One-year follow-up of the ASSENT-2 trial: A double-blind, randomized comparison of single-bolus tenecteplase and front-loaded alteplase in 16,949 patients with ST-elevation acute myocardial infarction

Background Single-bolus tenecteplase and accelerated alteplase were shown to be equivalent for 30-day mortality rates in the double-blind Assessment of the Safety of a New Thrombolytic (ASSENT-2) study. The aim of this study is to assess mortality rates after 1-year follow-up. Methods and results One-year vital status was obtained from 92.8% of the patients initially enrolled in the ASSENT-2 trial. Completeness of follow-up was similar for both groups. At 1 year, mortality rates were 9.1% for alteplase and 9.2% for tenecteplase (risk ratio, 1.01; 95% CI, 0.91–1.12). The mortality rate between 30 and 365 days after enrollment was 2.6% for alteplase and 2.8% for tenecteplase (risk, 1.07; 95% CI, 0.88–1.30). A lower 30-day mortality rate in patients treated with tenecteplase after 4 hours of symptom-onset persisted at 1-year follow-up (10.9% vs 12.6% for alteplase), but was no longer statistically significant. There were also no significant differences in mortality rates between the 2 treatments in other major subgroups. In a Cox regression model, no significant interaction was observed between treatment assignment and age, sex, time-to-treatment, Killip class, body weight, and history of previous myocardial infarction, infarction location, systolic blood pressure, or heart rate. Conclusions One year after randomization, mortality rates remain similar in patients with acute myocardial infarction treated with an accelerated infusion of alteplase or a single bolus of tenecteplase.