Noncardiac Surgery in the Cardiac Patient

1. Noncardiac Surgeryin the Cardiac Patient David Putnam, MD Albany Medical College

2. Coronary heart disease is the most frequent cause of perioperative cardiac mortality and morbidity after noncardiac surgery

3. Noncardiac SurgeryMagnitude of the Problem 25 million patients undergo noncardiac surgery each year in the United States 3 million patients have clinical evidence or multiple risk factors for CAD 4 million patients are > 65 years old Nearly 1/3 of surgical patients are at risk for cardiovascular complications

4. Noncardiac SurgeryMagnitude of the Problem Aging of the population Lower threshold for performing major procedures on elderly patients Patients with multiple comorbid illnesses

5. Noncardiac SurgeryMagnitude of the Problem Advances in anesthesia, post-op analgesia, and surgical technique have contributed to a reduced rate of major cardiac complications Overall risk of cardiac complications with noncardiac surgery remains low Risk of perioperative MI: 0.1% Risk of cardiac death: 0.4%

6. Non-Cardiac SurgeryRisk of Perioperative MI/Death No history of ischemic heart disease: 0.1% History of prior MI: 6%

7. Reinfarction in Post-MI Patients

8. Non-Cardiac Surgery Although consultants are frequently asked to �clear� a patient for surgery, their role is considerably more complex

9. Noncardiac Surgery: General Successful perioperative evaluation and treatment of cardiac patients Teamwork and communication between Patient Primary Care Physician Anesthesiologist Surgeon Medical Consultant

10. Preop: Role of Consultant Assess individual patient�s risk of cardiac complications Determine if specialized testing is appropriate Recommend risk reduction strategies Participate in postoperative medical management

11. Pre-Operative Cardiac Evaluation What is the question?

12. Pre-Operative Cardiac Evaluation Can this patient reasonably have noncardiac surgery?

13. Pre-Operative Cardiac Evaluation Would coronary revascularization improve the long-term prognosis from a cardiac standpoint and protect the patient from adverse events during the necessary noncardiac surgery?

14. Preoperative Risk Assessment Dripps-ASA classification Goldman classification ACC recommendations

15. ASA Physical Status Assessment Class I: Healthy patient/elective operation Class II: Patient with mild systemic disease Class III: Severe systemic disease that limits activity but is not incapacitating Class IV: Incapacitating systemic disease that is a constant threat to life Class V: Moribund patient not expected to survive 24 hours with or without operation

16. Dripps-ASA ClassificationShortcomings Subjective Poorly reproducible in certain subsets Elderly Obese Prior MI Mild systemic diseases

17. Preoperative Cardiac AssessmentGoldman Classification Predicts life-threatening cardiac complications or perioperative cardiac death based on presence of preoperative risk factors

18. Goldman Multifactorial Index

19. Goldman Multifactorial Index

20. Preoperative Cardiac Assessment American College of Cardiology Recommendations JACC 1996;27:910-948

21. Noncardiac Surgery: General Indications for further cardiac testing/treatments are the same as those in the nonoperative setting Urgency of noncardiac surgery Patient�s risk factors Specific surgical considerations

22. Noncardiac Surgery: General Preoperative testing should be limited to circumstances in which the results affect patient treatment and outcomes

23. Noncardiac Surgery: General A conservative approach to the use of expensive tests and treatments is recommended

24. Preop Cardiac Evaluation:Considerations Type of surgery Functional capacity Clinical history and physical examination

25. Noncardiac Surgery: Higher Risk Procedures Vascular Prolonged, complicated Thoracic Abdominal Head and neck Total hip replacement

26. Preop Cardiac Evaluation Patients with a low functional capacity (less than 4 Mets) have a worse prognosis than patients with a good functional capacity

27. Preop Cardiac Evaluation Clinical data from a careful history and physical examination are the critical initial steps

28. Noncardiac Surgery: Preoperative Clinical Evaluation Identification of potentially serious cardiac disorders Prior MI Angina pectoris Congestive heart failure Symptomatic arrhythmias Significant valvular heart disease

29. Noncardiac Surgery:Preoperative Clinical Evaluation Preexisting manifested heart disease Presence Severity Stability Prior treatment

30. Noncardiac Surgery: Preoperative Clinical Evaluation Always History Physical exam ECG Commonly Echocardiogram/EST Sometimes Cardiac cath/MUGA scan

31. Preoperative ECG�sRecommended Intrathoracic surgery Intraperitoneal surgery Aortic surgery Neurosurgical procedure Emergency operations

32. Preoperative ECG�sRecommended History/physical suggesting heart disease Men > 40-45 years old Women > 55 years old Systemic conditions that may be associated with unrecognized cardiac abnormality Medications that can cause cardiac toxicity or ECG changes Patients at risk for major electrolyte abnormalities

33. Methods of Assessing Cardiac Risk:Exercise Stress Testing Provides substantial information about risk of perioperative MI/cardiac death Poor functional capacity, particularly associated with myocardial ischemia predicts high risk Gradient of increasing ischemic risk seen in association with degree of functional capacity, symptoms of ischemia, severity of ischemia, and hemodynamic instability

34. Methods of Assessing Cardiac Risk:Pharmacological Stress Testing Dipyridamole or adenosine with thallium/sestamibi High sensitivity/specificity for perioperative events, especially in intermediate risk group Perioperative ischemic events appear to correlate with the magnitude of ischemia Pharmacological stress testing involving echocardiogram is a viable option

35. Methods of Assessing Cardiac Risk:Resting LV Function LVEF < 35% increases risk of surgery Severe diastolic dysfunction increases risk of surgery Evaluate LV function in presence of CHF Probable evaluation of LV function with history of CHF or dyspnea of unknown etiology

36. Management Options after Noninvasive Testing Intensified medical therapy Cardiac catheterization Cancel or delay surgery Proceed with surgery Coronary revascularization prior to surgery

37. Noninvasive Pre-Op Testing The good news is that noninvasive tests are sensitive to the presence of CAD The bad news is that the positive predictive value is poor because the likelihood of perioperative events is less than 10%

38. Methods of Assessing Cardiac Risk:Coronary Angiography Appropriate in certain patients at high risk, including those with evidence of significant ischemia or suspicion of left main/three-vessel CAD Indications are similar to those in the nonoperative setting Essential that management with PTCA/CABG is a viable option

39. Coronary AngiographyClass I Indications High-risk results during noninvasive testing Angina pectoris unresponsive to adequate medical therapy Most patients with unstable angina Nondiagnostic or equivocal noninvasive test in a high-risk patient undergoing a high-risk noncardiac surgical procedure

40. Coronary AngiographyClass II Indications Intermediate-risk results during noninvasive testing Nondiagnostic or equivocal noninvasive test in a lower-risk patient undergoing a high-risk noncardiac surgical procedure Urgent noncardiac surgery in a patient convalescing from acute MI Perioperative MI

41. Noncardiac Surgery:Preoperative CABG Indications are same as those in the nonoperative setting Cardiac risk of CABG often exceeds that of noncardiac surgery Rarely indicated simply to get a patient through the perioperative period

42. Noncardiac Surgery:Preoperative PTCA No controlled trials Several small observational studies suggest that cardiac death is infrequent in patients who have PTCA prior to noncardiac surgery Indications are similar to those in nonoperative setting

43. Noncardiac Surgery: Emergency/Immediate Surgery Consultant may function best by making recommendations for perioperative medical management and surveillance Postoperative risk stratification may be appropriate for some patients who have not had such an assessment

44. Major Clinical Predictors of Increased Perioperative Cardiovascular Risk Unstable coronary syndromes Recent MI with evidence of ischemic risk Unstable or severe angina Decompensated CHF Significant arrhythmias High-grade AV block Symptomatic ventricular arrhythmias SVT�s with uncontrolled ventricular rate Severe valvular disease

45. Noncardiac Surgery: Major Clinical Predictors Cancel or delay surgery if surgery is elective Many of these patients are referred for coronary angiography

46. Major Clinical Predictors

47. Intermediate Predictors on Increased Perioperative Cardiovascular Risk Mild angina pectoris Prior MI by history or pathological Q-waves Compensated or prior CHF Diabetes mellitus

48. Noncardiac Surgery:Intermediate Clinical Predictors Consideration of functional capacity ( risk increased in patients unable to meet 4-METs of activity ) Consideration of level of surgery-specific risk Type of surgery Degree of hemodynamic stress

49. Cardiac Event Risk Stratification High Risk ( > 5% ) Emergent major operations, particularly in the elderly Aortic and other major vascular Peripheral vascular Anticipated prolonged surgical procedures associated with large fluid shifts and/or blood loss

50. Cardiac Event Risk Stratification Intermediate Risk ( < 5% ) Carotid endarterectomy Head and neck Intraperitoneal and intrathoracic Orthopedic Prostate

51. Cardiac Event Risk Stratification:Patients w/ Intermediate Predictors Patients with moderate/excellent functional capacity can generally undergo intermediate-risk surgery Consider further noninvasive testing Poor functional capacity/intermediate-risk surgery Moderate functional capacity/high-risk surgery

52. Intermediate Predictors

53. Minor Predictors of Increased Perioperative Cardiovascular Risk Advanced age Abnormal ECG Rhythm other than sinus Low functional capacity Uncontrolled systemic hypertension

54. Noncardiac Surgery:CABG within Five Years Stable clinical status without recurrent symptoms/signs of ischemia Further cardiac testing generally not necessary

55. Noncardiac Surgery:Stable Angina/CABG > 5 Years Coronary evaluation within past two years? Favorable findings Usually not necessary to repeat testing unless there has been a change in symptoms

56. Cardiac Event Risk Stratification:Patients w/ Minor Predictors Noncardiac surgery generally safe Further testing on an individual basis ( patients with several minor clinical predictors facing higher-risk operations, ie vascular surgery )

57. Minor Predictors

58. Management of Specific Preoperative Cardiovascular Conditions

59. Noncardiac Surgery: Hypertension Severe hypertension should be controlled before surgery when possible Continuation of preoperative antihypertensive treatment through the perioperative period is critical

60. Hypertension Perioperative swings of pressure often occur in hypertensive patients Patients who are adequately treated preoperatively have less marked deviations of blood pressure Surges of BP most common during: Induction Intubation Skin incicision 12 to 24 hours post-op

61. Noncardiac Surgery:Valvular Heart Disease Indications for evaluation/treatment identical to those in nonoperative setting Symptomatic stenotic lesions associated with risk of perioperative CHF/shock Symptomatic regurgitant lesions usually better tolerated perioperatively

62. Patients on Anticoagulants Preop Risk of surgical hemorrhage vs. danger of serious embolization

63. Patients on Anticoagulants PreopLow Risk for Thromboembolism Discontinue coumadin 3 days preop Restart coumadin postop

64. Patients on Anticoagulants PreopHigh Risk for Thromboembolism Discontinue coumadin 3 days preop Begin heparin by constant infusion, maintaining PTT 1.5 - 2.5 X control Discontinue heparin 6 - 8 hrs preop Shortly after surgery, restart IV heparin and po coumadin Discontinue heparin infusion when PT is therapeutic Low molecular weight heparin may be used as an alternative agent to IV fractionated heparin

65. Patients on Coumadin PreopRisk for Thromboembolism Higher Risk Atrial fibrillation with structural heart disease Prosthetic mitral valve with or without a fib Prosthetic aortic valve with a fib Lower Risk Atrial fibrillation without structural heart disease Prosthetic aortic valve with sinus rhythm and normal ejection fraction

66. The optimal management of patients with known coronary artery disease remains complex.

67. Noncardiac Surgery:Medical Rx of CAD Continuation of preoperative medications into the operative and postoperative period recommended for ischemic protection Beta blockers reduce the incidence of postoperative ischemia

68. Beta Blockade in Patients Undergoing Major Vascular Surgery Randomized trial of 112 patients Started on bisoprolol one week prior to surgery Followed for 30 days Cardiac complication rate/placebo: 33.9% Cardiac complication rate/bisoprolol: 3.4% Poldermans D. NEJM 1999;341:1789-1794

69. Noncardiac Surgery:Intraoperative Nitroglycerin Insufficient data on use of prophylactic intraoperative nitroglycerin Vasodilatory properties when combined with anesthetic agent may lead to hypotension and ischemia Hemodynamic effects of other agents needs to be considered

70. Noncardiac Surgery:Congestive Heart Failure Patients with preop CHF are at increased risk for postoperative exacerbation Treatment of manifestations of heart failue before surgery may reduce complication rates Overdiuresis may lead to hypotension New onset of CHF in patients without prior history suggests postop MI

71. Noncardiac Surgery:Arrhythmias & Conduction Abnormalities Careful evaluation for underlying cardiopulmonary disease, drug toxicity, or metabolic abnormality Indications for antiarrhythmic therapy and cardiac pacing identical to those in the nonoperative setting

72. Noncardiac Surgery:Evaluation of Pulmonary Function Patients scheduled for thoracic surgery Patients scheduled for upper abdominal surgery Patients w/ history of heavy smoking/cough Obese patients Patients > 70 years of age Patients with pulmonary disease Value of routine PFT�s remains controversial NEJM 1999;340:937

73. PFT�s: Indicators of High Risk Morbidity/Mortality Spirometric Maximal breathing capacity < 50% predicted FEV1 < 2.0 liters Arterial Blood Gases Arterial PCO2 > 45 mm/hg Hypoxemia not reliable

74. Noncardiac Surgery:Anesthetic Agent Choice should be left to the discretion of the anesthesia care team Opiod-based anesthetics popular because of cardiovascular stability, but high doses result in postoperative ventilation All inhalational agents have cardiovascular effects

75. Any anesthetic technique that does not effectively eliminate pain will be associated with markedly increased cardiac demands

76. Noncardiac Surgery:Anesthetic Agent Neuraxial Techniques Spinal and epidural anesthesia Cause sympathetic blockade Infrainguinal procedures associated with mininal hemodynamic changes Abdominal procedures may result in more profound effects: hypotension/reflex tachycardia

77. Noncardiac Surgery:Anesthetic Agent Monitored Anesthesia Local anesthesia supplemented by intravenous sedation/analgesia Failure to produce complete anesthesia may lead to increased stress response producing myocardial ischemia

78. Noncardiac Surgery:Perioperative Pain Management Patient-controlled intravenous and/or epidural analgesia Reduces severity and duration of postoperative pain Reduction in postoperative catecholamine surges and hypercoagulability Theoretically may decrease myocardial ischemia

79. Noncardiac Surgery:Pulmonary Artery Catheters Patients most likely to benefit Recent MI complicated by CHF Patients with significant CAD undergoing procedures associated with significant hemodynamic stress Patients with systolic/diastolic dysfunction, cardiomyopathy, and valvular disease undergoing high-risk operations

80. Noncardiac Surgery: Postop Ischemia Myocardial ischemia more common, more severe in early postoperative phase Infarction is frequently silent Non-Q MI often occurs on the first or second postoperative days Q-wave MI often occurs on the second to fourth postoperative days CHF/pulmonary edema commonly occurs on postop day 2 or later

81. Noncardiac Surgery:Surveillance for Perioperative MI Few studies have examined the optimal method Indicators of ischemia Clinical symptoms ECG changes Elevation of cardiac enzymes

82. Noncardiac Surgery:Surveillance for Perioperative MI Patients without known CAD: surveillance should probably be restricted to patients with signs of cardiovascular dysfunction Patients with known or suspected CAD undergoing high-risk procedures: baseline, then serial ECG�s recommended Cardiac enzymes reserved for patients with evidence of cardiovascular dysfunction

83. Noncardiac Surgery:ST-Segment Monitoring ST changes indicating myocardial ischemia are strong predictors of perioperative MI in patients at high clinical risk Postoperative ischemia is a significant predictor of long-term MI/cardiac death ST depression in low-risk patients may be a nonspecific finding

84. Noncardiac Surgery:Postop Rx and Long-Term Management Assessment and management of modifiable risk factors for cardiovascular disease May be first opportunity for a systematic cardiovascular evaluation in many patients Patients who experience repetitive postop myocardial ischemia and/or myocardial infarction are at substantially increased risk