Prevalence, characteristics and prognostic value during long-term follow-up of nonsustained ventricular tachycardia after myocardial infarction in the thrombolytic era

OBJECTIVES The purpose of this study was ro determine the prevalence, characteristics and the predictive value of nonsustained ventricular tachycardia (VT) for subsequent death and arrhythmic events after acute myocardial infarction (AMI). BACKGROUND Nonsustained VT has been linked to an increased risk for sudden death in coronary patients. It is unknown whether this parameter tan be used for selection of high-risk patients to receive a, implantable defibrillator for primary prevention of sudden death in patients shortly after AMI. METHODS In 325 consecutive infarct survivors, 24-h Holter monitoring was performed 10 +/- 6 days after AMI. All patients underwent coronary angiography, determination of left ventricular function and assessment of heart rate variability (HRV). Mean follow-up was 30 +/- 22 months. RESULTS There was a low prevalence (9%) of nonsustained VT shortly alter AMI. Nonsustained VT together with depressed left ventricular ejection fraction (LVEF) was found in only 2.4% of patients. During follow-up, 25 patients reached one of the prospectively defined end points (primary composite end point of cardiac death, sustained VT or resuscitated ventricular fibrillation; secondary end point: arrhythmic events). Kaplan Meier event probability analyses revealed that only HRV, LVEF and status of the infarct-related artery were univariate predictors of death or arrhythmic events. The presence of nonsustained VT carried a relative risk of 2.6 for the primary study end point but was not a significant predictor if only arrhythmic events were considered. On multivariate analysis, only HRV, LVEF and the status of the infarct artery were found to be independently related to the primary study end point. CONCLUSIONS There is a low prevalence of nonsustained VT shortly after HMI. Only 2% to 3%: of all infarct survivors treated according to contemporary guidelines demonstrate both depressed LVEF and nonsustained VT The predictive value of nonsustained VT for subsequent mortality and arrhythmic events is inferior to that of impaired autonomic tone, LVEF or infarct-related artery patency. Accordingly, the use of nonsustained VT to select patients for primary;implantable cardioverter/deftbrillator prevention trials shortly after AMI appears to be limited. (C) 1999 by the American College of Cardiology.