RESUMEN

PURPOSE OF REVIEW: Cardiac sarcoidosis (CS) is an inflammatory disease of unknown etiology that can lead to life-threatening arrhythmias, heart failure, and death. Advanced cardiac imaging modalities have improved the clinician's ability to detect this disease. The purpose of this review is to discuss the recent evidence of cardiac metabolic imaging as assessed by [18F]FDG PET and [123I]BMIPP SPECT in the evaluation of CS patients. RECENT FINDINGS: [18F]FDG PET is the gold standard to identify myocardial inflammation. [123I]BMIPP SPECT can uncover early myocardial damage as well as advanced stages of CS when fibrosis prevails. In presence of inflammation, myocardial [18F]FDG uptake is increased, but in contrast, BMIPP myocardial uptake is reduced or even suppressed. Thus, a complementary role of cardiac metabolic imaging by [18F]FDG PET and BMIPP SPECT has been proposed to detect the whole spectrum of CS. [18F]FDG PET is considered an important tool to improve the diagnosis and optimize the management of CS. The role of [123I]BMIPP SPECT in diagnosing CS is still under investigation. Further studies are needed to evaluate the clinical utility of combined cardiac metabolic imaging in the diagnosis, prognosis, and for selecting treatments in CS patients.

Asunto(s)

RESUMEN

RESUMEN Introducción: Estudios recientes sugieren combinar los hallazgos de la resonancia magnética cardíaca (RMC) y los de la tomografía por emisión de positrones (PET) para incrementar la sensibilidad del diagnóstico de la sarcoidosis cardíaca (SC). Objetivo: Evaluar el valor complementario de la RMC y la PET en el diagnóstico de la SC. Material y métodos: Entre diciembre 2018 y Julio 2020, 6 pacientes (4 hombres y 2 mujeres) fueron referidos a nuestro servicio con sospecha de SC para evaluación de inflamación del miocardio. Se efectuó un estudio de perfusión miocárdica en reposo (13N Amonio) y de 18F-Fluordesoxiglucosa (FDG)-PET para evaluar inflamación y/o fibrosis. A todos los pacientes se les realizó previamente una RMC con gadolinio. Resultados: La edad media fue de 60 ± 9 años. El 50% de los pacientes presentaban antecedente de sarcoidosis sistémica y el otro 50% sospecha de SC aislada. Ninguno de los pacientes presentó inflamación activa del miocardio por PET. Con la combinación de los patrones-PET y el realce por RMC se reclasificó a los pacientes: 50% tuvo menos del 10% de probabilidad de padecer SC y el otro 50% se clasificó como posible. Ninguno de los pacientes recibió tratamiento inmunosupresor. Conclusión: En nuestra población de pacientes con sospecha de SC e inflamación, realizamos un estudio PET luego de la RMC para calcular probabilidades de padecer SC. En ausencia de un patrón oro, se sugiere que el diagnóstico de SC se base en probabilidades de acuerdo a patrones de imágenes y cuadro clínico específicos.

ABSTRACT Background: Recent studies suggest combining the findings of cardiac magnetic resonance (CMR) and positron emission tomography (PET) to increase sensitivity in the diagnosis of cardiac sarcoidosis (CS). Objective: To evaluate the complementary value of CMR and PET in the diagnosis of CS. Methods: From December 2018 to July 2020, 6 patients (4 males and 2 females) with suspected CS were referred to our facility for evaluation of myocardial inflammation. A resting 13N Ammonia myocardial perfusion test and a 18F Fluorodeoxyglucose (FDG) PET were performed to evaluate myocardial inflammation and/or fibrosis. All patients had a previous gadoliniumenhanced CMR. Results: The average age was 60 ± 9 years. Fifty percent of the patients had a history of systemic sarcoidosis and the remaining 50% had suspected isolated CS. None of the patients had active myocardial inflammation based on the PET findings. With the combination of PET patterns and enhanced CMR, the patients were reclassified as follows: 50% had less than 10% chance of having CS and the other 50% was classified as possible cases of CS. None of the patients received immunosuppressants. Conclusion: In our patient population with suspected CS and inflammation, we conducted a PET study following a CMR to assess the potential for CS. In the absence of a gold standard, it is suggested that the diagnosis of CS should be based on probabilities according to specific imaging patterns and clinical features.

Asunto(s)

RESUMEN

Resumen La miocarditis de células gigantes es una enfermedad rara, con gran impacto en cuanto a la mortalidad de pacientes usualmente jóvenes y sanos, que provoca diversas presentaciones clínicas como: la falla cardiaca, las arritmias ventriculares refractarias y los bloqueos. Su diagnóstico se establece con un alto índice de sospecha y con la confirmación por medio de la biopsia endomiocárdica por presencia de células gigantes multinucleadas sin presencia de un patrón granulomatoso. Su tratamiento inmunomodulador ha cambiado de manera importante en los últimos años, con una evidente disminución en los índices de mortalidad, aunque aún se requieren estrategias complementarias de manejo como el uso de dispositivos intracardiacos y/o el trasplante cardiaco para lograr mejores desenlaces a largo plazo.

Abstract Giant cell myocarditis is a rare condition with a great impact with regards to mortality of otherwise young and healthy patients, causing multiple clinical presentations, such as heart failure, refractory ventricular arrhythmias and blocks. Its diagnosis is reached with a high degree of suspicion and with the confirmation by means of a endomyocardial biopsy with the presence of multinucleated giant cells without a granulomatous pattern. Its immunomodulatory treatment has considerably changed during the last years, with a clear reduction in mortality rates, though complementary management strategies are still required, such as the use of intracardiac devices and/or heart transplantation in order to achieve better longterm results.

Asunto(s)