Introduction: Chimeric Antigen receptor T- Cell (CAR-T) immunotherapy has been a breakthrough for various hematological malignancies. Cardiotoxicites such as heart failure, arrhythmia and acute coronary syndrome occur in approximately 1/3 of patients who develop cytokine release syndrome (CRS) following CAR-T. High grade CRS (Grade ≥ 2) and elevated troponin level are associated with increased risk of cardiotoxicity. It is unclear whether active cardiotoxicity surveillance with serial cardiac biomarker measurements during CAR-T would allow early detection of cardiotoxicity. Methods: This was retrospective cohort study involving patients diagnosed with non-Hodgkin lymphoma treated with CAR-T therapy (Axicabtagene ciloleucel- Yescarta, tisagenlecleucel- Kymriah, Brexucabtagene autoleucel- Tecartus). Baseline cardiac workup with electrocardiogram (ECG), transthoracic echocardiogram (TTE), troponin (Reference <0.03ng/mL), B-natriuretic peptide (BNP, <100pg/mL) were uniformly performed in all participants. Follow up ECG, Troponin and BNP were obtained at day 5 after CAR-T and at development of CRS Grade ≥2. When clinically indicated, cardiac MRI with gadolinium contrast was performed. Cardiac MRI diagnosis of myocarditis was based on Lake Louise Criteria. Results: A total of 47patients undergoing CAR-T therapy were studied. Baseline comorbidities were not predictive of CRS or cardiac events. There were 39 patients with low grade CRS (82.9%) and 8 patients (17.0%) with grade 2 CRS. Five patients had elevated troponin I levels (Grade 1 CRS - 3; Grade 2 CRS - 2). Cardiac MRIs were performed in three patients (two normal studies, one with mild myocarditis). Five patients (10.6%) had an adverse cardiac event (Myocarditis with heart failure - 1; new-onset atrial fibrillation - 3; Type 2 myocardial infarction -1). Conclusion: Adverse cardiac events are a relatively common occurrence in patients receiving CART therapy. Active surveillance for cardiotoxicity using cardiac biomarkers in CAR-T patients may play an adjunctive role in the early identification of adverse cardiac events. Larger studies are needed to adjudicate the use of such screening measures in these high-risk patients.