Long-term prognostic significance of ventricular late potentials after a first acute myocardial infarction

• Published in: The American heart journal Vol. 134; no. 6; pp. 1019 - 1028
• Main Authors: Zimmermann, Marc, Sentici, Ali, Adamec, Richard, Metzger, Jacques, Mermillod, Bernadette, Rutishauser, Wilhelm
• Format: Journal Article
• Language: English
• Published: New York, NY Mosby, Inc 01.12.1997; Elsevier
• Subjects: Action Potentials; Adult; Aged; Aged, 80 and over; Biological and medical sciences; Cardiology. Vascular system; Coronary heart disease; Electrocardiography; Female; Heart; Humans; Male; Medical sciences; Middle Aged; Myocardial Infarction - mortality; Myocardial Infarction - physiopathology; Predictive Value of Tests; Prognosis; Signal Processing, Computer-Assisted; Stroke Volume; Survival Analysis; Ventricular Function, Left; Human; Prognosis; Infarct; Retarded potential; Arrhythmia; Cardiovascular disease; SAECG; Coronary heart disease; Myocardial disease; Long term; Electrodiagnosis; Follow up study; Heart disease; Myocardium; Complication; Predictive factor
• ISSN: 0002-8703; 1097-6744
• DOI: 10.1016/S0002-8703(97)70021-8

Ventricular late potentials (VLP) have been shown to be independent predictors of arrhythmic events after myocardial infarction. However, many studies have had one or more limitations: limited follow-up period, small study group, possible selection bias, inadequate statistical analysis, or inclusion of patients with previous infarction. The purpose of this study was to assess the long-term prognostic value of VLP in a large group of unselected patients after a first acute myocardial infarction. Time-domain signal averaging was performed in 458 patients (380 male, 78 female, mean age 59 ± 11 years) a mean of 10 days (range 7 to 13 days) after a first acute myocardial infarction. The overall prevalence of VLP was 20% (90 of 458 patients). By univariate analysis a left ventricular ejection fraction <40% ( p = 0.002) and the presence of an occluded infarct-related artery ( p = 0.006) were the only statistically significant predictors for the development of VLP. During a median follow-up of 70 months, 21 (5%) patients died suddenly, and 11 (2%) patients had documented sustained ventricular tachycardia. The presence of VLP ( p < 0.0001), older age ( p = 0.02), and an occluded infarct-related artery ( p = 0.045) were the only variables significantly associated with the occurrence of serious arrhythmic events during follow-up. The probability of having no arrhythmic events was 99% at 1 year and 96% at 5 years in the absence of VLP and 87% at 1 year and 80% at 5 years in the presence of VLP (4.6-fold increase in arrhythmic risk; 95% confidence interval: 2.3 to 9.1). VLPs are powerful predictors of serious arrhythmic events in patients after a first acute myocardial infarction, and their prognostic value, although waning with time, persists for at least 7 years. This study also provides further evidence that an open infarct-related artery may reduce the arrhythmic risk after myocardial infarction. (Am Heart J 1997;134:1019-28.)