P144 PEMBROLIZUMAB–INDUCED MYOCARDITIS

Abstract

Abstract Introduction Patients treated with Immunocheckpoint Inhibitors (ICI) can develop adverse cardiovascular events, most frequently myocarditis, but also arrhythmias, conduction abnormalities, pericarditis, Takotsubo syndrome, ACS, heart failure, cardiac arrest. Myocarditis occurs early, within the first 3–4 administrations of therapy, and is fraught with a high mortality rate. Case Presentation 80–year–old patient with renal pelvic carcinoma who underwent nephroureterectomy and subsequent adrenalectomy. Twenty days after the first cycle of Pembrolizumab, the patient is admitted to cardiology for syncope and ECG finding of Left Posterior Fascicular Block (LPFB) and right bundle branch block (RBBB) with significant increase in troponin without any alterations in regional kinetics and normal ventricular function (EF). The patient also complains of widespread muscle pain and severe hyponatremia on blood tests. On ECG monitoring, alternation of RBBB with associated LPFB and Left Posterior Fascicular Block, left bundle branch block, first and second degree atrio–ventricular block (AV block) and on day II appearance of complete paroxysmal AV block controlled with temporary pacemaker implantation. On the 4th day, we documented changes in the segmental motion of the left ventricle (LV) and progressive gradual worsening of the EF. During the hospitalization the patient manifested episodes of general malaise with profuse sweating and marked hypotension with possible SIADH picture. In suspicion of acute myocarditis, peripheral myositis and possible Pembrolizumab SIADH, the patient was treated with high dose methylprednisolone (1000 mg / day) with little benefit. On the 6th day the patient was found in critical condition, severely suffering, hypotensive and oliguric, resigned herself. Conclusions Our case highlights how even a single dose of Pembrolizumab can trigger an acute inflammatory pattern affecting the myocardium with prevalent involvement of the conduction tissue even before the appearance of alterations in the kinetics and ventricular dysfunction. During ICI therapy cycles it is therefore important to monitor the ECG and troponin levels in order to be able to diagnose myocardial involvement early. In fact, although this complication is rare, it is burdened by a high mortality rate. The only treatment currently available involves the suspension of immunotherapy and the administration of high–dose methylprednisolone.