Tehran University of Medical Sciences International Journal of Hematology-Oncology and Stem Cell Research 2008-2207 15 4 2021 10 14 206 212 Mohsen Esfandbod Department of Clinical Hematology and Bone Marrow Transplantation, Vali-e-Asr Hospital, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran Mina Naderi Department of Internal Medicine, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran Azadeh Sadat Naseri Department of Cardiology, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran Ayat Ahmadi Knowledge Utilization Research Center, Tehran University of Medical Sciences, Tehran, Iran Mohammadtaghi Noroozi Department of Internal Medicine, Medical Oncology-Hematology Ward, Sina Hospital, Tehran University of Medical Science (TUMS), tehran, iran Saeid Sadeghi Joni Department of Radiology, Razi Hospital, Guilan University of Medical Sciences, Rasht, Iran 2020 05 23 2020 09 10 Background: Trastuzumab is an efficient monoclonal antibody used in the treatment of Her2-positive breast cancer. Despite its prominent effect on Her2-positive patients’ disease-free Survival. Trastuzumab-induced cardiotoxicity is still one of the main challenges.  Angiotensin-converting enzyme inhibitors (ACE inhibitors) are one of the most potent agents used in heart failure, which also showed confirmed cardioprotective effects against anthracycline and doxorubicin. We aimed to assess the cardioprotective effects of Carvedilol in a randomized clinical trial study. Materials and Methods: sixty non-metastatic Her-2 positive patients (30 cases; 30 controls) were entered to the study via a simple randomization method. Carvedilol was administered for the patients with the starting dose of 3.125 mg twice a day and started 7 days before trastuzumab administration. The dose has been increased in a three-week period to reach 12.5 mg twice a day and continued until the end of therapy. All the patients underwent an echocardiography after receiving Adriamycin and Cyclophosphamide in order to measure basal Ejection Fraction (EF) and Pulmonary Artery Pressure (PAP). Each patient underwent a follow-up echocardiography in 3,6,9 and 12 months after initiation of the treatment. Finally, all the patients went through the last episode of echocardiography 1 month after the end of treatment. All the Measured PAP and EF has been recorded and analyzed Results: EF and PAP changes for both groups had no significant changes during the course of treatment with Trastuzmab (p-value = 0.628 and p-value = 0.723, respectively). 7 patients in the intervention group and 2 patients in the control group presented with EF decrease. Also, 8 patients in the intervention and 9 patients in the control groups showed PAP increase. Conclusion: According to our results, in patients with HER2-positive breast cancer treated with trastuzumab, Carvedilol showed no significant protective effect on trastuzumab-induced cardiotoxicity. https://ijhoscr.tums.ac.ir/index.php/ijhoscr/article/view/1346 https://ijhoscr.tums.ac.ir/index.php/ijhoscr/article/download/1346/886