Is a patient with Coronary Artery Disease (CAD) and Heart Failure with Reduced Ejection Fraction (HFrEF) of 50% classified as American Society of Anesthesiologists (ASA) 2 or 3?

ASA Classification for Patients with CAD and HFrEF of 50%

A patient with Coronary Artery Disease (CAD) and Heart Failure with Reduced Ejection Fraction (HFrEF) of 50% should be classified as ASA 3. 1

Understanding ASA Classification for Cardiac Patients

The American Society of Anesthesiologists (ASA) physical status classification system categorizes patients based on their preoperative health status:

• ASA 1: Healthy patient
• ASA 2: Patient with mild systemic disease
• ASA 3: Patient with severe systemic disease
• ASA 4: Patient with severe systemic disease that is a constant threat to life

Why This Patient is ASA 3:

1. Severe Systemic Disease Definition:

   • According to the ASA classification guidelines, both CAD and heart failure are considered severe systemic diseases 1
   • The UK National Institute for Clinical Excellence specifically categorizes patients with cardiovascular disease as ASA 3 when they have significant cardiac comorbidities 1

2. Impact of CAD:

   • CAD is associated with worse outcomes in heart failure patients 2
   • CAD portends higher rates of cardiovascular death and heart failure hospitalization (40.6 vs. 30.1/100 patient-years in patients with vs. without CAD) 2

3. Heart Failure Considerations:

   • While an ejection fraction of 50% is at the borderline between HFrEF and HFpEF, the presence of both CAD and heart failure represents significant cardiac pathology
   • Current guidelines classify HF with EF 41-49% as HF with mildly reduced EF (HFmrEF), which still represents significant cardiac dysfunction 1

Important Clinical Implications

• Preoperative Testing Requirements:

  • Patients with CAD and heart failure require more extensive preoperative evaluation, including ECG and potentially additional cardiac testing 1
  • Electrolyte measurements are recommended for all patients with cardiovascular disease classified as ASA 3 1

• Perioperative Risk:

  • CAD with heart failure significantly increases perioperative risk compared to either condition alone
  • These patients have reduced cardiac reserve and are more vulnerable to hemodynamic changes during surgery

• Medication Management:

  • Guideline-directed medical therapy (GDMT) should be maintained perioperatively when possible, as it is associated with reduced mortality in patients with CAD and HFrEF 3
  • Careful monitoring of fluid status and hemodynamics is essential

Common Pitfalls to Avoid

1. Misclassifying as ASA 2:

   • Some might incorrectly classify this patient as ASA 2 if they focus only on the relatively preserved EF of 50%
   • This ignores the combined impact of two serious cardiac conditions (CAD + HF)

2. Overclassifying as ASA 4:

   • Without evidence of the disease being a constant threat to life (such as unstable angina or decompensated heart failure), ASA 4 would be inappropriate
   • ASA 4 would be appropriate for patients with severe, unstable cardiac disease

3. Ignoring Functional Capacity:

   • Some research suggests that ASA 3 patients can be further subdivided based on functional capacity measured in metabolic equivalents (METs) 4
   • This additional assessment can help refine risk stratification within the ASA 3 category

In conclusion, the combination of CAD and HFrEF, even with an EF of 50%, represents severe systemic disease that significantly impacts perioperative risk and management, warranting an ASA 3 classification.