Cardiotoxicity Conundrum: Distinguishing Immune Checkpoint Inhibitor Myocarditis From Fluorouracil Cardiotoxicity in...

Area of Science:

• Cardiology
• Oncology
• Pharmacology

Background:

• Immune checkpoint inhibitors (ICIs) have revolutionized cancer therapy but can cause rare cardiotoxicities.
• Concurrent chemotherapy, like fluorouracil (5FU), presents distinct cardiac risks.
• Overlapping toxicities complicate diagnosis in combination cancer treatments.

Observation:

• A patient developed cardiogenic shock after starting ICI and 5FU therapy.
• Initial treatment for both ICI myocarditis and 5FU cardiotoxicity led to rapid improvement.
• A subsequent successful rechallenge with nivolumab suggested 5FU as the primary cause.

Findings:

• Distinguishing cardiotoxicity from combined ICI and chemotherapy is difficult.
• Diagnostic tests alone may not suffice; clinical assessment is vital.
• Accurate identification of the cardiotoxic agent is crucial for patient management.

Implications:

• This case underscores the need for careful evaluation of cardiotoxicity in patients on combination therapy.
• Prompt diagnosis influences subsequent treatment decisions and cancer prognosis.
• Understanding drug-specific cardiotoxic profiles is essential for safe and effective cancer care.