Presentation on theme: "Anesthesia for patients with coronary artery disease undergoing non-cardiac surgery Gamal Fouad S Zaki, MD Professor of Anesthesiology Ain Shams University."— Presentation transcript:
Anesthesia for patients with coronary artery disease undergoing non-cardiac surgery Gamal Fouad S Zaki, MD Professor of Anesthesiology Ain Shams University
In Non-Cardiac Surgery: Stress associated with surgery is extreme & persistent 4-5% of patients with or at risk of heart disease suffer cardiac complications perioperatively Shah 1990, Badner 1998, Kumar 2001Perioperative MI carries a % hospital mortality Shah 1990, Badner 1998, Kumar 2001 Cardiac arrest has a hospital mortality of 65% and is an independent predictor of death during the following 5 yrs
Epidemiology Incidence of CAD on the rise age group >65 years:Aging population: age group >65 years: –will increase by 25% in next 30 years (USA) –Largest number of surgical procedures Number of non-cardiac surgical procedures in older persons will increase Prevalence of CAD increases with age More likely to get patient with CAD in OR
Historical Background Late90 s Perioperative MI identified as a problem Goldman Cardiac Risk Index Detsky: Modified Cardiac Risk Index Specialized tests for risk stratification Intraoperative risk factors identified Postop Ischemia main outcome predictor β-Blockers fight ischemia ACC/AHA Guidelines From Risk Stratification to Risk Modification
Myocardial Oxygen Balance Supply Demand Coronary blood flow CPP=AoDP-LVEDP Arterial O 2 Content Inotropic state Systolic wall tension Heart Rate Slow, empty, well perfused
Pathology of Atheroma Foam Cells T-Lymphocytes Triggers of Plaque Rupture: Smoking Hypercholesterolemia Inflammatory Response Shear Stress
Pathophysiology of Perioperative MI Unknown: –Myocardial O 2 supply/demand imbalance (perioperative stress) –Rupture of Atheromatous plaques: Dawood MM, Gutpa DK, et al. Pathology of fatal perioperative myocardial infarction: implications regarding pathophysiology and prevention. Int J Cardiol 1996;57: Triggers of plaque rupture: hemodynamic sheer stress, coronary spasm, plaque ischemia and inflammatory process Perioperative factors: systemic inflammatory response, sympathetic hyperactivity, and hypercoagulability (platelet hyperaggregability)
Preoperative assessment Goals: Identify high risk patients who may benefit from pharmacologic optimization and/or revascularization Plan for intraoperative management Plan for postoperative management Produce a risk assessment useful for patient and surgeon
Preoperative Preparation Components: History / Examination Non-Invasive Testing Preoperative Optimization: –Control medical conditions: HTN, BA –Employ pharmacologic protection –Minimal role for preoperative revascularization CABG, Angioplasty
Lee Revised Cardiac Risk Index High risk surgical procedure History of ischemic heart disease History of congestive heart failure History of TIA or stroke Preoperative insulin therapy Preoperative serum creatinine >2.0 mg/dL
Update 2002 Based on Clinical Predictors functional capacity, underlying medical conditions, surgicalrisk Intervention rarely necessary to reduce surgical risk unless indicated w/o surgery EvaluationClearancePreoperative Evaluation: not Clearance Produce risk profile useful for making treatment decisions by: patient, surgeon, anesthesiologist Testing: only when likely to influence treatment Modified Cardiac Risk Index: Detsky
History: Exercise Tolerance Reilly et al. Self-reported exercise tolerance and the risk of serious perioperative complications. Arch Intern Med. 1999;159: non-cardiac surgery pts Questioned about number of blocks they could walk, or flights of stairs they could climb Poor exercise tolerance: < 4 blocks or 2 flights, (< 6 METs: metabolic equivalents) more periop complications (20.4% vs. 10.4%), more myocardial ischemia, cardiovascular and neurologic complications If assessment not possible (knee): further testing
Cardiac stress testing Why does inducible ischaemia on stress testing not predict perioperative events satisfactorily?Why does inducible ischaemia on stress testing not predict perioperative events satisfactorily? Stress testing predicts intermediate and long term prognosis of CAD patients. (Lee, Boucher. N Engl J Med 2001;344:1840) The culprit is extrapolating this to short term perioperative (96 hrs) outcome Difference may be in the etio-pathology: plaque rupture vs. supply/demand imbalance
Dobutamine Stress Echocardiography Commonly chosen, good predictive value New or worsened RWMA: positive Represent areas at risk of ischemia Dynamic assessment of LV function Patients with RWMA in 1-4 segments benefit from beta blockers >5 segments do not benefit, need intervention. Boersma et al. JAMA 2001
Low predictive value of positive non-invasive tests, preop revascularization not beneficial Trigger a cascade of riskier interventions Increased cost, delayed surgery β-blockers and may be statins shown to reduce perioperative ischemia Need to shift emphasis from risk stratification to risk modification: drugs
Grayburn et al. Cardiac events in patients undergoing noncardiac surgery: shifting the paradigm from noninvasive risk stratification to therapy. Ann Intern Med 2003;138:506 The paradigm is shifting from predicting which patient is at high risk for having a perioperative cardiac event to minimizing the likelihood of such an event with specific perioperative pharmacologic therapy
Preoperative Revascularization prior CABG confers protection against perioperative cardiac events Paul SD, Eagle KA. Med Clin N Amer 1995 Not recommended for all high risk patients for non- cardiac surgery. Combined risks of CABG followed by non-cardiac surgery is greater than surgery alone. Angioplasty: not recommended before non-cardiac surgery, angioplasty within one month of non-cardiac surgery associated with increased complications and death. Kaluza et al. Catastrophic outcomes of noncardiac surgery soon after coronary stenting. J Am Coll Cardiol 2000;35: ACC/AHA Guidelines recommended waiting a minimum of 2-4 weeks after Angioplasty
Design: RCT; 200 Veterans for non-cardiac surgery Inclusion: Known CAD or 2 or more CAD risk factors. Exclusion: CHF, 3rd degree AVB, Bronchospam, HR<55 or SBP<100
Intervention: –Perioperative: Atenolol 5mg given IV on call to OR. Repeated 5 minutes later. –Postoperative: Same regimen repeated immediately post-op. Starting on POD#1 Atenolol mg PO qd (or placebo) was given. Outcome: –Primary: All cause of mortality at D/C and at 2 years. –Secondary: Survival free from MI, unstable angina, CHF, need for revascularization. Results: –6 in-hospital deaths, including 3 from PMI (2 in placebo group and 1 in atenolol) NS –30 deaths during 2 years follow-up including 21 deaths in placebo and 9 in atenolol.
Overall Survival in 2 Years after Noncardiac Surgery among 192 Patients in Atenolol and Placebo Groups Who Survived to Hospital Discharge.
Event-free Survival in 2 Years after Noncardiac Surgery in 192 patients in Atenolol and Placebo Groups who Survived to Hospital Discharge
: RCT 112 patientsDesign: RCT 112 patients Inclusion: abdominal aortic or infrainguinal arterial reconstruction with: Age>70, angina, prior MI, CHF, ventricular arrhythmias, diabetes, class III symptoms AND Dobutamine echo stress induced wall motion abnormalities AND Not on a beta blocker already, no extensive resting wall motion abnormalities, no evident LM or 3VD. Intervention: Bisoprolol 5mg qd (or placebo) started at least 1 week prior to surgery; increased to 10mg if HR>60, continued postoperatively Stopped for HR<50 or SBP<100. Endpoints: Death from cardiac causes or nonfatal MI
Results Mortality: 9 (17%) cardiac deaths in placebo arm vs 2 (3.4%) in bisoprolol arm p=.002 ARR 13.5%; NNT=7. Nonfatal MI: 9 (17%) nonfatal MIs in placebo group and 0 in bisoprolol group ARR 17%; NNT=6 Combined endpoint 34% in placebo arm suffered cardiac death or nonfatal MI vs 3.4% in the bisoprolol group ARR 31%; NNT=3 Advantages over Manganos study: Patient homogeneity. Higher risk patients Exclusion of prior beta blocker use. Use of oral β-blocker
Kaplan-Meier estimates of cumulative percentage of patients who died of cardiac causes or had a non- fatal MI during perioperative period.
Retrospective study of 800,000 major noncardiac surgery pts, of whom 18% received BB in the first 2 hospital days. Perioperative BB associated with a reduced risk of in- hospital death among high-risk (RCRI), but not low-risk, patients. Patient safety may be enhanced by increasing the use of beta-blockers in high-risk patients.
Intraoperative Management Monitoring: ECG Non-Invasive BP Temperature Arterial lineInvasive Blood Pressure: Arterial line CVP TEE PA Catheter ?
Intraoperative Management Monitoring: ECG V 5 most sensitive London et al. Anesthesiol 1988 V 4 most sensitive Landesberg et al. Anesthesiol 2002 Two or 3 precordial leads will detect >90% of ischemia from 12 leads OR monitors: only one precordial lead Automated ST-segment analysis of at least 2 leads considered standard.
Intraoperative Myocardial Ischemia: Localization by continuous 12-lead electrocardiography. London M et al. Anesthesiology 1988
Landesberg et al. Anesthesiol 2002 Histogram showing the incidence in which prolonged ischemia was first noted by each lead at the onset of ischemia in all 38 longest ischemic events and in the 12 ischemic events that progressed to MI
Landesberg et al. Anesthesiol 2002 Histogram showing the incidence of all leads demonstrating greater than 1 mm relative ST deviation during peak ischemia and the lead with maximal ST deviation in the 12 patients with myocardial infarction.
TEE Intraoperative Management Monitoring: TEE Regional function is evaluated in terms of: Wall Motion (endocardial excursion) & / or Wall Thickening
Intraoperative Management: Regional or General Anesthesia Long lasting debate No scientific evidence supporting either More important: sound physiologic goals: Hemodynamic stability, normothermia, avoidance of anemia Although 50% of ECG ischemia is hemodynamically silent, there is association between Tachycardia and both intraoperative and postoperative ischemia
Intraoperative Management: Regional or General Anesthesia Opioid based gives hemodynamic stability but may require postoperative ventilation Often GA + epidural block Anesthetic Preconditioning: mito K ATPVolatile Agents: possess Cardioprotective properties, Anesthetic Preconditioning: reduce infarct size, attenuate endothelial dysfunction: open mitochondrial ATP sensitive K channel: mito K ATP Only Epidural Anesthesia/Analgesia with local anesthetics+opioids capable of attenuating neuroendocrine stress response
Cardiac Troponin I in the SEVO and Propofol Groups SEVO Propofol
Volatile agents and opioids induce preconditioning
Myocardial EdemaInfarct Size LAD Ligation in Anesthetized dogs
Intraoperative Management: Regional or General Anesthesia Rodgers A. Reduction of postoperative mortality and morbidity with epidural or spinal anaesthesia: results from overview of randomised trials. BMJ 2000; 321(7275): 1493 Meta-analysis of 141 trials, 9559 patients Mortality reduced by 1/3 with neuraxial blockade 103/4871 vs. 144/4688 patients Decreased odds of DVT(44%), PE (55%), transfusion (50%), pneumonia (39%), and respiratory depression (59%) (all p<0.001)
Intraoperative Management: Regional or General Anesthesia Rigg JR. Epidural anaesthesia and analgesia and outcome of major surgery: a randomised trial. Lancet 2002; 359(9314): Prospective trial, with1 of 9 comorbid states, 915 patients, major abdominal surgery Randomized: Epidural + General A with postop epidural analgesia (72 hrs) vs. General A 30 day Mortality: 23/447 Epidural vs. 19/441 control No difference in mortality and major morbidity Significant reduction in Respiratory failure & Pain Scores with Epidural
Intraoperative Management: Regional or General Anesthesia Singh N et al. The effects of the type of anesthesia on outcomes of lower extremity infrainguinal bypass. J Vasc Surg 44: , November 2006 Prospectively collected database of National Surgical Quality Improvement Program (NSQIP) The NSQIP database identified 14,788 patients (GETA, 9757 pts; SA, 2848 pts; EA, 2183 pts) underwent infrainguinal arterial bypass 99% Males, Mean Age: 65.8 yrs
Intraoperative Management: Regional or General Anesthesia Singh N et al. The effects of the type of anesthesia on outcomes of lower extremity infrainguinal bypass. J Vasc Surg 44: , November 2006 Type of anesthesia affected graft failure Compared to SA and EA, GETA associated with: –More graft failure at 30 days –More cardiac events (MI, C Arrest), –More postoperative pneumonia No difference between SA and EA regarding graft failure and cardiac events GETA is not the best strategy
Intraoperative Management: Regional or General Anesthesia BOTH My Preference: BOTH EpiduralEpidural Catheter inserted after fluid preloading, test dose, then 8 ml of your favorite LA, wait for sure signs of onset of block, then induce: General AnesthesiaGeneral Anesthesia: Fentanyl 2μg/kg, wait for at least 3min, Thiopentone 2-4 mg/kg, your favorite non-depolarizer, ETT, Isoflurane %, or Sevo 1-2%, normocarbia. Maintain Epidural block (LA + Opioid), Little or no IV fentanyl PostopPostop: Ropivacaine 0.2% + Fentanyl 2μg/ml SEVO
Postoperative Management: First 3 postoperative days: Period of greatest risk of cardiac complications Hypercoagulability, Increased adrenergic stress Management focused on factors increasing risk of cardiac complications: –Tachycardia –Anemia –Hypothermia, shivering –Hypertension –Hypoxemia –Inadequate analgesia
Postoperative Management: Most postoperative ischemia is silent: Most MIs preceded by prolonged ST depression Early detection and aggressive management MAY prevent progression to MI Detective strategy: (Silent) –ST-segment Monitoring: automated, continuous –12 Lead ECG q. 8 hrs in day1, then daily for day 2, 3 –Serial Enzymes: Cardiac Troponins (TnT, TnI)
Postoperative Management: Cardiac Troponins (TnT, TnI)Cardiac Troponins (TnT, TnI) More specific than CK-MB More prognostic value, Suggest treatment strategy Unstable Angina: some have small rise TnT<0.1 ng/ml, increased M&M, respond to LMWH, Gp II b -III a blockers Time to risePeak riseNormalized CK-MB3-5 hrs10-18 hrs2-3 days Gold standard Not Prognostic low specificity TnT3.8 hrs18 hrs, 3ds5-14 days High sensetivity & specificity, Prognostic TnI3-12 hrs24 hrs5-10 days not affected by CRF, slow rise
Postoperative Management: Cardiac complications Treatment based on extrapolation from non- operative setting, AHA/ACC guidelines: Transmural Q-wave MI Non Q-wave MI (NQWMI) Unstable Angina
Postoperative Management: Transmural Q-wave MI Goal: quickly reopen occluded vessel Aspirin: early Thrombolytics contraindicated post surgery?? If Lytics CI: consider Cath/Stent β-Blockers: aggressive block NTG: only for ongoing ischemia ACE Inhibitors: improve LV remodelling Heparin: when lytics CI Magnesium: good, Statins: evolving evidence LMWH, Gp II b /III a blockers: no evidence
Postoperative Management: Non Q-wave MI (NQWMI) Majority of perioperative MI Higher Morbidity, equal Mortality to QWMI Cardiac status closer to Unstable Angina Diagnosis: Cardiac Enzymes β-Blockers & Aspirin for all NQWMI NTG: only for ongoing ischemia Heparin: 48 hours, improves outcome LMWH: used instead, caution, no reversal Gp II b /III a blockers ?? Used in non-operative
Postoperative Management: Unstable Angina Goal: prevent progression to MI, death β-Blockers & Aspirin: dec MI, Mortality NTG: only for ongoing ischemia, nitrate tolerance develops in hrs continuous administration Heparin: 48 hours, improves outcome Angio / stent?? Troponin Positive Unstable Angina (Minor Myocardial Injury): LMWH & Gp II b /III a blockers: Abciximab, Agrastat
Epilogue: CAD patients are high risk patients Optimum strategy is multimodal: –Improved preoperative assessment –Sympatholytic pharmacologic optimization –Intraoperative management based on physiologic goals & scientific evidence –Postoperative Monitoring: detective Postoperative MI, U Angina: inc M & M: β-Blockers & Aspirin, selective use of invasive procedures