Prognostic evaluation of post-myocardial infarction patients by two-dimensional, echocardiography, ventricular late potentials and baroreflex sensitivity

Background. Although many variables are useful predictors of post-infarction mortality, their predictive positive values are weak when applied individually. The aim of this study was to determine the prognostic value of the combination of left ventricular ejection fraction, ventricular late potentials and baroreflex sensitivity. Patients and methods. We studied 69 consecutive post-infarction patients. On the day of their discharge from the coronary unit, all patients underwent a two-dimensional echocardiography, to determine the ejection fraction as well as a high resolution electrocardiogram to detect late potentials. To a subset of 49 patients was carried out to learn their baroreflex sensitivity. The patients were followed for 14 +/- 7 months and the following cardiac end points were considered: sudden cardiac death, non sudden cardiac death and non-fatal episodes of sustained ventricular tachycardia or ventricular fibrillation. Results. There were 8 end points: 3 sudden cardiac deaths, 3 non sudden cardiac deaths and 2 succesfully resuscited sustained ventricular tachycardia episodes. The rate of fibrynolisis was 55%. An ejection fraction < 45%, the presence of late potentials and a baroreflex sensitivity < 3.0 msec/mmHg were univariated predictors with predictive positive values of 33%, 24% and 16%, respectively. When ejection fraction < 45%, late potentials and baroreflex sensitivity < 3.0 were combined, we found a significant increase in the positive predictive value (50%). Conclusion. The combined determination of ejection fraction, ventricular late potentials and baroreflex sensitivity allows us to identify subset postinfarction patients with a high rate of cardiac complications.