Controversies in Perioperative Medicine

Transcription

1 Controversies in Perioperative Medicine Staying Abreast & Ahead of the Guidelines Hugo Quinny Cheng, MD Division of Hospital Medicine University of California, San Francisco

2 Controversies in Perioperative Medicine Preoperative Cardiac Evaluation Guidelines: Preoperative stress testing Coronary stents in the surgical patient Medical management: β-blockers & statins Other Updated Guidelines: Endocarditis Prophylaxis Perioperative Anticoagulation

3 Revised Cardiac Risk Index The New Standard Cardiac Risk Index Predictors: Higher risk operation* Ischemic heart disease Congestive heart failure Diabetes requiring insulin Creatinine > 2 mg/dl Stroke or TIA Predictors Complications** 0 0.5% 1 1.3% 2 4% 3 or more 9% * Defined as intraperitoneal, intrathoracic, or suprainguinal vascular surgery ** Defined as MI, pulmonary edema, cardiac arrest, complete heart block Lee, et al. Circulation, 1999

4 Question 1: Utility of Stress Testing A 68 y.o. man will undergo open repair of a 6-cm abdominal aortic aneurysm. He has no cardiac history and can walk 2 blocks at normal pace. He has long-standing diabetes & HTN. Meds: PEx: ECG: lovastatin, atenolol, insulin, benazepril, ASA BP=115 / 70 HR=60; normal heart & lung exam NSR, LVH, otherwise normal Should this patient undergo a preoperative stress test?

5 73 y.o. man s/f repair of AAA. No cardiac history, but has long-standing diabetes & HTN. ECG: LVH only Should this patient undergo a preoperative stress test? 1. Go to O.R. without further preoperative testing 2. Noninvasive stress test prior to surgery

6 Noninvasive Stress Testing Predictive value of Stress Testing: Mainly studied in vascular surgery patients Strong negative predictive value ~ 98% (neg LR = ) Weak positive predictive value ~ 10-20% (pos LR = 2-3) Adds little information to lower risk patients More useful for cases with increased risk

7 2002 (old) ACC/AHA Guideline Perform stress test in patients with at least 2 of the following: 1) Cardiovascular disease or diabetes 2) Undergoing high risk surgery major vascular surgery prolonged surgery with major fluid shifts or blood loss 3) Poor functional capacity cannot walk 2 blocks at normal pace or climb a flight of stairs carrying 10 lbs. load

8 2007 ACC/AHA Guideline Good Functional Capacity? no or? yes Go to OR no predictors* 1 or 2 predictors 3 predictors Go to OR * CAD, CHF, DM, CKD, CVA/TIA Control HR & go to OR (IIa) no or (IIb) Vascular surgery? yes Consider stress test if results will change management (IIa)

9 770 vascular patients with 1 or 2 of following: Age > 70, MI, angina, CHF, DM, stroke / TIA, Cr > 1.8 No stress test (n = 384) Stress test (n = 386) 30-day CV Death or MI 1.8% 352 with no or limited ischemia 34 with extensive ischemia (9%): 12 had PCI or CABG 1.1% 15% oldermans et al. JACC, %

10 Preoperative Revascularization in High-Risk Patients (DECREASE-V pilot) 101 patients undergoing vascular surgery, all with: 3 risk predictors for cardiac complications & Extensive ischemia on DSE or P-Mibi 1. Coronary angiogram 2. CABG or PCI 3. Medical Management Medical management alone Endpoint: Cardiac Death or Nonfatal MI Poldermans, et al. JACC, 2007

11 Extensive Ischemia Predicts High Risk 40% Death or MI 30% 20% 10% 0% Revascularization + Medical Mgt Medical Management Poldermans, et al. JACC, 2007

12 Stress Testing Conclusions Current Guidelines: Recommend stress test mainly for vascular surgery patients with 3 or more risk predictors & poor functional status if results will change management Current Evidence: Limited ischemia predicts acceptable risk with careful medical management Extensive ischemia in vascular patients predicts high risk that may not be modifiable -- will you cancel surgery?

13 Question 2: Coronary Stents A woman falls and suffers a cervical spine fracture. One month ago, she received a sirulimus-eluting stent for stable angina. The neurosurgeon won t operate unless aspirin and clopidogrel are held for her surgery. Non-operative management in a halo for next 2 months is offered as an alternative. What do you recommend to the patient & surgeon?

14 Patient with recently placed drug-eluting stent has a c-spine fracture. Surgeon won t operate unless aspirin & clopidogrel are held perioperatively. 1. Hold ASA & clopidogrel 2. Hold ASA & clopidogrel but bridge with heparin 3. Keep her in a halo for next 2 months

15 Beware of Coronary Stents Risk Factor for Cardiac Mortality (192 patients having surgery after stenting) Cardiac Death RF + RF - Early Surgery Bare-metal stent < 4 wk Drug-eluting stent < 3-6 mo Antiplatelet drugs held for surgery 13% 5.5% 0.6% 0% Antiplatelet drugs held & early surgery (versus continued therapy & early surgery) 31% 0% Schouten O, et al. JACC, 2007

16 Does Heparin Bridge Prevent Stent-related Complications? Prospective study of 103 patients with coronary stent placed within 12 months having noncardiac surgery Antiplatelet drugs continued or held < 3 days All patients received therapeutic heparin drip or enoxaparin 1 mg/kg SQ daily 14% of patient stented within 35 days of surgery suffered cardiac death or MI, or needed re-do PCI 4% of all patients suffered excessive bleeding

17 2007 ACC/AHA Guidelines If surgery is anticipated in the next 12 months, patients who need PCI should have balloon angioplasty or a bare metal stent instead of a drug eluting stent Delay elective surgery requiring stopping antiplatelet agents in patients with recent PCI: Balloon angioplasty: 4 weeks Bare metal stent: 4-6 weeks Drug eluting stent: 12 months If clopidogrel must be stopped, try to continue ASA No established role for bridging anticoagulants

18 Question 3: Beta-blockers A 75 y.o. woman will undergo removal of hardware from an infected hip prosthesis tomorrow. She has a history of diabetes and a remote stroke, but no current cardiovascular symptoms. 1. Definitely start β-blocker 2. Probably start β-blocker 3. Probably avoid β-blocker 4. Definitely avoid β-blocker

19 2006 ACC/AHA Guidelines for β-blockers Definite indications (class I): Already using β-blocker to treat angina, HTN, arrhythmia Patients with ischemic potential having vascular surgery Probable indications (class IIa): CAD or multiple risk predictors* in vascular or other intermediate-to-high risk operation Possible indications (class IIb): All vascular surgery patients Single risk predictor* in any intermediate-high risk surgery *Predictors: Coronary disease, CHF, renal insufficiency, diabetes

20 Casting Doubt on β-blockers Diabetic Postoperative Mortality & Morbidity (DIPOM): 921 diabetic patients not previously on β-blocker undergoing major surgery Metoprolol XL or placebo started immediately before surgery, continued for maximum 8 days No difference in fatal or nonfatal cardiac outcomes 5% placebo vs. 6% metoprolol at 30 days Bradycardia & hypotension more common in treated pts. Juul et al. BMJ, 2006

21 Relationship Between Heart Rate and Complications How Low Should We Go? Retrospective review found lower pulse predicts better outcome in β-blocked vascular surgery patients Poldermans et al. JACC, 2006

22 POISE: PeriOperative Ischemia Evaluation 8351 patients with s/f major noncardiac surgery CAD, CHF, CVA/TIA, CKD, DM, or high-risk surgery Not already taking β-blocker Metoprolol XL (immediately preop until 30 days postop) Placebo Patients followed for 30 days after surgery: Serial ECG and cardiac enzymes 1 Endpoint: cardiac mortality & nonfatal arrest or MI Poise Study Group. Lancet, 2008

23 POISE: Treatment Protocol 2-4 h OR 0-6 h 12 h 1st dose Metoprolol 100 mg XL* 2nd dose Metoprolol 100 mg XL* 3rd & daily dose Metoprolol 200 mg XL*^ * Study drug held for SBP < 100 or HR < 50 ^ Daily dose reduced to 100 mg if persistent bradycardia or hypotension

24 POISE: Results 8% 7% 6% 5% 4% 3% 2% 1% 6.9% 5.8% Placebo Metoprolol XL 3.1% 2.3% Metoprolol XL: Reduced cardiac events (mostly nonfatal MI) but Increased risk of stroke & total mortality 0% CV Death, Cardiac Arrest, Nonfatal MI Total Mortality Poise Study Group. Lancet, 2008

25 β-blockers: Where Are We Now? Beta-blockade does prevent perioperative cardiac complications in higher risk patients Real risk of clinically important hypotension and bradycardia, causing stroke & other complications Aggressive beta-blockade immediately prior to surgery may increase risk Risk-to-benefit ratio unfavorable for many patients

26 UCSF Recommendations in 2008 Definite indications: Already using β-blocker to treat angina, HTN, arrhythmia Patients with ischemic potential having vascular surgery Possible indications: Patients with ischemic potential having high-risk nonvascular surgery (e.g., > 5 hours or > 500 cc blood loss) Multiple risk predictors* in vascular or other high-risk surgery (*Coronary disease, renal insufficiency, diabetes) Titrate dose up gradually (rarely start immediately preop)

27 Can Statins Prevent Perioperative Cardiac Complications? Systematic Review of Observational Studies: Statins associated with lower mortality (OR = 0.7) and fewer postoperative MI after noncardiac surgery Danger of Statin Withdrawal? Cohort study of 298 vascular surgery patients on statins Interruption of statin treatment associated with higher risk of cardiac death and MI (hazard ratio = 7) Effect persisted after controlling for confounders and propensity score Kapoor, AS et al. BMJ, 2006 Schouten, O et al. Am J Cardiol, 2007

28 DECREASE III 497 statin naive patients s/f vascular surgery Fluvastatin XL 80 mg/day Started > 1 month preop Continued > 1 mo postop Placebo Patients followed for 30 days after surgery: 1 Endpoint: myocardial ischemia (ECG or troponin) 2 Endpoint: cardiac death or nonfatal MI Poldermans et al. Presented at ESC, 2008

29 DECREASE III: Results 20% 15% 10% 19.0% 10.9% Placebo Fluvastatin XL 10.1% Fluvastatin XL: Reduced the composite outcome of cardiac death & nonfatal MI 5% 4.8% No difference in rates of LFT or CPK elevation 0% Myocardial Ischemia Cardiac Death or MI Poldermans et al. Presented at ESC, 2008

30 Statins: 2007 ACC/AHA Guideline Definite indications (class I): Continue statin if already taking prior to surgery Probable indications (class IIa): All vascular surgery patients Possible indications (class IIb): At least one risk predictor* in any intermediate risk surgery *Coronary disease, renal insufficiency, diabetes, CVA/TIA

31 Question 4: Endocarditis Prophylaxis 50 y.o. woman with moderate calcific aortic stenosis should get endocarditis prophylaxis when undergoing which of the following procedures? 1. Major oral surgery 2. Hemicolectomy 3. Cholecystectomy 4. All of the above 5. None of the above

32 Endocarditis Prophylaxis: 2007 AHA Guideline Key Points of 2007 AHA Guideline: Bacteremia from daily activities more likely to cause IE than procedures Prophylaxis can prevent very few cases of IE Limits prophylaxis to conditions with high risk for poor outcomes from IE Limits prophylaxis to dental/oral/respiratory tract procedures

33 Indications for IE Prophylaxis High risk cardiac conditions: Prosthetic valve (mechanical or biological) Prior endocarditis Cyanotic congenital heart disease if unrepaired, incompletely repaired, or repaired with prosthetic material within prior 6 months Heart transplant with post-transplant valvulopathy Procedures: Dental procedure manipulating gingival tissue or periapical region of teeth or perforating of the oral mucosa

34 IE Prophylaxis for Dental Procedures Preferred: Amoxicillin 2 gm p.o. Allergy to penicillin/ampicillin: Cephalexin 2 gm p.o. Clindamycin 600 mg p.o. Azithromycin 500 mg p.o. or Clarithromycin 500 mg p.o. Parenteral route needed: Ampicillin 2 gm IM or IV Cefazolin 1 gm or Ceftriaxone 1 gm IM or IV Clindamycin 600 mg IM or IV All regimens given as single dose, min before procedure

35 Question 5: Perioperative Anticoagulation Two patients who take coumadin underwent THA. One has atrial fibrillation due to HTN. The other has a mechanical AVR. Neither has a history of stroke or any other comorbidity. Coumadin is being restarted. How should their anticoagulation be managed?

36 Two patients who take coumadin underwent THA. One has AF due to HTN. The other has a mechanical AVR. Neither has a history of stroke any other comorbidity. 1. Heparin bridge for AVR only 2. Heparin bridge for AF only 3. Heparin bridge for both 4. Heparin bridge for neither

37 Thromboembolic Risks with Non-rheumatic Atrial Fibrillation 7% Annual Stroke Risk 6% 5% 4% 3% 2% 1% 0% Without Coumadin With Coumadin Albers et al. Chest, 2001

38 Effect of Comorbidity on Thromboembolic Risk in Atrial Fibrillation CHADS2 Score: 1 point each for CHF, HTN, Age>75, Diabetes and 2 points for Stroke/TIA Score 0-2: < 5% annual stroke risk Score 3-4: 5-10% Score 5-6: > 10%

39 Thromboembolic Risks with Mechanical Valves 7% Annual Incidence 6% 5% 4% 3% 2% 1% Valve Thrombosis Embolism 0% Without Coumadin With Coumadin Cannegieter, et al. Circulation, 1994

40 Effect of Mechanical Valve Location & Design on Thromboembolic Risk Valve Location: Aortic RR = 1.0 Mitral RR = 1.8 Valve Design: Caged Ball RR = 1.0 Tilting Disk RR = 0.7 Bi-leaflet RR = 0.6 Cannegieter, et al. Circulation, 1994

41 Perioperative Anticoagulation: 2008 ACCP Guidelines Atrial Fib. CHADS2 = 5-6; recent CVA; rheumatic AF CHADS2 = 3-4 CHADS2 = 0-2 Mechanical Valve Any MVR; older (cagedball or tilting disc) AVR; recent CVA Bileaflet AVR plus one additional stroke risk Bileaflet factor AVR without AF or other stroke risk factor Recommendation Full dose heparin bridge Full or low dose heparin bridge Low dose or no heparin bridge Full dose = therapeutic dose of heparin IV or LMWH SC Low dose = DVT prophylaxis dose of heparin SC or LMWH SC