Antiplatelet therapy following TAVI time to rando

Authors: R Delewi J J Piek

Publish Date: 2014/01/08

Volume: 22, Issue: 2, Pages: 62-63

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Abstract

Following the introduction of transcatheter aortic valve implantation TAVI it is now possible to treat elderly patients with severe aortic stenosis and a high surgical risk This advancement in interventional cardiology has led to increased survival health status and quality of life However as with many invasive interventional procedures TAVI is associated with the risk of cerebral embolisation and consequent ischaemic cerebrovascular events with possible neurological impairment The risk estimates of postprocedural stroke associated with TAVI vary from 15 to 10  and have been reported both early and late after the procedure In the PARTNER Cohort B study the Canadian multicentre TAVI registry and the study by Nuis et al about 50  of the stroke events occurred more than 24 h postprocedure 1 In addition to clinically overt stroke asymptomatic silent cerebral infarcts have been frequently observed on MRI with a prevalence ranging from 62 to 93  2 Although asymptomatic accumulating evidence implicates that these silent cerebral infarcts are related to risk of future stroke cognitive decline dementia and depression Whether stroke occurs due to incomplete endothelialisation of the valve or by new onset of silent atrial fibrillation is unknown Early postprocedural stroke 24 h is more likely the result of embolisation during valve implantationGiven this high incidence of cerebral events adequate anticoagulation is probably required both during the procedure and in the following months However the exact regimen of anticoagulation involves a clinical dilemma with the therapeutic potential of reducing ischaemic complications at the expense of increasing the bleeding risk The overall incidence of bleeding following TAVI has been reported in 41  of the patients in the metaanalysis conducted by Généreux et al of which 16  were lifethreatening 3 It is important to bear in mind that lifethreatening bleeding is associated with a six to ninefold increase in 30day mortality after procedure and acts as an independent predictor of 1year mortality 4 Therefore for clinical decisionmaking on antithrombotic treatment it is important to find a balance between prevention of ischaemic complications and avoidance of bleeding riskThe recently published study by Nijenhuis et al addresses this clinical dilemma regarding decisionmaking on anticoagulation treatment of elderly patients treated with TAVI 5 As pointed out by the authors the current European and American guidelines merely provide recommendations based on retrospective registries The European Society of Cardiology guidelines recommend a combination of low aspirin and a thienopyridine early after TAVI followed by aspirin or a thienopyridine alone In those cases where there is an indication for treatment with vitamin K antagonists such as in atrial fibrillation a combined treatment of vitamin K antagonist and aspirin or a thienopyridine is in general installed However the guidelines do not provide any recommendations on the duration of dual antiplatelet therapy DAPTAs observed in the survey undertaken in the Netherlands a wide heterogeneity in the duration of dual antiplatelet therapy DAPT and loading dose of clopidogrel was noted In twothirds of the centres n = 9 DAPT was prescribed for 3 months In one centre where only transapical TAVI is performed no concomitant clopidogrel was prescribed at all The duration of concomitant clopidogrel was dependent on the type of prosthesis in only two centres according to the recommendations of the respective manufactures 6 months versus 3 months for supraannular Core Valve™ and intraannular prostheses eg SAPIEN™ JenaValve respectively Whether the decision on the duration of concomitant clopidogrel and its loading dose indeed should be dependent on the valve type SAPIEN™ or Medtronic Core Valve™ or procedural approach transfemoral or apical has not been described in the literature Moreover clinical decisionmaking becomes more complex in circumstances where there is a high bleeding risk PCI 1 year prior to TAVI triple therapy preTAVI and newonset atrial fibrillation This is nicely illustrated in the survey of the participating centres showing different approaches to these scenarios

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