Variations in the use of emergency PCI for the treatment of re-infarction following intravenous fibrinolytic therapy: impact on outcomes in HERO-2

Abstract

Patients who suffer re-infarction during initial hospitalization for ST-elevation myocardial infarction (STEMI) have decreased survival compared to patients without re-infarction, so treatment of re-infarction may influence survival. To determine whether the utilization of reperfusion therapies varied within 12 h of re-infarction and was associated with 30-day mortality, we studied 552 patients with re-infarction of 17,073 patients with STEMI enrolled in HERO-2 in five regions (Russia, Eastern Europe, Western Countries, Asia, and Latin America). Patients presenting within 6 h of symptom-onset were randomized to receive either bivalirudin or unfractionated heparin intravenously just prior to streptokinase. Re-infarction occurred in 2.8 and 3.6% of bivalirudin and heparin treated patients, respectively (P = 0.004), but treatment assignment did not influence mortality after re-infarction. Patients with re-infarction had a higher 30-day mortality than those without re-infarction (24 vs. 10%; P < 0.001 by Cox model). Within 12 h of re-infarction, fibrinolytic therapy was administered to 12.0 and 8.2% underwent percutaneous coronary intervention (PCI); these two treatments were more frequently utilized in patients from Western countries (n = 112), compared to patients from other countries (n = 440) (34.8 and 16.1% compared to 6.1 and 6.1%, respectively, P < 0.001). Mortality was 15% in patients receiving reperfusion therapy for re-infarction and 27% for those with conservative management, hazard ratio (HR) 0.53 (95% CI 0.32-0.88), P = 0.01. In multiple Cox regression analysis which included adjustment for clinical variables and randomized treatment assignment, 30-day mortality after re-infarction varied by region (highest Latin America 29%, lowest Western countries 15%; P = 0.01). Other independent prognostic factors included age, time from randomization to re-infarction, and Killip class at randomization. The HR for PCI treatment of re-infarction was 0.18 [(95% CI 0.04-0.76), P = 0.02] in analyses which excluded deaths within 12 h. Treatment of re-infarction with reperfusion therapies was markedly under-utilized, especially in non-western countries. PCI for re-infarction, in particular, was associated with a lower 30-day mortality, which may reflect both patient selection and effects of treatment.