397 HEART FAILURE WITH REDUCE VENTRICULAR EJECTION FRACTION FOLLOWING THERAPY WITH RITUXIMAB IN A PATIENT AFFECTED BY MPO ANCA RELATED MICROSCOPIC POLYANGITIIS

Abstract

Abstract Introduction Rituximab is a chemotherapeutic drug widely used for the treatment of oncologic and rheumatologic diseases. Its cardiotoxic profile has not yet been defined in detail; only a few isolated case reports delineate cardiovascular adverse reactions following its use. In the cases described in literature, the drug was used to treat neoplastic diseases, often in combination with other chemotherapeutic drugs. We present a clinical case of heart failure with reduced ventricular ejection fraction (HFrEF), developed following therapy with Rituximab and a single administration of Cyclophosphamide, in a patient affected by MPO-ANCA-related Microscopic Polyangiitis. Case Report 54-year-old man arrived at the emergency department for weight loss, fever, asthenia, and lower limbs oedema; laboratory findings where diagnostic for acute kidney injury (AKI). His past history was unremarkable. He was admitted to the nephrology department where he was diagnosed with MPO-ANCA-related microscopic polyangiitis. Echocardiography on admission showed normal left systolic ventricular function. He underwent diuretic therapy, intermittent hemodialysis, plasmapheresis and immunosuppressive therapy with steroids, Rituximab (two administration of 375 mg/m2 i.v. one week apart) and Cyclophosphamide (one administration of 300 mg i.v.). Following the achievement of good clinical and hemodynamic compensation, the patient was discharged. However, 5 days later, the patient came back to the hospital, prior to the follow-up that was scheduled for the continuation of immunosuppressive therapy, with symptoms of worsening dyspnea related to acute pulmonary edema. A transthoracic echo showed severe left ventricular systolic dysfunction for global hypokinesia. Cardiac MRI showed hypokinetic dilated cardiomyopathy with severely depressed systolic function (EF 30%) in the absence of lesions compatible with edema and myocardial fibrosis/necrosis. No coronary artery disease was detected with CT coronary angiogram. Given the absence of signs of ischemic cardiopathy or inflammatory related cardiomyopathy, we considered this new onset of HFrEF likely due to cardiotoxicity from chemotherapy drugs, which, in agreement with nephrology colleagues, were discontinued. The patient was started on heart failure medication with Bisoprolol 2,5 mg once daily and Ramipril 2,5 b.i.d., mineralocorticoid receptor antagonist and glifozines were not administered due to the renal injury. Given the HFrEF and numerous features of non-sustained ventricular tachycardia found on EKG monitoring during hospitalization, the patient was discharged with a wearable ICD. He was discharged after 3 weeks in stable clinical conditions with a follow-up appointment in a month. Conclusion Our clinical case provides further evidence regarding the cardiotoxic effect of Rituximab. In contrast with the other cases in literature, Rituximab was used for the treatment of rheumatologic and non-neoplastic pathology, without being combined with several other chemotherapeutics but only with a low-dose administration of Cyclophosphamide. In light of the above, it is worth mentioning that when chemotherapeutics are used, not only in oncology but also in rheumatology, even when their cardiotoxicity profile has not been defined in detail, as in the case of Rituximab, it is essential to use the utmost caution in assessing cardiac function before and after drug administration, so that early detection of cardiotoxicity will be possible.