What cardiac tests are most appropriate for an 84-year-old patient with moderate aortic stenosis (AS), impaired renal function, and a history of multiple myeloma undergoing hip replacement surgery?

Pre-Operative Cardiac Testing for Hip Replacement in an 84-Year-Old with Moderate Aortic Stenosis

For this 84-year-old patient with moderate aortic stenosis, GFR 44, and history of myeloma undergoing hip replacement, obtain a transthoracic echocardiogram (TTE) and 12-lead ECG; do not perform stress testing or coronary angiography unless the patient has symptoms of myocardial ischemia or unstable coronary syndrome.

Essential Pre-Operative Testing

Transthoracic Echocardiography (TTE)

• TTE is the cornerstone test to establish the severity of aortic stenosis and assess left ventricular function before noncardiac surgery 1.

• Key measurements needed include:

  • Aortic valve area, peak velocity, and mean gradient to confirm moderate AS severity 1
  • Left ventricular ejection fraction (LVEF) and regional wall motion abnormalities 1
  • Right ventricular size and function 1
  • Pulmonary artery systolic pressure estimation 1
  • Assessment for mitral valve disease (regurgitation, stenosis, annular calcification) 1

• If the patient has had a recent TTE within the past year and remains clinically stable, repeat echocardiography may not be necessary 2, 3.

• For moderate AS without symptoms or clinical changes, echocardiography is typically recommended every 1-2 years 1, 3.

12-Lead Electrocardiogram (ECG)

• A preoperative resting 12-lead ECG is reasonable for patients with known structural heart disease (including moderate AS) undergoing intermediate or high-risk surgery 1.
• The ECG helps identify:
  • Left ventricular hypertrophy patterns 1
  • Conduction abnormalities 1
  • Arrhythmias, particularly atrial fibrillation 1
  • Evidence of prior myocardial infarction 1

Testing NOT Recommended

Stress Testing

• Routine preoperative stress testing should NOT be performed in this patient 1.

• Stress testing is contraindicated in patients with severe or symptomatic aortic stenosis 1.

• Even for moderate AS, stress testing is not indicated unless:

  • The patient has symptoms suggesting unstable coronary syndrome 1
  • There is clinical evidence of active myocardial ischemia 1
  • The patient's functional capacity is unknown AND testing would change management 1

• For patients with adequate functional capacity (≥4 METs), stress testing does not improve outcomes and should be avoided 1.

Coronary Angiography

• Routine coronary angiography is NOT indicated for preoperative evaluation unless the patient has unstable coronary syndromes or significant symptoms of myocardial ischemia 1.
• Coronary angiography before noncardiac surgery has not been shown to reduce mortality or perioperative MI risk 1.
• The CARP trial demonstrated no benefit of preoperative coronary revascularization before major vascular surgery 1.

Advanced Cardiac Imaging (CT/MRI)

• Cardiac CT or MRI is NOT indicated for routine preoperative evaluation before hip replacement 1.
• These modalities are reserved for:
  • Pre-TAVR planning (not applicable here) 1
  • Assessment of thoracic aortic disease when suspected 1
  • Evaluation when echocardiography is inadequate or inconclusive 1

Special Considerations for This Patient

Renal Function (GFR 44)

• The impaired renal function (GFR 44) is a relative contraindication to contrast-enhanced studies 1.
• If coronary angiography were needed (which it is not in this case), low-volume contrast techniques or alternative imaging would be required 1.
• Non-contrast echocardiography is the ideal imaging modality given the renal impairment 1.

Moderate Aortic Stenosis and Hip Fracture Surgery

• Patients with moderate AS can safely undergo orthopedic surgery including hip fracture repair with appropriate perioperative management 4, 5.
• A study of elderly patients (median age 84.5 years) with severe AS undergoing hip fracture repair showed 30-day mortality of only 6.2%, comparable to controls without AS 4.
• Even patients with severe AS (aortic valve area <0.5 cm²/m²) can undergo noncardiac surgery with acceptable risk when proper intraoperative hemodynamic monitoring is used 5.

History of Myeloma

• The myeloma history does not change cardiac testing recommendations but may affect:
  • Anemia assessment (obtain hemoglobin/hematocrit) 1
  • Renal function monitoring (already noted with GFR 44) 1
  • Risk of perioperative complications unrelated to cardiac status 1

Perioperative Management Priorities

Hemodynamic Monitoring

• Intraarterial blood pressure monitoring should be strongly considered during surgery 5.
• In a series of patients with severe AS undergoing noncardiac surgery, intraarterial monitoring was used in 71% of procedures with excellent outcomes 5.

Anesthesia Team Communication

• The anesthesia team must be explicitly informed of the moderate AS diagnosis to integrate this into the anesthetic plan 6, 5.
• Key perioperative goals include:
  • Maintaining preload (avoid hypovolemia) 6
  • Maintaining afterload (treat hypotension promptly with phenylephrine) 5
  • Maintaining sinus rhythm and avoiding tachycardia 6
  • Avoiding myocardial depression 6

Common Pitfalls to Avoid

• Do not delay urgent or semi-urgent hip surgery to obtain extensive cardiac testing 1.
• Hip fractures require timely surgical intervention, and delays increase morbidity and mortality 4.
• Do not order stress testing in patients with moderate-to-severe AS, as it may be contraindicated and will not change management 1.
• Do not assume that moderate AS requires aortic valve replacement before hip surgery 6, 4, 5.
• The decision for valve replacement should be based on AS symptoms and severity, not the need for noncardiac surgery 6.
• Do not use contrast-enhanced imaging unnecessarily in patients with GFR <45 mL/min 1.