Introduction and objectives: Implantable cardiac defibrillators (ICD) have been shown to improve survival in patients with myocardial infarctionand LVEF < 0.30 or LVEF < 0.40 + nonsustained ventricular tachycardia + inducible sustained arrhythmias. However, these risk stratification criteria have not been evaluated in patients who are candidates for primary percutaneous transluminal coronary angioplasty (PTCA). The objective of this study was to assess the impact of both strategies on the indication for ICD in a consecutive series of post-infarction patients treated with primary PTCA.
Patients and method: One hundred and two consecutive patients with myocardial infarction (80 men, mean age 63.6 11.5 years) included in a single-center-based regional program of primary PTCA were included in the study. A 24-h continuous ECG recording was obtained 2 to 6 weeks after the acute event, and LVEF was determined by 2D-echocardiography one month after the infarct. Patients with nonsustained ventricular tachycardia and LVEF < 0.40 underwent programmed ventricular stimulation using a standard protocol.
Results: Twenty-two patients (21.6%; 95% CI, 13.6-29.6) showed at least one episode of nonsustained ventricular tachycardia in the 24 h recording. Six of them had LVEF < or = 0.40, and sustained ventricular arrhythmia was induced in 2 out of 5. LVEF < or = 0.30 was found in 3 patients, none of whom had nonsustained ventricular tachycardia. Thus, 5 patients had an indication for ICD according to either of the two risk stratification criteria.
Conclusions: The prevalence of nonsustained ventricular tachycardia in post-infarction patients treated with primary PTCA is high. However, because most of them have preserved ventricular function, primary prevention with an ICD is indicated in approximately 5% of the population.