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Brain & Heart Cardiac sarcoidosis with AVB and VA

benefit in heart failure. Class I antiarrhythmics, such as A long-term follow-up study revealed that one-third
quinidine and flecainide, are typically avoided due to of patients who initially presented with VAs experienced a
their potential to worsen arrhythmias in the presence of subsequent cardiac relapse. The relapse rate was similar to
structural heart disease. 13,15 that of patients with second-degree AVB but significantly
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lower than that in patients with third-degree AVB (83%).
3.4. Ablation Using data from the Myocardial Inflammatory Diseases in
In cases refractory to medical therapy, catheter ablation Finland Study Group Registry, Nordenswan et al. evaluated
might be considered. A multicenter retrospective study the risk of major adverse cardiac events, such as death,
involving 158 patients showed that although CS has a high transplantation, and life-threatening tachyarrhythmias,
rate of VA recurrence after ablation, these rates are similar based on the initial presentation with AVB versus
to those observed in other structural cardiomyopathies AVB accompanied with VAs and/or severe LV systolic
(46% vs. 40%). 48-50 Higher rates of VT recurrence were dysfunction. Over a median follow-up period of 2.8 years,
noted when active inflammation was present at the time 24% of patients with AVB ± non-severe LV systolic
of ablation, likely due to ongoing cycles of inflammation dysfunction experienced an event, whereas this rate was
and scarring, indicating that the timing of intervention more than double (56%) in those with AVB and VAs or
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affects prognosis in non-emergency cases. In addition, the severe LV systolic dysfunction at diagnosis, indicating a
induction of arrhythmia post-ablation in CS may not be higher risk of further arrhythmias or recurrence when VAs
associated with worse outcomes, such as VT recurrence, are present at diagnosis. 53
transplant, or death, unlike other cardiomyopathies. 45 A Japanese study evaluated 53 patients with CS who
3.5. Prognosis initially presented with either AVB or VAs (n = 22 vs.
n = 31), evaluating major adverse cardiac events over a
Hoogendoorn et al. investigated the impact of delayed 36-month follow-up period. This study reported that AVB
diagnosis on the prognosis of patients with VAs. They was associated with a better composite endpoint than VT
compared patients diagnosed within 6 months of their and/or heart failure (log-rank test, P = 0.046), largely due
initial presentation (n = 5) with those diagnosed after to fewer hospitalizations for heart failure. The mortality
6 months (n = 10), who had an average delay of 24 months. rates were similar between the two groups. 54
The later-diagnosed group had poorer outcomes, including
reduced cardiac function, than the early-diagnosed group Isolated AVB often remains undiagnosed for extended
receiving immunosuppression, which showed generally periods, with average delays in diagnosis ranging
stable function. This group also experienced more VT from 8 to 18 months, which has significant prognostic
ablations, more hospitalizations for heart failure, and higher implications. 24,53 The frequent occurrence of unexplained
mortality (50% vs. 20%) over a mean follow-up period of second- and third-degree heart block in patients who
55 months. Ahmed et al. also highlighted the importance are later diagnosed with both cardiac and extracardiac
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of early diagnosis and initiation of immunosuppression sarcoidosis 11,12 underscores the need for prompt
in AVB cases. Their retrospective single-center review of investigation for CS in these cases.
77 patients revealed that early diagnosis was linked to fewer 4. Conclusions
device upgrades and lower maintenance steroid doses than
delayed diagnosis over a mean follow-up period of 54.9 This review highlights that sarcoidosis is frequently
± 45.3 months. Delayed diagnosis has been associated overlooked or diagnosed late, which impacts patient
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with more severe LV dysfunction than early diagnosis, prognosis. Early treatment initiation is beneficial for
leading to a higher risk of hospitalization for heart failure, maintaining LVEF, likely due to reduced scarring and
increased mortality, and a greater number of appropriate better LVEF at diagnosis. There is a high incidence of
ICD therapies. 24,52 Despite this, the risk of sudden cardiac CS in cases of “idiopathic” AVB or VAs; therefore, these
death remains high in patients with AVB, ranging from 9% cases should be investigated. Initially, non-invasive
to 14% over 5 years if AVB is the sole initial presentation methods such as CMR and 18F-FDG PET should be used,
and rising to 34% if AVB is accompanied with VAs. followed by endomyocardial biopsy if needed. However,
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Studies have consistently shown that the most common endomyocardial biopsy has low sensitivity and specificity
initial presentation of CS – (unexplained AVB) – has for diagnosing CS. 10,25 CMR may also help predict disease
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worse outcomes, including a more severe clinical course, progression, particularly with regard to right ventricular
higher mortality, and increased risk of sudden cardiac death LGE. A stepwise management approach – starting with
compared with other presentations or AVB in the absence of immunosuppression, followed by using an ICD, and finally
sarcoidosis. 11,23,41,53 Key findings are summarized in Table 2. considering catheter ablation – has proven effective in the

Volume 2 Issue 4 (2024) 9 doi: 10.36922/bh.3515