PARIS – , though they also had more major bleeding events than patients receiving placebo plus aspirin.
The subset of patients who had received prior percutaneous coronary intervention (PCI) stood to benefit more from extended dual antiplatelet therapy (DAPT), according to clinical trial results presented to an overflow crowd at the annual congress of the European Society of Cardiology.
Findings from the full study, named The Effect of Ticagrelor on Health Outcomes in Diabetes Mellitus Patients Intervention Study (THEMIS), and from the PCI subgroup analysis were published concurrently with the presentation (N Engl J Med. 2019 Sep 1: DOI: 10.1056/NEJMoa1908077; Lancet. 2019 Sep 1: DOI:https://doi.org/10.1016/S0140-6736(19)31887-2).
“This strategy of long-term dual antiplatelet therapy may be beneficial in selected patients at low risk of bleeding, but at high risk of ischemic events,” said the study’s co-principal investigator Deepak Bhatt, MD, professor of medicine at Harvard Medical School, Boston, and executive director of interventional cardiology programs at Boston’s Brigham and Women’s Hospital. In a video interview, he hypothesized that “prior PCI may serve as a sort of ‘stress test’ for bleeding,” thus identifying a subset of patients who might benefit from long-term DAPT.
Ischemic events, the primary efficacy outcome of THEMIS, occurred in 7.7% of patients taking the P2Y12 receptor antagonist ticagrelor and 8.5% of those receiving placebo, for a hazard ratio of 0.90 favoring ticagrelor (P = .04). Ischemic events included cardiovascular deaths, myocardial infarctions (MIs), and stroke.
Looking at secondary endpoints, Dr. Bhatt said that there was no difference in cardiovascular deaths between study arms, but that ischemic strokes, all MIs, and ST segment elevation MIs were all less common for patients taking ticagrelor. All-cause mortality was similar between study groups.
Though ischemic events dropped, “This benefit was achieved at the expense of more bleeding,” said Dr. Bhatt. Major bleeding, the primary safety outcome, was seen in 2.2% of those taking ticagrelor and 1.0% of the placebo group, for a hazard ratio of 2.32 (P less than .001). Dr. Bhatt and his collaborators used the Thrombolysis in Myocardial Infarction (TIMI) criteria for major bleeding for ascertainment of this outcome.
Intracranial hemorrhage was also more common for patients on ticagrelor, though incidence was low and the absolute difference was small between groups. This complication occurred in 0.7% of ticagrelor patients and 0.5% of placebo patients, yielding a hazard ratio of 1.71 (P = .0005). “This excess wasn’t in spontaneous or procedural intracranial bleeding, but rather in traumatic intracranial hemorrhage,” said Dr. Bhatt.
Fatal bleeds affected just 0.2% of those on ticagrelor and 0.1% of those receiving placebo; this difference wasn’t statistically significant.