ANESTHESIA FOR NON CARDIAC SURGERY IN PATIENTS WITH CORONARY STENTS

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Dr. Mahesh Vakamudi Professor and Head Department of Anesthesiology, Critical Care and Pain Medicine (ISO 9001:2008 CERTIFIED) Sri Ramachandra University Chennai. ANESTHESIA FOR NON CARDIAC SURGERY IN PATIENTS WITH CORONARY STENTS. Magnitude of the problem. - PowerPoint PPT Presentation

Transcript of ANESTHESIA FOR NON CARDIAC SURGERY IN PATIENTS WITH CORONARY STENTS

  • Dr. Mahesh VakamudiProfessor and HeadDepartment of Anesthesiology, Critical Care and Pain Medicine (ISO 9001:2008 CERTIFIED)Sri Ramachandra UniversityChennai

  • Magnitude of the problem2 million patients undergo PCI annually90% of these patients receive one or more intracoronary stents5% of these patients will undergo non cardiac surgery in the first year after stenting

  • Coronary artery bypass surgeriesPercutaneous coronary interventionsNUMBER>Stents commonly placedIncrease procedural successDecrease restenosis

  • Why this lecture?In patients who have coronary stents, perioperative coronary stent thrombosis is a catastrophic complicationNon cardiac surgery, especially if surgery is performed immediately after stenting and particularly if dual antiplatelet therapy is discontinued increases this riskMaintain balance between risk of bleeding and stent thrombosis is our dilemma.What do we do? Thats what this lecture is about

  • Which patients are prone for stent thrombosis?Patients with a suboptimal angiographic resultThose with high risk lesionsSmall vesselsBifurcation lesionsThose with diabetes and renal failureThose whose dual antiplatelet therapy has been stopped

  • Scoring system for LSTRisk score for prediction of LSTLow0691319MediumHighVery High

  • Why thrombosis?Early surgery

  • Discontinuation of Aspirin and ClopidogrelLoss of antiplatelet effectRebound increase in COX 1 and TXB2Increased thrombin and decreased fibrinolysisSurgeryProthrombotic stateLoss of anti-inflammatory protection by clopidogrelStent thrombosisMI&

  • Coronary angioplasty without stentsBare metal stentsDrug eluting stentsPlatform + Carrier(Stent + Drug)Antiproliferative and immunosuppressive propertiesbut

  • Incidence of deathsBare metal stentsKaluza GL, Joseph J, Lee JR, Raizner ME, Raizner AE. Catastrophic outcomes of noncardiac surgery soon after coronary stenting. J Am Coll Cardiol 2000;35:1288 94.8 out of 25 patients who underwent surgery within 2 weeks died 7 of MI, 1 of bleedingNone out of 15 patients who underwent surgery after 15 days died

  • Wilson SH, Fasseas P, Orford JL, et al. Clinical outcome of patients undergoing noncardiac surgery in the two months following coronary stenting. J Am Coll Cardiol 2003;42:23440.The risk of death, MI, or stent thrombosis was elevated for 6 weeks, not for just 2 weeksSharma AK, Ajani AE, Hamwi SM, et al. Major noncardiac surgeryfollowing coronary stenting: when is it safe to operate? CatheterCardiovasc Interv 2004;63:1415.Of 27 patients who underwent non cardiac surgery within 3 weeks of BMS, 86% of those who stopped antiplatelets diedBare metal stents

  • DESFirst generation DES eluteSirolimusPaclitaxelSecond generation DES eluteZotarolimusEverolimus

  • Nasser et al. (20) reported sirolimus-eluting stent (SES) thrombosis in 2 patients after surgery performed 4 and 21 months after SES implantation.McFadden et al. (19) reported DES thrombosis in 3 patients undergoing surgery late (343 to 442 days) after implantation.Drug eluting stents

  • Avoid preoperative coronary revascularization, unless there exists a strong and proven indicationConsider balloon angioplasty if surgery is needed within 6 weeks. Avoid stentsChoose BMS ifSurgery needed from 6 weeks to 12 monthsBleeding diathesisPatient unable or unwilling to receive long term clopidogrelChoose DES if surgery is needed after 12 monthsBMS 6 weeksDES 12 monthsContinue antiplatelet therapy during surgerySurgeonsanesthesiologists cardiologists

  • Avoiding revascularizationCARP trial510 stable patients with CAD undergoing major vascular surgeryRandomized to revascularization (by CABG or PCI) or no revascularization Similar incidence of postoperative MI and 27 month survival in both the groups

  • Revascularization without stents (Balloon only)Patients with acute coronary syndrome and those with profound ischemia on non invasive testing do need revascularizationCan be done without stents: Percutaneous balloon angioplastyIn this study, when surgery was done 11 days after PCI, only 1 patient died and 1 had an AMIGottlieb A, Banoub M, Sprung J, Levy PJ, Beven M, Mascha EJ.Perioperative cardiovascular morbidity in patients with coronary arterydisease undergoing vascular surgery after percutaneous transluminalcoronary angioplasty. J Cardiothorac Vasc Anesth 1998;12:501 6.

  • When surgery after Balloon angioplasty?2002 ACC AHA guidelinesDelaying noncardiac surgery for 6 to 8 weeks was discouraged because restenosis could have occurredPerforming noncardiac surgery too early after the PCI also may be risky because acute or subacute closure after balloon angioplasty usually occurs within hours to days after the procedure.Delay surgery for 1 week after balloon angioplasty

  • If stenting cant be avoidedComplex lesion or inability to achieve optimal result with balloon angioplastyChoose the right stentSurgery needed with 12 months: Choose BMSSurgery can be delayed for > 12 mth: DESBMS endothelialize more rapidly than DESSirolimus eluting stent preferable as it requires 3 mths of antiplatelet therapy than a paclitaxel eluting stent that requires 6 mths of clopidogrel

  • Delay surgery6 weeks BMS12 months DES

  • Time from stent until surgery (months)Major adverse cardiac events (%)1086420246810121416180Bare metal stentsDrug eluting stents

  • RISK OF PERIOPERATIVE STENT THROMBOSIS WITH DESStents implanted in left main coronary arteryStents implanted in bifurcationsGreater total stent length (multiple/overlapping stents)Heightened platelet activity (surgery, DM, malignancy)In stent restenosisLeft ventricular dysfunctionLocalized hypersensitivity vasculitisPenetration by stent into necrotic corePlaque disruption into non stented segmentRenal failureDiabetes mellitusResistance to antiplateletsInappropriate discontinuation of antiplatelet medications

  • Periop antiplatelet therapyContinue dual antiplatelet thearpy during and after surgeryDiscontinue clopidogrel but bridge the patient to surgery with Glycoprotein IIb/IIIa inhibitor or an antithrombin, and restart clopidogrel as soon as possible after surgeryDiscontinue clopidogrel before surgery and restart it as soon as possible after surgery

  • Impact of aspirin on bleedingMost studies in cardiac and vascular surgerySafe in doses of 75 150 mgIncreases bleeding by a factor of 1.5, no effect on morbidity and mortalityAvoid in TURP and intracranial surgery (as bleeding in these situations can be life threatening)

  • Option 1 : Continue therapyDental extractionsCataract surgeryDermatologic surgery

  • Option 2: Bridging therapyBridge using short acting antiplatelet or an anticoagulantPlatelet inhibitors are the more logical choice as stent thrombosis is a platelet mediated phenomenonCessation of heparin in a patient not on antiplatelets can cause rebound effect and stent thrombosis

  • Bridging therapyA shortacting GP IIb/IIIa inhibitor (tirofiban or eptifibatide) or thrombin inhibitor, or both, is substituted for clopidogrel during the perioperative periodRolePrevent platelet aggregationDisplace fibrinogen from GP IIb/IIIa receptorsBlock signaling processes

  • Bridging therapyTirofiban and eptifibatide are administered parenterallyHave half-lives 2 hEliminated by renal clearance.Infusion rate is reduced by half in patients with reduced renal functionPlatelet function returns to 60%90% of normal after the infusion is stopped for 68 h.

  • When bridging therapy?Surgeries with high risk of bleedingIntracranialSpinalRetinal

  • Other drugsReversible P2Y12 receptor antagonists are undergoing clinical trialsCangrelor is a parenteral, reversible direct P2Y12 inhibitorHalf-life of 59 min allows 100% recovery of platelet function 1 h after the infusion is discontinued4 mcg/kg/min infusion achieves complete platelet inhibition when measured at 4 minAZD6140 is an oral, reversible direct P2Y12 receptor antagonist with a half life of 12 hrs.

  • Problems with bridging therapyExpensiveLogistically difficultExposes patients to risks associated with a prolonged hospitalizationSome claim that it confers no protection against intraoperative stent thrombosis

  • Option 3: Stop antiplateletsNeurosurgeryRestart clopidogrel after surgery600 mg loading dose Maximal inhibition of platelet aggregation in 2 4 hours (takes 6 hrs with 300 mg)Reduces the incidence of hyporesponsiveness to platelets (which are activated due to surgery)

  • Steps: Preoperative evaluationDetermine the type of stent: BES, SES, PESWhen were stents implanted?Determine location of stent in coronary circulationHow complicated was the revascularization?Is there a previous history of stent thrombosis?What antiplatelet regimen is being followed?Determine co-morbidities?What is the recommended duration of antiplatelet therapy for this patient?Co-ordinate with cardiologist

  • StepsPerform procedure in centers where there is 24 hr interventional cardiology coverage for emergency PCI

  • Intraop managementTight hemodynamic controlUse of beta blockersGood HR controlGood BP controlDecrease sympathetic outflow and therefore decrease platelet activation

  • Regional anesthesia in patients on antiplateletsAdvantagesAttenuation of hypercoagulable stateSystemically absorbed LA have antiplatelet effectFollow ASRA guidelinesFor patients receiving bridging therapy with eptifibatide or tirofiban, 8 h must elapse before a neuraxial blockade can be performed

  • Management of stent thrombosisST segment elevation acute myocardial infarctionReperfusionThrombolytic therapy less effective than primary PCIPlatelet mediated phenomenonRisk of bleedingAll that is