ClinicalDevicesLong-term monitoring of arrhythmias with cardiovascular implantable electronic devices in patients with cardiac sarcoidosis
Introduction
Sarcoidosis is a multisystem disorder of unknown etiology, characterized by the presence of noncaseating granulomas. Nearly every organ system can be affected, including the heart. Cardiac involvement is associated with increased risk for ventricular arrhythmias (VAs), atrioventricular conduction block (AVB), and sudden cardiac death (SCD). Cardiac involvement in sarcoidosis is often clinically silent and therefore underrecognized. Autopsy series have suggested cardiac involvement in up to 25% of patients, whereas clinically overt cardiac involvement was seen in 5%–10% of cases.1 Because patients with cardiac sarcoidosis (CS) are at increased risk for SCD, screening for CS and subsequent risk stratification for SCD are imperative.2, 3, 4, 5 An implantable cardioverter-defibrillator (ICD) is recommended for patients with VA, third-degree AVB, or left ventricular ejection fraction (LVEF) <35%.2,6 Also, scar detected by cardiac magnetic resonance imaging (CMR) is strongly related to the occurrence of VA and SCD.7, 8, 9 However, less is known about patients with a preserved ejection fraction, a small amount of scar tissue and no or mild cardiac symptoms.2,6 Patients with extracardiac sarcoidosis (ECS) diagnosed with CS after screening for cardiac involvement often fulfill these criteria. In 2014, we routinely incorporated the use of implantable loop recorders (ILRs) in our center for continuous heart rhythm surveillance in CS patients without an ICD indication.10 This regimen facilitates early detection of VA and other arrhythmias in all CS patients with a cardiovascular electronic implantable device (CIED). In this study, we report the incidence of important arrhythmias and mortality after long-term monitoring in a large, predominantly Caucasian population of CS patients identified after systematic screening in an ECS population.
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Study design
A retrospective single-center cohort study was performed in the St. Antonius Hospital, a Dutch, tertiary referral center for sarcoidosis. All patients with ECS who were referred to our CS multidisciplinary team (MDT) for CS diagnosis between January 2014 and January 2019 were retrospectively observed by chart review. The study was approved by the local institutional review board (R&D/Z19.004). No written informed consent was required. The research reported in this study adhered to the
Study population
In total, 114 of 547 patients (21%) were diagnosed with CS. Nine patients were lost to follow-up. Table 1 lists the baseline characteristics of 105 included patients. Complete follow-up on arrhythmias was available in 97 CIED patients. LVEF at baseline was predominantly preserved with mean LVEF of 57.6% ± 9.2%. In 2 patients, LVEF was <35%. In 91% of patients, LGE was present on CMR, and 70% showed active inflammation according to cardiac uptake on FDG-PET/CT. At the time of diagnosis, 39.0% of
Discussion
This is the first study reporting the use of CIED for long-term monitoring of arrhythmias in patients with CS diagnosed after systematic screening in an ECS population. Regular 24-hour Holter ECG might miss clinically important arrhythmias. Therefore, the use of ILR for continuous heart rhythm surveillance was incorporated in our daily practice in patients with CS considered at low risk for SCD.
In this study of CS patients without overt cardiac symptoms at initial presentation, the combination
Conclusion
Overall, the annualized event rate of VA and cardiac death in predominantly Caucasian CS patients without overt cardiac symptoms at initial presentation is 1.7%. Within the high-risk group, the annualized event rate is almost 10%. In low-risk patients, long-term arrhythmia monitoring with ILR enabled early detection of arrhythmias, without showing an impact on prognosis. Future prospective studies should focus on a risk stratification model based on predefined selection criteria, including
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Cited by (5)
Cardiac sarcoidosis: phenotypes, diagnosis, treatment, and prognosis
2023, European Heart JournalManagement of the arrhythmic manifestations of cardiac sarcoidosis
2023, Frontiers in Cardiovascular MedicineUsefulness of insertable cardiac monitors for risk stratification: current indications and clinical evidence
2023, Expert Review of Medical Devices
Funding Sources: The authors have no funding sources to disclose.
Disclosures: The authors have no conflicts of interest to disclose.
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Dr Annelies Bakker and Dr Harold Mathijssen contributed equally to the manuscript.