In a patient being evaluated for lung lobectomy with forced expiratory volume in one second (FEV1) < 1.5 L who cannot perform an exercise test, can a resting transthoracic echocardiogram replace pre‑operative exercise testing for cardiac risk assessment?

Echocardiography Cannot Replace Exercise Testing for Preoperative Risk Assessment in Lung Lobectomy

Resting echocardiography is not an appropriate substitute for exercise testing in this clinical scenario and should only be used for specific cardiac indications, not as a replacement for cardiopulmonary risk stratification.

The Role of Echocardiography in Preoperative Assessment

Echocardiography has a very limited and specific role in preoperative evaluation for lung resection:

• Echocardiography is indicated only for patients with an audible cardiac murmur, not as a routine screening tool or exercise test replacement 1
• Resting echocardiography provides information about cardiac structure and function but does not assess integrated cardiopulmonary reserve, which is the critical determinant of perioperative risk in lung resection 1
• The guidelines make no provision for using echocardiography as a substitute for exercise testing in risk stratification 1

The Correct Approach for FEV1 < 1.5 L

Since your patient has FEV1 < 1.5 L, they fall into the high-risk category requiring systematic evaluation:

Step 1: Calculate Predicted Postoperative Values

• Perform full pulmonary function tests including TLCO (transfer factor) 1
• Measure oxygen saturation on room air at rest 1
• Calculate estimated postoperative FEV1 (ppoFEV1) using the anatomical formula: ppoFEV1 = preFEV1 × (19 - segments removed) / 19 1, 2
• Calculate estimated postoperative TLCO (ppoTLCO) using the same formula 1, 2
• Express both values as percentage of predicted normal 1, 2

Step 2: Risk Stratification Based on Calculated Values

• If ppoFEV1 >40% predicted AND ppoTLCO >40% predicted AND SaO2 >90% on air: average risk, proceed with surgery 1
• If ppoFEV1 <40% predicted AND ppoTLCO <40% predicted: high risk 1
• All other combinations: exercise testing is required 1

Step 3: Alternative Testing When Formal Exercise Testing is Impossible

If the patient truly cannot perform cardiopulmonary exercise testing, the guidelines provide alternatives:

• Shuttle walk test: A distance <250 meters (25 shuttles) or desaturation >4% indicates high surgical risk 1
• Stair climbing test: Inability to climb 3 flights of stairs (12 meters) suggests high risk for lobectomy 3
• These low-technology tests can be performed when formal cardiopulmonary exercise testing is unavailable 1

Critical Pitfalls to Avoid

The most important caveat: The reason exercise testing is required is because it assesses the integrated cardiopulmonary response to stress, which resting pulmonary function tests and echocardiography cannot evaluate 1. A patient may have acceptable resting cardiac function on echocardiogram but still have inadequate cardiopulmonary reserve for major surgery.

• Do not proceed to surgery based solely on resting tests when ppoFEV1 or ppoTLCO fall in indeterminate ranges 1
• Modern VATS techniques may allow safer resection in borderline patients, with acceptable mortality even when ppoFEV1 or ppoDLCO <40% (mortality 0.7-2.0% for VATS vs 4.8-5.2% for open) 4
• Consider limited resection (wedge or segmental) instead of lobectomy if exercise capacity proves inadequate 5

Multidisciplinary Discussion Required

Patients with FEV1 <1.5 L who cannot perform exercise testing should have their management formally discussed at a multidisciplinary meeting between chest physician, surgeon, and oncologist 1. This allows consideration of alternative treatment strategies including radical radiotherapy if surgical risk is deemed prohibitive 1.