Cardiac Sarcoidosis Research Articles

Background: Cardiac sarcoidosis (CS) is a rare but increasingly recognized indication for heart transplantation (HTx). While current guidelines include CS in transplant considerations, clinical uncertainty remains as to whether the timing and pattern of diagnosis—early clinical recognition vs. incidental histological diagnosis at explantation—affect post-transplant outcomes. Research Question: We hypothesized that timing and pattern of CS diagnosis influence post-HTx outcomes. Specifically, patients diagnosed before listing (early-recognized) may have worse outcomes due to systemic inflammation, whereas those diagnosed incidentally at explant (incidental CS) may represent cardiac-limited disease with more favorable prognosis. Methods: We conducted a meta-analytic review of published studies reporting post-HTx outcomes in CS patients. Cases were grouped as: (1) Early-recognized CS: diagnosed pre-listing, often with clinical or historical suspicion of systemic or extracardiac involvement. (2) Incidental CS: diagnosed solely via histological exam of explanted hearts, typically without prior systemic involvement. Outcomes were compared between these groups and with non-CS recipients within the same datasets. Results: Across six studies including >18,500 HTx recipients, 182 CS patients were identified (88 early-recognized, 94 incidental). Early-recognized CS showed 1- and 5-year survival of 78.5–79%, recurrence in up to 14%, and a trend toward increased acute rejection. These patients often required stronger immunosuppression, yet systemic inflammation may have persisted. In contrast, incidental CS showed similar or better survival (5-year up to 83%), minimal recurrence, and lower rejection rates, suggesting milder or cardiac-limited disease. UNOS-based analyses revealed lower acute rejection risk in CS vs. non-CS (OR 0.56) with similar survival. Conclusions: The timing and pattern of CS diagnosis appear to impact post-transplant outcomes. Patients with incidental, cardiac-limited CS identified at explantation may experience favorable outcomes, whereas those with early-recognized CS and possible prior systemic involvement may face higher recurrence risk. These findings support individualized approaches to immunosuppression and transplant candidacy evaluation in CS.

Introduction/Background: Genetic cardiomyopathy (GEN-CM) has overlapping features of inflammation and arrhythmias with cardiac sarcoidosis (CS) and non-genetic myocarditis (MYOC); however, the treatments are very different, making it critical to distinguish them accurately. Radiomics is an AI-based approach to pixel-based analysis for CMR images with the potential for broad implementation for this diagnostic problem using publicly available software. Research Questions/Hypothesis: We tested the hypothesis that CMR radiomics would have an area under the curve (AUC) of ≧ 0.8 for diagnosing GEN-CM relative to CS and MYOC. Methods/Approach: The study design was a secondary analysis of an observational cohort from an academic medical center. We evaluated contrast-enhanced CMR images from 145 patients in the University of Minnesota CMR Registry with either GEN-CM, CS, or MYOC. Radiomics was applied to SSFP cine end-diastolic images and late gadolinium enhancement (LGE) images. Principal component analysis (PCA) generated combinations of radiomics features ordered based on the percent of variance explained, and the most predictive PCA predictors for the two models (Model 1: GEN-CM v. CS; Model 2: GEN-CM v. MYOC) were chosen. Bootstrapping (resampling with replacement) was used to generate 100 different samples from the original dataset, and receiver operating characteristic (ROC) curves with 95% confidence bands were used to report the AUC and 95% CI for each model. Results/Data: Among 145 patients (age 43.2 ± 16.0 years, 31% female) who had GEN-CM (n=50), CS (n=47) or MYOC (n=48), the most prominent features influencing the diagnosis were the maximum mean absolute deviation in pixel intensity, the maximum run length non-uniformity (normalized), and the large area emphasis feature, which were all higher in GEN-CM v. CS and GEN-CM v. MYOC ( Figure 1 ). Four PCA predictors (three LGE predictors and one cine predictor) were identified for Model 1, and four PCA predictors (two LGE predictors and 2 cine predictors) were identified for Model 2. The AUC for Model 1 was 0.90 (95% CI 0.83 to 0.95), and the AUC for Model 2 was 0.88 (AUC 0.81 to 0.94), indicating a high level of performance ( Figure 2 ). Conclusions: Radiomics applied to CMR cine and LGE images provides a high level of performance for the diagnosis of genetic cardiomyopathy, accurately distinguishing it from cardiac sarcoidosis and non-genetic myocarditis with contributions from both CMR imaging sequences.

Background: Patients with cardiac sarcoidosis (CS) generally have a poor prognosis, due to an increased risk for arrhythmias, heart failure (HF), and sudden cardiac death often necessitating device therapy. However, in patients with preserved left ventricular ejection fraction (LVEF), the optimal device—implantable cardioverter-defibrillator (ICD) vs. permanent pacemaker (PPM)—remains unclear. Our study assessed the impact of ICD vs. PPM in CS on clinical outcomes, including mortality, hospitalization, and HF development in this population. Objective: Evaluate mortality, hospitalization, and development of HF in patients with CS and normal LVEF who received an ICD vs PPM. Methods: We conducted a retrospective cohort analysis using the TriNetX Research Network, which aggregates electronic health records from 102 healthcare organizations. Adult patients (≥18 years) with CS and a LVEF > 35% receiving either an ICD (n=1,403) or PPM (n=115) after initial diagnosis were included. Patients with reduced LVEF and prior ventricular tachycardia were excluded. Propensity score matching (1:1) was used to adjust for baseline differences across 12 demographic, clinical, and laboratory variables (n = 113 in each group). The primary outcomes were all-cause mortality, hospitalizations, and incidence of HF following device implantation. Risk ratios, Kaplan-Meier survival analysis, hazard ratios, and p-values were used for comparative analysis. Results: Following propensity score matching, mortality was similar between cohorts: 10.6% (12/113) in the ICD group vs. 11.5% (13/113) in the PPM group (risk difference -0.009%, 95% CI: -0.09-0.07, p =0.83; HR: 0.93, 95% CI: 0.42-2.03, p=0.91). The rates of hospitalization were similar as well: 55.6% (63/113) in ICD group vs. 29.6% (56/113) in the PPM group (risk difference 0.06%, 95% CI: -0.07-0.19, p= 0.35; HR: 1.14, p=0.56). However, the rates of heart failure diagnosis post-device implantation was greater in ICD group (40.9%, 18/44) vs. PPM group (20.4%, 10/49, risk difference: 0.21, 95% CI: 0.02-0.39, p=0.03). Conclusion: In CS patients with preserved LVEF, ICD implantation did not improve mortality or hospitalization rates compared to PPM. However, incident HF was significantly more frequent in the ICD group, potentially reflecting unmeasured confounding factors influencing device selection. These findings underscore the need for prospective studies to better inform device choice in this complex population.

Background: Cardiac sarcoidosis (CS) is a rare, but potentially life-threatening manifestation of systemic sarcoidosis. While both cardiac magnetic resonance imaging (CMRI) and fluorodeoxyglucose positron emission tomography (FDG-PET) are widely used as non-invasive imaging modalities, their relative diagnostic accuracy remains unclear. We aimed to evaluate the diagnostic performance of CMRI compared to FDG-PET for detecting CS. Methods: A systematic literature search was conducted across PubMed, EMBASE, and Cochrane CENTRAL through May 2025 to identify studies evaluating the diagnostic accuracy of CMRI and/or FDG-PET for CS. Studies were included if they reported sufficient data to calculate diagnostic accuracy metrics against a clinical or histological reference standard. A bivariate random-effects model was used to estimate pooled sensitivity, specificity, diagnostic odds ratios (DOR) along with corresponding 95% confidence intervals (CI). The positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LR+), negative likelihood ratio (LR-) and Youden Index were also calculated. A summary receiver operating characteristic (SROC) diagnostic model was used to calculate the area under curve (AUC) and evaluate overall diagnostic performance. A p-value <0.05 was considered significant in all cases. Results: A total of 41 studies were included, out of which 23 reported data for CMRI and 32 for FDG-PET. CMRI demonstrated significantly superior overall diagnostic performance compared to FDG-PET (p = 0.013 for AUC comparison) for the detection of cardiac sarcoidosis. Pooled sensitivity and specificity for CMRI were 0.90 (95% CI: 0.85-0.94) and 0.82 (95% CI: 0.69-0.90) respectively, both higher than FDG-PET, which showed a sensitivity of 0.78 (95% CI: 0.69-0.84) and specificity of 0.78 (0.72-0.84). CMRI also yielded a greater DOR of 41.7 (95% CI: 19.40-89.6) versus 12.50 (95% CI: 7.71-20.30), AUC of 0.92 (95% CI: 0.82-0.91) versus 0.83 (0.74-0.83) and YI of 0.72 (95% CI: 0.59-0.80) versus 0.56 (95% CI: 0.47-0.63) compared to FDG-PET. Conclusion: CMRI demonstrated a significantly greater diagnostic performance for detection of CS compared to FDG-PET with a superior sensitivity, specificity, DOR, AUC and YI, highlighting CMRI as a more robust imaging modality for CS. However, direct comparative studies and standardized diagnostic criteria remain essential to confirm these findings and guide clinical imaging strategies.

Background: We aimed to evaluate the outcomes of patients with confirmed and possible cardiac sarcoidosis who had an ICD implant and identify predictors of ventricular arrhythmias and mortality in this patient population. Methods: We performed a retrospective study patients with a diagnosis of cardiac sarcoidosis (CS) at Mayo Clinic and had an ICD implanted for primary or secondary prevention indication. Adult patients (≥18 years) with a diagnosis of possible or confirmed (biopsy-proven) CS with an ICD implanted between 1993 and 2022 were included. Primary outcomes included sustained ventricular arrhythmia (VT) resulting in a documented appropriate ICD shock and death from any cause. Secondary outcomes included ICD-related complications. Results: We identified 148 patients, in which 23 patients (15.5%) experienced VT events with a total of 160 treated episodes. 4 patients (2.7%) experienced inappropriate ICD shocks (11 episodes). During a median follow up of 3.1 years, 26 patients deceased, and the overall survival was 98% and 77% at 1 and 5 year. Older age, CAD, CKD, paced rhythm and QRS duration were associated with worse survival (Figure 1 – 4) . Device related complications were rare, except for the higher percentage of CHF in patients with VT after implant, however this was not statistically significant. Patients with ICD therapies were younger (53 vs 58 years, p=0.029), had higher LGE burden (26.9 vs 16.3%, p=0.01), and higher percentage of LV mass (26.9 vs 16.3, p=0.011). Multivariate logistic regression model which showed that patients with biopsy proven sarcoidosis had significantly higher odds of VT events (OR: 3.04, 95% CI: 1.02 to 9.08, p = 0.046). In patients with increased LV mass (every 10 g increase), the odds of developing VT increased by 1.49 (95% CI: 1.02 to 2.19, p = 0.041). LV mass and LGE percentage showed fair ability of predicting the outcome by ROC analysis. Youden’s index showed 26 for LV mass and 16% for LGE percent as the optimal cut-off points for predicting VT outcomes (Figure 5) . The sensitivity, specificity, positive predictive value, negative predictive value were 81.8%, 74.1%, 37.5%, 95.6% and 75.4% respectively for an LV mass of 26 grams and 81.8%, 63.8%, 30.0%, 94.9% and 66.7% respectively for an LGE percentage of 16%. Conclusion: LGE burden continues to be a major predictor for VT events in patients with CS. Myocardial tissue burden and electrical abnormalities from CS predict mortality than myocardial function loss.

Background: 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET) is valuable for the diagnosis of cardiac sarcoidosis (CS). Although current guidelines recommend maintaining the initial maximum dose of prednisolone (PSL) for one month after its initiation, the prognostic significance of FDG-PET performed at one month following the initiation of PSL remains unclear. We sought to investigate whether FDG-PET performed at one month after the initiation of PSL was associated with adverse events in patients with CS. Methods: We examined 110 consecutive CS patients performed FDG-PET at diagnosis and one month following the initiation of PSL between January 2010 and January 2025 in a university hospital. All patients were initiated on an initial dose of PSL at 30 mg/day or 1 mg/kg/day, or an equivalent dose. We calculated the change in the maximum standardized uptake value (SUVmax) on FDG-PET from diagnosis to one month after the initiation of PSL. A responder to the maximum dose of prednisolone was defined as a decrease in SUVmax of at least 25%, while a non-responder was defined as a decrease of less than 25% or any increase, in line with previous reports. Patients were classified as either responders (n = 84) or non-responders (n = 26). The primary outcome was a composite of sustained ventricular tachycardia/fibrillation (VT/VF), worsening heart failure (HF), and all-cause death. Results: The median age was 63 ± 11 years, and 87 patients (79.1%) were female. The median left ventricular ejection fraction (LVEF) was 45 (IQR 37–60) %. Patients with non-responder had higher cardiac troponin T levels and lower estimated glomerular filtration rate compared to those with responder. There were no significant differences in age, past history, LVEF, brain natriuretic peptide levels between the groups. During a median follow-up period of 3.3 (IQR 1.1–6.2) years, the primary outcome occurred in 34 patients (30.9%). Patients with non-responder showed significantly higher incidence of primary outcome ( P = 0.006) ( Figure ). In multivariable Cox analyses, non-responder status was significantly associated with the primary outcome, sequentially adjusted for history of VT/VF (HR 2.32, P = 0.022) and then for LVEF (HR 2.15, P = 0.036). Conclusions: FDG-PET performed one month after initiating PSL was associated with adverse events in patients with CS, suggesting its utility in risk stratification and therapeutic decision-making prior to starting PSL tapering.

Introduction: 18FDG-PET scan has emerged as a modality for identifying inflammatory cardiomyopathies such as cardiac sarcoidosis (CS) by detecting glucose uptake. Guidelines allow for diagnosis of CS based on clinical presentation and 18FDG-avidity without requiring tissue biopsy. However, patients with genetic cardiomyopathies can be 18FDG-avid, potentially leading to misdiagnosis as isolated CS. Objectives: To evaluate the prevalence of pathogenic and likely pathogenic (P/LP) variants in 18FDG-avid cardiomyopathy and assess the association between FDG-avidity, genetic variants, and heart failure outcomes. Methods: A multi-center retrospective cohort study combined patients from three centers who underwent both a cardiac 18FDG-PET scan and commercial genetic testing for genetic cardiomyopathies. We excluded patients with biopsy-proven sarcoidosis, as well as those with incomplete 18FDG suppression. Chi-square tests were used to compare between group characteristics, and Kaplan-Meier survival analyses were performed to evaluate time to event outcomes, including a composite of death, LVAD implantation, or heart transplant, based on 18FDG-avidity and genetic status. Results: Among 459 patients who underwent both a cardiac 18FDG-PET scan and genetic testing, 389 (33% female; mean age 54 years) met the inclusion criteria. 18FDG-avidity was identified in 158 (40%). Within this subgroup, 19 (12%) had a P/LP variant compared with 19% of the 18FDG-negative patients (p=0.051; Figure 1). Baseline characteristics were similar, and a wide array of genes was implicated in 18FDG-avid cardiomyopathy (Figure 2). Survival analysis revealed no significant difference between the four genotype-FDG subgroups (p=0.13, Figure 3), and 18FDG-avidity was not significantly associated with the composite endpoint in the overall cohort (p=0.35), nor within the subset of patients with P/LP variants (p=0.84), suggesting that 18FDG-avidity did not predict clinical outcomes. The presence of a P/LP variant was associated with an increased incidence of the composite endpoint (p=0.047). Conclusion: 18FDG-avidity is frequently noted in patients with genetic cardiomyopathy, but was not associated with adverse clinical outcomes, suggesting it may not reflect clinically relevant inflammation. P/LP variants were significantly associated with survival outcomes, highlighting the value of genetic testing in patients with suspected inflammatory cardiomyopathy.

Background: Atrial myopathy includes structural remodeling processes that result in adverse cardiovascular conditions. Metabolic inflexibility, defined by altered substrate availability, plays an important role in atrial fibrillation (AF) initiation and progression. Atrial dilation is a result of AF’s structural remodeling processes, while atrial uptake of 18F-fluorodeoxyglucose (FDG) in positron emission tomography (PET) imaging reflects underlying metabolic shifts. Aim: We aim to investigate the relationship between atrial FDG uptake and atrial dilation. Hypothesis: Atrial FDG uptake reflects an active remodeling process within the atrial myocardium and is associated with increased volumes. Methods: Patients undergoing FDG-PET for the evaluation of cardiac sarcoidosis (CS) were assessed for atrial avidity. Atrial FDG uptake, a semi-quantitative measure, was quantified using standardized uptake value SUV-mean, SUV-max, and normalized to the blood pool as the target-to-background ratio (TBR). Atrial volume assessment was obtained from cardiac magnetic resonance imaging (CMR) scans done prior to PET. Right atrial volume index (RAVi) was obtained from monoplanar 4 chamber view while left atrial volume index (LAVi) was obtained from biplanar method. Results: One hundred and fifty-eight patients (age 61 ± 15 years, 37% female, BMI 29.6 ± 6.5 kg/m2) were included in the study. CS was noted in 43 (27.2%) patients and AF in 49 (31%) patients. Regression analysis showed an association between LAVi and atrial TBRmax (β=0.005, p =0.007) but no association between RAVi and atrial TBRmax (β=0.002, CI -0.002-0.006 p =0.08) after adjustment for AF and cardiac sarcoidosis. Location specific analysis showed that RAVi was associated with right (OR 1.03, p =0.01) and biatrial uptake (OR 1.05 p =0.02). However, LAVi was only associated with biatrial uptake (OR 1.04, p =0.04). Patients with atrial avidity had a significantly higher LAVi and RAVi (46.8±21.7 vs 38.1±13.9 mL/m 2 , p=0.02, 44.4±18.4 vs 36.5±13.1 mL/m 2 , p=0.02). In AF patients specifically, this relationship remained significant with RAVi (51.5±20.6 vs 39.1±14.4 mL/m 2 , p=0.02) while no difference was found with respect to LAVi (54.2±23.5 vs 42.8±14.4 p=0.06). Conclusion: Atrial-specific FDG uptake is associated with dilation of the corresponding chamber. This suggests that altered substrate utilization may contribute to localized atrial remodeling. Further research is needed to explore the temporal nature of this association.

Background: Atrial fibrillation (AF) is marked by underlying inflammation and metabolic changes. Atrial 18F-Fludeoxyglucose (FDG) positron emission tomography (PET) can be used to assess these changes. Previous studies show increased FDG avidity in AF. Aim: We aim to investigate atrial uptake differences between paroxysmal AF (pAF) and persistent AF (perAF). Hypothesis: Patients with perAF exhibit a greater atrial FDG-PET avidity and demonstrate higher quantitative uptake measures compared to those with pAF. Methods: Patients undergoing FDG-PET for the evaluation of cardiac sarcoidosis (CS) were assessed for atrial avidity. Atrial FDG uptake, a semi-quantitative measure, was quantified using standardized uptake value (SUV)-mean, SUV-max, and normalized to the blood pool as the target-to-background ratio (TBR). Qualitatively, intensity with respect to liver uptake (less vs equal or greater), pattern (focal vs diffuse), and location were reported. AF types were determined using patient’s electronic medical records. Results: One hundred and twenty-six patients (age 67 ± 12 years, 26% female, BMI 29.8 ± 6.5 kg/m2) were included in the study. 35 pts (27.4%) met diagnostic criteria for cardiac sarcoidosis (CS). 79 (62.7%) patients had pAF, 39 (31%) had perAF, 8 (6.3%) had an unspecified subtype. Atrial avidity was seen in 45 patients and distributed accordingly: 30 in the right atrium, 13 bi-atrial, and 2 left atrial. Avidity had a predominant diffuse pattern (66.7%) with intensity equal or greater than the liver’s (62%). 23 (58%) of the avid atria were in perAF patients while only 22 (38%) were in pAF patients. Quantitively, aTBRmax was significantly higher in perAF group (1.35 ± 0.51 vs 1.14 ± 0.39, p=0.03). PerAF was associated with a higher aTBRmax (B=0.2, CI 0.03-0.37, p=0.02) after adjusting for cardiac sarcoidosis. Conclusion: Persistent AF is associated with higher qualitative and quantitative atrial FDG-PET avidity compared to paroxysmal AF. Additional studies are needed to better understand causality and mechanisms behind these associations.

Description of Case: A 58 year old man with non-ischemic cardiomyopathy (LVEF 21%) secondary to presumed (non-biopsy proven) cardiac sarcoidosis on prednisone and infliximab status post CRT-D placement, recurrent admissions for VT, and CKD presented to the emergency room with right upper quadrant pain. Chest x-ray revealed right lower lobe pneumonia and he was started on broad-spectrum antibiotics. He was admitted to the ICU and rapidly developed severe acute hypoxemic respiratory failure requiring intubation, maximum ventilator support, and neuromuscular paralysis. He concomitantly developed severe shock requiring high doses of three vasopressors. In this setting, he had hemodynamically unstable runs of monomorphic VT treated with IV amiodarone and lidocaine. He suffered a VT arrest (Image 1), with rates below his device detection zone, and was externally defibrillated. A Shock Team call was convened. He was cannulated on to veno-arterial-venous (V-AV) ECMO for refractory hypoxemia, VT and SCAI E cardiogenic shock. He underwent placement of an axillary Impella 5.5 for LV mechanical unloading. With time, his respiratory and circulatory status improved to the point of being able to liberate to V-V ECMO, which was subsequently decannulated, remaining on low-level Impella support throughout. His course was complicated by anuric renal failure requiring dialysis, mechanical device-related hemolysis, and a large, mobile right atrial thrombus. This clot appeared to be adherent to a PFO and was removed via AngioVac suction thrombectomy with live intra-cardiac echocardiographic guidance (Images 2, 3). Weaning of anti-arrhythmic drugs resulted in recurrence of VT. His back-up pacing rate was increased and he was deeply sedated, started on procainamide, and empirically treated for a sarcoidosis flare with pulse dose steroids, with residual breakthrough VT. Due to his ongoing infections, coagulopathy, multi-organ failure, and VT storm, he was deemed not a candidate for advanced therapies. He was transitioned to comfort-oriented care and passed away. Discussion: This case illustrates the utility of a less conventional ECMO configuration in patients with combined cardiopulmonary failure, while also highlighting the challenge of treating VT storm in a patient with inflammatory cardiomyopathy and septic shock. Finally, we demonstrate the role for suction thrombectomy in extracting large, mobile intra-cardiac thrombi to prevent embolic phenomena.

Introduction: Cardiac 18 FDG-PET is an imaging modality frequently used to diagnose inflammatory cardiomyopathies such as cardiac sarcoidosis. Japanese Circulation Society (JCS) guidelines propose a set of criteria for non-invasively diagnosing isolated cardiac sarcoidosis using 18 FDG-PET. Recent data suggests that many patients with 18 FDG-avid PET have genetic cardiomyopathies. We hypothesize that 18 FDG -avidity may be a marker of inflammation or metabolic dysregulation which is pro-arrhythmic. Objectives: To compare the clinical presentation and prevalence of pathogenic variants in patients with and without 18 FDG -avidity and to determine whether 18 FDG -avidity predicts VT/VF free survival. Methods: A retrospective cohort study utilizing patients from University of Washington and Oregon Health Science University who underwent 18 FDG -PET and had genetic testing through Invitae. Patients with biopsy proven sarcoidosis were excluded. Chi-square statistical testing was used to compare groups and Cox-regression was used to assess survival free from the composite endpoint of VT/VF or mortality. Results: A total of 202 patients with genetic testing and 18 FDG -PET were identified across 2 institutions yielding 100 patients with 18 FDG -avidity and 102 patients with 18 FDG -negative PET. A total of 35 patients had pathogenic or likely pathogenic (P/LP) genetic variants, 37% of whom were 18 FDG -avid (Figure 1; P-value 0.1). Patient demographics and presenting clinical features were similar between 18 FDG -avid and 18 FDG -negative patients (Table 1). P/LP variants ( 18 FDG -avid, 18 FDG -negative) include DSP (1,4), FLNC (1,1), LMNA (3,8), MYBPC3 (1,0), MYH7 (1,2), TTN (5,4). Of the 100 18 FDG -avid patients, 51% met JCS criteria for isolated cardiac sarcoidosis and 14% (n=7) of 18 FDG -avid patients meeting JSC criteria had P/LP variants. In Cox regression analysis, VT/VF free survival was similar between 18 FDG -avid patients with and without P/LP variants and 18 FDG -negative patients with and without LP/P variants (p=0.26). 18 FDG-avid patients had similar VT/VF free survival to 18 FDG-negative patients (p=0.21). Conclusion: There was a similar prevalence of P/LP variants amongst patients with and without 18 FDG -avidity. JCS criteria was commonly met by patients with 18 FDG -avidity and amongst 18 FDG -avid patients with P/LP variants suggesting a lack of specificity for isolated cardiac sarcoidosis. Cardiac FDG-avidity was not associated with increased VT/VF/mortality.

Background: Electroanatomic mapping (EAM) guidance for endomyocardial biopsies (EMB) has been suggested to be feasible and safe, but the diagnostic yield remains unclear for cardiomyopathies. Objective: We aimed to evaluate the diagnostic efficacy of EAM and intracardiac echocardiography (ICE)-guided EMBs. Methods: We retrospectively reviewed patients who underwent EMB from August 2018 to July 2024. EMB was guided by EAM using CARTO system (Biosense Webster, Irvine, CA), and ICE. After accessing the right femoral vein, samples (3-6 per suspected site) were collected using a disposable bioptome and steerable sheath. For left ventricular (LV) biopsies, we used a transseptal approach, and for atrial biopsies, we targeted the atrial septum. In cases of abnormal EAM, multiple samples were taken from the identified areas. When EAM was normal, biopsy targeting was guided by adjunctive imaging. EMB was considered positive if pathology demonstrated findings that directly corroborated the diagnosis. Results: Of 87 patients who underwent EMB, the median age was 61 years, and 33% were female. EMB sites included the right ventricle (RV) and LV (15/87), RV only (27/87), LV only (38/87), right atrium (RA) and LV (3/87), and RA only (4/87). Pre-procedural imaging was common: cardiac MRI (80%), cardiac PET (65.6%), and/or pyrophosphate scan (8%). Mean LV ejection fraction was 44%, and mean scar burden was 11% on MRI. The overall diagnostic yield was 18%, encompassing a wide spectrum of pathologies (Figure 1A). Positive biopsy results were significantly associated with pre-procedural suspicion of amyloidosis (Odds Ratio {OR} 6.5, 95% CI 1.2-35.5), myocarditis (OR 6.5, 95% CI 1.2-35.5), or cardiac masses (OR 3.9, 95% CI 1.1-13.9), and sampling from both RA and LV (Figure 1B). EAM and ICE during EMB (Figure 1C) were used in 85% and 99% of cases, respectively. No procedural complications were observed. Conclusions: In our cohort, EAM-guided EMB is a safe diagnostic tool with the best yield for pre-procedural suspicion of amyloidosis, myocarditis, or cardiac masses. Future studies investigating the role of potential tools to optimize biopsies for undifferentiated cardiomyopathies and cardiac sarcoidosis could significantly improve the potential value of EAM-guided EMB.

Background: A subset of patients with non-dilated left ventricular cardiomyopathy (ND-LVCM) presents with restrictive-like physiology despite preserved left ventricular size. However, the pathological and imaging correlates of this diastolic dysfunction remain insufficiently characterized. Hypothesis: We hypothesized that diastolic dysfunction in ND-LVCM is associated with myocardial fibrosis or infiltration and corresponds with specific echocardiographic and MRI findings. Methods: We retrospectively analyzed 169 patients with ND-LVCM (LV end-diastolic diameter <55 mm) who underwent endomyocardial biopsy, cardiac MRI, and echocardiography including global longitudinal strain (GLS). Fibrosis was quantified using Masson's trichrome staining and categorized into interstitial, subendocardial, or perivascular patterns. In cardiac amyloidosis, Congo red–positive deposition was semi-quantified as diffuse, scattered, or perivascular. Restrictive-like physiology was defined by LA diameter >40 mm, E/e′ >15, elevated BNP, and LVEF ≥50%. Results: Diagnoses included cardiac amyloidosis (n=56), sarcoidosis (n=14), Fabry disease (n=12), hypertensive cardiomyopathy (n=49), and hypertrophic cardiomyopathy (n=38). Approximately 40% of patients exhibited restrictive-like physiology. These patients demonstrated significantly greater fibrosis burden (median 10.1% vs. 5.6%, p<0.001), higher prevalence of interstitial and perivascular fibrosis, and more frequent mid-wall or subepicardial late gadolinium enhancement (LGE) on MRI. Echocardiography showed reduced GLS and shortened deceleration time in these cases. In amyloidosis, diffuse deposition was particularly associated with more pronounced impairment in diastolic markers. Fabry disease was characterized by impaired relaxation without overt restrictive features, while sarcoidosis presented with heterogeneous diastolic profiles. Conclusions: Restrictive diastolic physiology in ND-LVCM spans multiple etiologies and correlates with distinct histologic and imaging features. An integrated approach combining echocardiography, MRI, and myocardial biopsy offers valuable insights into disease mechanisms and may aid in the differentiation of restrictive cardiomyopathy phenotypes.

Background: Chagas cardiomyopathy is a common cause of nonischemic cardiomyopathy in Latin America and often presents with ventricular arrhythmias. With increasing global migration, the prevalence of Chagas cardiomyopathy in non-endemic regions is rising, including the United States. As such, evaluating the etiology of ventricular arrhythmias requires a broad differential. We present the diagnostic work up of a patient presenting with monomorphic ventricular tachycardia (VT), ultimately found to have Chagas cardiomyopathy. Case: A 54-year-old Spanish-speaking male with no past medical history presented after being found unconscious and diaphoretic. Electrocardiogram demonstrated sustained monomorphic VT. After stabilization, transthoracic echocardiography revealed a left ventricular (LV) ejection fraction 30-35% with global hypokinesis and severely dilated LV cavity. Coronary angiography revealed patent coronaries. Further workup with cardiac magnetic resonance imaging demonstrated transmural late gadolinium enhancement in the basal to mid-lateral wall corresponding with hypokinetic myocardium, with a LV thrombus adjacent to the mitral valve and developing apicolateral aneurysm. An 18-fludeoxyglucose positron emission tomography scan was done which showed increased glucose uptake in the dysfunctional mid-lateral to apicolateral and anterolateral myocardium, without extracardiac evidence of sarcoid. Serologic testing was notable for an initially positive Lyme IgM, but confirmatory testing was negative. Further, serologies for Trypanosoma cruzi returned positive. Discussion: Although imaging was initially concerning for cardiac sarcoidosis, it did not meet clinical diagnostic criteria given absence of extracardiac involvement and presence of positive Trypanosoma cruzi titers. Empiric treatment was initiated for suspected Lyme carditis as he endorsed a history of rash resembling erythema migrans prior to presentation but was discontinued once confirmatory testing was negative. He was ultimately diagnosed with Chagas cardiomyopathy, but given his high-risk Rassi score, antiparasitic therapy was deferred and confirmatory testing was not pursued. He was started on guideline-directed medical therapy for cardiomyopathy and anticoagulation for LV thrombus. Amiodarone was initiated for VT, and an automatic implantable cardioverter defibrillator was placed for secondary prevention.

Diagnoses and outcomes of patients referred for FDG PET/CT for suspected cardiac sarcoidosis.

Overlooked and Underdiagnosed: Cardiac Sarcoidosis and Unexplained Ventricular Tachycardia and Fibrillation.

Prognostic value of the clinical phenotype in patients with cardiac sarcoidosis: SARCO phenotype.

Cardiac Sarcoidosis A Brief Review of the Evolving Role of Diagnostic Imaging.

Cardiac hemangioma (CH) is a rare benign cardiac tumor whose clinical manifestations—including arrhythmias, heart failure, and pericardial effusion—vary by anatomical location. Sarcoidosis is a multisystem disorder of unknown etiology characterized by non-caseating granulomas, commonly involving the lungs, eyes, and skin, with cardiac involvement being relatively uncommon. To date, no cases of concurrent cardiac hemangioma and cardiac sarcoidosis have been reported worldwide. We herein describe a patient with established sarcoidosis who, during follow-up, exhibited progressive enlargement of a cardiac mass. Surgical resection confirmed the co-existence of cardiac hemangioma and cardiac sarcoidosis within the same anatomical region. Based on these findings, we propose a pathophysiological mechanism wherein cardiac sarcoidosis causes microvascular injury, leading to structural alterations that may promote the development of cardiac hemangioma. The following report details the diagnostic and therapeutic course of this patient.

Primary or iatrogenic left atrial tachycardias (LATs) can occur in patients undergoing atrial fibrillation (AF) catheter ablation. We aimed to investigate the background characteristics of the occurrence of LATs during and after AF catheter ablation. We retrospectively studied 5465 consecutive patients who underwent catheter ablation of AF with and without ATs between March 2014 and September 2021. LATs were defined as ATs with those circuits or origins that were partially or completely included in the LA. The LAT and non-LAT groups included 388 and 5077 patients, respectively. A total of 504 LATs (macroreentry, 80.2%; localized reentry, 10.9%; focal activation, 8.9%) consisted of 31 (6.2%) primary and 473 (93.8%) iatrogenic LATs. A multivariate analysis demonstrated that a female gender, non-paroxysmal AF, ischemic heart disease (IHD), hypertrophic cardiomyopathy (HCM), cardiac sarcoidosis, larger LA diameter, left ventricular hypertrophy (LVH), and prior LA linear and electrogram-based ablation were independent positive predictors of LATs (odds ratios [ORs]: 2.00, 1.56, 3.37, 1.85, 16.9, 1.04, 1.90, 2.35 and 3.06; p < 0.05). Further, an older age, non-paroxysmal AF, IHD, and larger LA diameter were independent positive predictors of primary LATs (ORs: 1.08, 17.1, 4.95, and 1.12; p < 0.05). A female gender, non-paroxysmal AF, larger LA diameter, prior LA linear and electrogram-based ablation, and the presence of IHD, HCM, cardiac sarcoidosis, and LVH may increase the risk of LATs associated with AF catheter ablation, and an older age, non-paroxysmal AF, larger LA diameter, and IHD may increase the risk of primary LATs, especially macroreentrant LATs.