Cardiac Contraindications to Starting Chemotherapy

Risk Stratification and Cardioprotective Strategies

• The American Society of Clinical Oncology recommends that patients with severe left ventricular dysfunction (LVEF <40%), decompensated heart failure, recent myocardial infarction, unstable angina, and uncontrolled arrhythmias require stabilization, alternative regimens, or dose modification before initiating cardiotoxic agents 1, 2
• All patients require comprehensive cardiovascular evaluation before starting potentially cardiotoxic chemotherapy, including assessment of cardiac structure, performance, and hemodynamics, according to the European Society of Medical Oncology 3, 1
• Baseline echocardiogram with LVEF measurement is recommended for all patients receiving anthracyclines, especially with CV risk factors, age >60 years, previous CVD, or prior mediastinal irradiation, as suggested by the American Heart Association 3, 1
• LVEF <54% is identified as a risk factor for development of heart failure in patients undergoing trastuzumab therapy, with a reported incidence of 27% when combined with anthracyclines, according to the American College of Cardiology 1, 6
• Prior anthracycline exposure approaching cumulative dose limits (doxorubicin 500-550 mg/m²) is associated with a 4-36% incidence of cardiotoxicity, as reported by the National Comprehensive Cancer Network 7, 6
• The use of 5-Fluorouracil (5-FU) presents unique risks, including prior coronary vasospasm, recent acute coronary syndrome, or unstable angina, which require stabilization and ischemic workup before administration, as recommended by the American Society of Clinical Oncology 5, 6

Clinical Decision Algorithm

• The European Society of Medical Oncology suggests that patients with decompensated heart failure, acute coronary syndrome, or unstable angina require stabilization before proceeding with chemotherapy 3, 5
• Measuring baseline LVEF is crucial, with LVEF ≥54% allowing for standard monitoring, LVEF 40-53% requiring consideration of alternative regimens or cardioprotective strategies, and LVEF <40% necessitating deferment of cardiotoxic chemotherapy, as recommended by the American College of Cardiology 1, 2
• Agent-specific risk assessment is necessary, including screening for prior coronary vasospasm, recent ACS, or significant CAD for 5-FU, calculating cumulative dose exposure for anthracyclines, and assessing LVEF thresholds for trastuzumab, as suggested by the National Comprehensive Cancer Network 5, 6, 1

Monitoring During Treatment

• Serial cardiac function monitoring is essential, with measurements at baseline, 3, 6, and 9 months during treatment, and 12 and 18 months after initiation, as recommended by the American Society of Clinical Oncology 2
• Cardiac biomarkers, such as troponin I and BNP, should be measured at baseline and periodically to identify at-risk patients, according to the European Society of Medical Oncology 2
• Frequent vital signs monitoring during infusion, particularly with 5-FU or paclitaxel, is crucial, as suggested by the American Heart Association 3, 1