What is the recommended preoperative evaluation and management for patients undergoing surgery to minimize cardiac and pulmonary risk?

Preoperative Medical Evaluation and Risk Stratification

For patients undergoing noncardiac surgery, use the Revised Cardiac Risk Index (RCRI) to stratify cardiac risk, assess functional capacity in metabolic equivalents (METs), and proceed with surgery if functional capacity is ≥4 METs without further testing—reserving stress testing only for patients with ≥3 risk factors and poor functional capacity when results will change management. 1

Risk Stratification Framework

Surgical Urgency Classification

• Emergency surgery (<6 hours): Proceed immediately with minimal evaluation—check vital signs, volume status, hematocrit, electrolytes, renal function, and ECG only 1, 2
• Urgent surgery (6-24 hours): Allow limited clinical evaluation, screen for unstable coronary syndromes, decompensated heart failure, significant arrhythmias, and severe valvular disease 2, 3
• Time-sensitive surgery (1-6 weeks delay acceptable): Permits optimization of medical conditions including most oncologic procedures 1
• Elective surgery (>1 year delay acceptable): Full preoperative evaluation and optimization 1

Surgical Risk Classification

• Low-risk procedures (<1% risk of major adverse cardiac events): Include cataract surgery and plastic surgery—proceed without further cardiac testing 1, 2
• Elevated-risk procedures (≥1% risk): Require systematic risk assessment using the algorithm below 1

Cardiac Risk Assessment Algorithm

Step 1: Identify Active Cardiac Conditions

Screen for the following conditions that mandate delay of elective surgery for stabilization 1, 2:

• Unstable coronary syndromes (unstable angina, recent MI within 30 days)
• Decompensated heart failure (NYHA Class IV, worsening symptoms)
• Significant arrhythmias (high-grade AV block, symptomatic ventricular arrhythmias, supraventricular arrhythmias with uncontrolled rate >100 bpm)
• Severe valvular disease (severe aortic stenosis, symptomatic mitral stenosis)

If active cardiac conditions present: Delay surgery, treat condition, and discuss management in multidisciplinary team 2, 3

Step 2: Calculate Revised Cardiac Risk Index (RCRI)

Assign one point for each of the following 1, 2, 3, 4:

• High-risk surgery (intraperitoneal, intrathoracic, or suprainguinal vascular procedures)
• History of ischemic heart disease
• History of congestive heart failure
• History of cerebrovascular disease
• Insulin-dependent diabetes mellitus
• Preoperative serum creatinine >2.0 mg/dL or renal failure
• Age >75 years (some indices include this)

Risk stratification by RCRI score 4:

• 0 risk factors: Very low risk—proceed to surgery
• 1-2 risk factors: Low-intermediate risk—assess functional capacity
• ≥3 risk factors: High risk—assess functional capacity and consider stress testing if results will change management

Step 3: Assess Functional Capacity

Determine functional capacity in metabolic equivalents (METs) 1:

Excellent functional capacity (>10 METs): Can perform strenuous sports like swimming, singles tennis, football, basketball, or skiing 1

Good functional capacity (7-10 METs): Can perform heavy work around the house like scrubbing floors or moving heavy furniture 1

Moderate functional capacity (4-7 METs): Can climb a flight of stairs or walk up a hill, walk on level ground at 4 mph, run a short distance, do heavy housework, or participate in moderate recreational activities 1

Poor functional capacity (<4 METs): Cannot perform activities listed above, limited to self-care activities 1

Step 4: Decision Algorithm Based on Risk and Functional Capacity

For patients with 0-2 risk factors 1:

• If functional capacity ≥4 METs: Proceed to surgery without further testing
• If functional capacity <4 METs or unknown: May proceed to surgery or consider stress testing only if results will change management (e.g., willingness to undergo revascularization)

For patients with ≥3 risk factors 1, 4:

• If functional capacity >10 METs: Proceed to surgery without further testing
• If functional capacity 4-10 METs: May proceed to surgery without further testing
• If functional capacity <4 METs or unknown: Consider pharmacological stress testing if results will impact decision-making or allow 30-day period to optimize medical therapy before surgery

Step 5: Stress Testing Indications

Stress testing is reasonable when 1:

• Patient has elevated risk (≥3 RCRI factors) AND poor/unknown functional capacity
• Results will change management (decision to perform surgery, willingness to undergo revascularization, or perioperative care strategy)

Preferred modality: Pharmacological stress testing (dobutamine stress echocardiography or myocardial perfusion imaging) for patients unable to exercise 1

Critical caveat: Routine preoperative coronary revascularization performed exclusively to reduce perioperative cardiac events is NOT recommended—it does not decrease MI or death rates 1, 4

Preoperative Testing Recommendations

Electrocardiography

• Reasonable (Class IIa): Patients with known coronary heart disease or significant structural heart disease undergoing elevated-risk surgery 1
• May be considered (Class IIb): Asymptomatic patients undergoing elevated-risk surgery 1
• NOT useful (Class III): Asymptomatic patients undergoing low-risk surgery 1

Left Ventricular Function Assessment

• Reasonable (Class IIa): Patients with dyspnea of unknown origin OR patients with heart failure and worsening dyspnea or change in clinical status 1
• May be considered (Class IIb): Reassessment in clinically stable patients with previously documented LV dysfunction if no assessment within one year 1
• NOT recommended (Class III): Routine preoperative evaluation of LV function 1

Chest Radiography

• Reasonable: Patients at risk of postoperative pulmonary complications if results would change perioperative management 1
• NOT recommended: Routine use for predicting postoperative pulmonary complications 5

Laboratory Testing

Electrolytes and creatinine 1:

• Patients with chronic kidney disease, heart failure, or taking diuretics, ACE inhibitors, ARBs, or other medications predisposing to electrolyte abnormalities

Hemoglobin A1c 2, 3:

• Measure preoperatively for risk stratification in diabetic patients
• Target <7% to reduce complications including infections and ischemic events

Serum albumin 2, 3:

• Assess preoperatively as hypoalbuminemia correlates with increased ventilator time, acute kidney injury, infection, longer hospital stays, and mortality

Complete blood count 1:

• Patients with diseases increasing risk of anemia or when significant perioperative blood loss anticipated

Coagulation studies 1:

• Reserved for patients with history of bleeding, medical conditions predisposing to bleeding, or taking anticoagulants

Urinalysis 1:

• Only for patients undergoing invasive urologic procedures or implantation of foreign material

Pulmonary Risk Assessment

High-Risk Patient Factors

Counsel patients with the following risk factors about increased pulmonary complications 1, 5:

• Advanced age ≥65 years (odds ratio 2.09-3.04 depending on age bracket)
• Chronic obstructive pulmonary disease (odds ratio 1.79)
• Functional dependence
• Congestive heart failure
• Recent weight loss
• Obstructive sleep apnea
• Myelopathy (for spine surgery patients)

Pulmonary Function Testing

NOT recommended routinely 5: Preoperative spirometry and chest radiography should not be used routinely for predicting postoperative pulmonary complication risk

Consider testing when 1, 5:

• Active pulmonary symptoms present
• Suspected pulmonary disease requiring confirmation
• Lung resection surgery planned (specific criteria apply)

For lung resection surgery specifically 1, 5:

• Post-bronchodilator FEV1 >1.5 liters generally suitable for lobectomy
• Post-bronchodilator FEV1 >2.0 liters generally suitable for pneumonectomy
• If estimated postoperative FEV1 and TLCO both >40% predicted with O2 saturation >90%: average risk
• If both <40% predicted: high risk requiring further evaluation

Preoperative Optimization Strategies

Cardiovascular Optimization

Beta-blocker management 1, 2, 3, 6, 4:

• Continue in patients already taking beta-blockers for angina, symptomatic arrhythmias, or hypertension
• Consider initiating in patients with known ischemic heart disease or myocardial ischemia undergoing elevated-risk surgery
• Timing: Start between 30 days and minimum 2 days before surgery (ideally 1 month)
• Dosing: Begin with low dose (bisoprolol 2.5-5 mg/day), titrate to heart rate 60-70 bpm with systolic BP >100 mmHg
• Critical warning: Do NOT routinely withdraw chronically administered beta-blockers before surgery—abrupt discontinuation can cause severe exacerbation of angina, MI, and ventricular arrhythmias

Statin therapy 3, 4:

• Initiate in all patients undergoing vascular surgery regardless of risk factors
• Start ideally 30 days before surgery using long-acting formulations (e.g., fluvastatin 80 mg/day)
• Sharply decreases MI, stroke, and death perioperatively and long-term

ACE inhibitors/ARBs 2, 3:

• Consider before surgery in patients with heart failure and systolic LV dysfunction (LVEF <40%)
• Restart postoperatively only after confirming patient is euvolemic to decrease risk of perioperative renal dysfunction

Lifestyle Modifications

Smoking cessation 2, 3:

• Implement at least 4 weeks before surgery to reduce respiratory and wound-healing complications

Alcohol abstinence 2, 3:

• Strongly recommended for 4 weeks preoperatively in patients consuming >2 units of alcohol per day

Metabolic Optimization

Diabetes management 2, 3:

• Target hemoglobin A1c <7%
• Control blood glucose concentration during perioperative period in patients with diabetes or acute hyperglycemia at high risk for myocardial ischemia

Common Pitfalls to Avoid

• Viewing evaluation as "medical clearance" rather than comprehensive risk assessment and optimization 2, 3
• Ordering tests that won't change management: Stress testing in low-risk patients or those with excellent functional capacity delays surgery without benefit 1, 4
• Performing prophylactic coronary revascularization: Does not reduce perioperative cardiac events 1, 4
• Abruptly stopping beta-blockers perioperatively: Can precipitate acute coronary events 6
• Starting beta-blockers too close to surgery or at high doses: Improper timing and dosing may increase stroke and death rates 4
• Failing to communicate findings: All recommendations must be clearly communicated to surgeon, anesthesiologist, and perioperative team 1, 2
• Delaying urgent surgery for extensive testing: When surgery is time-sensitive, limited evaluation suffices 2, 3

Special Populations

Elderly patients (≥65 years) 1, 3:

• Age alone causes only small increase in risk
• Greater risks associated with urgency and significant cardiac, pulmonary, and renal disease
• Require surgery four times more often than younger population
• Pre-assessment by senior geriatrician and senior anesthetist recommended for higher-risk cases

Obese patients 3:

• Increased risk of cardiopulmonary complications
• Cardiac symptoms (exertional dyspnea, lower-extremity edema) are nonspecific
• Physical examination and ECG often underestimate cardiac dysfunction
• May require additional respiratory assessment

Patients with obstructive sleep apnea 3:

• Screen with STOP-BANG questionnaire
• High-risk patients may need polysomnography for further evaluation