Diagnosis and Treatment of Cardiac Sarcoidosis

Impact of High-Sensitivity Cardiac Troponin T on Clinical Outcomes in Patients With Cardiac Sarcoidosis

BACKGROUND

The prognostic utility of high-sensitivity cardiac troponin T (hs-cTnT) on clinical outcomes in cardiac sarcoidosis (CS) remains unknown, so we evaluated hs-cTnT in the chronic phase of CS.

METHODS AND RESULTS

We enrolled 92 consecutive patients with CS in the chronic phase after medical therapies. Patients were divided into 2 groups according to hs-cTnT level: 0.014 ng/mL: high hs-cTnT (n=37); normal hs-cTnT (n=55). The primary endpoint was cardiac death and the secondary endpoint was cardiac death, ventricular tachyarrhythmias, or hospitalization for heart failure. The mean age of patients was 63±11 years, and 75 received steroid treatment. During a median follow-up of 63 months, there were 9 cardiac deaths: 7 (19%) patients with high hs-cTnT and 2 (4%) patients with normal hs-cTnT. The rate of cardiac death was higher in patients with high hs-cTnT than in those with normal hs-cTnT (log-rank, P<0.01). Cox proportional hazard analysis showed that hs-cTnT was an independent predictor of cardiac death. The events rate was higher in patients with high hs-cTnT than in those with normal hs-cTnT (log-rank, P<0.01): cardiac death, ventricular tachyarrhythmias or hospitalization for heart failure occurred in 24 (65%) patients with high hs-cTnT and 11 (20%) patients with normal hs-cTnT.

CONCLUSIONS

Elevated hs-cTnT was linked with adverse outcomes in CS patients, suggesting it is an effective prognostic biomarker.

Can FDG-PET Imaging Identify Cardiac Sarcoidosis Disease Phenotypes?

PURPOSE OF REVIEW

Despite the scarcity of data, most guidelines have advocated for the treatment of cardiac sarcoidosis with corticosteroids. However, there is heterogeneity in disease presentation and response to treatment, which can make treatment challenging. The ability to identify disease phenotypes to allow for tailored therapy is therefore highly desirable. This review will seek to outline the disease phenotypes of cardiac sarcoidosis and the role that FDG-PET imaging can play in identifying these phenotypes to optimize disease diagnosis and treatment management.

RECENT FINDINGS

FDG PET can identify cardiac sarcoidosis and is being increasingly used to monitor therapeutic response to immunosuppressive therapy, to follow treatment response after discontinuation of corticosteroid therapy, and to evaluate for disease relapse. Modern quantitative techniques using FDG PET imaging may allow for even better phenotypic disease characterization and the ability to track the response to immunosuppression more accurately. FDG PET currently plays an important role in cardiac sarcoidosis diagnosis. However, it also affords us the opportunity to offer insights into cardiac sarcoidosis disease phenotypes to better understand the underlying disease process and in the future may allows us to tailor therapies accordingly.

Current Practices and Emerging Therapies to Optimize Heart Failure Management in Cardiac Sarcoidosis: A Systematic Review

Cardiac sarcoidosis (CS) is a distinctive manifestation of sarcoidosis, a multisystemic inflammatory disorder that is characterized by non-necrotizing granulomas. CS can lead to arrhythmias, heart failure (HF), and sudden cardiac death. The diagnosis of CS involves imaging in the form of a two-dimensional echocardiogram, cardiac magnetic resonance imaging (MRI), an 18-fluoro-deoxyglucose positron emission tomography (FDG-PET) scan, and an endomyocardial biopsy. Treatment of CS entails corticosteroids, immunosuppressive agents, monoclonal antibodies, and, in advanced cases, heart transplantation (HTx). This systematic review follows Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines, focusing on HF in sarcoidosis patients. Eligibility criteria include recent (2019-2024) research papers on sarcoidosis-induced heart failure, excluding other causes. The databases searched were PubMed, Google Scholar, and ScienceDirect. From 36,755 initial articles, 2,060 remained after filtering, and 17 were selected for quality assessment. Based on quality assessment, 11 studies were included in the final review. In CS, a variety of treatment strategies can be implemented. Corticosteroids are the first-line therapeutic options, and in the majority of cases, they are very successful in controlling the disease progression. Immunosuppressive agents like methotrexate and azathioprine are used to avoid long-term steroid use. Both corticosteroids and immunosuppressives act by reducing inflammation and preventing myocardial scarring. Biological agents like infliximab and adalimumab prevent disease progression by targeting specific inflammatory pathways and are used in refractory cases. Regular HF management drugs like angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), sodium-glucose transport protein 2 (SGLT2) inhibitors, beta-blockers, and diuretics help in optimizing cardiac function. In severe cases, a left ventricular assist device (LVAD) may be required. The ultimate treatment for end-stage CS is HTx, which has to be supplemented with a strong, individualized regimen of glucocorticoids and immunosuppressives to avoid graft rejection and to control sarcoidosis. Due to a lack of standard protocols for management and limited knowledge about CS, the ideal treatment of HF is still a matter of debate. Hence, further research and clinical trials need to be performed to optimize patient outcomes.

Diagnostics, treatment and outcomes of cardiac sarcoidosis in a Norwegian cohort

BACKGROUND

Evidence-based guidelines for cardiac sarcoidosis (CS) regarding use of second- and third-line agents, treatment duration, surveillance and prognostic factors are lacking.

OBJECTIVE

To analyze the clinical presentation, diagnostics, treatment, monitoring and clinical outcomes in a Norwegian cohort.

METHODS

Using discharge diagnoses between 2017 through 2020 from a large tertiary center, we identified 52 patients with CS. We performed a systematic chart review following a pre-specified checklist. The primary outcome of major cardiovascular events (MACE) was defined as a composite of cardiovascular hospitalization, defibrillator therapy, cardiac transplantation, or death.

RESULTS

18-fluorodeoxyglucose positron emission tomography (FDG-PET) showed pathological tracer uptake in 35/36 (97%) of immunosuppression-naïve patients. Immunosuppressive treatment was administered to 49/52 patients (94%) for a median of 43 (IQR 34) months; 69% were treated with second-line (methotrexate, azathioprine, mycophenolate mofetil) and 25% with third-line (rituximab, infliximab) agents, respectively. Rituximab reduced inflammation as assessed by interval FDG-PET imaging and was overall well tolerated. Median duration to first MACE was 6 (IQR 10) months and 17/23 patients (74%) experienced a MACE within 12 months from CS diagnosis. No mortality was recorded and 20% achieved full remission. Age below the median of 53 years at time of diagnosis was associated with an increased risk of a MACE.

CONCLUSION

Long-term immunosuppression including a liberal use of non-steroidal agents, appeared essential in treating CS. Although the burden of cardiovascular events was substantial, the survival was excellent in this contemporary cohort. Prospective randomized studies are urgently needed to define the best therapy for these patients.

[Imaging diagnostics of cardiac sarcoidosis]

Cardiac involvement is clinically apparent in approximately 5% of all patients with systemic sarcoidosis, whereas evidence of cardiac involvement by imaging studies can be found in approximately 20% of cases. Occasionally, isolated cardiac sarcoidosis is encountered and is the only sign of the disease. The most frequent cardiac manifestations of the multifocal granulomatous inflammation include atrioventricular (AV) blocks and other conduction disorders, ventricular arrhythmias, sudden cardiac death and left and right ventricular wall disorders. Accordingly, symptoms that should raise suspicion include palpitations, lightheadedness and syncope. The diagnostic approach to cardiac sarcoidosis is not straightforward. Typical echocardiographic findings include regional thinning and contraction abnormalities particularly in basal, septal and lateral locations. Infrequently, myocardial hypertrophy may be present; however, the sensitivity of echocardiography is low and cardiac sarcoidosis can be present even when an echocardiogram is unrevealing. Cardiac magnetic resonance imaging (MRI) frequently shows late gadolinium enhancement (LGE) in a multifocal pattern often involving the basal septum and lateral walls. The sensitivity and specificity of MRI for detecting cardiac sarcoidosis are high. Fluorodeoxyglucose positron emission tomography (FDG-PET) plays an important role in the diagnostic algorithm due to its ability to visualize focal inflammatory activity both in the myocardium and in extracardiac locations. This may help target the optimal location for biopsy in order to obtain histologic proof of sarcoidosis and can also be used to follow the response to anti-inflammatory treatment. Notably, the sensitivity of endomyocardial biopsy is poor due to the patchy nature of myocardial involvement. In clinical practice, either histologic evidence of noncaseating granulomas from the myocardium or evidence from extracardiac tissue in combination with typical cardiac imaging findings are required to establish the diagnosis.