According to current guidelines and clinical practice, PCI patients already taking an oral anticoagulant generally end up on triple therapy comprising the anticoagulant plus clopidogrel and aspirin. However, there is no supporting evidence base for this approach and the triple therapy regimen is known to increase bleeding complications. Now a new study– the first randomized trial to address this situation, according to the investigators– may have a large impact on clinical practice by demonstrating that the omission of aspirin in this context appears to be safe and may reduce adverse events.
Results of the WOEST (What is the Optimal Antiplatelet and Anticoagulant Therapy in Patients with Oral Anticoagulantion and Coronary Stenting) trial were presented by Willem Dewilde at the ESC in Munich today. Investigators in the Netherlands and Belgium randomized 573 patients to triple therapy or dual therapy of an anticoagulant plus clopidogrel for at least one month after implantation of a bare-metal stent or one year after a drug-eluting stent. Two-thirds of the patients were receiving oral anticoagulation for atrial fibrillation.
The primary endpoint, the total number of bleeding events, was dramatically reduced in the dual therapy group at one year:
- 44.9% in the triple therapy group versus 19.5% (HR 0.36, CI 0.26-0.50)
There were 3 intracranial bleeds in each group. Most of the difference in bleeding occurred in TIMI minor and minimal bleeding. The difference in TIMI major bleeding (3.3% versus 5.8%) did not achieve statistical significance.
Clinical events, the trials’s secondary endpoint, were numerically lower in the dual therapy group. The difference in mortality achieved statistical significance.
- Mortality: 7 deaths (2.6%) in the dual therapy group versus 18 deaths (6.4%) in the triple therapy group, p=0.027
- MI: 3.3% versus 4.7%, p=0.382
- TVR: 7.3% versus 6.8%, p=0.876
- Stroke: 1.1% versus 2.9%, p=0.128)
- Stent thrombosis: 1.5% versus 3.2%, p=0.165
“The WOEST study demonstrates that omitting aspirin leads to less bleedings but does not increase the risk of stent thrombosis, stroke or myocardial infarction,” said Dewilde in an ESC press release. “Although the number of patients in the trial is limited, this is an important finding with implications for future treatment and guidelines in this group of patients known to be at high risk of bleeding and thrombotic complications.”
David Holmes said the trial addressed “an incredibly important issue” and predicted that it would “change the way we practice medicine, it will change practice right away.” Keith Fox said that the evidence base prior to WOEST was extremely limited and that the trial showed that there was no hazard in doing without aspirin. The ESC discussant, Marco Valgimigli, said the trial showed it was safe to drop aspirin and provided another demonstration that “we have hit the wall” with anticoagulation.
Republished with permission from CardioExchange, a NEJM group publication.