Why did the hematologist order a stress echo for a male patient undergoing radiation and chemotherapy for colon cancer?

Why the Hematologist Ordered a Stress Echo

The hematologist likely ordered a stress echo to screen for chemotherapy-induced cardiotoxicity and assess for coronary artery disease, both of which are critical complications in patients receiving cancer treatment that can significantly impact morbidity, mortality, and quality of life. 1, 2

Primary Indications for Stress Echo in Cancer Patients

Cardiotoxicity Surveillance

• Chemotherapy agents used for colon cancer, particularly fluoropyrimidines (5-FU, capecitabine) and oxaliplatin, can cause direct myocardial damage and coronary vasospasm, necessitating cardiac monitoring even during active treatment 3
• Stress echocardiography evaluates both resting left ventricular ejection fraction (LVEF) and contractile reserve, which helps identify subclinical left ventricular dysfunction before it becomes symptomatic 1, 2
• A reduction in contractile reserve during stress testing can predict future cardiac dysfunction, even when resting LVEF appears normal 2

Coronary Artery Disease Assessment

• Chemotherapy and radiation therapy accelerate atherosclerotic processes, increasing the risk of coronary artery disease that may manifest years after treatment 2
• Stress echocardiography is the first-line noninvasive test for detecting stress-induced regional wall motion abnormalities indicative of myocardial ischemia 1
• This is particularly important because patients with cancer have different patterns of coronary disease, with higher prevalence of left anterior descending artery lesions compared to non-cancer patients 1

Timing and Clinical Context

Baseline Risk Stratification

• The ACR Appropriateness Criteria (2025) recommend establishing baseline cardiac function before initiating potentially cardiotoxic therapy 1
• For patients with pre-existing cardiovascular risk factors (age ≥60, hypertension, diabetes, prior cardiac disease), stress testing provides more comprehensive risk stratification than resting echocardiography alone 4, 5

During Active Treatment

• Stress echo can be performed during chemotherapy to detect early signs of cardiotoxicity when intervention with cardioprotective medications (beta-blockers, ACE inhibitors) may prevent progression 5, 2
• The test provides simultaneous assessment of ischemia, ventricular function, and valvular disease, making it efficient for comprehensive cardiac evaluation 1, 2

Advantages Over Resting Echo Alone

Enhanced Sensitivity

• Stress echocardiography unmasks subclinical dysfunction that may not be apparent at rest, particularly important in cancer patients who may have reduced physical activity levels 2
• Contractile reserve assessment during stress predicts which patients will develop overt heart failure, allowing for earlier intervention 2

Comprehensive Evaluation

• Beyond the primary indication, stress echo provides additional information including resting LVEF, valvular function, and pericardial assessment 1
• This is particularly valuable in cancer patients who may have multiple potential cardiac complications from their treatment regimen 3

Common Clinical Pitfalls

Misinterpretation of "Normal" Resting Function

• A normal resting LVEF does not exclude significant cardiotoxicity—stress testing may reveal impaired contractile reserve that predicts future dysfunction 2
• Relying solely on resting imaging may miss the window for cardioprotective intervention 5

Delayed Cardiac Assessment

• Most treatment-associated cardiac dysfunction develops within the first year after completion of therapy, but ischemic complications can occur during active treatment 4, 2
• Waiting for symptoms before ordering cardiac testing often means irreversible myocardial damage has already occurred 5, 6

Alternative Considerations

If stress echo is technically inadequate or contraindicated:

• Cardiac MRI with stress perfusion is the optimal alternative, providing superior tissue characterization and functional assessment without radiation exposure 7, 8
• Pharmacologic stress myocardial perfusion imaging (SPECT/PET) is second-line if MRI is unavailable, though it involves radiation exposure 7

Ongoing Management

• Serial imaging should use the same modality to maintain reproducibility and accurately track changes over time 7
• Maintain a low threshold for cardiology consultation if any decline in function or new symptoms develop during or after cancer treatment 7, 5
• Biomarker monitoring (troponin, BNP) in conjunction with imaging may identify patients needing more intensive cardiac surveillance 4, 5