Withdrawal of clopidogrel

Withdrawal of clopidogrel • Premature clopidogrel discontinuation → the most significant independent predictor of stent thrombosis • Mortality rate linked to stent thrombosis of 45%. • 2/3 late DES thromboses were linked to stopping antiplatelet drugs Withdrawal of clopidogrel • Stopping clopidogrel to allow major surgery during the first 3 weeks after PCI and stenting → mortalities : 30% - 86%. • Maintain full anti-platelet therapy in the perioperative period, particularly for DES, even if the time from PCI is relatively long. Withdrawal of aspirin • ↑ 2倍 risk of ACS Stopped within the previous 3 weeks v.s. continued antiplatelet therapy. • ↑3倍 CAD cardiac complication rate after aspirin withdrawal. – higher in patients with coronary stents. • These data support the continuation of aspirin perioperatively. Withdrawal of aspirin • When for situations such as intracranial neurosurgery, – maximum interruption : 5–7 days – treatment resumed as soon as possible after surgery (within 12–24 h). • However, in patients with stents, aspirin must never be stopped. Withdrawal of aspirin • High predictive value for thrombotic events： – – – – – – – – – stenting of small vessels, multiple lesions, long stents, ostial or bifurcation lesions, suboptimal stent result, low ejection fraction, advanced age, renal failure, diabetes • In these situations, the advice is to maintain long-term dual antiplatelet therapy. Hemorrhagic risks Hemorrhagic risks • ↑ rate of severe spontaneous bleeding aspirin alone v.s. dual therapy – 0.7 v.s 1.13% (37% increase in relative risk) – 2.7 v.s 3.7% (27% increase in relative risk) Patients on aspirin • ↑ 1.5 倍 intraoperative hemorrhagic risk without an increase in surgical mortality or morbidity. • A modest rise in bleeding rate, but no differences in surgical complications or outcome linked to hemorrhage in most procedures – In vascular surgery, the increase in bleeding complications was only 2.46% Patients on aspirin • Although aspirin increases bleeding by approximately 20–30%, surgeons could not differentiate patients on aspirin from patients on placebo just from surgical bleeding. Patients on aspirin • Rise in bleeding rate only in specific procedures – Cardiac surgery with cardiopulmonary bypass – Tonsillectomy – Transurethral prostatectomy • Photoselective vaporization with the potassium-titanyl-phosphate (KTP) – Intracranial neurosurgery Patients on dual therapy • ↑ surgical bleeding and the transfusion rate probably by a factor of 50% • but not morbidity or the mortality, with the exception of intracranial surgery. Withdrawing or Continuing Anti-platelet agents Maintaining • Surgical blood loss ↑ ( 2.5-20% with Aspirin, 30-50% with Aspirin/Clopidogrel ) But… In most cases, no increase in mortality rate • Transfusion rate ↑ But… Complication rate of transfusion is 0.4% Withdrawing or Continuing Anti-platelet agents Withdrawing • Platelet adhesiveness ↑ - Rebound effect, SIRS, acute phase reaction to OP… • Infarction and death rates ↑ in acute coronay syndrome • Stent thrombosis, results in MI & mortality • Some DES are highly dependent on anti-platelet agents during 1st year after PCI • Emergency PCI post-OP takes more risk Modify the Algorithm • Former Withdrawing all antiplatelet agents 7-10 days before surgery • Modified Aspirin alone Second prevention: Maintain Primary prevention: Safely withdrawn 7 days? Clopidogrel with Aspirin Clopidogrel: Depends Aspirin: Maintain Modify the Algorithm Surgery in closed spaces Ex: Intracranial surgery, Spinal surgery in medullary canal, Posterior chamber of the eye… Small post-operative hemorrhage can have disastrous consequences !!! → Withdraw Aspirin or Clopidogrel 7 days → A “bridge” with GP-IIb/IIIa inhibitor & Heparin Regional and Neuraxial Blockade Clopidogrel with Aspirin are contra-indication of regional anesthesia (RA) - Due to spinal or epidural hematoma • Neuroaxial blockade is safer than GA in all patients with CAD? Ans: Only high thoracic (>T6) epidural blockade • Cardiac “sympatholysis” v.s. Effect of antiplatelet agents… → The winner is antiplatelet agents Miscellaneous… • Platelet transfusion - The only way to re-establish coagulation - Half-life of Clopidogrel: 4Hr → Transfusion could be started in 6-8Hr • Possible substitutes - Heparin - NSAID ( Ibuprofen, Indobufen ) - Shorter acting GP-IIb/IIIa inhibitor ( Tirofiban / Aggrastat®, Eptifibatid <<< Half life: 2Hr ) • Postoperative - Treatment must be restarted as soon as possible - Monitoring: Cardiac enzyme, ECG Thank you for your attention !!