Grape Polyphenols for Prevention of Chemotherapy-Induced Cardiotoxicity

Inclusion Criteria: * Female patients aged 30 to 75 years. * Histologically confirmed breast cancer. * Planned treatment with anthracycline- and/or trastuzumab-based chemotherapy. * High or very high risk of chemotherapy-induced cardiotoxicity (≥20%), based on clinical assessment. * Eastern Cooperative Oncology Group (ECOG) performance status 0-3. * Ability to take oral study products. * Willingness to comply with study procedures and follow-up visits. * Written informed consent provided prior to any study procedures. Exclusion Criteria: * ECOG performance status of 4. * Pre-existing severe cardiovascular disease that would interfere with study participation. * Permanent atrial fibrillation or other clinically significant arrhythmias. * Severe hepatic or renal impairment. * Active central nervous system tumors or metastases. * Uncontrolled arterial hypertension. * Acute gastrointestinal diseases that may impair absorption. * Known allergy or intolerance to grape products or study components. * Participation in another interventional clinical trial that may interfere with the outcomes of this study.