Diagnostic accuracy of cardiac MRI, FDG-PET, and myocardial biopsy for the diagnosis of cardiac sarcoidosis: a protocol for a systematic review and meta-analysis.

BACKGROUND: CS constitutes a rare but potentially underdiagnosed and fatal disease. Its diagnosis remains difficult owing to the infrequent and indistinguishable symptoms and the lack of formal diagnostic criteria dependent upon the diagnostic techniques used. Early diagnosis and treatment, however, may help to counter its poor prognosis.We aim to characterize and compare the diagnostic accuracy of cardiac MRI, FDG-PET and myocardial biopsy for the diagnosis of cardiac sarcoidosis and to advance and compare methods for complex diagnostic test accuracy reviews and meta-analysis. METHODS: Following a systematic review on DTA studies on the aforementioned topic, a four-part approach to meta-analysis will be used: (1) direct comparison of index tests with clinical reference standard, (2) indirect comparison of index tests with clinical reference standard, (3) addition of an alternative test to that indirect comparison (4) and Bayesian meta-analysis using results of part 3 as informative prior for comparisons analogous to part 1 and 2. DISCUSSION: The most widely recognized diagnostic algorithm for cardiac sarcoidosis is considered out of date, as it precedes the introduction of imaging techniques in diagnostic pathways. These novel imaging techniques, like CMR and FDG-PET scan, have emerged as promising diagnostic tools which may fill the current diagnostic gap. Thus, a systematic review and evaluation of CS diagnosis are much needed. Such an attempt is anticipated to alter the current diagnostic guidelines for CS by shedding more light on the role of sophisticated imaging techniques on prompt CS therapy and follow-up. TRIAL REGISTRATION: PROSPERO, CRD42019047126.

Long-Term Outcomes of Catheter Ablation of Ventricular Tachycardia in Patients With Cardiac Sarcoidosis.

BACKGROUND: Catheter ablation (CA) of ventricular tachycardia (VT) in patients with cardiac sarcoidosis can be challenging because of the complex underlying substrate. We sought to determine the long-term outcome of CA of VT in patients with cardiac sarcoidosis. METHODS AND RESULTS: We enrolled 31 patients (age, 55±10 years) with diagnosis of cardiac sarcoidosis based on Heart Rhythm Society criteria and VT who underwent CA. In 23 (74%) patients, preprocedure cardiac magnetic resonance imaging and positron emission tomographic (PET) evaluation were performed. Preprocedure magnetic resonance imaging was positive for late gadolinium enhancement in 21 of 23 (91%) patients, whereas abnormal 18-fluorodeoxyglucose uptake was found in 15 of 23 (65%) cases. In 14 of 15 patients with positive PET at baseline, PET was repeated after 6.1±3.7-month follow-up. After a median follow-up of 2.5 (range, 0-10.5) years, 1 (3%) patient died and 4 (13%) underwent heart transplant. Overall VT-free survival was 55% at 2-year follow-up. Among the 16 (52%) patients with VT recurrences, CA resulted in a significant reduction of VT burden, with 8 (50%) having only isolated (1-3) VT episodes and only 1 patient with recurrent VT storm. The presence of late gadolinium enhancement at magnetic resonance imaging, a positive PET at baseline, and lack of PET improvement over follow-up were associated with increased risk of recurrent VT. CONCLUSIONS: In patients with cardiac sarcoidosis and VT, CA is effective in achieving long-term freedom from VT or improvement in VT burden in the majority of patients. The presence of late gadolinium enhancement at magnetic resonance imaging, a positive PET scan at baseline, or lack of improvement at repeat PET over follow-up predict worse arrhythmia-free survival.

Primary Cardiac Sarcoidosis with Syncope and Refractory Atrial Arrhythmia: A Case Report and Review of the Literature.

We discuss the case of a 38-year-old black man who presented at our hospital with his first episode of syncope, recently developed atrial arrhythmias refractory to pharmacologic therapy, and a left atrial thrombus. He was diagnosed with primary cardiac sarcoidosis characterized by predominant involvement of the epicardium that caused atrial fibrillation and atrial flutter. Histologic analysis of his epicardial lesions yielded a diagnosis of sarcoidosis. This patient's atrial arrhythmia was successfully treated with a hybrid operation that involved resection of his atrial appendage, an Epicor maze procedure, and radiofrequency ablation during a catheter-based electrophysiologic study. The cardiac sarcoidosis was successfully managed with corticosteroid therapy. Our case report shows that sarcoidosis can initially manifest itself as syncope with new-onset atrial arrhythmia. Sarcoidosis is important in the differential diagnosis because of its progressive nature and its potential for treatment with pharmacologic, surgical, and catheter-based interventions.