Management of cardiac sarcoidosis.

Cardiac sarcoidosis (CS) is a form of inflammatory cardiomyopathy associated with significant clinical complications such as high-degree atrioventricular block, ventricular tachycardia, and heart failure as well as sudden cardiac death. It is therefore important to provide an expert consensus statement summarizing the role of different available diagnostic tools and emphasizing the importance of a multidisciplinary approach. By integrating clinical information and the results of diagnostic tests, an accurate, validated, and timely diagnosis can be made, while alternative diagnoses can be reasonably excluded. This clinical expert consensus statement reviews the evidence on the management of different CS manifestations and provides advice to practicing clinicians in the field on the role of immunosuppression and the treatment of cardiac complications based on limited published data and the experience of international CS experts. The monitoring and risk stratification of patients with CS is also covered, while controversies and future research needs are explored.

Significant delayed conduction and characteristic ventricular tachycardias in patients with cardiac sarcoidosis and electrical storm.

INTRODUCTION: Electrical storm (ES) of ventricular tachyarrhythmias (VTAs) is an important cause of sudden death in patients with cardiac sarcoidosis (CS). VTAs in CS are associated with myocardial scarring and inflammation. However, little is known about the risk factors of ES in patients with CS and VTAs. The objective of this study is to clarify the characteristics and risk factors for the development of ES in patients with CS. METHODS: The study population included consecutive 52 patients with CS and sustained VTA. Twenty-five out of 52 patients experienced ES. We evaluated clinical characteristics, imaging modalities, and electrocardiogram (ECG) parameters to determine the risk factors associated with ES. RESULTS: Half of the patients experienced VTAs as the initial symptom of sarcoidosis, and eight patients had ES as the initial VTA episode. There were no differences in cardiac imaging abnormalities between patients with and without ES. Among ECG markers, significant QRS fragmentation (odds ratio [OR]: 7.9, p = .01) and epsilon waves (OR: 12.24, p = .02) were associated with ES. Among the ventricular tachycardia (VT) characteristics, multiple morphologies of monomorphic VTs (OR: 10.9, p < .01), short VT cycle lengths (OR: 12.5, p < .01), and polymorphic VT (OR: 13.5, p < .01) were associated with ES. Bidirectional VTs were detected in 10 patients with ES and one patient without ES. Immunosuppressive therapy relieved ES in some patients. CONCLUSIONS: ES was common in patients with CS and VTAs. Significant depolarization abnormalities that appeared as QRS fragmentation, epsilon waves, and specific VT characteristics were associated with ES.

Pathogenic pathways and therapeutic targets of inflammation in heart diseases: A focus on Interleukin-1.

BACKGROUND: An exuberant and dysregulated inflammatory response contributes to the development and progression of cardiovascular diseases (CVDs). METHODS: This narrative review includes original articles and reviews published over the past 20 years and found through PubMed. The following search terms (or combination of terms) were considered: "acute pericarditis," "recurrent pericarditis," "myocarditis," "cardiac sarcoidosis," "atherosclerosis," "acute myocardial infarction," "inflammation," "NLRP3 inflammasome," "Interleukin-1" and "treatment." RESULTS: Recent evidence supports the role of inflammation across a wide spectrum of CVDs including myocarditis, pericarditis, inflammatory cardiomyopathies (i.e. cardiac sarcoidosis) as well as atherosclerotic CVD and heart failure. Interleukins (ILs) are the signalling mediators of the inflammatory response. The NACHT, leucine-rich repeat and pyrin-domain containing protein 3 (NLRP3) inflammasome play a key role in producing IL-1ß, the prototypical pro-inflammatory cytokine involved in CVDs. Other pro-inflammatory cytokines (e.g. tumour necrosis factor) have been implicated in cardiac sarcoidosis. As a proof of this, IL-1 blockade has been proven efficacious in pericarditis and chronic coronary syndrome. CONCLUSION: Tailored strategies aiming at quenching the inflammatory response have emerged as promising to treat CVDs. In this review article, we summarize recent evidence regarding the role of inflammation across a broad spectrum of CVDs. We also review novel evidence regarding targeted therapeutic strategies.

Potential application of 68Ga-FAPI PET/CT for diagnosing cardiac sarcoidosis.

Detecting cardiac sarcoidosis; a potentially life-threatening condition is challenging and requires a multimodality imaging approach using echocardiography, PET/CT and CMR. Although 18F-FDG is the recommended PET tracer for evaluating cardiac sarcoidosis, it is limited by physiological cardiac FDG uptake and requires stringent patient preparation/ dietary modifications before imaging. We hereby present a case of cardiac sarcoidosis demonstrating myocardial FAPI uptake on cardiac PET, highlighting the potential role of 68Ga-FAPI PET in the evaluation of cardiac sarcoidosis.

Role of serial 18F-fludeoxyglucose positron emission tomography in determining the therapeutic efficacy of immunosuppression and clinical outcome in patients with cardiac sarcoidosis.

BACKGROUND: Myocardial inflammation and perfusion defects detected by 18F-fludeoxyglucose (FDG) and Rubidium-82 positron emission tomography (PET) may be associated with ventricular arrhythmias (VAs) in cardiac sarcoidosis (CS). The role of serial quantitative PET in determining the effect of treatment on myocardial inflammation and clinical outcomes is yet to be defined. METHODS: Newly diagnosed CS patients with active myocardial inflammation (maximum standardised uptake value (SUVmax) ≥ 2.5) were treated with immunosuppression, then underwent repeat FDG-PET, Rubidium-82, and echocardiographic imaging 6-12 months later. Serial changes in SUVmax, SUVmean, inflammatory extent, perfusion defect (PD) extent, metabolism/perfusion mismatch extent, global cardiac metabolic activity, and left ventricular ejection fraction (LVEF) were assessed. The primary endpoint was a composite of all-cause mortality, serious VA and heart-failure (HF) hospitalisation. Event data were recorded from the date of the second FDG-PET. RESULTS: The study population consisted of 113 patients (66% male, age: 55 ± 11 years, LVEF: 54 ± 13%). SUVmax reduced from 4.5 (interquartile range: 3.3-7.1) to 2.7 (2.2-3.6). Overall, 94 (83%) patients saw serial reduction in SUVmax, with 42 (37%) demonstrating complete response (SUVmax <2.5). Following a median of 46 (25-57) months, 28 (25%) patients reached the endpoint (8 deaths, 17 VAs, and 3 HF hospitalisations). PD extent (Hazard ratio 1.03, 95% confidence interval: 1.01-1.05; p = 0.035) was a significant predictor of outcome following treatment, even after accounting for LVEF and change in SUVmean. The risk of adverse events was the greatest in those with a pre-treatment or post-treatment PD extent of >10%. CONCLUSION: In our cohort with active CS, following a treatment-induced reduction in myocardial inflammation, PD extent was the main predictor of adverse events.

A Comprehensive Review on the Electrocardiographic Manifestations of Cardiac Sarcoidosis: Patterns and Prognosis.

PURPOSE OF REVIEW: Cardiac sarcoidosis (CS) refers to cardiac involvement in sarcoidosis and is usually associated with worse outcomes. This comprehensive review aims to elucidate the electrocardiographic (ECG) signs and features associated with CS, as well as examine modern techniques and their importance in CS evaluation. RECENT FINDINGS: The exact pathogenesis of CS is still unclear, but it stems from an abnormal immunological response triggered by environmental factors in individuals with genetic predisposition. CS presents with non-cardiac symptoms; however, conduction system abnormalities are common in patients with CS. The most common electrocardiographic (ECG) signs include atrioventricular blocks and ventricular tachyarrhythmia. Distinct patterns, such as fragmented QRS complexes, T-wave alternans, and bundle branch blocks, are critical indicators of myocardial involvement. The application of advanced ECG techniques such as signal-averaged ECG, Holter monitoring, wavelet-transformed ECG, microvolt T-wave alternans, and artificial intelligence-supported analysis holds promising outcomes for opportune detection and monitoring of CS. Timely utilisation of inexpensive and readily available ECG possesses the potential to allow early detection and intervention for CS. The integration of artificial intelligence models into ECG analysis is a promising approach for improving the ECG diagnostic accuracy and further risk stratification of patients with CS.

Cardiac Sarcoidosis: Utilizing Cardiac MRI and PET-CT.

PURPOSEOF REVIEW: Cardiac sarcoidosis is an inflammatory condition that has been associated with deleterious cardiac manifestations. The diagnosis of cardiac sarcoidosis is challenging and can be guided by advanced cardiac imaging. RECENT FINDINGS: Endomyocardial biopsy lacks sensitivity in confirming a diagnosis of cardiac sarcoidosis. Studies have shown that the use of cardiac magnetic resonance imaging (MRI) and cardiac Positron Emission Testing (PET) are associated with increased sensitivity and specificity in the diagnosis of cardiac sarcoidosis. Cardiac MRI and cardiac PET CT, although distinct entities, are complimentary in the diagnosis, prognostication of major cardiac events, and aid in the treatment algorithm in patients with cardiac sarcoidosis.

Cardiac sarcoidosis: phenotypes, diagnosis, treatment, and prognosis.

Cardiac sarcoidosis (CS) results from epithelioid cell granulomas infiltrating the myocardium and predisposing to conduction disturbances, ventricular tachyarrhythmias, and heart failure. Manifest CS, however, constitutes only the top of an iceberg as advanced imaging uncovers cardiac involvement 4 to 5 times more commonly than what is clinically detectable. Definite diagnosis of CS requires myocardial biopsy and histopathology, but a sufficient diagnostic likelihood can be achieved by combining extracardiac histology of sarcoidosis with clinical manifestations and findings on cardiac imaging. CS can appear as the first or only organ manifestation of sarcoidosis or on top of pre-existing extracardiac disease. Due to the lack of controlled trials, the care of CS is based on observational evidence of low quality. Currently, the treatment involves corticosteroid-based, tiered immunosuppression to control myocardial inflammation with medical and device-based therapy for symptomatic atrioventricular block, ventricular tachyarrhythmias, and heart failure. Recent outcome data indicate 90% to 96% 5-year survival in manifest CS with the 10-year figures ranging from 80% to 90%. Major progress in the care of CS awaits the key to its molecular-genetic pathogenesis and large-scale controlled clinical trials.

"Function follows form": Role of cardiac magnetic resonance for ventricular arrhythmia risk stratification in patients with cardiac sarcoidosis.

INTRODUCTION: Cardiac involvement is common and may become clinically relevant in approximately 5%-10% of patients with systemic sarcoidosis. Although reduced left ventricular ejection fraction is a recognized predictor of mortality, recent studies have suggested an increased risk of ventricular arrhythmia (VAs) and sudden cardiac death (SCD) in patients with cardiac sarcoidosis (CS) and evidence of late gadolinium enhancement-cardiac magnetic resonance (LGE-CMR), irrespective of the underlying left ventricular systolic function. We performed a meta-analysis to assess the correlation between VAs/SCD and presence of LGE-CMR in CS patients. METHODS: We systematically searched Medline, Embase, and Cochrane electronic databases up to January 2, 2023, for studies enrolling patients with suspected or confirmed CS undergoing LGE-CMR. Clinical outcomes of interest included clinically relevant VAs, defined as sustained ventricular tachycardia, ventricular fibrillation, SCD, or aborted SCD during follow-up. The effect size was estimated using a random-effect model as risk ratio (RR) and relative 95% confidence interval (CI). RESULTS: A total of 14 studies fulfilled the selection criteria and were included in the final analysis. Among 1273 patients, LGE was detected in 465 (36.5%; Group LGE+). Males accounted for 45.2% (95% CI: 40.5%-55.7%) of the total population and the average age was 56.8 (95% CI: 52.7%-60.9) years. A total of 104 (22.3%) of 465 LGE+ patients experienced a clinically relevant VA, compared to 6 (0.7%) of 808 LGE- ones. LGE+ was associated with a ninefold increased risk in life-threatening VAs (22.3% vs. 0.7%; RR = 9.52; 95% CI [5.18-17.49]; p < .0001) compared to patients without LGE (heterogeneity I2 = 0%). CONCLUSION: In our meta-analysis, LGE+ in patients with CS was associated with a ninefold increased risk in life-threatening VAs compared to patients without LGE.

Sex and Race Differences in Cardiac Sarcoidosis Presentation, Treatment and Outcomes.

BACKGROUND: Although sex- and race-based patterns have been described in the extracardiac organ involvement of sarcoidosis, cardiac sarcoidosis (CS)-specific studies are lacking. METHODS: We studied CS presentation, treatment and outcomes based on sex and race in a tertiary-center cohort. Multivariable adjusted Cox proportional hazards and survival analyses were performed for primary composite outcomes (left ventricular assist device, heart transplantation, all-cause death) and for secondary outcomes (ventricular arrhythmia and all-cause death. RESULTS: We identified 252 patients with CS (108 female, 109 Black). At presentation with CS, females vs males (P = 0.001) and Black vs White individuals (P = 0.001) more commonly had symptomatic heart failure (HF), with HF most common in Black females (ANOVA P < 0.001). Treatment differences included more corticosteroid use (90% vs 79%; P = 0.020), higher 1-year prednisone dosage (13 vs 10 mg; P = 0.003) and less frequent early steroid-sparing agent use in males (29% vs 40%; P = 0.05). Black participants more frequently received a steroid-sparing agent (75% vs 60%; P = 0.023). Composite outcome-free survival did not differ by sex or race. Male sex had an adjusted hazard ratio of 2.34 (95% CI 1.13, 4.80; P = 0.021) for ventricular arrhythmia. CONCLUSION: CS course may differ by sex and race and may contribute to distinct clinical CS phenotypes.

Heart transplantation in end-stage heart failure secondary to cardiac sarcoidosis: an updated systematic review.

The prevalence of cardiac sarcoidosis is increasing with improved cardiac imaging and may lead to severe heart failure, cardiomyopathy, and arrhythmias that warrant heart transplant consideration. This study aimed to evaluate the outcomes of heart transplantation in sarcoidosis. We systematically searched PubMed/MEDLINE, EMBASE and Cochrane Library following the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. We identified 15 articles that examined patients with cardiac sarcoidosis. The study aimed to evaluate the outcomes of heart transplantation in cardiac sarcoidosis. We systematically searched EMBASE, PubMed/MEDLINE, and Cochrane Library following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. We identified 15 studies that examined 1075 patients with cardiac sarcoidosis who underwent heart transplantation. A total of five studies reported individual patient data. Forty-two patients have been pooled for further analysis. There were 22 male patients, 14 female patients, and 7 patients whose gender was not reported. Among these patients, 10 patients had concomitant pulmonary sarcoidosis at the time of diagnosis. The mean survival was reported for all 42 patients. The mean survival in months was 71.4 months, with a range of 2 days to 288 months. Three patients died of graft failure, 2 patients from septic shock, 2 patients from pneumonia, 1 patient from cervical cancer, and 1 patient from sudden cardiac death. One patient developed a malignant arrythmia in the setting of CMV myocarditis post-heart transplant. Sarcoidosis recurrence after heart transplant was reported in 3 of 30 patients..Patients with cardiac sarcoidosis have shown to have favorable outcomes after heart transplant. Despite these outcomes, some centers still hesitate to pursue heart transplant for CS patients. Carefully selected patients with advanced-stage heart failure due to cardiac sarcoidosis have encouraging outcomes after transplantation. Further studies will be needed to evaluate the outcomes of heart transplantation in sarcoidosis.

Clinical features and prognosis of isolated cardiac sarcoidosis diagnosed using new guidelines with dedicated FDG PET/CT.

BACKGROUND: Diagnostic guidelines for isolated cardiac sarcoidosis (iCS) were first proposed in 2016, but there are few reports on the imaging and prognosis of iCS. This study aimed to evaluate the use of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) imaging in predicting iCS prognosis. METHODS AND RESULTS: We retrospectively reviewed the clinical and imaging data of 306 consecutive patients with suspected CS who underwent FDG PET/CT with a dedicated preparation protocol and included 82 patients (55 with systemic sarcoidosis including cardiac involvement [sCS], 27 with iCS) in the study. We compared the FDG PET/CT findings between the two groups. We examined the relationship between the CS type and the rate of adverse cardiac events. The iCS group had a significantly lower target-to-background ratio than the sCS group (P = 0.0010). The event-free survival rate was significantly lower in the iCS group than the sCS group (log-rank test, P < 0.0001). iCS was identified as an independent prognostic factor for adverse events (hazard ratio 3.82, P = 0.0059). CONCLUSION: iCS was an independent prognostic factor for adverse cardiac events in patients with CS. The clinical diagnosis of iCS based on FDG PET/CT and new guidelines may be important.

FDG uptake patterns in isolated and systemic cardiac sarcoidosis.

AIMS: We aimed to investigate the pre-treatment characteristics and treatment responses of isolated and systemic cardiac sarcoidosis (ICS and SCS) from FDG-PET/CT studies and to compare the prognoses of the two groups. METHODS: FDG-PET/CT images taken before and after treatment of 31 ICS and 91 SCS patients were analyzed retrospectively. Treatment response and recurrence were determined from the course of FDG-PET/CT. Treatment response and the incidence of both recurrence and major adverse cardiac events (MACE) were assessed in 16 ICS and 35 SCS patients who had been treated for more than 2 years. RESULTS: A focal uptake pattern was more often observed than a focal-on-diffuse uptake pattern in both the ICS (74.2%) and SCS (63.7%) groups. Right ventricular involvement was significantly more frequent in SCS than ICS (44.0% vs. 9.6%, p < .001). SUVmax, cardiac metabolic volume (CMV), and cardiac metabolic activity (CMA) were significantly higher in SCS than ICS (SUVmax, 9.1 ± 4.1 vs. 4.8 ± 2.1; CMV, 118.0 ± 111.3 ml vs. 68.3 ± 94.7 ml; CMA, 541.6 ± 578.7 MBq vs. 265.1 ± 396.0 MBq, p < .001). Treatment responses in the two groups were similar, and complete resolution of cardiac uptake after immunosuppressive treatment was obtained in 62.5% of ICS patients and 77.1% of SCS patients (not significantly different). Likewise, no significant difference was found in the incidence of recurrence (40.0% for ICS, 44.4% for SCS) or MACE (25.0% for ICS, 22.8% for SCS). CONCLUSION: SCS patients had more active and extensive CS lesions than ICS patients before treatment, but the two groups showed similar treatment responses and prognoses.

Prednisone vs methotrexate in treatment naïve cardiac sarcoidosis.

BACKGROUND: Side effects limit the long-term use of glucocorticoids in cardiac sarcoidosis (CS), and methotrexate has gained attention as steroid sparing agent although the supporting evidence is poor. This study compared prednisone monotherapy, methotrexate monotherapy or a combination of both, in the reduction of myocardial Fluorine-18 fluorodeoxyglucose (FDG) uptake and clinical stabilization of CS patients. METHODS AND RESULTS: In this retrospective cohort study, 61 newly diagnosed and treatment naïve CS patients commenced treatment with prednisone (N = 21), methotrexate (N = 30) or prednisone and methotrexate (N = 10) between January 2010 and December 2017. Primary outcome was metabolic response on FDG PET/CT and secondary outcomes were treatment patterns, major adverse cardiovascular events, left ventricular ejection fraction, biomarkers and side effects. At a median treatment duration of 6.2 [5.7-7.2] months, 71.4% of patients were FDG PET/CT responders, and the overall myocardial maximum standardized uptake value decreased from 6.9 [5.0-10.1] to 3.4 [2.1-4.7] (P < 0.001), with no significant differences between treatment groups. During 24 months of follow-up, 7 patients (33.3%; prednisone), 6 patients (20.0%; methotrexate) and 1 patient (10.0%; combination group) experienced at least one major adverse cardiovascular event (P = 0.292). Left ventricular ejection fraction was preserved in all treatment groups. CONCLUSIONS: Significant suppression of cardiac FDG uptake occurred in CS patients after 6 months of prednisone, methotrexate or combination therapy. There were no significant differences in clinical outcomes during follow-up. These results warrant further investigation of methotrexate treatment in CS patients.

Diagnostic yield of whole-body 18F-FDG PET/CT in patients with suspected cardiac sarcoidosis.

BACKGROUND: Whole-body F-18 FDG PET has been included in the 2014 Heart Rhythm Society guidelines for cardiac sarcoidosis evaluation to identify alternate sites of biopsy prior to endomyocardial biopsy. The purpose of this study was to evaluate the diagnostic yield of whole-body F-18 FDG PET/CT. METHODS: All adult patients with suspected cardiac sarcoidosis undergoing same-day cardiac F-18 FDG PET/CT and whole-body F-18 FDG PET/CT between 10/1/2016 and 6/14/2021 to assess potential biopsy sites were retrospectively identified. Clinical indications, findings, recommendations, and outcomes were assessed. RESULTS: Eighty-eight patients were included. Extracardiac PET findings suggestive of sarcoidosis were present in 30 patients (34%), 27 of which had thoracic findings (90%). Sarcoidosis was diagnosed in 11% of patients. Only 1% (1/88) was diagnosed by extrathoracic biopsy of a whole-body PET finding. Incidental findings were common (31%), resulting in 11 additional tests or interventions. Recommendations from extrathoracic findings affected treatment in one case: a drainage catheter placement into an unsuspected pelvic abscess. CONCLUSION: Addition of whole-body F-18 FDG PET/CT to cardiac F-18 FDG PET/CT for the identification of extrathoracic sites of biopsy in patients with suspected cardiac sarcoidosis has marginal diagnostic yield but commonly results in incidental findings that rarely affect patient outcome.

Potential clinical utility of 68Ga-DOTATATE PET/CT for detection and response assessment in cardiac sarcoidosis.

BACKGROUND: Somatostatin receptor is expressed in sarcoid granulomas, and preliminary clinical studies have shown that myocardial sarcoidosis can be identified on somatostatin receptor-targeted PET. We examined the potential clinical use of 68Ga-DOTATATE PET/CT for diagnosis and response assessment in cardiac sarcoidosis compared to 18F-FDG PET/CT. METHODS: Eleven cardiac sarcoidosis patients with 18F-FDG PET/CT were prospectively enrolled for cardiac 68Ga-DOTATATE PET/CT. The two PET/CT studies were interpreted independently and were compared for patient-level and segment-level concordance, as well as for the degree of radiotracer uptake. Follow-up 68Ga-DOTATATE PET/CT was performed in eight patients. RESULTS: Patient-level concordance was 91%: ten patients had multifocal DOTATATE uptake (active cardiac sarcoidosis) and one patient showed diffuse DOTATATE uptake. Segment-level agreement was 77.1% (Kappa 0.53 ± 0.07). The SUVmax-to-blood pool ratio was lower on 68Ga-DOTATATE PET/CT (3.2 ± 0.6 vs. 4.9 ± 1.5, P = 0.006 on paired t test). Follow-up 68Ga-DOTATATE PET/CT showed one case of complete response and one case of partial response, while 18F-FDG PET/CT showed four cases of response, including three with complete response. CONCLUSION: Compared to 18F-FDG PET/CT, 68Ga-DOTATATE PET/CT can identify active cardiac sarcoidosis with high patient-level concordance, but with moderate segment-level concordance, low signal-to-background ratio, and underestimation of treatment response.

Complete resolution of focal-on-diffuse myocardial activity pattern on FDG PET-CT by prolonging the dietary preparation protocol in cardiac sarcoidosis.

Patient preparation is crucial for reliable interpretation of cardiac inflammation FDG PET. We share our experience of improved reporting confidence and propose a simple approach of prolonging preparation (from 24 to 48 hours) with the high-fat, no-carbohydrate, and protein-permitted diet followed by fasting in cardiac sarcoidosis in cases with diffuse or focal-on-diffuse myocardial FDG uptake.

Impact of respiratory gating and ECG gating on 18F-FDG PET/CT for cardiac sarcoidosis.

BACKGROUND: The aim of this study was to estimate the impact of respiratory and electrocardiogram (ECG)-gated FDG positron emission tomography (PET)/computed tomography (CT) on the diagnosis of cardiac sarcoidosis (CS). METHODS AND RESULTS: Imaging from thirty-one patients was acquired on a PET/CT scanner equipped with a respiratory- and ECG-gating system. Non-gated PET images and three kinds of gated PET/CT images were created from identical list-mode clinical PET data: respiratory-gated PET during expiration (EX), ECG-gated PET at end diastole (ED), and ECG-gated PET at end systole (ES). The maximum standardized uptake value (SUVmax) and cardiac metabolic volume (CMV) were measured, and the locations of FDG accumulation were analyzed using a polar map. The mean SUVmax of the subjects was significantly higher after application of either respiratory-gated or ECG-gated reconstruction. Conversely, the mean CMV was significantly lower following the application of respiratory-gated or ECG-gated reconstruction. The segment showing maximum accumulation was shifted to the adjacent segment in 25.8%, 38.7%, and 41.9% of cases in EX, ED, and ES images, respectively. CONCLUSION: In FDG PET/CT scanning for the diagnosis of CS, gated scanning is likely to increase quantitative accuracy, but the effect depends on the location and synchronization method.

FDG-PET/CT and rest myocardial perfusion imaging to predict high-degree atrioventricular block recovery in cardiac sarcoidosis.

BACKGROUNDS: High-degree atrioventricular block (AVB) recovery in CS has been shown to be highly variable despite immunosuppressive treatment, with no reliable tool available to predict odds of reversibility. This study sought to evaluate the potential of combined fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) and resting myocardial perfusion imaging (rMPI) to predict reversibility of newly diagnosed high-grade AVB in cardiac sarcoidosis (CS). METHODS: We performed a single-center, retrospective analysis of patients with CS presenting with high-grade AVB who underwent combined FDG-PET/CT and rMPI. The 2016 JCS and the 2014 HRS diagnostic criteria were used for the diagnosis of CS. Patients with a history of coronary artery disease or prior immunosuppressive treatment were excluded. Patients were divided into AVB recovery and non-recovery subgroups. CS disease staging was based on FDG-PET and rMPI findings: (Stage 0) normal FDG-PET and rMPI (Stage 1) positive FDG-PET and normal rMPI (Stage 2) positive FDG-PET with perfusion deficits on rMPI (Stage 3) normal FDG-PET with perfusion deficits on rMPI. RESULTS: Twenty-seven patients, including 13 demonstrating AVB recovery, were identified. Eleven out of fourteen (78.6%) patients presenting with stage 1 CS demonstrated AVB recovery. Stage 1 CS was significantly more present in the recovery group compared to the non-recovery group (84.6% vs 21.4%, P = .002). Eleven presented with stage 2 CS, with only 2 (18.2%) recovering AV nodal conduction. Stage 2 CS presented more frequently in the non-recovery group (64.3% vs 15.4%, P = .020). CONCLUSIONS: Combined FDG-PET and rMPI employed to stage CS disease presenting with high-degree AVB appears to have good performance for predicting likelihood of recovery.

Optimal left ventricular ejection fraction in risk stratification of patients with cardiac sarcoidosis.

AIMS: Identifying patients with cardiac sarcoidosis (CS) who are at an increased risk of sudden cardiac death (SCD) poses a clinical challenge. We sought to identify the optimal cutoff for left ventricular ejection fraction (LVEF) in predicting ventricular arrhythmia (VA) and all-cause mortality and to identify clinical and imaging risk factors in patients with known CS. METHODS AND RESULTS: This retrospective cohort included 273 patients with well-established CS. The primary endpoint was a composite of VA and all-cause mortality. A modified receiver operating curve analysis was utilized to identify the optimal cutoff for LVEF in predicting the primary composite endpoint. Cox proportional hazard regression analysis was used to identify independent risk factors of the outcomes. At median follow-up of 7.9 years, the rate of the primary endpoint was 38% (83 VAs and 32 all-cause deaths). The 5-year overall survival rate was 97%. The optimal cutoff LVEF for the primary composite endpoint was 42% in the entire cohort and in subjects without a history of VA. Younger age, history of VA, lower LVEF, and any presence of scar by cardiac magnetic resonance (CMR) imaging and/or positron emission tomography (PET) were found to be independent risk factors for the primary endpoint and for VA, whereas lower LVEF, baseline NT-proBNP, and any presence of scar were independent risk factor of all-cause mortality. CONCLUSION: Among patients with CS, a mild reduction in LVEF of 42% was identified as the optimal cutoff for predicting VA and all-cause mortality. Prior VA and scar by CMR or PET are strong risk factors for future VA and all-cause mortality.