National Guideline Clearinghouse

Guidelines for perioperative cardiovascular evaluation for noncardiac surgery

Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Perioperative Cardiovascular Evaluation for Noncardiac Surgery).
National Guideline Clearinghouse 1996
SOURCE(S):
Circulation 1996 Mar 15;93(6):1278-317 [229 references]
J Am Coll Cardiol 1996 Mar 15;27(4):910-48 [229 references]
1996 Mar 15
MAJOR RECOMMENDATIONS:

Explanation of classification system for the guideline recommendations:
Class I, conditions for which there is evidence for and/or general agreement that a procedure be performed or a treatment is of benefit;
Class II, conditions for which there is a divergence of evidence and/or opinion about the treatment;
Class III, conditions for which there is evidence and/or general agreement that the procedure is not necessary.
General Approach
Successful perioperative evaluation and treatment of cardiac patients undergoing noncardiac surgery requires careful teamwork and communication between patient, primary care physician, anesthesiologist, and surgeon. In general, indications for further cardiac testing and treatments are the same as those in the nonoperative setting, but their timing is dependent on such factors as the urgency of noncardiac surgery, the patient's risk factors, and specific surgical considerations. Coronary revascularization before noncardiac surgery to enable the patient to "get through" the noncardiac procedure is appropriate only for a small subset of patients at very high risk. Preoperative testing should be limited to circumstances in which the results will affect patient treatment and outcomes. A conservative approach to use of expensive tests and treatments is recommended.
Preoperative Clinical Evaluation
The initial history, physical examination, and electrocardiographic (ECG) assessment should focus on identification of potentially serious cardiac disorders, including coronary artery disease (CAD) (e.g., prior myocardial infarction [MI], angina pectoris), congestive heart failure (CHF), and electrical instability (e.g., symptomatic arrhythmias).
In addition to identifying the presence of preexisting manifested heart disease, it is essential to define disease severity, stability, and prior treatment. Other factors that help determine cardiac risk include functional capacity, age, comorbid conditions (e.g., diabetes mellitus, peripheral vascular disease, renal dysfunction, chronic pulmonary disease), and type of surgery (vascular procedures and prolonged, complicated thoracic, abdominal, and head and neck procedures considered higher risk).
Indications for Angiography.
Class I indications (helpful), for patients with suspected or proven CAD, are high-risk results during noninvasive testing; angina pectoris unresponsive to medical therapy; unstable angina pectoris in most patients; and nondiagnostic or equivocal noninvasive test in a high-risk patient undergoing a high-risk procedure.
Class II indications (may be helpful) are intermediate-risk results during noninvasive testing; nondiagnostic or equivocal noninvasive test in a patient at lower risk undergoing a higher risk procedure; urgent noncardiac surgery in a patient recovering from acute MI; and perioperative MI.
Class III indications (not necessary) are low-risk noncardiac surgery in patients with known CAD and low-risk results on noninvasive testing; screening for CAD without appropriate noninvasive testing; patients who are asymptomatic after coronary vascularization and have excellent exercise capacity; mild, stable angina in patients with good left ventricular function and low-risk noninvasive test results; patients who are not candidates for revascularization because of concomitant illness; prior technically adequate normal coronary angiogram within 5 years; severe left ventricular dysfunction in patients not considered candidates for revascularization; and patients unwilling to undergo revascularization.
Description of the algorithm for the stepwise approach to preoperative cardiac assessment:
Step 1. What is the urgency of noncardiac surgery? Certain emergencies do not allow time for preoperative cardiac evaluation. Postoperative risk stratification may be appropriate for some patients who have not had such an assessment before.
Step 2. Has the patient undergone coronary revascularization in the past 5 years? If so, and if clinical status has remained stable without recurrent symptoms/signs of ischemia, further cardiac testing is generally not necessary.
Step 3. Has the patient had a coronary evaluation in the past 2 years? If coronary risk was adequately assessed and the findings were favorable, it is usually not necessary to repeat testing unless the patient has experienced a change or new symptoms of coronary ischemia since the previous evaluation.
Step 4. Does the patient have an unstable coronary syndrome or a major clinical predictor of risk? When elective noncardiac surgery is being considered, the presence of unstable coronary disease, decompensated CHF, symptomatic arrhythmias, and/or severe valvular heart disease usually leads to cancellation or delay of surgery until the problem has been identified and treated.
Step 5. Does the patient have intermediate clinical predictors of risk? The presence or absence of prior MI by history or ECG, angina pectoris, compensated or prior CHF, and/or diabetes mellitus helps further stratify clinical risk for perioperative coronary events. Consideration of functional capacity and level of surgery-specific risk allows a rational approach to identifying patients most likely to benefit from further noninvasive testing.
Step 6. Patients without major but with intermediate predictors of clinical risk and moderate or excellent functional capacity can generally undergo intermediate-risk surgery with little likelihood of perioperative death or MI. Conversely, further noninvasive testing is often considered for patients with poor functional capacity or moderate functional capacity but higher-risk surgery and especially for patients with two or more intermediate predictors.
Step 7. Noncardiac surgery is generally safe for patients with neither major nor intermediate predictors of clinical risk and moderate or excellent functional capacity (4 METs or greater). Further testing may be considered on an individual basis for patients without clinical markers but poor functional capacity who are facing higher-risk operations, particularly those with several minor clinical predictors of risk who are to undergo vascular surgery.
Step 8. The results of noninvasive testing can be used to determine further preoperative management. Alternatively, the results may lead to a recommendation to proceed with surgery. In some patients, the risk of coronary intervention or corrective cardiac surgery may approach or even exceed the risk of the proposed noncardiac surgery. This approach may be appropriate, however, if it also significantly improves the patient's long-term prognosis.
For some patients, a careful consideration of clinical, surgery-specific, and functional status attributes leads to a decision to proceed to coronary angiography.
Recommendations for Preoperative Noninvasive Evaluation of Left Ventricular Function
Class I. Patients with current or poorly controlled CHF. (If previous evaluation has documented severe left ventricular dysfunction, repeat preoperative testing may not be necessary.)
Class II. Patients with prior CHF and patients with dyspnea of unknown etiology.
Class III. As a routine test of left ventricular function in patients without prior CHF.
Recommendations for Assessment of Risk for Coronary Artery Disease and Functional Capacity
Recommendations: which test? No specific recommendations can be made for individual patients. The following should be considered appropriate as indicated in specific situations: resting left ventricular function, exercise stress testing, pharmacological stress testing, ambulatory ECG monitoring, and coronary angiography. In most ambulatory patients the test of choice is exercise ECG testing, which can both provide an estimate of functional capacity and detect myocardial ischemia through changes in the ECG and hemodynamic response. In patients with important abnormalities on their resting ECG (left bundle branch block, left ventricular hypertrophy with strain pattern, digitalis effect, etc), other techniques such as exercise echocardiography or exercise myocardial perfusion imaging should be considered.
Recommendations for Perioperative Medical Therapy before Noncardiac Surgery
There are very few randomized trials of medical therapy before noncardiac surgery to prevent perioperative cardiac complications, and they do not provide enough data from which to draw firm conclusions or recommendations. Preliminary studies, however, suggest that appropriately administered -blockers reduce perioperative ischemia and may ultimately be shown to reduce risk of MI and death. Clearly, this is an area where further research would be valuable.
Perioperative Therapy With ß-Blockers
Class I. ß-blockers required in the recent past to control symptoms of angina or patients with symptomatic arrhythmias or hypertension.
Class II. Preoperative assessment identifies untreated hypertension, known coronary disease, or major factors for coronary disease.
Class III. Contraindication to ß-blockade.
Recommendations for Preoperative Intensive Care
Based on the scant evidence, preoperative preparation in an intensive care unit may benefit certain high-risk patients, particularly those with decompensated CHF. Preparation of such patients should occur under close supervision.
General Guidelines for Perioperative Prophylaxis for Venous Thromboembolism^*

Type of Patient/Surgery Recommendation

Minor surgery in a patient <40 years old with no correlates of venous thromboembolism risk. Early ambulation

Moderate-risk surgery in a patient >40 years old with no correlates of thromboembolism risk ES; LDH (2 h preoperatively and every 12 h after), or IPC (intraoperatively and postoperatively).

Major surgery in a patient >40 years old with clinical conditions associated with venous thromboembolism risk LDH (every 8 h) or LMWH. IPC if prone to wound bleeding.

Very high-risk surgery in a patient with multiple clinical conditions associated with thromboembolism risk LDH, LMWH, or dextran combined with IPC. In selected patients, perioperative warfarin (INR 2.0- 3.0) may be used.

Total hip replacement LMWH (postoperative, subcutaneous twice daily, fixed dose unmonitored) or warfarin (INR 2.0-3.0, started preoperatively or immediately after surgery) or adjusted dose unfractionated heparin (started preoperatively). ES or IPC may provide additional efficacy.

Total knee replacement LMWH (postoperative, subcutaneous, twice daily, fixed dose unmonitored) or IPC.

Hip fracture surgery LMWH (preoperative, subcutaneous, fixed dose unmonitored) or warfarin (INR 2.0-3.0). IPC may provide additional benefit.

Intracranial neurosurgery IPC with or without ES. Consider addition of LDH in high-risk patients.

Acute spinal cord injury with lower-extremity paralysis Adjusted dose heparin or LMWH for prophylaxis. Warfarin may also be effective. LDH, ES, and IPC may have benefit when used together.

Patients with multiple trauma IPC, warfarin, or LMWH when feasible, serial surveillance with duplex ultrasonography may be useful. In selected very high-risk patients, consider prophylactic caval filter.

ES indicates graded compression elastic stockings; LDH, low-dose subcutaneous heparin; IPC, intermittent pneumatic compression; LMWH, low molecular weight heparin.
^*Developed from Clagett et al.
+Clinical conditions associated with increased risk of venous thromboembolism: advanced age; prolonged immobility or paralysis; previous venous thromboembolism; malignancy; major surgery of abdomen, pelvis, or lower extremity; obesity; varicose veins; congestive heart failure; myocardial infarction; stroke; fracture(s) of the pelvis, hip or leg; hypercoagulable states; and possibly high-dose estrogen use.
Recommendations for Intraoperative Nitroglycerin
Class I. High-risk patients previously on nitroglycerin who have active signs of myocardial ischemia without hypotension.
Class II. As a prophylactic agent for high-risk patients to prevent myocardial ischemia and cardiac morbidity, particularly in those who have required nitrate therapy to control angina. The recommendation for prophylactic use of nitroglycerin must take into account the anesthetic plan and patient hemodynamics and must recognize that vasodilation and hypovolemia can readily occur during anesthesia and surgery.
Class III. Patients with signs of hypovolemia or hypotension.
Recommendations for Transesophageal Echocardiography
Currently there is insufficient evidence to determine the cost-effectiveness of TEE for its use as a diagnostic monitor or to guide therapy during noncardiac surgery. Guidelines for the appropriate use of TEE are being developed by the American Society of Anesthesiologists and the Society of Cardiovascular Anesthesiologists.
Recommendations for Intra-aortic Balloon Counterpulsation Device
There is currently insufficient evidence to determine the value of prophylactic placement of an intra-aortic balloon counterpulsation device for high-risk noncardiac surgery.
Recommendations for Pulmonary Artery Catheters
Practice parameters for the intraoperative use of a pulmonary artery catheter have recently been published by the American Society of Anesthesiologists. These parameters approach the decision to place the pulmonary artery catheter as the interrelationship between three variables: patient disease, surgical procedure, and practice setting. With regard to the surgical procedure, the extent of intraoperative and postoperative fluid shifts is a dominant factor.
Intraoperative Use of Pulmonary Artery Catheters
Class I. Patients at risk for major hemodynamic disturbances that are most easily detected by a pulmonary artery catheter who are undergoing a procedure that is likely to cause these hemodynamic changes in a setting with experience in interpreting the results (e.g., suprarenal aortic aneurysm repair in a patient with angina).
Class II. Either the patient's condition or the surgical procedure (but not both) places the patient at risk for hemodynamic disturbances (e.g., total hip replacement in a patient with chronic renal insufficiency).
Class III. No risk of hemodynamic disturbances.
Recommendations for Intraoperative and Postoperative Use of ST-Segment Monitoring
Proper use of computerized ST-segment analysis in appropriate high-risk patients may provide increased sensitivity to detect myocardial ischemia during the perioperative period and may identify patients who might benefit from further postoperative and long-term interventions. Therefore, computerized monitoring of the ST segment can provide useful information in appropriate high-risk patients, if available. The cost-effectiveness of computerized ST-segment analysis for reducing perioperative morbidity, however, has not been documented. Further research is required.
Recommendations for Surveillance for Perioperative Myocardial Infarction
Further evaluation regarding the optimal strategy for surveillance and diagnosis of perioperative MI is required before one method is advocated. In patients without evidence of CAD, surveillance should be restricted to patients who develop perioperative signs of cardiovascular dysfunction. In patients with known or suspected CAD undergoing surgical procedures associated with a high incidence of cardiovascular morbidity, ECGs at baseline, immediately after the surgical procedure, and daily on the first 2 days postoperatively appears to be the most cost-effective strategy. Measurements of cardiac enzymes are best reserved for patients at high risk or those who demonstrate ECG or hemodynamic evidence of cardiovascular dysfunction.

CLINICAL ALGORITHM(S):
A clinical algorithm is provided for the approach to preoperative cardiac assessment.
DEVELOPER(S):
American College of Cardiology (ACC) - Medical Specialty Society
American Heart Association (AHA) - Professional Association
COMMITTEE:
Committee on Perioperative Cardiovascular Evaluation for Noncardiac Surgery
GUIDELINE AVAILABILITY:
Electronic copies: Available from the American College of Cardiology (ACC) and the American Heart Association (AHA).
Print copies: Available from ACC, Educational Services, 9111 Old Georgetown Road, Bethesda, MD 20814. Also available from AHA, Office of Scientific Affairs, 7272 Greenville Avenue, Dallas, TX 75231-4596.
Copyright to the original guideline is owned by the American College of Cardiology (ACC) and the American Heart Association (AHA). NGC users are free to download a single copy for personal use. Date Modified: Monday, June 07, 1999

Explanation of classification system for the guideline recommendations: Class I, conditions for which there is evidence for and/or general agreement that a procedure be performed or a treatment is of benefit; Class II, conditions for which there is a divergence of evidence and/or opinion about the treatment; Class III, conditions for which there is evidence and/or general agreement that the procedure is not necessary. General Approach Successful perioperative evaluation and treatment of cardiac patients undergoing noncardiac surgery requires careful teamwork and communication between patient, primary care physician, anesthesiologist, and surgeon. In general, indications for further cardiac testing and treatments are the same as those in the nonoperative setting, but their timing is dependent on such factors as the urgency of noncardiac surgery, the patient's risk factors, and specific surgical considerations. Coronary revascularization before noncardiac surgery to enable the patient to "get through" the noncardiac procedure is appropriate only for a small subset of patients at very high risk. Preoperative testing should be limited to circumstances in which the results will affect patient treatment and outcomes. A conservative approach to use of expensive tests and treatments is recommended. Preoperative Clinical Evaluation The initial history, physical examination, and electrocardiographic (ECG) assessment should focus on identification of potentially serious cardiac disorders, including coronary artery disease (CAD) (e.g., prior myocardial infarction [MI], angina pectoris), congestive heart failure (CHF), and electrical instability (e.g., symptomatic arrhythmias). In addition to identifying the presence of preexisting manifested heart disease, it is essential to define disease severity, stability, and prior treatment. Other factors that help determine cardiac risk include functional capacity, age, comorbid conditions (e.g., diabetes mellitus, peripheral vascular disease, renal dysfunction, chronic pulmonary disease), and type of surgery (vascular procedures and prolonged, complicated thoracic, abdominal, and head and neck procedures considered higher risk). Indications for Angiography. Class I indications (helpful), for patients with suspected or proven CAD, are high-risk results during noninvasive testing; angina pectoris unresponsive to medical therapy; unstable angina pectoris in most patients; and nondiagnostic or equivocal noninvasive test in a high-risk patient undergoing a high-risk procedure. Class II indications (may be helpful) are intermediate-risk results during noninvasive testing; nondiagnostic or equivocal noninvasive test in a patient at lower risk undergoing a higher risk procedure; urgent noncardiac surgery in a patient recovering from acute MI; and perioperative MI. Class III indications (not necessary) are low-risk noncardiac surgery in patients with known CAD and low-risk results on noninvasive testing; screening for CAD without appropriate noninvasive testing; patients who are asymptomatic after coronary vascularization and have excellent exercise capacity; mild, stable angina in patients with good left ventricular function and low-risk noninvasive test results; patients who are not candidates for revascularization because of concomitant illness; prior technically adequate normal coronary angiogram within 5 years; severe left ventricular dysfunction in patients not considered candidates for revascularization; and patients unwilling to undergo revascularization. Description of the algorithm for the stepwise approach to preoperative cardiac assessment: Step 1. What is the urgency of noncardiac surgery? Certain emergencies do not allow time for preoperative cardiac evaluation. Postoperative risk stratification may be appropriate for some patients who have not had such an assessment before. Step 2. Has the patient undergone coronary revascularization in the past 5 years? If so, and if clinical status has remained stable without recurrent symptoms/signs of ischemia, further cardiac testing is generally not necessary. Step 3. Has the patient had a coronary evaluation in the past 2 years? If coronary risk was adequately assessed and the findings were favorable, it is usually not necessary to repeat testing unless the patient has experienced a change or new symptoms of coronary ischemia since the previous evaluation. Step 4. Does the patient have an unstable coronary syndrome or a major clinical predictor of risk? When elective noncardiac surgery is being considered, the presence of unstable coronary disease, decompensated CHF, symptomatic arrhythmias, and/or severe valvular heart disease usually leads to cancellation or delay of surgery until the problem has been identified and treated. Step 5. Does the patient have intermediate clinical predictors of risk? The presence or absence of prior MI by history or ECG, angina pectoris, compensated or prior CHF, and/or diabetes mellitus helps further stratify clinical risk for perioperative coronary events. Consideration of functional capacity and level of surgery-specific risk allows a rational approach to identifying patients most likely to benefit from further noninvasive testing. Step 6. Patients without major but with intermediate predictors of clinical risk and moderate or excellent functional capacity can generally undergo intermediate-risk surgery with little likelihood of perioperative death or MI. Conversely, further noninvasive testing is often considered for patients with poor functional capacity or moderate functional capacity but higher-risk surgery and especially for patients with two or more intermediate predictors. Step 7. Noncardiac surgery is generally safe for patients with neither major nor intermediate predictors of clinical risk and moderate or excellent functional capacity (4 METs or greater). Further testing may be considered on an individual basis for patients without clinical markers but poor functional capacity who are facing higher-risk operations, particularly those with several minor clinical predictors of risk who are to undergo vascular surgery. Step 8. The results of noninvasive testing can be used to determine further preoperative management. Alternatively, the results may lead to a recommendation to proceed with surgery. In some patients, the risk of coronary intervention or corrective cardiac surgery may approach or even exceed the risk of the proposed noncardiac surgery. This approach may be appropriate, however, if it also significantly improves the patient's long-term prognosis. For some patients, a careful consideration of clinical, surgery-specific, and functional status attributes leads to a decision to proceed to coronary angiography. *Recommendations for Preoperative Noninvasive Evaluation of Left Ventricular Function* *Class I.* Patients with current or poorly controlled CHF. (If previous evaluation has documented severe left ventricular dysfunction, repeat preoperative testing may not be necessary.) *Class II.* Patients with prior CHF and patients with dyspnea of unknown etiology. *Class III.* As a routine test of left ventricular function in patients without prior CHF. *Recommendations for Assessment of Risk for Coronary Artery Disease and Functional Capacity* *Recommendations: which test?* No specific recommendations can be made for individual patients. The following should be considered appropriate as indicated in specific situations: resting left ventricular function, exercise stress testing, pharmacological stress testing, ambulatory ECG monitoring, and coronary angiography. In most ambulatory patients the test of choice is exercise ECG testing, which can both provide an estimate of functional capacity and detect myocardial ischemia through changes in the ECG and hemodynamic response. In patients with important abnormalities on their resting ECG (left bundle branch block, left ventricular hypertrophy with strain pattern, digitalis effect, etc), other techniques such as exercise echocardiography or exercise myocardial perfusion imaging should be considered. *Recommendations for Perioperative Medical Therapy before Noncardiac Surgery* There are very few randomized trials of medical therapy before noncardiac surgery to prevent perioperative cardiac complications, and they do not provide enough data from which to draw firm conclusions or recommendations. Preliminary studies, however, suggest that appropriately administered -blockers reduce perioperative ischemia and may ultimately be shown to reduce risk of MI and death. Clearly, this is an area where further research would be valuable. *Perioperative Therapy With ß-Blockers* *Class I. ß-blockers required in the recent past to control symptoms of angina or patients with symptomatic arrhythmias or hypertension. Class II. Preoperative assessment identifies untreated hypertension, known coronary disease, or major factors for coronary disease. Class III. Contraindication to ß-blockade. Recommendations for Preoperative Intensive Care* Based on the scant evidence, preoperative preparation in an intensive care unit may benefit certain high-risk patients, particularly those with decompensated CHF. Preparation of such patients should occur under close supervision. General Guidelines for Perioperative Prophylaxis for Venous Thromboembolism^*
Type of Patient/Surgery	Recommendation

Minor surgery in a patient <40 years old with no correlates of venous thromboembolism risk.	Early ambulation
Moderate-risk surgery in a patient >40 years old with no correlates of thromboembolism risk	ES; LDH (2 h preoperatively and every 12 h after), or IPC (intraoperatively and postoperatively).
Major surgery in a patient >40 years old with clinical conditions associated with venous thromboembolism risk	LDH (every 8 h) or LMWH. IPC if prone to wound bleeding.
Very high-risk surgery in a patient with multiple clinical conditions associated with thromboembolism risk	LDH, LMWH, or dextran combined with IPC. In selected patients, perioperative warfarin (INR 2.0- 3.0) may be used.
Total hip replacement	LMWH (postoperative, subcutaneous twice daily, fixed dose unmonitored) or warfarin (INR 2.0-3.0, started preoperatively or immediately after surgery) or adjusted dose unfractionated heparin (started preoperatively). ES or IPC may provide additional efficacy.
Total knee replacement	LMWH (postoperative, subcutaneous, twice daily, fixed dose unmonitored) or IPC.
Hip fracture surgery	LMWH (preoperative, subcutaneous, fixed dose unmonitored) or warfarin (INR 2.0-3.0). IPC may provide additional benefit.
Intracranial neurosurgery	IPC with or without ES. Consider addition of LDH in high-risk patients.
Acute spinal cord injury with lower-extremity paralysis	Adjusted dose heparin or LMWH for prophylaxis. Warfarin may also be effective. LDH, ES, and IPC may have benefit when used together.
Patients with multiple trauma	IPC, warfarin, or LMWH when feasible, serial surveillance with duplex ultrasonography may be useful. In selected very high-risk patients, consider prophylactic caval filter.
ES indicates graded compression elastic stockings; LDH, low-dose subcutaneous heparin; IPC, intermittent pneumatic compression; LMWH, low molecular weight heparin. ^Developed from Clagett et al. +Clinical conditions associated with increased risk of venous thromboembolism: advanced age; prolonged immobility or paralysis; previous venous thromboembolism; malignancy; major surgery of abdomen, pelvis, or lower extremity; obesity; varicose veins; congestive heart failure; myocardial infarction; stroke; fracture(s) of the pelvis, hip or leg; hypercoagulable states; and possibly high-dose estrogen use. Recommendations for Intraoperative Nitroglycerin* *Class I.* High-risk patients previously on nitroglycerin who have active signs of myocardial ischemia without hypotension. *Class II.* As a prophylactic agent for high-risk patients to prevent myocardial ischemia and cardiac morbidity, particularly in those who have required nitrate therapy to control angina. The recommendation for prophylactic use of nitroglycerin must take into account the anesthetic plan and patient hemodynamics and must recognize that vasodilation and hypovolemia can readily occur during anesthesia and surgery. *Class III.* Patients with signs of hypovolemia or hypotension. *Recommendations for Transesophageal Echocardiography* Currently there is insufficient evidence to determine the cost-effectiveness of TEE for its use as a diagnostic monitor or to guide therapy during noncardiac surgery. Guidelines for the appropriate use of TEE are being developed by the American Society of Anesthesiologists and the Society of Cardiovascular Anesthesiologists. *Recommendations for Intra-aortic Balloon Counterpulsation Device* There is currently insufficient evidence to determine the value of prophylactic placement of an intra-aortic balloon counterpulsation device for high-risk noncardiac surgery. *Recommendations for Pulmonary Artery Catheters* Practice parameters for the intraoperative use of a pulmonary artery catheter have recently been published by the American Society of Anesthesiologists. These parameters approach the decision to place the pulmonary artery catheter as the interrelationship between three variables: patient disease, surgical procedure, and practice setting. With regard to the surgical procedure, the extent of intraoperative and postoperative fluid shifts is a dominant factor. *Intraoperative Use of Pulmonary Artery Catheters* *Class I.* Patients at risk for major hemodynamic disturbances that are most easily detected by a pulmonary artery catheter who are undergoing a procedure that is likely to cause these hemodynamic changes in a setting with experience in interpreting the results (e.g., suprarenal aortic aneurysm repair in a patient with angina). *Class II.* Either the patient's condition or the surgical procedure (but not both) places the patient at risk for hemodynamic disturbances (e.g., total hip replacement in a patient with chronic renal insufficiency). *Class III.* No risk of hemodynamic disturbances. *Recommendations for Intraoperative and Postoperative Use of ST-Segment Monitoring* Proper use of computerized ST-segment analysis in appropriate high-risk patients may provide increased sensitivity to detect myocardial ischemia during the perioperative period and may identify patients who might benefit from further postoperative and long-term interventions. Therefore, computerized monitoring of the ST segment can provide useful information in appropriate high-risk patients, if available. The cost-effectiveness of computerized ST-segment analysis for reducing perioperative morbidity, however, has not been documented. Further research is required. *Recommendations for Surveillance for Perioperative Myocardial Infarction* Further evaluation regarding the optimal strategy for surveillance and diagnosis of perioperative MI is required before one method is advocated. In patients without evidence of CAD, surveillance should be restricted to patients who develop perioperative signs of cardiovascular dysfunction. In patients with known or suspected CAD undergoing surgical procedures associated with a high incidence of cardiovascular morbidity, ECGs at baseline, immediately after the surgical procedure, and daily on the first 2 days postoperatively appears to be the most cost-effective strategy. Measurements of cardiac enzymes are best reserved for patients at high risk or those who demonstrate ECG or hemodynamic evidence of cardiovascular dysfunction.