of the present study was to assess the relative prognostic value of clinical variables, the exercise electrocardiography test and the pharmacological stress echocardiography test either with dipyridamole or dobutamine early after a first uncomplicated acute myocardial infarction in a large, multicentre, prospective study.

Methods and results: Seven hundred and fifty-nine in-hospital patients (age=56+/-10 years) with a recent and first clinical uncomplicated myocardial infarction, with baseline echocardiographic findings of satisfactory quality, an interpretable ECG and able to exercise underwent a resting 2D echocardiogram, a pharmacological stress test with either dipyridamole or dobutamine and an exercise electrocardiography test at a mean of 10 days from the infarction; they were followed-up for a median of 10 months. During the follow-up, there were 13 deaths, 23 non-fatal myocardial infarctions and 59 re-hospitalizations for unstable angina. When all spontaneous events were considered, with multivariate analysis, the difference between the wall motion score index at rest and peak stress (delta wall motion score index), and exercise duration were independent predictors of future spontaneous events (relative risk 7.2; 95% CI=2.73-19.1; P=0.000; relative risk 1.1, 95% CI=1.02-1.18; P=0.008, respectively). Kaplan-Meier survival estimates showed a better outcome for those patients with a negative pharmacological stress echocardiography test compared to patients with low dose positivity (94.7 vs 74.8%, P=0.000).

Conclusion: Stress echocardiography tests provide stronger information than historical and exercise electrocardiography test variables. Pharmacological echocardiography as well as the exercise ECG is able to predict all spontaneously occurring events when the presence as well as the timing, severity, and extension of stress-induced wall motion abnormalities are considered.