Each year, more than 300 million surgeries occur globally. Cardiac complications remain among the biggest contributors to postoperative morbidity and mortality and are responsible for over one-third of perioperative deaths. 

The latest 2024 ACC/AHA guideline provides updated, evidence-based recommendations for perioperative cardiac management, emphasizing risk assessment, patient stratification, and tailored interventions for patients with ischemic heart disease (IHD) undergoing noncardiac surgery.

Preoperative Cardiac Risk in Patients with IHD

Risk Stratification

Patient risk: Evaluation begins with a detailed history and physical exam focused on cardiovascular symptoms (chest pain, dyspnea), previous cardiac events or interventions (MI, PCI, CABG), current clinical status, medications, risk factors (age, hypertension, diabetes, dyslipidemia, smoking), and comorbidities such as CVA, PAD, CKD, COPD, OSA.

Functional capacity is also key, measured by the Duke Activity Status Index (DASI), with scores above 34 (or the ability to climb 2 flights of stairs) suggesting low perioperative risk.

Surgical risk: Risk level varies by procedure. High-risk surgeries include aortic and major vascular procedures with intermediate-risk examples including orthopedic, urologic , or gynecologic surgery. Procedure duration, hemodynamic compromise, blood loss, and anesthesia type also factor. The 2024 AAC update now states the following definitions for surgical urgency:

  • Emergency: Now defined as <2 hours to intervention (previously <6 hours).
  • Urgent: Surgery needed within 24 hours.
  • Time-sensitive: Surgery typically needed within up to 3 months (expanded from 6 weeks).
  • Elective: Can be delayed indefinitely as required for optimization of evaluation and management plan.

Cardiac risk stratification tools: The current ACC (and ESC) guidelines do not endorse a single preferred tool for calculating cardiac risk. Newer calculators now exist, adding to the 2014 guideline recommendations for Lee Revised Cardiac Risk Index (RCRI), Gupta Myocardial Infarction or Cardiac Arrest (MICA) calculator, and the Bilimoria American College of Surgeons Surgical Risk Calculator (ACS-SRC). These tools are all discussed in Chapter 9. 

Clinical risk categories are now defined as:

  • Low risk: <1% risk of major adverse cardiac events (MACE).
  • Elevated risk: ≥1% MACE risk. Risk modifiers not included in these calculators include severe valvular disease, pulmonary hypertension, congenital heart disease, prior CABG or PCI, CIEDs, frailty, and recent stroke.

Use of Cardiac Testing

Routine testing is not warranted unless it will change management. Electrocardiograms (ECGs) are appropriate for patients with known coronary artery disease (CAD) or undergoing intermediate/high-risk procedures. Echocardiography is reserved for suspected valvular disease or new or worsening symptoms of heart failure. 

Stress testing is indicated only if management may change and recommended for symptomatic or high-risk patients with poor exercise capacity. These patients may be considered for pharmacologic stress testing (nuclear imaging or dobutamine stress echo) to look for reversible areas of myocardial ischemia.

Cardiac CT Angiography (CCTA) is another option, looking for left main disease. However, it may misclassify some low-risk patients as high-risk and should be used judiciously. 

Invasive coronary angiography (ICA) is the gold standard for anatomical assessment of coronary artery disease and is appropriate for patients with high-risk abnormal noninvasive tests or severe, unstable anginal symptoms. In line with guidelines, the decision to perform ICA should be independent of the need for noncardiac surgery.

Biomarkers 

BNP/NT-proBNP and troponin may enhance risk prediction in patients over 65 years or with known CVD. Elevated levels suggest increased risk for postoperative events and may guide further testing. See Chapter 10 for further information.

Functional Capacity

The ACC society guidelines state that standardized assessment is recommended, as subjective clinician opinion can be unreliable.

  • Duke Activity Status Index (DASI): DASI score >34 (≈5 METs) predicts lower perioperative risk; a DASI of 25 (≈4 metabolic equivalents, METs) may be more practical in real-world patients, although associated with a slightly higher risk.
  • Functional capacity below 4 METs prompts consideration of further testing if it will change management.

The 2024 ACC/AHA stepwise approach detailed in Chapter 11 provides guidance to preoperative cardiac risk assessment. 

Medical Optimization

Medical management remains the cornerstone of risk reduction:

  • Dual antiplatelet therapy (DAPT) management depends on timing post-stenting: ideally, elective surgery should be delayed for 6 months after PCI  (12 months if done in the setting of ACS or complex anatomy), but if deemed time-sensitive, may be performed after completion of 3 months of DAPT.
  • Aspirin should be continued in patients with stents, MI or stroke, and for carotid endarterectomy.
  • Beta-blockers reduce myocardial ischemia and should be continued. For the few patients with an indication to initiate beta-blockers before surgery, these  must be started at least 7 days prior and titrated, if possible, to avoid bradycardia or hypotension.
  • Statins are beneficial and should be continued or initiated in appropriate patients with indications.
  • ACE inhibitors/ARBs can be withheld preop if used for hypertension (and BP is controlled) but resumed postop if stable. They can be continued for patients with heart failure.

Surgical Timing and Revascularization

Prophylactic revascularization (CABG/PCI) prior to surgery has not shown a clear benefit and is not recommended unless independently indicated. Timing of surgery post-intervention is critical: elective surgery should be delayed at least 14 days after balloon angioplasty, 30 days after bare-metal stent placement and optimally 6 months after drug-eluting stent placement.

Postoperative Care

Close monitoring of blood pressure, continuation of cardiac medications, and troponin surveillance in high-risk patients are essential for early detection and management of complications. Shared care models between surgical and medical teams can improve outcomes.