How to Manage the Anticoagulation During Percutaneous Coronary Intervention?
The current European Society of Cardiology (ESC) guidelines on patients with AF presenting with ACS and/or undergoing PCI or valve interventions recommend uninterrupted OAC with no addition of heparin in the elective setting in those patients at moderate to high risk of thromboembolism (CHA2DS2-VASc score of ≥2) if the INR is >2.5.16 As the patient in this case report had unstable INR levels, VKA was replaced with NOAC. Whether it is safe for patients treated with NOAC to undergo PCI without additional periprocedural heparin or bridging is unknown, except for dabigatran. A small randomised Phase IIa study found that in patients treated with dabigatran alone during elective PCI, the rate of thrombotic events was increased in comparison with patients treated with unfractionated heparin (UFH).17 In patients on NOAC undergoing PCI, addition of low-dose heparin (60 IU/kg) is recommended to prevent catheter thrombosis.18,19
At presenty, the X-PLORER (Exploring the Efficacy and Safety of Rivaroxaban to Support Elective Percutaneous Coronary Intervention) study is investigating whether rivaroxaban can prevent thrombosis and other adverse ischaemic events in comparison with UFH during elective PCI.20 This study will hopefully shed some more light on heparin use during PCI in NOAC-treated patients. The Stenting and Oral Anticoagulant (STENTICO) registry found a significant difference in bleeding risk between the radial and the femoral approach (3.8 % versus 10.3 %; P=0.01) in patients on OAC undergoing PCI, which resulted in the general consideration that in order to reduce periprocedural bleeding risk, the radial access should be adopted, especially in the OAC-treated patient.21 Another consideration in the prevention of bleeding during PCI, is to avoid glycoprotein IIb/IIIa inhibitors in patients on NOAC, unless they are required for the management of complications that emerge during PCI such as thrombus formation during the procedure or no-reflow.22 Stent thrombosis was a frequent consequence after implantation of early generation DES in patients undergoing PCI.23 The risk of developing stent thrombosis with newgeneration DES is comparable to that with bare-metal stents (BMS).24–26 Thus, current guidelines recommend that when considering implanting a stent during PCI, second-generation DES and BMS are preferred over first-generation DES.16
Which Antiplatelet Agents Should be Given in Patients with Acute Coronary Syndrome and AF?
Elective or NSTEMI patients on (N)OAC undergoing PCI with coronary stenting require TT including an antithrombotic regimen that consists of a loading dose of aspirin 150–300 mg followed by 75–100 mg/day and a loading dose of clopidogrel 300–600 mg followed by a daily intake of 75 mg.
Although there are no reports of RCTs comparing NOAC and VKA in patients with AF undergoing PCI, the ESC position paper states that in patients who require TT, NOACs could be used instead of VKA.16 Data supporting the current guidelines are mostly based on the post-hoc analysis from the Randomised Evaluation of Long-term Anticoagulation Therapy (RELY) trial.27 A total of 6,952 patients with AF in the RELY study were, at some point during the study, on antiplatelet therapy when comparing the different dabigatran doses (110 mg or 150 mg twice daily [BID]) and VKA. Of this subgroup, there were 812 patients who were simultaneously on aspirin, clopidogrel and VKA or dabigatran, and it was observed that the relative risk of bleeding was similar whether dabigatran or VKA was given in conjunction with DAPT. In addition, 110 mg dabigatran was associated with the lowest rates of absolute bleeding, regardless of the patient’s use of only VKA, VKA and a single antiplatelet agent or VKA with DAPT.27 When considering adding NOAC to DAPT, it is advised to use the lower tested dose for stroke prevention in AF patients (dabigatran 110 mg BID, rivaroxaban 15 mg once daily or apixaban 2.5 mg BID).16
The new P2Y12 inhibitors ticagrelor and prasugrel, which are recommended as the drugs of choice in patients presenting with ACS, are both more potent than clopidogrel. There has been only one small observational study comparing prasugrel (n=21) with clopidogrel (n=356) in patients undergoing a DES implantation, who received DAPT and had an indication for OAC.28 The patients receiving prasugrel had an increased risk of bleeding (HR 4.6; 95 % CI [1.9–11.4]; P<0.001), compared with clopidogrel. Another study investigating a P2Y12 inhibitor was a Swedish registry, in which ACS patients on ticagrelor and VKA (n=107) were compared with patients treated with aspirin, clopidogrel and VKA (n=159).29 The rates of thrombotic events (recurrent ACS, stroke/transient ischaemic attack and embolism) and major bleeding events were similar in both treated groups (4.7 % versus 3.2 % and 7.5 % versus 7.0 %, respectively). Nonetheless, the regular use of both P2Y12 inhibitors should not be recommended until further research concerning the safety and efficacy of combining prasugrel or ticagrelor with OAC has been completed.