Preoperative Management of the Cardiac Patient For Non-Cardiac Surgery Henry L. Green, MD, FACC, FACP June 6, 2007 Perform a complete history and physical examination Identify non-cardiac risk factors Medication history, including non-prescription and alternative medications Drug allergies Alcohol, tobacco and illicit drug use Surgical and anesthetic history Identify cardiac risk features High risk: Recent myocardial infarction or acute coronary syndrome Decompensated heart failure Unstable angina – Canadian Class 3 or 4 Symptomatic arrhythmias (high grade atrioventricular block, symptomatic ventricular arrhythmias, supraventricular arrhythmias with uncontrolled rate) Symptomatic or severe valvular heart disease Intermediate risk: Stable angina – Canadian Class 1 or 2 Prior myocardial infarction Prior heart failure Moderate valvular disease Diabetes, a coronary risk equivalent – especially if insulin-dependent Renal insufficiency Minor risk: Advanced age Abnormal electrocardiogram (LVH, LBBB, ST-T abnormalities) Rhythm other than sinus (e.g. atrial fibrillation) Low functional capacity What is the patient’s functional status? Poor functional status implies higher perioperative risk, predicts postoperative complications, and impedes the patient’s rehabilitation. History Can the patient walk, climb stairs or perform other daily activities without symptoms? Does the patient exercise? A patient that can carry a bag of groceries up one flight of stairs, or who can walk at three to four miles per hour is doing the equivalent of four METs. Patients who are not able to do this are considered in 1

poor physical condition. This type of evaluation is limited, as patients will often miscalculate their ability. Objective evaluation A more realistic approach is to actually take the patient for a walk, or even watch him climb stairs. Treadmill stress testing gives even more quantitative information, but adds cost. Be aware of major comorbidities Stroke Renal insufficiency Pulmonary disease Diabetes Is the planned surgery a high-risk procedure? High risk procedures Emergency surgery, especially in the elderly Aortic or major vascular operations, including peripheral vascular disease Extensive operations involving large volume shifts or blood loss Intermediate risk surgery Abdominal or thoracic surgery Carotid endarterectomy Head and neck surgery Orthopedic surgery Prostate surgery Low risk surgery Endoscopy Superficial biopsy Breast surgery Cataract surgery When is non-invasive testing needed? No testing is needed for some patients If the patient has low risk clinical features and good functional status, and the surgery is low risk, then further testing is usually not indicated. Consider stress testing in patients with any two of the following: 1. Intermediate risk patients 2. Poor functional capacity 3. High risk surgery Stress testing may demonstrate that the patient falls into a higher or lower risk category than was originally thought.

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High-risk patient should be considered for invasive testing and possible revascularization. Unstable angina or angina that does not respond well to medical therapy Stress test indicating high-risk Stress test equivocal but surgery is intermediate or high risk Optimize medical therapy Beta-blockers Beta-blockers reduce complications and mortality in the following settings: Ischemic heart disease (angina, prior myocardial infarction, or positive stress test) Vascular surgery in patients with multiple risk factors Intermediate or high-risk surgery in patients with multiple risk factors, and possibly in those with a single risk factor It is reasonable to give them for patients having vascular surgery even if they are low risk Heart failure Diabetes, especially insulin requiring Poor functional status, if due to coronary artery disease or heart failure Beta-blocker therapy can be initiated as follows: Optimally, one should introduce them at least several weeks prior to elective surgery. The dose must be individualized. A typical initial dose would be metoprolol 25 mg twice a day, subsequently titrated to a heart rate between 50 and 60 beats per minute. If surgery is urgent, beta-blockade may be introduced more rapidly with esmolol given intravenously, adjusting the dose to a heart rate of sixty beats per minute. Beta-blockers should be continued intraoperatively and postoperatively, maintaining a heart rate under 80. Statins Statins may have a role in stabilizing plaques, and may be given preoperatively. Some drugs should be withheld Aspirin is usually discontinued for seven days, and clopidogrel at least five days. NSAID’s should be stopped for one to three days, depending on the drug. Warfarin is usually held until the INR is under 1.5. If withdrawing anticoagulation for four or five days jeopardizes the patient, he or she should be ―bridged‖ with unfractionated or low molecular weight heparin. For details, see tutorial on Thromboembolism

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Specific heart diseases Surgery after stenting Drug-eluting stents should not be used in patients for whom surgery is planned within the foreseeable future, owing to the risk of stent thrombosis if anti-platelet therapy is interrupted. If surgery can be delayed, then a bare metal stent can be employed, and anti-platelet therapy should be given for two or preferably four weeks. Clopidogrel should be held for five days before major surgery, to avoid bleeding. If surgery cannot be delayed, it may be reasonable to continue antiplatelet therapy and advise the surgeon of the risk of surgery. Platelet transfusions can be given. Valvular heart disease If possible, patients with aortic or mitral stenosis should have the problem corrected prior to elective surgery. Valvular regurgitation may be helped by afterload reduction with afterload reducing drugs. Managing comorbidities Hypertension Mild to moderate hypertension does not appear to affect outcome adversely, unless there is target organ damage. However, more severe degrees of hypertension (e.g. systolic pressure over 180 or diastolic pressure over 110) should be carefully brought under control prior to elective surgery. This must be balanced against any risk of delaying surgery. If urgent control of hypertension is required immediately prior to surgery, intravenous nitroprusside or labetalol are often used. Antihypertensive drugs should be continued, as a rule. Abrupt withdrawal of betablockers or clonidine can cause a dramatic rise in blood pressure. However, angiotensin II inhibitors can result in hypotension, if the patient receives a general anesthetic. They should be held on the morning of surgery. Diabetes Diabetics should not take oral hypoglycemic agents on the day of surgery. In particular, metformin should be withheld for 24 hours prior to surgery and for two to three days afterward, because of the risk of lactic acidosis. Insulin should be given according to one of several recommended regimens. Both intraoperative and postoperative ―tight‖ glycemic control has been shown to improve morbidity.

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Pulmonary disease Pulmonary risk factors include smoking, poor exercise tolerance, and chronic obstructive lung disease. Cigarette smoking should be stopped at least two months prior to surgery. Patients should be instructed in incentive spirometry. Bronchospasm and active pulmonary infection should be treated. Many believe that spinal or epidural anesthesia is safer than general anesthesia for these patients. Pancuronium should be avoided. The duration of surgery should be limited to less than three hours. If possible, laparoscopic surgery is preferable. Upper abdominal and thoracic procedures convey the greatest risk of pulmonary complications. Postoperative surveillance Continue to monitor the cardiac status ECG’s should be done on the first two postoperative days. Biomarkers should be measured in high-risk patients on the first and second days as well. One should also seek evidence of heart failure. This is often due to fluid overload. Measurement of intake and output, daily weights and careful examination of the patient are useful here. General measures Postoperative pain should be well controlled, particularly in the cardiac patient Anemia should be corrected. Fluid and electrolyte balance Aspirin, statin drugs and ACE inhibitors should be continued. Inotropic agents should be avoided if possible. Thromboembolism protection, either with compression devices, or subcutaneous unfractionated or low molecular weight heparin. Observe for urinary retention. Do not forget to remove the Foley catheter as soon as it is no longer needed. Infection control Watch for respiratory, central line, skin and pulmonary infections Respiratory care, such as breathing exercises, incentive spirometry, or formal consultation with the respiratory therapy department. Physical therapy is often indicated after major operations Nutrition is an important factor in recovery, infection prevention and wound healing. Bowel function should not be neglected Skin, mouth and eye care as required in debilitated patients Long-term therapy Cardiovascular risk factors, such as hypertension, hyperlipidemia, smoking and other life style issues should be addressed. Correctable cardiac problems should

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also be dealt with. Optimize cardiac and other medical therapy based on the current guidelines. References: Mukherjee D and Eagle KA. Perioperative cardiac assessment for noncardiac surgery. Circulation 2003; 107:2771-4 Fleisher LA et al. ACC/AHA 2006 Guideline update on perioperative cardiovascular evaluation for noncardiac surgery. Circulation 2006; 113:2662-74 Eagle KA et al. ACC/AHA guideline update for perioperative cardiovascular evaluation for noncardiac surgery—executive summary.. J Am Coll Cardiol 2002;39:542-553. Michota FA and Frpst SD The preoperative evaluation. Cleveland Clin J Med 2004;71:63-9 Weitz HH. How soon can a patient undergo noncardiac surgery after receiving a drugeluting stent? Cleveland Clin J Med 2005;72:818-820 Fleisher LA. Preoperative evaluation of the patient with hypetension. JAMA 2002; 287:2043-6

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