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Brain & Heart Cardiac sarcoidosis with AVB and VA

significant difference between patients with early CS who comparisons between patients presenting with VAs versus
had normal LVEF and right ventricular function (n = 23) AVB have not yet been reported. Notably, more severe
and control patients without cardiac disease (n = 97). A left disease is associated with a higher proportion of LGE,
ventricular global longitudinal strain value of −16.3% had which is observed in 88% of patients with AVB and VT
82% sensitivity and 81% specificity for diagnosing CS. The or LVEF <35% compared with 74% of patients with AVB
22
most common predictor of CS in patients with AVB and alone. LGE in the right ventricle is also linked to higher
28
VAs is the presence of sarcoidosis in another organ system, rates of sustained VT than LGE in other areas, although
with up to 99% of patients with CS having involvement this finding is based on a small-scale retrospective study.
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of at least one other organ system. 5,11,23,24 The WASOG Newer T2 mapping sequences in CMR, in conjunction
guidelines mandate the involvement of two organs for a CS with LGE, can help differentiate active inflammation
diagnosis, based on clinical or histopathological evidence, from fibrosis, improving both sensitivity and specificity of
making it crucial to assess for cardiac involvement in CMR. The implication of T2 signal intensity on prognosis
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patients with extracardiac disease. remains unclear.
Notably, patients with CS are generally younger than 3. Management strategies in AVB versus
those with AVB from other causes, as shown in studies VAs
referenced in Table 2; the average age of patients with CS in
these studies ranged from 46 to 53 years. Differentiating CS 3.1. Corticosteroids and steroid-sparing agents
from GCM, another granulomatous disease with similar
presentations as CS and affecting a similar age group, poses According to a study by Cheng et al. from the American
a diagnostic challenge. The key differentiators include the Heart Association, the primary treatment for active CS
presence of granulomas outside the heart and variations is immunosuppression, with corticosteroids as the first-
31
in endomyocardial biopsy findings. A retrospective line therapy. However, evidence supporting their use
25
review in Finland reclassified 45 of 73 GCM diagnoses is limited, as no randomized controlled trials have been
as CS based on biopsy and 18F-FDG PET results. conducted. A retrospective cohort study of patients with
25
Endomyocardial biopsy has a low sensitivity due to patchy CS presenting with AVB and LVEF >50% revealed that
granuloma deposition within the heart, which may result in AVB completely resolved in 57% of patients treated with
missed inflammation. Therefore, detecting extracardiac corticosteroids, suggesting that these factors play a role
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granulomas using 18F-FDG PET is a less invasive method in preventing VAs. These results are limited by the small
for distinguishing these diseases and should be considered sample size (n = 7; treated with corticosteroids), which
before biopsy. When extracardiac disease is not present, may lead to an overestimation of the treatment effects.
25
biopsy remains the primary diagnostic method despite its A systematic review of corticosteroid use revealed
limitations. that they may help improve AV conduction, with 47%
of patients showing improvement when treated with
2.4. CMR imaging and FDG PET findings in AVB steroids. The efficacy appears to decrease with worsening
versus VAs
cardiac function at the start of treatment. 10,33 However,
CMR imaging and 18F-FDG PET are valuable for all studies reviewed had small sample sizes, and only
diagnosing CS. Late gadolinium enhancement (LGE) on a few of them assessed outcomes related to VAs. In a
CMR, indicating myocardial scarring and fibrosis, is a subsequent prospective study of patients with AVB and no
major diagnostic criterion according to JCS guidelines. 13 extracardiac disease, corticosteroid therapy led to recovery
In contrast, 18F-FDG PET is effective in detecting active of 1:1 conduction in only one of six patients after a mean
myocardial inflammation. Divakaran et al. showed that follow-up of 21 ± 9 months and did not show improved
18F-FDG PET has a high sensitivity (100%) for diagnosing outcomes. Two of these six patients experienced adverse
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CS but a relatively low overall specificity (33%). However, effects caused by the steroid treatment. The small sample
the presence of extracardiac uptake is pathognomonic, size and single-center setting limit the study’s power and
increasing the specificity of this method to 100% but comparability to other centers with different diagnostic
reducing its sensitivity to 83%, highlighting the challenge criteria or ethnic profiles. This highlights the uncertainty
of detecting isolated CS. Additionally, 18F-FDG PET may regarding corticosteroid efficacy, particularly for VAs.
26
play a prognostic role, with the extent of perfusion defects No significant prognostic difference has been reported
being a significant predictor of adverse events before and between high and moderate steroid doses, but a large-
34
after immunosuppressive treatment. Although LGE scale randomized controlled trial (CHASM CS-RCT)
27
is commonly observed (ranging from 44% to 100%) in is ongoing to investigate the effects of dosage and
studies involving patients with confirmed CS, 10,23,28 direct methotrexate augmentation on prognosis.

Volume 2 Issue 4 (2024) 4 doi: 10.36922/bh.3515