Preoperative Assessment of the Cardiac Patient for Non-cardiac Surgery

1. Preoperative Assessment of the Cardiac Patient for Non-cardiac Surgery John R. Butterly, M.D. Dartmouth-Hitchcock

2. Overview of ischemic heart disease General considerations Anesthetic Operative Clinical assessment Predictors of risk Clinical Procedural Disease specific states CAD, hypertension, CHF, valvular Preoperative therapy Issues Dartmouth-Hitchcock

3. Bottom Line • Indications for evaluation/intervention are the same as in the general population • Pre-operative evaluation should be seen as an opportunity to provide recommendations for care over the long-term as well as the immediate, peri-operative period • Intervention is rarely necessary to lower the risk of non-cardiac surgery Dartmouth-Hitchcock

4. Overview of Ischemic Heart Disease • Anatomy • Physiology • coronary • left ventricular • patient Dartmouth-Hitchcock

5. Supply blood O2 carrying capacity cardiac output systemic vascular resistance coronary resistance (Poiseuille) Demand Major determinants of MVO2 systolic work heart rate blood pressure (afterload) duration of systole ventricular wall tension (LaPlace) contractility myocardial mass Etiology of Ischemia T = PR coronary resistance ~ 1/R4 Dartmouth-Hitchcock

6. Ischemia vs Infarction • Implications of demand related problem vs supply related problem • stability • biology • endothelial function • plaque rupture/thrombosis Dartmouth-Hitchcock

7. General Considerations • A substantial proportion of all deaths in most series of non-cardiac operations arise from cardiovascular complications. • Stresses to cardiovascular system • decrease in myocardial contractility & respiration • fluctuations in temperature, afterload, preload, blood volume, & autonomic nervous system output Dartmouth-Hitchcock

8. General Considerations • Possible complications of anesthesia & surgery may impose additional burdens • hemorrhage • infection • pulmonary embolism • myocardial infarction Dartmouth-Hitchcock

9. Anesthetic Considerations • Factors influencing cardiovascular function • direct effect of anesthetic agent on heart • indirect effects mediated through the autonomic nervous system • level of ventilation • hypoxia • hypercarbia • acidosis Dartmouth-Hitchcock

10. General inhalation intravenous muscle relaxants Spinal/Epidural hemodynamic consideration Anesthetic Agents The skill & experience of the anesthesiologist, including the ability to monitor hemodynamics & respond quickly, are far more important than the specific agent used. Dartmouth-Hitchcock

11. Case Study • Fragilina Moribundi is a 93 yo, pleasantly demented woman who presents to your office speaking fluent diabinase. She is referred for pre-operative cardiac evaluation prior to her planned cataract surgery. • She has a history of a systolic murmur, and is s/p IMI in the distant past. • Her history is contributory only in the absence of sx’s suggestive of active ischemia or LV dysfunction • Her exam is remarkable for findings c/w severe aortic stenosis • Her EKG shows findings c/w OIMI Dartmouth-Hitchcock

12. Case Study • Appropriate actions/evaluation would include • stress testing with imaging to risk stratify and rule out active ischemia Dartmouth-Hitchcock

13. Case Study • Appropriate actions/evaluation would include • stress testing with imaging to risk stratify and rule out active ischemia • echocardiography to evaluate the severity of the aortic stenosis and baseline LV function Dartmouth-Hitchcock

14. Case Study • Appropriate actions/evaluation would include • stress testing with imaging to risk stratify and rule out active ischemia • echocardiography to evaluate the severity of the aortic stenosis and baseline LV function • cardiac catheterization with an eye towards balloon valvuloplasty, if severe aortic stenosis is confirmed, as a bridge to get her through the proposed surgery Dartmouth-Hitchcock

15. Case Study • Appropriate actions/evaluation would include • stress testing with imaging to risk stratify and rule out active ischemia • echocardiography to evaluate the severity of the aortic stenosis and baseline LV function • cardiac catheterization with an eye towards balloon valvuloplasty, if severe aortic stenosis is confirmed, as a bridge to get her through the proposed surgery • a discussion with the PCP re: the indications for the proposed surgery, and clearance for same with appropriate precautions Dartmouth-Hitchcock

16. Case Study • Mrs. Moribundi does well with her cataract extraction, but 2 months later presents to the ER with evidence for total bowel obstruction and free air under the diaphragm. You are emergently consulted by the general surgeons who want to take her to the OR. • Appropriate actions include: • emergency echocardiogram to evaluate status of valve and ventricle Dartmouth-Hitchcock

17. Case Study • Mrs. Moribundi does well with her cataract extraction, but 2 months later presents to the ER with evidence for total bowel obstruction and free air under the diaphragm. You are emergently consulted by the general surgeons who want to take her to the OR. • Appropriate actions include: • emergency echocardiogram to evaluate status of valve and ventricle • trip to the cath lab for emergency balloon valvuloplasty Dartmouth-Hitchcock

18. Case Study • Mrs. Moribundi does well with her cataract extraction, but 2 months later presents to the ER with evidence for total bowel obstruction and free air under the diaphragm. You are emergently consulted by the general surgeons who want to take her to the OR. • Appropriate actions include: • emergency echocardiogram to evaluate status of valve and ventricle • trip to the cath lab for emergency balloon valvuloplasty • trip to the cath lab for IABP placement prior to surgery Dartmouth-Hitchcock

19. Case Study • Mrs. Moribundi does well with her cataract extraction, but 2 months later presents to the ER with evidence for total bowel obstruction and free air under the diaphragm. You are emergently consulted by the general surgeons who want to take her to the OR. • Appropriate actions include: • emergency echocardiogram to evaluate status of valve and ventricle • trip to the cath lab for emergency balloon valvuloplasty • trip to the cath lab for IABP placement prior to surgery • discussion with anesthesia re: optimal peri-operative management/hemodynamic monitoring Dartmouth-Hitchcock

20. The Operation • Type • in general, surgical mortality is 25-50% higher in patients with underlying cardiovascular conditions compared to patients with normal cardiac function. • ophthalmologic surgery & TURP almost always safe • highest cardiovascular complication rates seen in vascular surgery • AAA • aortic cross-clamping, major fluid & electrolyte shifts • carotid / peripheral surgery • co-existing CAD, clinical underestimation of severity Dartmouth-Hitchcock

21. The Operation • Duration • correlation is general and mostly related to type of operation • exceptions • operative time prolonged due to complication • operation > 5 hours Dartmouth-Hitchcock

22. Cardiac Risk for Noncardiac Surgical Procedures • High (reported cardiac risk > 5%) • emergent major operations, esp. in elderly • aortic and other major vascular procedures • peripheral vascular procedures • anticipated prolonged procedure with large fluid shift/blood loss Dartmouth-Hitchcock

23. Cardiac Risk for Noncardiac Surgical Procedures • Intermediate (reported cardiac risk < 5%) • carotid endarterectomy • head and neck • intraperitoneal & intrathoracic • orthopedic • prostate Dartmouth-Hitchcock

24. Cardiac Risk for Noncardiac Surgical Procedures • Low (reported cardiac risk < 1%) • endoscopic procedures • superficial procedure • cataract • breast Dartmouth-Hitchcock

25. Case Study • Mr. A. Jean Jacques is a 58 year old gentleman referred for pre-operative evaluation because of one isolated PVC seen on a pre-op EKG. He is scheduled for nephrectomy for a renal mass the following morning He has no cardiac history of which he is aware. His only risk factor is that of a history of 3 years of smoking in college. Dartmouth-Hitchcock

26. Case Study • He considers himself fit, and is proud of being in good physical condition. He plays full court basketball on Saturdays, and wins. He climbed Mount Washington in October and was pleased that a few of his sons friends could not keep up with him. He denies dyspnea or chest discomfort, and his exam is remarkable in that he looks fit and has a resting pulse of 52 on no medications. Dartmouth-Hitchcock

27. Case Study • Appropriate next steps include • routine stress testing to risk stratify and rule out occult ischemia Dartmouth-Hitchcock

28. Case Study • Appropriate next steps include • routine stress testing to risk stratify and rule out occult ischemia • 24 hour Holter monitor to evaluate burden of ventricular ectopy Dartmouth-Hitchcock

29. Case Study • Appropriate next steps include • routine stress testing to risk stratify and rule out occult ischemia • 24 hour Holter monitor to evaluate burden of ventricular ectopy • echocardiogram to rule out unsuspected LV dysfunction Dartmouth-Hitchcock

30. Case Study • Appropriate next steps include • routine stress testing to risk stratify and rule out occult ischemia • 24 hour Holter monitor to evaluate burden of ventricular ectopy • echocardiogram to rule out unsuspected LV dysfunction • clear for surgery with no recommendations for further cardiac evaluation Dartmouth-Hitchcock

31. Clinical Assessment • History • Single most important part of evaluation to determine level of cardiovascular risk • Identify presence of cardiac condition • Evaluate severity, stability • Identify risk factors, co-morbid conditions • Determination of individual functional capacity • Taking a history for angina Dartmouth-Hitchcock

32. The asymptomatic patient • Silent ischemia • “active” silent ischemia • Type I - absence of any sx despite the presence of CAD & provocable ischemia (defective anginal warning system) • Type II - sx’s generally present, but patient also has silent episodes • “passive” silent ischemia • sedentary patient • patient limited for other reasons Dartmouth-Hitchcock

33. 1 MET Can you take care of self? Eat, dress, use toilet? Walk indoors in house? Walk a block or two on level at 2-3 mph? Do light housework like dusting or dishes? 4 METs 4 METs Climb a flight of stairs, walk up hill? Walk on level at 4 mph? Run a short distance? Heavy housework Golf, bowling, dancing, doubles tennis Swimming, singles tennis football, basketball, skiing >10 METs Functional Capacity Dartmouth-Hitchcock

34. Clinical Assessment • Physical examination • general appearance • evidence for CHF • evidence for PVD • heart sounds, murmur Dartmouth-Hitchcock

35. Clinical Assessment • Co-morbid conditions • pulmonary • diabetes mellitus * • renal impairment • hematologic disorders Dartmouth-Hitchcock

36. Clinical Assessment • Ancillary studies • CBC, PT/PTT, blood chemistry (electrolytes, BUN, creatinine) • ECG • CXR ?? Dartmouth-Hitchcock

37. Case Study • Alvin Falfa is a 63 yo dairy farmer from the Northeast Kingdom. He was discharged from North Country Hospital 3 weeks ago having sustained an uncomplicated, non-Q MI. He has been slowly increasing his activity and is asx. He was incidently found to have an iron deficiency anemia during his hospitalization, and this was felt to be the cause of his MI. Further w/u revealed a large, fungating mass in his cecum, biopsy positive for adenoCa. He is referred for pre-op evaluation prior to his right hemicolectomy which is scheduled for tomorrow morning. Dartmouth-Hitchcock

38. Case Study • Initial appropriate actions include: • postponement of the scheduled surgery Dartmouth-Hitchcock

39. Case Study • Initial appropriate actions include: • postponement of the scheduled surgery • stress testing for risk stratification and to determine whether or not there is inducible ischemia Dartmouth-Hitchcock

40. Case Study • Initial appropriate actions include: • postponement of the scheduled surgery • stress testing for risk stratification and to determine whether or not there is inducible ischemia • echocardiography to evaluate LV function Dartmouth-Hitchcock

41. Case Study • Initial appropriate actions include: • postponement of the scheduled surgery • stress testing for risk stratification and to determine whether or not there is inducible ischemia • echocardiography to evaluate LV function • cardiac catheterization with an eye towards intervention prior to abdominal surgery Dartmouth-Hitchcock

42. Case Study • Initial appropriate actions include: • postponement of the scheduled surgery • stress testing for risk stratification and to determine whether or not there is inducible ischemia • echocardiography to evaluate LV function • cardiac catheterization with an eye towards intervention prior to abdominal surgery • clearance for surgery after a discussion with anesthesia about appropriate peri-operative management/hemodynamic monitoring Dartmouth-Hitchcock

43. Clinical Predictors of Risk • Major • Unstable coronary syndromes • recent MI with evidence for ischemia • unstable or severe angina (Canadian class III or IV) • Decompensated CHF • Significant arrhythmia • high grade AV block • symptomatic ventricular arrhythmia (with organic disease) • supraventricular arrhythmia with uncontrolled rate • Severe valvular disease Dartmouth-Hitchcock

44. Clinical Predictors of Risk • Intermediate • Mild angina pectoris (Canadian class I or II) • Prior MI by history or pathological Q waves • Compensated or prior CHF • Diabetes mellitus • Renal insufficiency (creatinine > 2) Dartmouth-Hitchcock

45. Clinical Predictors of Risk • Minor • Advanced age • abnormal ECG (LVH, LBBB, ST-T change) • Rhythm other than sinus • Low functional capacity • History of stroke • Uncontrolled systemic hypertension Dartmouth-Hitchcock

46. Urgency of surgery Recent revascularization Recent coronary evaluation Major predictor of risk Intermediate predictor of risk functional capacity risk level of surgery Minor or no predictor of risk functional capacity risk level of surgery Determination of need for further cardiac testing Dartmouth-Hitchcock

47. Disease-Specific Approaches • Coronary Artery Disease • Hypertension • Congestive Heart Failure/Cardiomyopathy • Valvular Heart Disease • Arrhythmias & Conduction Defects • Pulmonary Vascular Disease Dartmouth-Hitchcock

48. Case Study • Hiram Wrisck is a 72 yo gentleman referred for evaluation prior to AAA. He describes himself as active, but his wife rolls her eyes behind his back when he says this. He has a positive history of hypertension and adult onset diabetes that recently became insulin dependent, but no history to suggest angina. A stress test done prior to his visit with you demonstrated 1.5mm ST depression in leads II, V4-6 at 4 METS (100 bpm) Dartmouth-Hitchcock

49. Case Study • Physical exam shows him to be an obese 72 year old man looking older than his stated age. He weighs 285#, pulse is 96 with frequent extra-systoles, BP 140/90 in right arm, 190/105 in left arm. The rest of the exam is remarkable for a II/VI SEM at the LSB, bilateral carotid and femoral bruits, and absent pedal pulses. Dartmouth-Hitchcock

50. Case Study • Appropriate next steps include • Repeat stress as a DSE to try to get a heart rate response closer to 85% PMHR Dartmouth-Hitchcock