The Phase III trial included 3,801 patients and compared the use of ticagrelor 180mg followed by 90mg twice daily for 12 months, versus clopidogrel 300mg, followed by 75mg/day for 12 months.
During the trial, both drugs were administered as early as possible within a maximum of 24 hours following the initial heart attack.
The initial study results have demonstrated that in patients aged 75 years or more whose STEMI heart attack was treated with thrombolytic therapy, ticagrelor was non-inferior to clopidogrel for major bleeding at 30 days.
Rates of major cardiovascular events were reported to be similar between ticagrelor and clopidogrel at 30 days, however because of the low number of events, statistical power to assess superiority was limited.
Further evaluation of safety and efficacy is scheduled to be carried out at 12 months.
TREAT study steering committee chair Dr Otavio Berwanger said: “Millions of people have a heart attack each year, and how they are treated in the immediate period that follows has huge implications on patient outcomes.
“Although pPCI is considered the gold standard, thrombolysis is also an effective alternative and commonly used treatment strategy, and due to the previous lack of safety data for ticagrelor in this population, many patients are currently limited to clopidogrel alongside thrombolytic therapy.
“With the latest ESC guidelines also indicating a potential role for potent P2Y therapy for these high-risk STEMI patients, the TREAT safety data has the potential to be practice-changing.”
Currently, seven million people are estimated to experience a heart attack every year, yet many will not have timely access to primary percutaneous coronary intervention (pPCI), a procedure to unblock damaged blood vessels to prevent further potentially deadly heart attacks.