Decreased prevalence of late potentials with mechanical versus thrombolysis-induced reperfusion in acute myocardial infarction

Objectives. We sought to evaluate the influence of the method used to achieve early coronary reperfusion (i.e., intravenous thrombolysis or percutaneous transluminal coronary angioplasty) on the prevalence of late potentials after acute myocardial infarction. Background. After myocardial infarction, late potentials are associated with an increased risk of ventricular tachyarrhythmi and sudden death. Although their prevalence is lower in patients with coronary reperfusion, the influence of the method used to achieve reperfusion remains debated. Methods. We retrospectively analyzed 109 patients with acute myocardial infarction who were treated within 6 h of symptom onset and had angiographically proved early reperfusion. signal-averaged electrocardiogram was recorded ≥5 days after infarction. Results. Reperfusion was successfully achieved by intravenous thrombolysis alone in 37 patients (34%), by “rescue” coronary angioplasty in 26 (24%) and by primary angioplasty in 46 (42%). There was no significant difference between groups in terms of gender ratio, infarct location, time to admission or to reperfusion, peak creatine kinase value or left ventricular ejection fraction. The prevalence of late potentials was similar in the two groups in which patency was achieved by primary and rescue coronary angioplasty (17.4% and 7.7%, respectively [p = NS]) but higher in patients who had successful thrombolysis (35.1%, p < 0.05). Multivariate analysis showed that the use of thrombolysis instead of angioplasty as the reperfusion method was the only variable significantly associated with the presence of late potentials. Conclusions. This study suggests that after acute myocardial infarction the prevalence of late potentials is lower when reperfusion is achieved by angioplasty (either primary or as rescue procedure after failed thrombolysis) than by thrombolysis.