Pericarditis and Cardiac Tamponade in Patients Treated with First and Second Generation Bruton Tyrosine Kinase Inhibitors: An Underappreciated Risk

Introduction. The introduction of Bruton's tyrosine kinase (BTK) inhibitors significantly improved the management of chronic lymphocytic leukemia (CLL). However, BTK carry the risk of cardiotoxicity, which is not only limited to atrial fibrillation. Case Reports. We report three cases of patients on BTK inhibitors who developed acute pericarditis and cardiac tamponade. We report the first patient who developed this complication on treatment with zanubrutinib. This patient's treatment was changed to zanubrutinib due to atrial fibrillation. Shortly after cardioversion, he developed cardiac tamponade and shock. He underwent pericardiocentesis, received treatment for acute pericarditis with steroids and colchicine, and made a full recovery. We also report two further cases, both involving patients treated with ibrutinib. These patients also developed acute pericarditis and cardiac tamponade and required pericardiocentesis. All three patients discontinued BTK therapy following the events. Conclusions. These three cases highlight the rare but potentially life-threatening risk of cardiac tamponade which can occur even with newer generations of BTK inhibitors. Haemato-oncologists should remain vigilant in patients who report dyspnea or who show sinus tachycardia on routine electrocardiography. Even in the absence of classical clinical signs of tamponade, patients require urgent evaluation with echocardiography and potentially emergency pericardiocentesis.