What Should be Done After the Percutaneous Coronary Intervention?
The use of PPIs is recommended to prevent gastrointestinal bleeding in all patients receiving OAC in combination with antiplatelet agents, as this type of bleeding is common among patients undergoing PCI.30 Following the PCI procedure, another consideration is whether to omit aspirin in patients who require TT. The What is the Optimal Antiplatelet and Anticoagulant Therapy in Patients with Oral Anticoagulation and Coronary Stenting (WOEST) study is the only published RCT that has investigated dual therapy (VKA and clopidogrel) in comparison with TT (VKA, aspirin, clopidogrel).31 This study consisted of 573 patients on chronic OAC undergoing PCI with stent implantation between 2008 and 2011. The primary endpoint was the occurrence of any bleeding event, and secondary endpoints were major adverse cardiac/cerebrovascular events. Dual therapy reduced the rates of any bleeding complication in comparison with TT (HR 0.36; 95 % CI: 0.26–0.50; P<0.001), while not increasing the rates of stent thrombosis (HR 0.44; 95 % CI [0.14–1.44]; P=0.165) or thrombotic endpoints (HR 0.69; 95 % CI [0.29–1.60]; P=0.382).
The finding that dual therapy appears to be as effective and safe as TT was supported by two other studies. A Danish registry of patients with AF reported that the risk of thrombosis and bleeding was not increased in patients treated with OAC and clopidogrel (n=548) compared with patients treated with OAC, clopidogrel and aspirin (n=1896).32 Another registry study (n=975) observed that VKA, clopidogrel and aspirin (TT), clopidogrel and aspirin (DAPT) and VKA and clopidogrel (dual therapy) were comparable in terms of safety and efficacy33.
Overall, these studies demonstrated that omitting aspirin from the TT did not lead to an increased risk of thromboembolic events and these data may imply that dual therapy (OAC and clopidogrel) may be an alternative to TT. However, it should be taken into account that these studies were not powered to detect differences in the occurrence of thrombotic events. Omission of clopidogrel from the antithrombotic regimen is not recommended in light of findings from a study by van Werkum et al., who showed that discontinuing clopidogrel within 30 days after PCI was the strongest predictor of stent thrombosis (HR 6.5; 95 % CI [8.0–167.8]).34 In contrast, the risk of developing late stent thrombosis may be reduced, as there have been several RCTs that have shown that patients who received 3 months of DAPT after PCI with second-generation DES implantation had similar rates of stent thrombosis compared with patients who received 12 months DAPT.35,36 For the reasons mentioned above, it seems unsafe to cease clopidogrel within the first 3 months after PCI, but one may consider to stop clopidogrel after 3 months of PCI in patients at high risk of bleeding.11