Antithrombotic management of patients on oral anticoagulation undergoing coronary artery stenting

Patients on oral anticoagulation(OAC),who are referred for coronary artery stenting account for about 5% of the whole population undergoing percutaneous coronary intervention(PCI).Although relatively small,this patient subset poses particular problems owing to the need to balance carefully the risk of bleeding against the risk of stent thrombosis and thromboembolism.Triple therapy(TT) of OAC,aspirin and clopidogrel appears as the most effective for prevention of stent thrombosis and thromboembolism.However,an increased incidence of major bleeding is to be expected during follow-up.Therefore,TT should be prolonged for as short a time as possible,and implantation of drug-eluting stents avoided.Frequent monitoring of international normalized ratio is also warranted,and the intensity of OAC should be targeted at the lower limit of the therapeutic range.Gastric protection should also be considered for all patients on medium-to long-term TT,owing to the observed highest incidence of bleeding at the gastrointestinal site.Peri-procedural management is cumbersome,and a substantial incidence of inhospital major bleeding has been reported.Since this latter is more related to procedural variables than to TT itself,choice of radial access,avoidance of glycoprotein Ⅱb/Ⅲa inhibitors,and preference for not interrupting effective OAC should be implemented.However,the evidence on which the recommendations for managing this patient subset are based is limited and of relative poor quality.While waiting for the results of ongoing,large prospective studies that are aimed at conclusively determining optimal medium-to long-term antithrombotic treatment,the official recommendations issued by the Working Group on Thrombosis of the European Society of Cardiology on the management of patients on OAC undergoing PCI with stenting should followed.

Incidence, clinical impact and risk of bleeding during oral anticoagulation therapy

Bleeding is the most important complication of oral anticoagulation (OAC) with vitamin K-antagonists. Whilst bleeding is unavoidably related to OAC, it may have a great impact on the prognosis of treated subjects by leading to discontinuation of treatment, permanent disability or death. The yearly incidence of bleeding during OAC is 2%-5% for major bleeding, 0.5%-1% for fatal bleeding, and 0.2%-0.4% for intracranial bleeding. While OAC interruption and/or antagonism, as well as administration of coagulation factors, represent the necessary measures for the management of bleeding, proper stratification of the individual risk of bleeding prior to start OAC is of paramount importance. Several factors, including advanced age, female gender, poor control and higher intensity of OAC, associated diseases and medications, as well as genetic factors, have been proven to be associated with an increased risk of bleeding. Most of these factors have been included in the development of bleeding prediction scores, which should now be used by clinicians when prescribing and monitoring OAC. Owing to the many limitations of OAC, including a narrow therapeutic window, cumber-some management, and wide interand intra-individual variability, novel oral anticoagulants, such as factor Xa inhibitors and direct thrombin inhibitors, have been recently developed. These agents can be given in f ixed doses, have little interaction with foods and drugs, and do not require regular monitoring of anticoagulation. While the novel oral anticoagulants show promise for effective thromboprophylaxis in atrial f ibrillation and venous thromboembolism, def initive data on their safety and eff icacy are awaited.

The risk of bleeding of triple therapy with vitamin K-antagonists,aspirin and clopidogrel after coronary stent implantation:Facts and questions

Background Triple therapy(TT)with vitamin K-antagonists(VKA),aspirin and clopidogrel is the recommended antithrombotic treatment following percutaneous coronary intervention with stent implantation(PCI-S)in patients with an indication for oral anticoagulation.TT is associated with an increased risk of bleeding,but available evidence is flawed by important limitations,including the limited size and the retrospective design of most of the studies,as well as the rare reporting of the incidence of in-hospital bleeding and the treatment which was actually ongoing at the time of bleeding.Since the perceived high bleeding risk of TT may deny patients effective strategies,the determination of the true safety profile of TT is of paramount importance.Methods All the 27 published studies where the incidence of bleeding at various time points during follow-up has been reported separately for patients on TT were reviewed,and the weakness of the data was analyzed.Results The absolute incidence of major bleeding upon discharge at in-hospital,≤1 month,6 months,12 months and≥12 months was:3.3%±1.9%,5.1%±6.7%,8.0%±5.2%,9.0%±8.0,and 6.2%±7.8%,respectively,and not substantially different from that observed in previous studies with prolonged dual antiplatelet treatment with aspirin and clopidogrel.Conclusions While waiting for the ongoing,large-scale,registries and clinical trials to clarify the few facts and to answer the many questions regarding the risk of bleeding of TT,this treatment should not be denied to patients with an indication for VKA undergoing PCI-S provided that the proper measures and cautions are implemented.