Perioperative Cardiovascular Evaluation for Noncardiac Surgery By :Mahmoud M Othman MD, Prof of Anesthesia & SICU, Mansoura faculty of Medicine.

General Approach 4 Team Work –Patient –Primary care physician –Anesthesiologist –Surgeon –Medical consultant

Preoperative Clinical Evaluation 4 Identification of serious cardiac disorder –CAD, CHF, Arrhythmias (Initial history, Physical examination, ECG) 4 Define disease severity, stability, and prior treatment 4 Functional capacity 4 Age 4 Comorbid conditions (DM, peripheral vascular disease, renal dysfunction, chronic pulmonary disease) 4 Type of surgery –Consider higher risk vascular procedures prolonged complicated thoracic, abdominal and head and neck procedures

Further Preoperative Testing to Assess Coronary Risk CAD is the most frequent cause of perioperative cardiac mortality and morbidity after noncardiac surgery 4 Step-wise Bayesian strategy clinical markers prior coronary evaluation and treatment functional capacity surgery-specific risk

Need for noncardiac surgery O.R. emergency Postoperative risk stratification and risk factor management Urgent or elective Coronary revascularization within 5 yrs Recurrent symptoms or signs Recent coronary evaluation Recent coronary angiogram or stress test? Intermediate Clinical predictors MajorMinor or No O.R. yes Unfavorable result and change in symptoms favorable result and no change in symptoms Stepwise Approach to Preoperative Cardiac Assessment no yes no

Major clinical predictors Unstable coronary syndromes Decompensated CHF Significant arrhythmias Severe valvular disease Major clinical predictors delay or cancel noncardiac surgery Medical management and risk factor modification Coronary angiography Subsequent care dictated by findings and treatment results Stepwise Approach to Preoperative Cardiac Assessment

Intermediate clinical predictors Mild angina pectoris Prior MI Compensated or prior CHF DM Intermediate clinical predictors Poor (<4METs) Moderate or excellent (>4METs) High surgical risk precedure Intermediate or low surgical precedure Low surgical risk procedure Noninvasive testing O.R. Postoperative risk stratification and risk factor reduction Consider coronary angiography Subsequent care dictated by findings and treatment results Low risk High risk Stepwise Approach to Preoperative Cardiac Assessment

Minor or no clinical predictors Poor(<4METs)Moderate or excellent(>4METs) High surgical risk procedure Intermediate surgical risk procedure Noninvasive testingO.R.Postoperative management Subsequent care by findings and treatment results Consider coronary angiography Minor clinical predictors Advanced age Abnormal ECG Rhythm other than sinus Low functional capacity History of stroke Uncontrolled systemic hypertension High risk low risk Stepwise Approach to Preoperative Cardiac Assessment

Clinical Predictors of Increased Perioperative Cardiovascular Risk (Myocardial Infarction, Congestive Heart Failure, Death) 4 Major Unstable coronary syndromes –Recent myocardial infarction with evidence of important ischemic risk by clinical symptoms or noninvasive study –Unstable or severe angina(Canadian Cardiovascular Society Class III or IV) Decompensated CHF Significant arrhythmias –High grade atrioventricular block –Symptomatic ventricular arrhythmias in the presence of underlying heart disease –Supraventricular arrhythmias with uncontrolled ventricular rate Severe valvular disease

Clinical Predictors of Increased Perioperative Cardiovascular Risk (Myocardial Infarction, Congestive Heart Failure, Death) 4 Intermediate Mild angina pectoris(Canadian Cardiovascular Society Class I or II) Prior myocardial infarction by history or pathological waves Compensated or prior CHF DM 4 Minor Advanced age Abnormal EKG(LVH, LBBB, ST-T abnormalities) Rhythm other than sinus(eg, atrial fibrillation) Low functional capacity(eg, unstable to climb one flight or stairs with a bag of groceries) History of stroke Uncontrolled systemic hypertension

Estimated Energy Requirements for Various Activities Can you take care of yourself? Eat. Dress, or use the toilet? Walk indoors around the house? Walk a block or two on level ground at 2-3 mphor km/hr Do light work around the house dusting or washing dishes? Climb a flight of stairs or walk up a hill Walk on level ground at 4 mph or 6.4 km/h? Run a short distance? Do heavy work around the house like scrubbing floors or moving heavy furniture? Participate in moderate recreational activities like golf, bowling, dancing, doubles tennis, or throwing a baseball or football? Participate in strenuous sports like swimming, singles tennis, football, basket ball, or skiing 1 MET 4 METs >10 METs

Cardiac Event Risk† Stratification for Noncardiac Surgical Procedures High (reported cardiac risk often >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 Intermediate (Reported cardiac risk generally <5%) Carotid endarterectomy Head and neck Intraperitoneal and intrathoracic Orthopedic Prostatic Low ‡ (reported cardiac risk generally <1%) Endoscopic procedures Superficial procedures Cataract Breast † Combind incidence of cardiac death and nonfatal myocardial infarction ‡ Further preoperative cardiac testing is not generally required.

Method of Assessing Cardiac Risk 4 Resting Left Ventricular Function 4 Exercise Stress Testing 4 Pharmacological Stress Testing 4 Ambulatory ECG monitoring 4 Coronary Angiography

Method of Assessing Cardiac Risk 4 Resting Left Ventricular Function –Increased risk: Ejection fraction < 35% severe diastolic dysfunction –CHF –prior CHF or dyspnea of unknown etiology

Method of Assessing Cardiac Risk 4 Exercise Stress Testing –treadmill or bicycle stress and ECG analysis, echocardiography –degree of functional incapacity, symptoms of ischemia, severity of ischemia(depth, time of onset, duration of ST depression), evidence of hemodynamic or electrical instability correlated with increasing ischemic risk

Method of Assessing Cardiac Risk 4 Pharmacological Stress Testing –for patients who are unable to exercise –Dipyridamole or adenosine with thallium myocardial perfusion imaging –Dobutamine echocardiography 4 Ambulatory ECG Monitoring 4 Coronary Angiography

Indications for Coronary Angiography in Perioperative Evaluation Before (or After) Noncardiac Surgery Class I:Patients with suspected or proven CAD –High-risk results during noninvasive testing –Angina pectoris unresponsive to adequate medical therapy –Most patient with unstable angina pectoris –Nondiagnostic or equivocal noninvasive test in a high- risk noncardiac surgical procedure Class I: conditions for which there is evidence for and/or general agreement that a procedure or a treatment is of benefit

Indications for Coronary Angiography in Perioperative Evaluation Before (or After) Noncardiac Surgery Class II: –Intermediate-risk results during noninvasive testing –Nondiagnostic or equivocal noninvasive test in a lower-risk patients undergoing a high-risk noncardiac surgical procedure –Urgent noncardiac surgery in a patient convalescing from acute MI –Perioperative MI Class II: conditions for which there is a divergence of evidence and/or opinion about the treatment

Indications for Coronary Angiography in Perioperative Evaluation Before (or After) Noncardiac Surgery Class III: –Low-risk noncardiac surgery in a patient with known CAD and low-risk results on noninvasive testing –Screening for CAD without appropriate noninvasive testing –Asymptomatic after coronary revascularization, with excellent exercise capacity(>7METs) –Mild stable angina in patients with good LV function, low-risk noninvasive test results –Patient is not a candidate for coronary revascularization because of concomitant medical illness –Prior technically adequate normal coronary angiogram within previous 5years –Severe LV dysfunction(e.g., EF<20%) and patient not considered candidate for revascularization procedure –Patient unwilling to consider coronary revascularization procedure Class III: conditions for which there is evidence and/or general agreement that the procedure is not necessary

Management of Preoperative Cardiovascular Conditions 4 Hypertension 4 Valvular Heart Disease 4 Myocardial Heart Disease 4 Arrhythmias and Conduction Abnormalities

Management of Preoperative Cardiovascular Conditions 4 Hypertension –Severe HBP(DBP >110) should be controlled before surgery when possible –Continuation of preoperative antihypertensive treatment is critical to avoid severe postoperative hypertension. –Consider the urgency of surgery and the potential benefit of more intensive medical therapy.

Management of Preoperative Cardiovascular Conditions 4 Valvular Heart Disease –Symptomatic stenotic lesions(MS or AS): associated with risk of perioperative severe CHF or shock and often require percutaneous valvotomy or replacement to lower cardiac risk. –Symptomatic regurgitant lesions(AR or MR): usually better tolerated perioperatively and may be stabilized before surgery with intensive medical therapy and monitoring

Management of Preoperative Cardiovascular Conditions 4 Myocardial Heart Disease –Dilated and hypertrophic cardiomyopathy are associated with an increased incidence of perioperative CHF. –Maximizing preoperative hemodynamic status and providing intensive postoperative medical therapy and surveillance.

Management of Preoperative Cardiovascular Conditions 4 Arrhythmias and Conduction Abnormalities –careful evaluation for underlying cardiopulmonary disease, drug toxicity, or metabolic abnormality. –Therapy: reverse any underlying cause and treat the arrhythmia

Preoperative Coronary Revascularization 4 Coronary Artery Bypass Graft Surgery 4 Coronary Angioplasty

Medical Therapy for Coronary Artery Disease 4 If patients require beta-blockers, calcium channel blockers, or nitrates before surgery, continue them into the operative and post-op period. 4 The same is true for therapies used to control CHF 4 Beta-blockers reduce postoperative ischemia, –Protection against ischemia may also reduce risk of MI

Anesthetic Considerations 4 Anesthetic agent –No one best myocardial protective anesthetic technique. –Opioid:cardiovascular stability, but need postoperative ventilation –Inhalational agent: myocardial depression –Neuraxial block: sympathetic blockade low level:minimal hemodynamic change abdominal operation: profound effects(hypotension, reflex tachycardia)

Anesthetic Considerations 4 Perioperative pain management –PCA(iv or epidural) leads to a reduction in postoperative catecholamine surges and hypercoagulability, both of which can theoretically impact myocardial ischemia.

Anesthetic Considerations 4 Intraoperative nitroglycerine –Helpful or harmful vasodilating properties of NTG with anesthetics can cause significant hypotension and even myocardial ischemia. 4 Transesophageal echocardiography –Guidelines for the use of TEE to diagnosis or guide therapy are being developed by ASA

Perioperative Surveillance 4 Pulmonary artery catheters –recent MI complicated by CHF –significant CAD with procedures assoc. with significant hemodynamic stress. –Systolic or diastolic LV dysfunction –cardiomyopathy –valvular disease with high risk operation

Perioperative Surveillance 4 Intraoperative and postoperative ST monitoring –Intraoperative and postoperative ST changes are strong predictors of perioperative MI in patients at high risk who undergo noncardiac surgery –proper use of computerized ST-segment analysis may improve sensitivity for detection of myocardial ischemia

Perioperative Surveillance 4 Surveillance for perioperative MI –Clinical symptoms –Postoperative ECG changes –CK-MB, troponin-I, troponin-T, CK-MB isoforms –In patients with known or suspected CAD undergoing high risk procedures, obtaining ECG at baseline, immediately after the procedure, and for the first 2 postoperative days appears to be cost effective –Use of cardiac enzymes is best reserved for patients with clinical, ECG, or hemodynamic evidence of cardiovascular dysfunction.

Postoperative Therapy and Long- Term Management 4 Postoperative management should include assessment and management of modifiable risk factors for CAD, heart failure, HBP, stroke, and other cardiovascular diseases. 4 Assessment for hypercholesterolemia, smoking, hypertension, DM, physical inactivity, peripheral vascular disease, cardiac murmur(s), arrhythmias, perioperativeischemia, and MI may lead to evaluation and treatments that reduce future cardiovascular risk