The Cardio-Oncology Checklist: Managing Anthracycline and Trastuzumab Toxicity

Managing the cardiotoxic effects of Anthracyclines (e.g., Doxorubicin) and Trastuzumab is a cornerstone of modern cardio-oncology. While both can lead to heart failure, their mechanisms and “reversibility” profiles differ significantly. Here is a clinical checklist for managing these toxicities.

---

1. Baseline Assessment (Pre-Treatment)

Before the first dose, establish a “cardiac starting point” to identify high-risk patients.

• Imaging: Obtain a baseline Echo with Global Longitudinal Strain (GLS). GLS is more sensitive than LVEF for detecting early subclinical injury.
• Biomarkers: Measure baseline Troponin (I or T) and BNP/NT-proBNP.
• Risk Scoring: Calculate risk using the HFA-ICOS assessment tool, accounting for age, prior CVD, hypertension, and previous chest radiation. That is a tool by Cardio‐Oncology Study Group of the Heart Failure Association of the European Society of Cardiology in collaboration with International Cardio‐Oncology Society.
• Optimization: Ensure BP is strictly controlled (target <130/80 mmHg) and start statins if the patient is high-risk.

---

2. Monitoring During Therapy

The frequency of monitoring depends on the specific drug and the patient’s baseline risk.

Anthracyclines (Type I Toxicity – “Irreversible”)

Mechanism: Myocyte death and replacement fibrosis (often dose-dependent).

• Monitoring: Usually at baseline, at a cumulative dose of 250 mg/m².
• Red Flags: A drop in LVEF >10 percentage points to a value below 50%, or a relative decrease in GLS >15% from baseline.

Trastuzumab (Type II Toxicity – “Reversible”)

Mechanism: Myocyte “stunning” or dysfunction without structural death.

• Monitoring: Typically every 3 months during the one-year course of therapy.
• Key Distinction: Unlike anthracyclines, trastuzumab toxicity is usually not dose-dependent and often improves after holding the medication.

---

3. Intervention Thresholds

If toxicity is detected, the “Stop, Start, or Continue” decision is critical.

Clinical Finding	Action Plan
Asymptomatic LVEF 40-49%	Start ACEI/ARB and Beta-blocker (Carvedilol preferred). Discuss “Treat-to-through” with Oncology.
Symptomatic Heart Failure	Hold chemotherapy immediately. Initiate standard GDMT (Guideline-Directed Medical Therapy).
Δ GLS decline >15% (Normal LVEF)	Consider starting cardioprotective therapy (ACEI/Statins) even if LVEF remains normal.
Elevated Troponin	Frequent monitoring; consider initiating ACEI to prevent LVEF decline.

---

4. Post-Treatment Surveillance

Cardiotoxicity can manifest years after the conclusion of chemotherapy.

• High-Risk Patients: Echo at 6 months and 12 months post-treatment.
• Long-term: Periodic screening every 1–5 years depending on the cumulative anthracycline dose and clinical status.
• Lifestyle: Emphasize “heart-healthy” habits, as these survivors have a higher lifetime risk of CAD and metabolic syndrome.

---