Salido Iniesta Mario, López López Laura, Carreras Costa Francesc, Sionis Alessandro
Hospital de la Santa Creu i Sant Pau IIB Sant Pau, Carrer de Sant Quintí, 89, 08041 Barcelona, Spain.
Eur Heart J Case Rep. 2020 Oct 4;4(5):1-6. doi: 10.1093/ehjcr/ytaa214. eCollection 2020 Oct.
Pembrolizumab is an immune check-point inhibitor (ICI), which acts by blocking the T lymphocyte PD-1 inhibitor receptor. It has been increasingly used in advanced or non-responsive tumours with promising results. However, acute myocarditis is an infrequent but potentially life-threatening autoimmune adverse effect related to ICIs.
This case deals with a 69-year-old gentleman on second-line therapy with pembrolizumab for advanced non-small cell lung cancer. Three weeks after first dose, the patient was diagnosed with an autoimmune hepatitis, treated with decreasing corticoid dosage, followed by acute heart failure. On admission, his electrocardiogram (ECG) showed diffuse repolarization changes and a transthoracic echocardiography revealed severe left ventricle impairment (left ventricular ejection fraction 32%). High-sensitivity cardiac troponin was elevated and a coronary angiogram was performed showing non-significant obstructive disease. An autoimmune myocarditis was suspected, and high-dose intravenous corticoid, intravenous vasodilators, and loop diuretics were started with favourable response. Cardiac magnetic resonance (CMR) imaging, performed 2 weeks after clinical onset, revealed extracellular oedema in the anteroseptal-apical left ventricle segments. A new transthoracic echocardiography, performed after 3 months, showed preserved left ventricle ejection fraction. Finally, the patient was readmitted due to an autoimmune myasthenia-like syndrome.
Acute autoimmune myocarditis related to ICIs is a challenging diagnosis and its incidence has been underestimated in early studies. Endomyocardial biopsy (EMB) is the gold standard test for its diagnosis. Nevertheless, a definite myocarditis diagnosis is possible without EMB when characteristic clinical syndrome, elevated myonecrosis markers, and electrocardiographic, echocardiographic, and CMR changes are present together.
帕博利珠单抗是一种免疫检查点抑制剂（ICI），通过阻断T淋巴细胞程序性死亡受体1（PD-1）发挥作用。它已越来越多地用于晚期或难治性肿瘤，效果良好。然而，急性心肌炎是一种与ICI相关的罕见但可能危及生命的自身免疫不良反应。
本病例涉及一名69岁男性，接受帕博利珠单抗二线治疗晚期非小细胞肺癌。首次用药三周后，患者被诊断为自身免疫性肝炎，接受了逐渐减量的皮质类固醇治疗，随后出现急性心力衰竭。入院时，他的心电图（ECG）显示弥漫性复极改变，经胸超声心动图显示严重左心室功能损害（左心室射血分数32%）。高敏心肌肌钙蛋白升高，冠状动脉造影显示无明显阻塞性病变。怀疑为自身免疫性心肌炎，开始使用大剂量静脉皮质类固醇、静脉血管扩张剂和袢利尿剂，反应良好。临床发病两周后进行的心脏磁共振（CMR）成像显示左心室前间隔-心尖段细胞外水肿。三个月后进行的新的经胸超声心动图显示左心室射血分数恢复正常。最后，患者因自身免疫性重症肌无力样综合征再次入院。
与ICI相关的急性自身免疫性心肌炎诊断具有挑战性，早期研究中其发病率被低估。心内膜心肌活检（EMB）是其诊断的金标准。然而，当出现特征性临床综合征、肌坏死标志物升高以及心电图、超声心动图和CMR改变时，即使没有EMB也有可能明确诊断心肌炎。
