Phenotyping of giant cell myocarditis versus cardiac sarcoidosis using cardiovascular magnetic resonance.

BACKGROUND: Giant cell myocarditis (GCM) and cardiac sarcoidosis (CS) are rare inflammatory diseases of the myocardium with poor prognosis. Little is known about the cardiovascular magnetic resonance (CMR) appearance of GCM and the methods ability to distinguish the two rare entities from one another. METHODS: We assessed a total of 40 patients with endomyocardial biopsy-proven GCM (n = 14) and CS (n = 26) concerning their clinical and CMR appearance in a blinded manner. RESULTS: Patients with GCM and CS were of similar median age (55 vs 56 years), and a male predominance was observed in both groups. In GCM, median levels of troponin T (313 vs 31 ng/L, p < 0.001), and natriuretic peptides (6560 vs 676 pg/mL, p < 0.001) were higher than in CS, and the clinical outcome worse (p = 0.04). On CMR imaging, the observed alterations of left and right ventricular (LV/RV) dimensions and function were similar. GCM showed multifocal LV late gadolinium enhancement (LGE) with a similar longitudinal, circumferential, and radial distribution as in CS, including suggested signature imaging biomarkers of CS like the "hook sign" (71% vs 77%, p = 0.702). The median LV LGE enhanced volume was 17% and 22% in GCM and CS (p = 0.150), respectively. The number of RV segments with pathologically increased T2 signal and/or LGE were most extensive in GCM. CONCLUSIONS: The CMR appearance of both GCM and CS is highly similar, making the differentiation between the two rare entities solely based on CMR challenging. This stands in contrast to the clinical appearance, which seems to be more severe in GCM.

Echocardiography in inflammatory heart disease: A comparison of giant cell myocarditis, cardiac sarcoidosis, and acute non-fulminant myocarditis.

Background: Giant cell myocarditis (GCM) and cardiac sarcoidosis (CS) are, in contrast to acute non-fulminant myocarditis (ANFM), rare inflammatory diseases of the myocardium with poor prognosis. Although echocardiography is the first-line diagnostic tool in these patients, their echocardiographic appearance has so far not been systematically studied. Methods: We assessed a total of 71 patients with endomyocardial biopsy-proven GCM (n = 21), and CS (n = 25), as well as magnetic resonance-verified ANFM (n = 25). All echocardiographic examinations, performed upon clinical presentation, were reanalysed according to current guidelines including a detailed assessment of right ventricular (RV) dysfunction. Results: In comparison with ANFM, patients with either GCM or CS were older (mean age (±SD) 55 ± 12 or 53 ± 8 vs 25 ± 8 years), more often of female gender (52% or 24% vs 8%), had more severe clinical symptoms and higher natriuretic peptide levels. For both GCM and CS, echocardiography revealed more frequently signs of left ventricular (LV) dysfunction in form of a reduced ejection fraction (p < 0.001), decreased cardiac index (p < 0.001) and lower global longitudinal strain (p < 0.001) in contrast to ANFM. The most prominent increase in LV end-diastolic volume index was observed in CS. In addition, RV dysfunction was more frequently found in both GCM and CS than in ANFM (p = 0.042). Conclusions: Both GCM and CS have an echocardiographic and clinical appearance that is distinct from ANFM. However, the method cannot further differentiate between the two rare entities. Consequently, echocardiography can strengthen the initial clinical suspicion of a more severe form of myocarditis, thus warranting a more rigorous clinical work-up.

Case report of eosinophilic granulomatosis with polyangitis presenting as acute myocarditis.

This case presents a challenging diagnosis of EGPA presenting as eosinophilic myocarditis. It is a condition that can mimic many other diseases and where prompt diagnosis and early treatment is essential for recovery. The diagnosis was made after an endomyocardial biopsy (EMB) and showed the importance of EMB in the diagnostic work-up.

Diagnosis, management, and outcome of cardiac sarcoidosis and giant cell myocarditis: a Swedish single center experience.

BACKGROUND: Cardiac sarcoidosis (CS) and giant cell myocarditis (GCM) are rare diseases that share some similarities, but also display different clinical and histopathological features. We aimed to compare the demographics, clinical presentation, and outcome of patients diagnosed with CS or GCM. METHOD: We compared the clinical data and outcome of all adult patients with CS (n = 71) or GCM (n = 21) diagnosed at our center between 1991 and 2020. RESULTS: The median (interquartile range) follow-up time for patients with CS and GCM was 33.5 [6.5-60.9] and 2.98 [0.6-40.9] months, respectively. In the entire cohort, heart failure (HF) was the most common presenting manifestation (31%), followed by ventricular arrhythmias (25%). At presentation, a left ventricular ejection fraction of < 50% was found in 54% of the CS compared to 86% of the GCM patients (P = 0.014), while corresponding proportions for right ventricular dysfunction were 24% and 52% (P = 0.026), respectively. Advanced HF (NYHA ≥ IIIB) was less common in CS (31%) than in GCM (76%). CS patients displayed significantly lower circulating levels of natriuretic peptides (P < 0.001) and troponins (P = 0.014). Eighteen percent of patients with CS included in the survival analysis reached the composite endpoint of death or heart transplantation (HTx) compared to 68% of patients with GCM (P < 0.001). CONCLUSION: GCM has a more fulminant clinical course than CS with severe biventricular failure, higher levels of circulating biomarkers and an increased need for HTx. The histopathologic diagnosis remained key determinant even after adjustment for markers of cardiac dysfunction.

Short- and long-term outcomes after heart transplantation in cardiac sarcoidosis and giant-cell myocarditis: a systematic review and meta-analysis.

Heart transplantation (HTx) is a valid therapeutic option for end-stage heart failure secondary to cardiac sarcoidosis (CS) or giant-cell myocarditis (GCM). However, post-HTx outcomes in patients with inflammatory cardiomyopathy (ICM) have been poorly investigated. We searched PubMed, Scopus, Science Citation Index, EMBASE, and Google Scholar, screened the gray literature, and contacted experts in the field. We included studies comparing post-HTx survival, acute cellular rejection, and disease recurrence in patients with and without ICM. Data were synthesized by a random-effects meta-analysis. We screened 11,933 articles, of which 14 were considered eligible. In a pooled analysis, post-HTx survival was higher in CS than non-CS patients after 1 year (risk ratio [RR] 0.88, 95% confidence interval [CI] 0.60-1.17; I2 = 0%) and 5 years (RR 0.72, 95% CI 0.52-0.91; I2 = 0%), but statistically significant only after 5 years. During the first-year post-HTx, the risk of acute cellular rejection was similar for patients with and without CS, but after 5 years, it was lower in those with CS (RR 0.38, 95% CI 0.03-0.72; I2 = 0%). No difference in post-HTx survival was observed between patients with and without GCM after 1 year (RR 1.16, 95% CI 0.05-2.28; I2 = 0%) or 5 years (RR 0.98, 95% CI 0.42-1.54; I2 = 0%). During post-HTx follow-up, recurrence of CS and GCM occurred in 5% and 8% of patients, respectively. Post-HTx outcomes in patients with CS and GCM are comparable with cardiac recipients with other heart failure etiologies. Patients with ICM should not be disqualified from HTx.

Incidental cardiac findings on somatostatin receptor PET/CT: What do they indicate and are they of clinical relevance?

We present the case of a 47-year-old man with a history of recurrent episodes of frontal headache, fever, and chest discomfort as well as longstanding, difficult to treat arterial hypertension. Clinical work-up revealed the unexpected finding of an underlying pheochromocytoma as well as recent "silent" myocardial infarction. Our case highlights the importance of paying attention to incidental cardiac findings on somatostatin receptor positron emission tomography/computed tomography, as routinely performed in patients with clinically suspected neuroendocrine tumors. These incidental cardiac findings cannot only indicate a primary or secondary (metastatic) neuroendocrine tumor, but also areas of myocardial inflammation, as somatostatin receptors cannot only be found on the majority of neuroendocrine tumors, but also among other tissues on the surface of activated macrophages and lymphocytes. The detection of myocardial inflammation is of clinical importance and its underlying etiology should be evaluated to prompt eventual necessary treatment, as it is a potential driving force for cardiac remodeling and poor prognosis.