Performance of cardiac PET/CT with and without phase analysis for detection of scar in cardiac sarcoidosis: Comparison to cardiac magnetic resonance imaging.

BACKGROUND: The presence of myocardial scar in CS patients results in poor prognosis and worse outcomes. 18F-fluorodeoxyglucose (18F-FDG) PET/CT excels at visualizing inflammation but is suboptimal at detecting scar. We evaluated PET/CT sensitivity to detect scar and investigated the incremental diagnostic value of automated PET-derived data. METHODS: 176 patients who underwent cardiac magnetic resonance (CMR) and N-13 ammonia/18F-FDG cardiac PET/CT for suspected CS within 3 months were enrolled. Scar was defined as late gadolinium enhancement (LGE) on CMR without concordant 18F-FDG uptake on 18F-FDG PET/CT. Accuracy of cardiac PET/CT at detecting scar (perfusion defect without concordant 18F-FDG uptake) was assessed before and after addition of automated PET-derived data. RESULTS: Sensitivity of PET/CT for scar detection was 45.3% (specificity 88.9%). Addition of PET-derived LV volumes and function in a logistic regression model improved sensitivity to 57.0% (specificity: 80.0%, AUC 0.72). Addition of phase analysis maximum segmental onset of myocardial contraction > 61 improved AUC to 0.75, correctly relabeling 16.3% of patients as scar (net reclassification index 8.2%). CONCLUSION: Sensitivity of gated PET MPI alone for scar detection in CS is suboptimal. Adding PET-derived volumes/function and phase analysis data results in improved detection and characterization of scar.

Imaging cardiac sarcoidosis and infiltrative diseases: diagnosis and therapeutic response.

Infiltrative heart disease is an encompassing term referring to different pathological entities that involve infiltration of the myocardium by either abnormal substances or inflammatory cells. These infiltrates can impair cellular function, induce necrosis and fibrosis, or otherwise disrupt myocardial architecture resulting in a wide spectrum of structural and functional impairment. Depending on the specific disorder and stage of disease, patients may present with minimal cardiac abnormalities, or may have findings of advanced restrictive and/or dilated cardiomyopathy. Furthermore, patients may often be misdiagnosed with more common conditions such as hypertensive, hypertrophic or ischemic cardiomyopathies. Correlation of cardiac findings with clinical, serologic or pathologic data is critical in many of these conditions. While cardiac involvement may be detected by echocardiography, other imaging modalities such as cardiac magnetic resonance, single-photon emission computed tomography, or positron emission tomography provide additional critical diagnostic, prognostic and therapeutic information. Advanced imaging modalities also provide quantitative data that can further risk stratify patients, monitor disease progression, and guide management. In this review we provide an overview of infiltrative heart disease from an imaging perspective, with a particular focus on cardiac sarcoidosis and cardiac amyloidosis.

Arrhythmic manifestations and outcomes of definite and probable cardiac sarcoidosis.

BACKGROUND: The 2014 Heart Rhythm Society consensus statement defines histological (definite) and clinical (probable) diagnostic categories of cardiac sarcoidosis (CS), but few studies have compared their arrhythmic phenotypes and outcomes. OBJECTIVE: The purpose of this study was to evaluate the electrophysiological/arrhythmic phenotype and outcomes of patients with definite and probable CS. METHODS: We analyzed the arrhythmic/electrophysiological phenotype in a single-center North American cohort of 388 patients (median age 56 years; 39% female, n = 151) diagnosed with definite (n = 58) or probable (n = 330) CS (2000-2022). The primary composite outcome was survival to first ventricular tachycardia/fibrillation (VT/VF) event or sudden cardiac death. Key secondary outcomes were also assessed. RESULTS: At index evaluation, in situ cardiac implantable electronic devices and antiarrhythmic drug use were more common in definite CS. At a median follow-up of 3.1 years, the primary outcome occurred in 22 patients with definite CS (38%) and 127 patients with probable CS (38%) (log-rank, P = .55). In multivariable analysis, only a higher ratio of the 18F-fluorodeoxyglucose maximum standardized uptake value of the myocardium to the maximum standardized uptake value of the blood pool (hazard ratio 1.09; 95% confidence interval 1.03-1.15; P = .003, per 1 unit increase) was associated with the primary outcome. During follow-up, patients with definite CS had a higher burden of device-treated VT/VF events (mean 2.86 events per patient-year vs 1.56 events per patient-year) and a higher rate of progression to heart transplant/left ventricular assist device implantation but no difference in all-cause mortality compared with patients with probable CS. CONCLUSION: Patients with definite and probable CS had similarly high risks of first sustained VT/VF/sudden cardiac death and all-cause mortality, though patients with definite CS had a higher overall arrhythmia burden. Both CS diagnostic groups as defined by the 2014 Heart Rhythm Society criteria require an aggressive approach to prevent arrhythmic complications.

The Mechanism and Natural History of Mitral Regurgitation in Cardiac Sarcoidosis.

Cardiac sarcoidosis (CS) is an infl/ammatory cardiomyopathy that can present with mitral regurgitation (MR), but few studies describe the mechanisms and natural history of MR in CS. We queried an institutional registry of 512 patients with CS for moderate or greater MR at diagnosis. Baseline demographic and echocardiography (TTE) data were collected. MR was classified by Carpentier type. Positron emission tomography was analyzed for 2-deoxy-2-[fluorine-18] fluoro-d-glucose (FDG) avidity of anterolateral and posteromedial papillary muscles. Follow-up TTE and positron emission tomography imaging of patients treated with immunosuppression was analyzed for MR severity and FDG avidity changes. Fifty-four patients were identified. Mean left ventricular ejection fraction was 39.3%, effective regurgitant orifice 0.34 cm2, and MR regurgitant volume 46.3 ml. Carpentier type I was the most common MR mechanism (46.3%). Forty-one patients had follow-up TTE (median follow-up 1.7 years, interquartile range 2.6 years). Evaluating preprocedural follow-up TTE only, MR severity was significantly reduced, with 37% of patients showing reduction by at least 1 severity grade (p = 0.04). With postprocedural TTE included, 61% of patients showed alleviation of MR severity with mean decrease in grade - 0.98 (p <0.001). Sixty-eight percent of patients had anterolateral/posteromedial FDG avidity. Papillary muscle FDG avidity resolved in 80% of patients (n = 20, median follow-up 1.6 years, interquartile range 2.5 years). In conclusion, Carpentier type I functional MR is the most common MR mechanism in CS. MR severity and papillary muscle FDG avidity decrease after treatment, and MR resolution is further strengthened by procedural intervention in a minority of patients, suggesting an overall favorable natural history of MR in CS.

Utilization of cardiac imaging in sarcoidosis.

INTRODUCTION: Cardiac sarcoidosis (CS) is the cardiac, and occasionally the only manifestation, of a systemic disease of unknown etiology inherently challenging to definitively diagnose due to the lack of a reliable gold standard, the current being endomyocardial biopsy, the yield of which is low owing to the patchy nature of involvement. Societal guidelines employ specific criteria to make a probabilistic diagnosis, integrating clinical assessment with conventional and advanced cardiac imaging. AREAS COVERED: This review begins with an introduction to CS, followed by a discussion of diagnostic guidelines commonly used, then delves into an in-depth review of the imaging modalities currently available to assess for CS. Particular attention is made to discussing findings, strengths, limitations, and future directions for each modality. EXPERT OPINION: The burden of CS may be significantly larger than previously thought. With the low yield of endomyocardial biopsy, advanced cardiac imaging is increasingly employed to determine CS likelihood. Cardiac magnetic resonance is adept at detecting myocardial scar and able to differentiate between CS and other cardiomyopathies. F-18 Fluorodeoxyglucose positron emission tomography is superior at detecting active disease (myocardial inflammation) which may be amenable to immunosuppressive treatment, as well as detecting extracardiac involvement and identifying potential biopsy sites.

Association of Angio-LncRNAs MIAT rs1061540/MALAT1 rs3200401 Molecular Variants with Gensini Score in Coronary Artery Disease Patients Undergoing Angiography.

Long non-coding RNAs (lncRNAs) have emerged as essential biomolecules with variable diagnostic and/or prognostic utility in several diseases, including coronary artery disease (CAD). We aimed for the first time to investigate the potential association of five angiogenesis-related lncRNAs (PUNISHER, SENCR, MIAT, MALAT1, and GATA6-AS) variants with CAD susceptibility and/or severity. TaqMan Real-Time genotyping for PUNISHER rs12318065A/C, SENCR rs12420823C/T, MIAT rs1061540C/T, MALAT1 rs3200401T/C, and GATA6-AS1 rs73390820A/G were run on the extracted genomic DNA from 100 unrelated patients with stable CAD undergoing diagnostic coronary angiography and from 100 controls. After adjusting covariates, the studied variants showed no association with disease susceptibility; however, MIAT*T/T genotype was associated with a more severe Gensini score. In contrast, MALAT1*T/C heterozygosity was associated with a lower score. The lipid profile, and to a lesser extent smoking status, male sex, weight, hypertension, and MALAT1 (T > C) (negative correlation), explained the variance between patients/control groups via a principal component analysis. Incorporating the principal components into a logistic regression model to predict CAD yielded a 0.92 AUC. In conclusion: MIAT rs1061540 and MALAT1 rs3200401 variants were associated with CAD severity and Gensini score in the present sample of the Egyptian population. Further large multi-center and functional analyses are needed to confirm the results and identify the underlying molecular mechanisms.

Routine Laboratory Biomarkers As Prognostic Indicators of Cardiac Sarcoidosis Outcomes.

Background: Biomarkers to monitor disease activity and predict major adverse cardiac events (MACE) in CS have not been described previously. We aimed to identify biomarkers to predict MACE in cardiac sarcoidosis (CS). Methods: Patients (N=232) diagnosed with CS were retrospectively enrolled. Biomarkers including angiotensin-converting enzyme (ACE), N-terminal brain natriuretic peptide (NT-proBNP), troponin T, and creatinine levels were evaluated against a primary end point of left ventricular assist device implantation, heart transplantation, or death, and a secondary end point of cardiac hospitalization-free survival. Results: Troponin T (hazard ratio [HR], 1.06 per 0.01 ng/mL; P=.006), NT-proBNP (HR, 1.31 per 1,000 pg/mL; P<.001), and creatinine (HR, 4.02 per mg/dL; P=.01) were associated with the primary end point, even after adjusting for ejection fraction. NT-proBNP, B-type natriuretic peptide (BNP), creatinine, albumin, and calcium were associated with the secondary end point (P<.05). ACE levels were associated with presence of late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) imaging (mean difference, 14.7; P=.03); 1,25 dihydroxyvitamin D (1,25-OHVit-D) was associated with uptake on cardiac 18F-flurodeoxyglucose position emission tomography (FDG-PET, P=.03). Conclusions: Troponin T, NT-proBNP, and creatinine predict clinically significant outcomes in CS. ACE levels correlated with LGE on CMR, and 1,25-OHVit-D levels correlated with FDG-PET activity.

Effect of Corticosteroid Therapy in Patients With Cardiac Sarcoidosis on Frequency of Venous Thromboembolism.

Sarcoidosis is a multisystem inflammatory condition with occasional cardiac involvement (CS), which may be associated with risk of venous thromboembolism (VTE). As data on VTE in CS are sparse and corticosteroid therapy has not been previously examined, we aim to determine the association between CS, corticosteroid treatment for CS, and VTE. Patients referred to our institution with concern for sarcoidosis and underwent a positron emission tomography (PET) scan were retrospectively assessed. Chi-squared and multivariate regression analyses were conducted to determine the association between a diagnosis of sarcoidosis, CS, corticosteroid use, and VTE events. Six hundred and forty nine patients were split into 3 categories: 235 with no sarcoidosis (NS), 91 with extra-cardiac sarcoidosis only (ECS), and 323 with CS (isolated CS and/or CS with extra cardiac sarcoid). Thirty nine CS, 7 ECS, and 9 NS patients developed PE while 44 CS, 3 ECS, and 18 NS patients developed DVT. On multivariate regression, neither CS nor ECS was an independent risk factor for VTE (p >0.05) but corticosteroid use was independently associated with VTE (HR 3.06, p = 0.007 for PE, HR 6.21, p <0.0001 for DVT). On logistic regression analysis, corticosteroid dose was found to be independently associated with both PE (p = 0.001) and DVT (p = 0.007). Optimal threshold for defining VTE risk with corticosteroid therapy was a prednisone-equivalent dose of 17.5 mg. In conclusion, contrary to previous studies, this current study found that neither sarcoidosis nor CS is an independent risk factor for VTE. Rather, corticosteroid therapy was associated with an increased risk of VTE.

Natural History of Patients Diagnosed with Cardiac Sarcoidosis at Left Ventricular Assist Device Implantation or Cardiac Transplantation.

To our knowledge, natural history has not been reported for cardiac sarcoidosis (CS) diagnosed by pathologic evaluation of the apical core at left ventricular assist device (LVAD) implantation or cardiac transplantation. We retrospectively identified 232 consecutive patients meeting CS criteria. Of these patients, 54 were diagnosed by pathologic confirmation of CS, 10 after evaluation of the apical core (LVAD implant) or explanted heart (transplant). We compared clinical characteristics at initial evaluation and outcomes for these 10 patients with those of 10 patients with known CS before LVAD implant/transplant. In the study group, five patients (50%) had confirmed extracardiac sarcoidosis before LVAD implant/transplant; five had not been diagnosed with sarcoidosis. Mean (standard deviation) left ventricular ejection fraction at initial evaluation was 23% (16%), and left ventricular end-diastolic dimension was 61 (10) mm. Four patients died during follow-up; however, no survival difference was found for the 10 patients diagnosed incidentally and the group with a previous diagnosis or institutional LVAD/transplant cohorts. Patients diagnosed with CS on pathological examination of the apical core/explanted heart may have severe dilated cardiomyopathy as the initial presentation. Outcomes for patients with CS after advanced heart failure therapies may be comparable with those of non-CS patients.

Identification of a novel presumed cardiac sarcoidosis category for patients at high risk of disease.

BACKGROUND: Histologic evidence is required for a definitive diagnosis of cardiac sarcoidosis (CS) by published guidelines; however, the sporadic nature of the disease may produce false negative biopsy results, causing CS to be underdiagnosed. We sought to establish a clinical category of CS absent histologic findings. METHODS: Patients evaluated for CS were stratified into 3 groups: probable CS and definite CS based on Heart Rhythm Society (HRS) criteria and presumed CS, ie, patients without any histologic evidence of sarcoidosis, but with unexplained high-grade atrioventricular block or ventricular arrhythmia and findings suggestive of CS on either cardiac magnetic resonance imaging or positron emission tomography. The primary end point was hospitalization-free and overall survival at 10 years. RESULTS: A total of 383 patients were included in the study: 59, definite CS; 223, probable CS; and 101, presumed CS (62, isolated CS and 39, systemic CS). Compared with patients meeting HRS criteria for CS, patients with presumed CS had lower odds of New York Heart Association class III or IV symptoms (odds ratio [OR], 0.44 [95% CI, 0.23-0.83]; P = .01) but greater odds of previous ventricular tachycardia (OR, 2.4 [95% CI, 1.4-4.0]; P = .001) or history of resuscitated sudden cardiac arrest (OR, 2.9 [95% CI, 1.0-8.6]; P = .05). Hospitalization-free and overall survival were similar among groups (P = .51 and P = .71, respectively). CONCLUSIONS: Clinical categorization of patients with presumed CS identified a high-risk cohort comparable to patients with histologic evidence of disease, although caution should be exercised in reaching this diagnosis without paying due diligence to the differential diagnosis.

Artificial Intelligence in COVID-19 Ultrastructure.

Artificial intelligence has found its way into numerous fields of medicine in the past decade, spurred by the availability of big data and powerful processors. For the COVID-19 pandemic, aside from predicting its onset, artificial intelligence has been used to track disease spread, detect pulmonary involvement in computed tomography scans, risk-stratify patients, and model virtual protein structure and potential therapeutic agents. This mini-review briefly discusses the potential applications of artificial intelligence in COVID-19 microscopy.

Adapting and evaluating a deep learning language model for clinical why-question answering.

OBJECTIVES: To adapt and evaluate a deep learning language model for answering why-questions based on patient-specific clinical text. MATERIALS AND METHODS: Bidirectional encoder representations from transformers (BERT) models were trained with varying data sources to perform SQuAD 2.0 style why-question answering (why-QA) on clinical notes. The evaluation focused on: (1) comparing the merits from different training data and (2) error analysis. RESULTS: The best model achieved an accuracy of 0.707 (or 0.760 by partial match). Training toward customization for the clinical language helped increase 6% in accuracy. DISCUSSION: The error analysis suggested that the model did not really perform deep reasoning and that clinical why-QA might warrant more sophisticated solutions. CONCLUSION: The BERT model achieved moderate accuracy in clinical why-QA and should benefit from the rapidly evolving technology. Despite the identified limitations, it could serve as a competent proxy for question-driven clinical information extraction.

Imaging and Quantification of Cardiac Sarcoidosis.

Cardiac sarcoidosis (CS) refers to the increasingly recognized cardiac involvement of an incompletely understood systemic disease entity-sarcoidosis. Endomyocardial biopsy can provide definitive diagnosis but is limited by its invasiveness and poor sensitivity. In the absence of a reliable gold standard, a combination of clinical, electrocardiographic, imaging, and histologic criteria are relied upon to provide probabilistic diagnosis. Within the last few years, societal documents have included advanced cardiovascular imaging modalities, 18F-FDG-PET/CT and cardiac magnetic resonance in their diagnostic algorithms. The current article provides a review of the imaging modalities used for screening and detection of CS, highlighting the principal findings of each with a specific focus on quantification, whenever applicable, and concluding with a proposed approach to the imaging of patients with suspected CS.