Epidemiology of Noncardiac Surgery

1. Epidemiology of Noncardiac Surgery Dr. Mohammed Naser

3. Overview • Important Decision points: • Urgent vs Elective Surgery • High risk surgery vs intermediate vs low -Active Cardiac Condition vs non-active Functional capacity on basis of pt ablility To perform certain activities

4. The Search For High Risk

5. Methods for Assessing Risk Pre-Operatively Is the surgery emergency PROCEED and manage post operatively according to AHA& ACC guidelines

6. If the surgery emergency..??

7. Active/Major Cardiac Conditions • Unstable Coronary Conditions • Decompensated CHF • Significant arrhythmias (i.e. 3⁰HB, new Vtach) • Severe Valvular Disease (aortic stenosis >40 mm hg gradient or valve area <1.0cm₂)???????

8. Non-Active Cardiac Factors • Intermediate Risk • Hx of CHD • History of prior CHF • Hx of stroke • Diabetes • Renal insufficiency • Minor Risk* • Age > 70 • Abnormal ECG • Nonsinus rhythm • Uncontrolled systolic BP * Not associated with cardiac risk

9. Six Independent predictors of cardiac risk • ischemic heart disease • congestive heart failure 3) cerebrovascular disease 4) high risk surgery (AAA, orthopedic sx) 5) pre-operative insulin tx for diabetes 6) preoperative creatinine for creat > 2 mg/dL Lee et al

10. Functional capacity

11. Functional Capacity • Functional status has shown to be a reliable periop and long-term predictor of cardiac events • MET: metabolic equivalent resting oxygen consumption of 70 kg, 40 yr old man at rest • Periop risk is increased if person cannot > 4 METS

12. Moderate recreational golf, dancing, baseball Strenuous sports swimming, basketball DO light house work i.e. Washing dishes Climb a flight of stairs Run a short distances Eat, dress 10 MET 1 MET 4 MET

13. The Trump Card: Functional Capacity • Perioperative cardiac risk is increased in patients unable to exercise 4 METs • Functional capacity can be estimated in the office • Energy expenditure for eating, dressing, walking around house, dishwashing ranges from 1-4 METs • Climbing a flight of stairs, running a short distance, scrubbing floors, and golf ranges from 4-10 METs • Swimming and singles tennis exceeds 10 METs

14. Surgery Risk Type

15. Surgery-Specific Risk: High Risk* • Major emergency surgery • Vascular surgery including: aortic surgery, infra-inguinal bypass • Prolonged surgery with large fluid shifts or blood loss * Reported risk of cardiac death or nonfatal MI >5%

16. Stepwise Approach • Step 1: Determine urgency of surgery • Step 2: Active cardiac condition?-→test • Step 3: Undergoing low-risk surgery? < 1%* • Step 4: Good functional capacity? *Combined morbidity and mortality < 1% even in high risk patients

17. The Catheterization Questions to Ask Yourself • Does this patient have symptomatic coronary disease that will have a mortality benefit from revascularization now? • Am I willing to send the patient to CABG? • Am I doing this just to know the anatomy?

18. Is pre-op coronary revasc advantageous? • If high risk surgery and patient has active cardiac issue • Functional test and perfusion Imaging and if • L main 50% or 3 VD, 2VD + LAD Prox, LVEF < 20%, aortic stenosis – consider revasc pre-op

19. STENTS If upcoming Sx is known then PTCA alone or BMS with 4-6 wks dual antiplatelet tx after If received DES.... • 1) postpone sx until > 12 months, • 2) do sx on both asa+clop • 3) do sx on single ap tx

20. Use of a DES for coronary revascularization before imminent or planned non cardiac sx that will necessitate d/c of antiplatelet agents is not recommended

21. Medical tx 1) beta blockers-if on keep them if not.... 2) Statins continue, ? Start -need randomized trials

22. Other Issues • DVT/PE prophylaxis • Anesthetic technique-volatile agent with general anesthetic - ↓ troponin ↑ LV function >> propofol, midazolam, balanced anesthesia (Grade B) • No evidence that epidural anesthesia >>general anesthesia for cardiac outcomes • Routine troponin monitoring not recommended

23. Surveillance for Perioperative Myocardial Infarction • ECGs • All intermediate and high-risk patients should get a post-op ECG. • As need for signs or symptoms of ischemia • Troponin / CK • In patients with signs or symptoms of ischemia • Do not do screening biomarkers

24. High Risk Features • Severe obstructive or restrictive pulmonary disease • Diabetes • Renal impairment • Anemia, polycythemia, thrombocytosis

25. PCI pre-op • ST-elevation MI • Unstable angina • Non ST elevation MI

26. 2007 ACC/AHA Perioperative Guidelines

27. Take Home Messages

28. Take Home Messages • Unstable syndromes require management prior to surgery. Look for • Unstable angina • Signs of heart failure • Stenotic valve lesions • Ventricular arrhythmias • Functional tolerance is the best single predictor of outcome • Be very specific in your history (one step at at time, regular or slow pace, etc) • If patient on beta blockers & statins continue them, more trials to mandate them • PCI/CABG only if patient needs it independent of surgery. Think twice because of stent data and delays.