The ASSENT-4 trial, designed to test a single-bolus thrombolytic in combination with percutaneous coronary intervention for acute myocardial infarction, was suspended in April with fewer than half of the planned 4,000 patients enrolled.
The Data Safety and Monitoring Board's decision to put the Assessment of the Safety and Efficacy of a New Treatment Strategy for Acute Myocardial Infarction (ASSENT-4) trial on hold “was based on an unexpectedly superior outcome in patients randomized to the direct [percutaneous coronary intervention] only arm,” according to a statement by the trial's executive committee.
To date 1,635 patients have been randomized to receive either a single bolus of Metalyse/ TNKase (tenecteplase) plus unfractionated heparin followed by immediate percutaneous coronary intervention (PCI) or PCI alone. The committee noted that “the rates of death and of [intracerebral hemorrhage] in the TNK-facilitated PCI arm are consistent with prior ASSENT fibrinolytic alone studies.”
The committee is currently collecting and assessing study data in order to determine the future of the investigation.
“This study shows that there is in fact a prothrombotic effect of thrombolysis. Thus, it is important to choose a particular strategy—either primary PCI or thrombolysis, but not … both,” Christopher Cannon, M.D., of Brigham and Women's Hospital in Boston, and a principal investigator with the Thrombolysis in Myocardial Infarction (TIMI) study group, told this newspaper.