Patients given clot busters to treat a fared equally well if they gave the standard blood-thinning medication clopidogrel versus the newer; more potent drug ticagrelor, according to research presented at the American College of Cardiology’s 68thAnnual Scientific Session. The trial, called TREAT, is the first large, international trial to assess ticagrelor’s safety and efficacy in patients taking fibrinolytic therapy, or “clot busters,” a class of drugs that break up the blood clots that cause heart attacks.
Clot busters are used to treat heart attacks when it is not feasible to perform percutaneous coronary intervention (PCI); a procedure to open blocked arteries that is the gold standard for treating ST-elevation myocardial infarction (STEMI); the most severe type of heart attack. In 2018; researchers the trial met its primary endpoint (major bleeding at 30 days) showing comparable safety between ticagrelor and clopidogrel.
The current pre-specified analysis of efficacy and safety at 12 months suggests ticagrelor and clopidogrel have comparable efficacy and offers further confirmation that ticagrelor is safe to use in this patient population, researchers said. Ticagrelor reduces clotting by preventing platelets from aggregating. It takes effect more quickly than clopidogrel.
Adverse cardiac events
A previous study called PLATO; ticagrelor was superior to clopidogrel at preventing adverse cardiac events in patients with acute coronary syndromes a group of conditions that includes heart attacks and unstable angina who were not given clot busters. TREAT was designed to determine whether these benefits extend to patients given clot busters after STEMI.
The use of clot busters is most common where PCI is not available 24 hours a day, which includes most lower- and middle-income countries as well as some higher-income countries. The trial, conducted in 10 countries on five continents, included a mix of higher-income and lower-income countries and thus has worldwide relevance.
The trial enrolled 3,800 patients treated for STEMI at more than 180 centers. All patients had received fibrinolytic therapy within 24 hours of their heart attack. Half of the participants randomly assigned to take ticagrelor and half took clopidogrel. Patients given an initial loading dose of their assigned drug and then continued taking the drug for 12 months.
At 12 months, researchers assessed rates of the key endpoint for the 12-month analysis; a composite of death from vascular causes, heart attack, stroke, severe recurrent ischemia, transient ischemic atta can k or another arterial thrombotic event. Eight percent of patients taking ticagrelor and 9.1 % of those taking clopidogrel suffered these events; a difference that was not statistically significant.
Heart attacks and strokes
Bleeding is the most common complication from blood thinners; which are used to help prevent heart attacks and strokes by reducing the body’s ability to clot blood. The TREAT researchers assessed rates of bleeding events using the criteria defined by the Thrombolysis in Myocardial Infarction (TIMI) score; as well as the Bleeding Academic Research Consortium (BARC) categories and the definition used in PLATO.
Rates of the most important types of bleeding such as major bleeding and major and minor bleeding combined low (between 1 and 2 %); not significantly different between the two groups; suggesting the safety of ticagrelor. However, rates of minor, non-clinically relevant bleeding (such as from a nosebleed or minor cut) significantly higher in the ticagrelor group; with 5.9 % reporting, such bleeds compared with 2.9 % among those taking clopidogrel. This difference and in line with previous studies.