Non-cardiac Surgery:Risk Assessment and Management Benico Barzilai, M.D., F.A.C.C. Section Head Clinical Cardiology Cleveland Clinic
Statement of the Problem The number of persons older than 65 years in the US will increase 25-35% over next 30 years Number of major noncardiac procedures will grow from 6 to 12 million in this group Intrabdominal,thoracic,vascular and orthopedic procedures have been associated with significant perioperative cardiovascular morbidity
Vision trial Over 15000 patients had fourth generation TroponinT six and 12 hours after surgery and days 1,2,and 3 One quarter over 75 years old and 20% major orthopedic surgery Elevated Trop T of at least 0.02 ng/ml in 11.6% of patients
Vision (continued) Troponin level Adj Hazard Ratio 0.02 2.41 0.03-0.29 5.00 0.30 or greater 10.48 Hazard ratio compared to reference group of undetectable troponin T of 30 day mortality
Role of the Consultant Identify conditions that need immediate treatment Clearing the patient without specific recommendations viewed as unhelpful Advising intraoperative monitoring and recommending specific type of anesthesia deemed unimportant by anesthesiologists
Active Cardiac Conditions Unstable coronary syndromes including recent MI Decompensated heart failure Significant arrhythmias High degree av block,ventricular or supraventricular arrhythmias Aortic or mitral stenosis
Revised Cardiac Index History of ischemic heart disease History of compensated or prior heart failure History of cerebrovascular disease Diabetes Mellitus Renal Insufficiency
Risk Factors and Risk
Stepwise Approach ACC 2009 Step one-does the patient have need for emergency noncardiac surgery? If yes proceed to surgery Optimize medical therapy Treat Hypertension, heart failure, heart rate
Step 2 Treat active cardiac conditions (CHF,ACS,valvular) per ACC/AHA guidelines Very important to look for these conditions Key role of the consultant to look for these conditions As an example if you are suspicious of a recent MI on ECG treat accordingly
Risk stratification for type of Surgery Vascular (>5%) Intermediate (1-5%) Low risk aortic surgery (e.g AAA) Intraperitoneal and intrathoracic Carotid Head and Neck Endoscopic Cataract Breast
Step 3 Is the patient undergoing low risk surgery? Proceed with surgery Many procedures have a morbidity and mortality rate less than 1% Remember patients with unstable coronary syndromes should still be treated accordingly Stent patients are a special category (discussed later)
Functional status Activities associated with less than 4 METSslow dancing, golfing with a cart,walking 2 to 3 mph Activites with more than 4 METScycling,climbing hills Ask can you walk up a flight of stairs,walk 4 MPH, moderate housework, walk four blocks
Step 4 Does the patient have a functional status with more than 4 METS without symptoms?-proceed to surgery. Multiple studies have shown excellent outcomes even in patients with multiple risk factors Consider beta blockade in appropriate patients e.g patients with history of CAD
Step 5 If the patient has poor or unknown functional status proceed to surgery if no risk factors (no DM,no CHF,no renal failure, no CAD, no hx of cerebrovascular disease If one or two risk factors continue with surgery or proceed with testing if it will change management Two studies have shown no difference proceeding with medical management (tight heart rate control)
Step 5 (continued) 3 or more risk factors Most studied is the vascular surgery population Class 2 indication to proceed with noninvasive testing but the level of evidence is poor In the nonvascular patient the level of evidence is very lacking but most authorities suggest proceeding with testing if it will change management
Assessment of LV function Class 2a- It is reasonable to assess LV function in patients with dyspnea of unknown origin It is reasonable to assess LV function in patients with known CHF for change in symptoms if not assessed in last 12 months Routine preoperative assessment is not indicated
Patients with Known CAD What is the ischemic threshold? What is the amount of myocardium at risk? What is the patient s ventricular function? Is medical therapy optimized?
Elective Coronary Revasularization (CARP) VA trial published in 2004 NEJM 5859 vascular surgery patients All patients cathed ; only enrolled if high grade lesion (left main disease excluded) Randomly assigned revascularization or proceeding to surgery No difference in postoperative MI or mortality at 2.7 years
Indications for Cardiac revascularization The guidelines emphasize the application of the ACC/AHA guidelines for revascularization to these patients-don t revascularize because the patient is going to noncardiac surgery Class 1 indications emphasize left main and triple vessel disease
Class I indications Stable angina and left main disease Stable angina and triple vessel disease (particularly in low EF) Two vessel disease with proximal LAD and low EF or ischemia on stress test Revasulariztion in patients with Unstable coronary ischemia or nonstemi STEMI
Stents Continue antiplatelet therapy and defer surgery for 4-6 weeks for bare metal stents (continue asa at time of surgery if possible ) Continue dual antiplatelet therapy for 12 months for DES (continue asa at time of surgery) Late stent thrombosis is still possible after 12 months
Perioperative Beta Blockade Poise trial-8351 patients received fixed dose metoprolol succinate 200 mg or placebo Drug started 2-4 hours prior to surgery Reduction in periop MI However increase in deaths at 30 days and increase in stroke Criticism for the fixed dosing
Guideline Interpretation Beta blockers should be continued in patients already taking beta blockers-class 1 Beta blockers titrated to heart rate and blood pressure who have ischemia on preop testing 2a Beta blockers are reasonable for vascular surgery patients with at least one risk factor- 2a Beta blockers are reasonable in patients with more than one risk factor (nonvascular surgery)-
Statin therapy Patients currently taking statins should continue them perioperatively class 1 Patients undergoing vascular surgery statin therapy is reasonable class 2a Patients with at least 1 risk factor undergoing intermediate risk surgery with at least one risk factor class 2b indication
Case Study 44 year old gentleman comes in for preop evaluation. 1 year history of insulin requiring diabetes mellitus 1 year history of hypertension Very active-goes square dancing Only chest pain Nov 2011
ECG
Echocardiogram-4Chamber
Echocardiogram-2Chamber
Future considerations Troponin measurement will become routine Trials of management of patients with low troponin levels are ongoing Future of beta blockade or other therapies to reduce heart rate is uncertain