Deep learning approach for automated segmentation of myocardium using bone scintigraphy single-photon emission computed tomography/computed tomography in patients with suspected cardiac amyloidosis.

BACKGROUND: We employed deep learning to automatically detect myocardial bone-seeking uptake as a marker of transthyretin cardiac amyloid cardiomyopathy (ATTR-CM) in patients undergoing 99mTc-pyrophosphate (PYP) or hydroxydiphosphonate (HDP) single-photon emission computed tomography (SPECT)/computed tomography (CT). METHODS: We identified a primary cohort of 77 subjects at Brigham and Women's Hospital and a validation cohort of 93 consecutive patients imaged at the University of Pennsylvania who underwent SPECT/CT with PYP and HDP, respectively, for evaluation of ATTR-CM. Global heart regions of interest (ROIs) were traced on CT axial slices from the apex of the ventricle to the carina. Myocardial images were visually scored as grade 0 (no uptake), 1 (uptakeribs). A 2D U-net architecture was used to develop whole-heart segmentations for CT scans. Uptake was determined by calculating a heart-to-blood pool (HBP) ratio between the maximal counts value of the total heart region and the maximal counts value of the most superior ROI. RESULTS: Deep learning and ground truth segmentations were comparable (p=0.63). A total of 42 (55%) patients had abnormal myocardial uptake on visual assessment. Automated quantification of the mean HBP ratio in the primary cohort was 3.1±1.4 versus 1.4±0.2 (p<0.01) for patients with positive and negative cardiac uptake, respectively. The model had 100% accuracy in the primary cohort and 98% in the validation cohort. CONCLUSION: We have developed a highly accurate diagnostic tool for automatically segmenting and identifying myocardial uptake suggestive of ATTR-CM.

Cardiovascular magnetic resonance for evaluation of cardiac involvement in COVID-19: recommendations by the Society for Cardiovascular Magnetic Resonance.

Coronavirus disease 2019 (COVID-19) is an ongoing global pandemic that has affected nearly 600 million people to date across the world. While COVID-19 is primarily a respiratory illness, cardiac injury is also known to occur. Cardiovascular magnetic resonance (CMR) imaging is uniquely capable of characterizing myocardial tissue properties in-vivo, enabling insights into the pattern and degree of cardiac injury. The reported prevalence of myocardial involvement identified by CMR in the context of COVID-19 infection among previously hospitalized patients ranges from 26 to 60%. Variations in the reported prevalence of myocardial involvement may result from differing patient populations (e.g. differences in severity of illness) and the varying intervals between acute infection and CMR evaluation. Standardized methodologies in image acquisition, analysis, interpretation, and reporting of CMR abnormalities across would likely improve concordance between studies. This consensus document by the Society for Cardiovascular Magnetic Resonance (SCMR) provides recommendations on CMR imaging and reporting metrics towards the goal of improved standardization and uniform data acquisition and analytic approaches when performing CMR in patients with COVID-19 infection.

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.

Cardiovascular magnetic resonance characterization of rheumatic mitral stenosis: findings from three worldwide endemic zones.

BACKGROUND: Cardiac remodeling in rheumatic mitral stenosis (MS) is complex and incompletely understood. The objective of this study was to evaluate cardiac structural and functional changes in a cohort of patients with rheumatic MS using cardiovascular magnetic resonance (CMR). METHODS: This retrospective study included 40 patients with rheumatic MS, consisting of 19 patients from India, 15 patients from China, and 6 patients from Mexico (median (interquartile range (IQR)) age: 45 years (34-55); 75% women). Twenty patients were included in the control group. CMR variables pertaining to morphology and function were collected. Late gadolinium enhancement (LGE) sequences were acquired for tissue characterization. Statistical analyses were performed using the Kruskal-Wallis test and the chi-square test. RESULTS: Compared to the control group, patients with MS had lower left ventricular (LV) ejection fraction (51% (42%-55%) vs 60% (57%-65%), p < 0.001), lower right ventricular (RV) ejection fraction (44% (40%-52%) vs 64% (59%-67%), p < 0.001), higher RV end-diastolic volume (72 (58-87) mL/m2 vs 59 (49-69) mL/m2, p = 0.003), larger left atrial volume (87 (67-108) mL/m2 vs 29 (22-34) mL/m2, p < 0.001), and right atrial areas (20 (16-23) cm2 vs 13 (12-16) cm2, p < 0.001). LGE was prevalent in patients with rheumatic MS (82%), and was commonly located at the RV insertion sites. Furthermore, the patient cohorts from India, China, and Mexico were heterogeneous in terms of baseline characteristics and cardiac remodeling. CONCLUSION: Our findings demonstrated that biventricular dysfunction, right and left atrial remodeling, and LGE at the RV insertion sites are underappreciated in contemporary rheumatic MS. Further studies are needed to elucidate the prognostic implications of these findings.

Diagnostic accuracy of SPECT and PET myocardial perfusion imaging in patients with left bundle branch block or ventricular-paced rhythm.

BACKGROUND: The difference in diagnostic accuracy of coronary artery disease (CAD) between vasodilator SPECT and PET myocardial perfusion imaging (MPI) in patients with left bundle branch block (LBBB) or ventricular-paced rhythm (VPR) is unknown. METHODS: We identified patients with LBBB or VPR who underwent either vasodilator SPECT or PET MPI and subsequent coronary angiography. LBBB/VPR-related septal and anteroseptal defects were defined as perfusion defects involving those regions in the absence of obstructive CAD in the left anterior descending artery or left main coronary artery. RESULTS: Of the 55 patients who underwent coronary angiography, 38 (69%) underwent SPECT and 17 patients (31%) underwent PET. PET compared to SPECT demonstrated higher sensitivity (88% vs 60%), specificity (56% vs 14%), positive predictive value (64% vs 20%), negative predictive value (83% vs 50%), and overall superior diagnostic accuracy (AUC .72 (95% CI .50-.93) vs .37 (95% CI .20-.54), P = .01) to detect obstructive CAD. LBBB/VPR-related septal and anteroseptal defects were more common with SPECT compared to PET (septal: 72% vs 17%, P = .001; anteroseptal: 47% vs 8%, P = .02). CONCLUSIONS: PET has higher diagnostic accuracy when compared to SPECT for the detection of obstructive CAD in patients with LBBB or VPR.

Are skin color and body mass index associated with social network structure? Findings from a male sex market study.

Objectives: There is a growing burden of HIV and sex-related diseases in South Asia and India. Sociological research illustrates that key axes of social stratification, such as race and ethnicity, affect social network structure which, in turn, impacts sexual health and wellbeing. Research on networks has increasingly begun to examine the ways in which networks drive or harness sexual behaviors, but has largely neglected the influence of culture and cultural markers in this continuum. Furthermore, much of the existing scholarship has been conducted in the U.S. or in Western contexts.Design: As part of an exploratory effort, we examined how skin color and body mass index (BMI) affected networks among 206 men who have with men (MSM) frequenting sex markets in Hyderabad, India. A novel phone-based network generation method of respondent-driven sampling was used for recruitment. In assessing how skin color and BMI drive these structures, we also compared how these factors contribute to networks relative to two more commonly referenced markers of social difference among Indians, caste and religion.Results: Our findings suggest that skin color and BMI contribute significantly more to network structure than do caste and religion.Conclusions: These findings tentatively illuminate the importance of individual-level heterogeneity in bodily attributes, factors which are seldom considered in conventional approaches to researching how social stratification and health inequalities are animated during the formation of networks.

Spontaneous coronary artery dissection and its association with takotsubo syndrome: Novel insights from a tertiary center registry.

BACKGROUND: Spontaneous coronary artery dissection (SCAD) is a relatively rare cause of acute coronary syndrome historically thought to primarily affect young, healthy women. The lack of multicenter collaborative research efforts has made it challenging to identify the precise etiology and pathological mechanisms underlying SCAD. However, there are many similarities in the patient demographics, clinical presentations, and predisposing stressors between SCAD and takotsubo syndrome (TTS). OBJECTIVES: The aim of this observational study was to examine the coronary and left ventriculographic features of patients with angiographically confirmed SCAD and determine the prevalence of concomitant TTS. METHODS: In this observational study, patients with angiographically confirmed SCAD were identified from the Massachusetts General Hospital SCAD registry. The coronary angiograms with simultaneous left ventriculograms (LVG) were carefully analyzed by an independent and blinded angiographic core laboratory. RESULTS: From our analysis of patients with SCAD who also underwent a LVG at time of coronary angiography, we identified a high prevalence of SCAD and concomitant TTS. CONCLUSIONS: Therefore, we present TTS as a plausible mechanistic etiology for SCAD in some patients. In light of this finding as well as the many similarities between SCAD and TTS, clinicians should be vigilant about the potential concomitant presence of these two entities. Additional future investigations further exploring the clinical implications of the association between SCAD and TTS are warranted.

Use of a once-daily NSAID in treatment of cyclic vomiting syndrome.

Cyclic vomiting syndrome (CVS) is a rare disorder characterized by episodes of intense vomiting and nausea separated by symptom-free periods. We report the case of a 71-year-old man who presented with a long history of poorly controlled CVS whose symptoms resolved with the addition of a once-daily dose of meloxicam, a semi-selective non-steroidal anti-inflammatory drug (NSAID). This is the first report of symptom alleviation in a CVS patient using a once-daily NSAID, as well as one with selectivity to COX-2 inhibition. This is important due to both the increased compliance seen with once-daily medications, as well as the decreased gastrointestinal effects seen with selective COX-2 inhibitors compared to nonselective NSAIDS.

Cardiac Neuroendocrine Tumor Metastases on 68Ga-DOTATATE PET/CT: Identification and Prognostic Significance.

Neuroendocrine tumor (NET) metastases to the heart are found in 1%-4% of NET patients and have been reported primarily in the form of individual cases. We investigated the prevalence, clinical characteristics, imaging features, and outcomes of NET patients with cardiac metastases on 68Ga-DOTATATE PET/CT. Methods: 68Ga-DOTATATE PET/CT of 490 consecutive patients from a single institution were retrospectively reviewed for sites of metastases. The cumulative cardiovascular event rate and overall survival of patients with cardiac NET metastases (CNMs) were compared with those of a control group of metastatic NET patients without cardiac metastases. In patients with CNMs, the cardiac SUVmax with and without normalization to the myocardial background uptake was compared with a separate cohort of 11 patients with active cardiac sarcoidosis who underwent 68Ga-DOTATATE PET/CT for research purposes. Results: In total, 270 patients with metastatic NETs were identified, 9 (3.3%) of whom had CNMs. All 9 patients had grade 1-2 gastroenteropancreatic NETs, most commonly from the small intestine (7 patients). The control group consisted of 140 patients with metastatic grade 1-2 gastroenteropancreatic NETs. On Kaplan-Meier analysis, there was no significant difference in the risk of cardiovascular adverse events (P = 0.91 on log-rank test) or mortality (P = 0.83) between the metastatic NET patients with and without cardiac metastases. The degree of cardiac DOTATATE uptake was significantly higher in CNMs than in patients with cardiac sarcoidosis without overlap, in terms of both cardiac SUVmax (P = 0.027) and SUVmax-to-myocardial background ratio (P = 0.021). Conclusion: Routine 68Ga-DOTATATE PET/CT can be used to identify CNMs in 3% of patients with metastatic NETs. CNMs do not confer added cardiovascular or mortality risk. A distinguishing feature of CNMs is their high degree of DOTATATE uptake compared with focal myocardial inflammation.

Relationship of Ketosis With Myocardial Glucose Uptake Among Patients Undergoing FDG PET/CT for Evaluation of Cardiac Sarcoidosis.

BACKGROUND: Fluorine-18 fluorodeoxyglucose (FDG) with positron emission tomography (PET) is the standard for detecting myocardial inflammation in cardiac sarcoidosis, requiring preparation with the ketogenic diet (KD) to achieve myocardial glucose suppression. Despite this, incomplete myocardial glucose suppression remains a significant issue, and strategies to reduce myocardial glucose uptake (MGU) and identify incomplete myocardial glucose suppression are required. This study sought to understand the relationship between point-of-care beta-hydroxybutyrate (BHB) and different patterns of MGU and between KD and fasting duration with MGU in patients undergoing evaluation for cardiac sarcoidosis. METHODS: We prospectively included 471 outpatients who underwent FDG-PET for cardiac sarcoidosis evaluation, followed the KD for 1 (n=100), 2 (n=29), and ≥3 days (n=342), fasted for at least 12 hours, and had BHB levels measured immediately before FDG injection. Images were classified as (1) no MGU (negative), (2) focal/multifocal (positive), (3) diffuse (nondiagnostic), or (4) nonspecific uptake (NS-MGU). RESULTS: Cardiac FDG-PET scans were interpreted as the following: 376 (79.83%) negative; 61 (12.95%) positive; 14 (2.97%) diffuse; and 20 (4.25%) NS-MGU. There was a strong negative relationship between BHB levels and MGU (P<0.0001). BHB levels increased significantly with KD duration (P<0.0001) and fasting time (P=0.0067). The combined rate of diffuse, NS-MGU, and positive scans (34%, 28%, 16%) decreased inversely with KD duration (1, 2, and ≥3 days, respectively). However, MGU was not different across different fasting times (P=0.6). Blood glucose levels were not associated with MGU (P=0.17) and only weakly associated with BHB levels (R2=0.03; P<0.001). CONCLUSIONS: We observed a strong inverse relationship between ketosis and patterns of MGU. Longer KD and fasting durations are associated with higher ketosis. However, only KD duration was associated with lower rates of MGU. Measurement of BHB levels before FDG-PET using point-of-care testing is feasible and may facilitate the management of patients referred for myocardial inflammation.

Arterial Properties and Ventricular-Arterial Interactions in Severe Aortic Stenosis: Impact on Prognosis.

BACKGROUND: Systemic arterial properties contribute to clinical heterogeneity and outcomes in degenerative calcific aortic stenosis (AS). Lumped parameters of afterload have previously been associated with adverse left ventricular remodeling, mortality, and poor exercise tolerance in this population, but most studies did not assess pulsatile aortic pressure-flow relations, the gold standard method for assessing arterial load. Moreover, arterial compliance is highly dependent on non-pulsatile (mean) arterial pressure, which influences prognosis in this population. METHODS: We retrospectively studied 135 patients with severe AS with same-day catheterization and echocardiogram. Invasive aortic pressures and echocardiographic flow waveforms were used to assess pressure-flow and pressure-volume relations using Windkessel modeling and wave separation analyses. We used Cox regression to assess the relationship between pulsatile load and time to death and heart failure hospital admission (DHFA). RESULTS: Total arterial compliance accounting for pressure-dependence (PD-TAC) was independently predictive of all-cause mortality (HR=0.80, 95%CI=0.66-0.97; p=0.023) and DHFA (HR=0.70; 95%CI=0.50-0.97; p=0.031) even after adjustment for age, race, gender, BMI, and comorbidities, while other arterial parameters were not. CONCLUSIONS: In patients with severe AS, pressure-dependent arterial compliance predicts adverse outcomes, while traditional pulsatile arterial load measures do not. Our findings suggest that methods accounting for pressure load on the arterial wall are advantageous in this population in which lower mean pressure can result from severe stenosis and ventricular dysfunction.

Persistent FDG Uptake at Apical Aneurysm in a Patient With Cardiac Sarcoidosis.

We present a case of cardiac sarcoidosis with persistent, focal fluorodeoxyglucose uptake at the left ventricular apical aneurysm concerning for ongoing active inflammatory injury, prompting aggressive immunosuppressive therapy. This case highlights the importance of understanding the various clinical entities that may resemble disease activity on fluorodeoxyglucose positron emission tomography/computed tomography imaging. (Level of Difficulty: Intermediate.).

The Role of Advanced Cardiovascular Imaging Modalities in Cardio-Oncology: From Early Detection to Unravelling Mechanisms of Cardiotoxicity.

Advances in cancer therapies have led to a global improvement in patient survival rates. Nevertheless, the price to pay is a concomitant increase in cardiovascular (CV) morbidity and mortality in this population. Increased inflammation and disturbances of the immune system are shared by both cancer and CV diseases. Immunological effects of anti-cancer treatments occur with both conventional chemotherapy and, to a greater extent, with novel biological therapies such as immunotherapy. For these reasons, there is growing interest in the immune system and its potential role at the molecular level in determining cardiotoxicity. Early recognition of these detrimental effects could help in identifying patients at risk and improve their oncological management. Non-invasive imaging already plays a key role in evaluating baseline CV risk and in detecting even subclinical cardiac dysfunction during surveillance. The aim of this review is to highlight the role of advanced cardiovascular imaging techniques in the detection and management of cardiovascular complications related to cancer treatment.

Durable Left Ventricular Assist Device Outflow Graft Obstructions: Clinical Characteristics and Outcomes.

PURPOSE: We report on the clinical course and management of patients supported with durable implantable LVADs who developed outflow graft obstructions at a large academic center. METHODS: We performed a retrospective review of patients receiving LVAD support from 2012 through 2020. Patients who developed an outflow graft obstruction diagnosed by computed tomography angiography (CTA) or angiogram were identified, and patient characteristics and outcomes were reported. RESULTS: Of the 324 patients supported by LVAD at our institution, 11 patients (3.4%) were diagnosed with outflow graft obstructions. The most common presentation was low flow alarms, which was present in 10/11 patients, and the remaining patient presented with lightheadedness. Patients had minimal LDH elevation with 8/11 presenting with less than 2-fold the upper limit of normal. Transthoracic echocardiograms were not diagnostic, but CTA enabled non-invasive diagnoses in 8/11 of the patients. Three patients with extrinsic compression of the outflow graft successfully underwent endovascular stent placement, and three patients with outflow cannula kinks received supportive care. Of the five patients diagnosed with intraluminal thromboses, one received a heart transplant, one underwent an outflow graft revision, and three received supportive care due to comorbidities. CONCLUSION: Outflow graft obstructions remain a rare, but serious complication. The true prevalence of this entity is likely underestimated due to the non-specific clinical presentation. CTA is a pivotal non-invasive diagnostic step. Patients with external compression were successfully treated with endovascular stenting.

Myocardial Injury on CMR in Patients With COVID-19 and Suspected Cardiac Involvement.

BACKGROUND: Myocardial injury in patients with COVID-19 and suspected cardiac involvement is not well understood. OBJECTIVES: The purpose of this study was to characterize myocardial injury in a multicenter cohort of patients with COVID-19 and suspected cardiac involvement referred for cardiac magnetic resonance (CMR). METHODS: This retrospective study consisted of 1,047 patients from 18 international sites with polymerase chain reaction-confirmed COVID-19 infection who underwent CMR. Myocardial injury was characterized as acute myocarditis, nonacute/nonischemic, acute ischemic, and nonacute/ischemic patterns on CMR. RESULTS: In this cohort, 20.9% of patients had nonischemic injury patterns (acute myocarditis: 7.9%; nonacute/nonischemic: 13.0%), and 6.7% of patients had ischemic injury patterns (acute ischemic: 1.9%; nonacute/ischemic: 4.8%). In a univariate analysis, variables associated with acute myocarditis patterns included chest discomfort (OR: 2.00; 95% CI: 1.17-3.40, P = 0.01), abnormal electrocardiogram (ECG) (OR: 1.90; 95% CI: 1.12-3.23; P = 0.02), natriuretic peptide elevation (OR: 2.99; 95% CI: 1.60-5.58; P = 0.0006), and troponin elevation (OR: 4.21; 95% CI: 2.41-7.36; P < 0.0001). Variables associated with acute ischemic patterns included chest discomfort (OR: 3.14; 95% CI: 1.04-9.49; P = 0.04), abnormal ECG (OR: 4.06; 95% CI: 1.10-14.92; P = 0.04), known coronary disease (OR: 33.30; 95% CI: 4.04-274.53; P = 0.001), hospitalization (OR: 4.98; 95% CI: 1.55-16.05; P = 0.007), natriuretic peptide elevation (OR: 4.19; 95% CI: 1.30-13.51; P = 0.02), and troponin elevation (OR: 25.27; 95% CI: 5.55-115.03; P < 0.0001). In a multivariate analysis, troponin elevation was strongly associated with acute myocarditis patterns (OR: 4.98; 95% CI: 1.76-14.05; P = 0.003). CONCLUSIONS: In this multicenter study of patients with COVID-19 with clinical suspicion for cardiac involvement referred for CMR, nonischemic and ischemic patterns were frequent when cardiac symptoms, ECG abnormalities, and cardiac biomarker elevations were present.

A 61-Year-Old Man with Chest Pain.

A 61-Year-Old Man with Chest Pain A 61-year-old man presented for evaluation of chest pain that had been progressively worsening for 2 days. How do you approach the evaluation?

The Role of Multimodality Imaging in the Evaluation of Heart Failure with Preserved Ejection Fraction.

Heart failure with preserved ejection fraction (HFpEF) is highly prevalent, affecting approximately half of all patients with HF. The diagnosis of HFpEF can be notoriously challenging in clinical practice, given the many overlapping etiologies of dyspnea or reduced exercise tolerance in patients at risk for HFpEF. Multimodality imaging has an important role in establishing the diagnosis of HFpEF and the presence of elevated left ventricular filling pressures, identifying specific etiologies of HFpEF that can benefit from approved therapies, and discerning distinct phenogroups or mechanistic abnormalities that may inform the development of novel therapeutics.

Multimodality imaging for the diagnosis of infiltrative cardiomyopathies.

Infiltrative cardiomyopathies result from the deposition or anomalous storage of specific substances in the heart, leading to impaired cardiac function and heart failure. In this review, we describe the utility of a variety of imaging modalities for the diagnosis of infiltrative cardiomyopathies and provide algorithms for clinicians to use to evaluate patients with these disorders. We have divided infiltrative cardiomyopathies into two different categories: (1) infiltrative cardiomyopathies characterised by increased wall thickness (eg, cardiac amyloidosis and Anderson-Fabry disease (AFD)) and (2) infiltrative cardiomyopathies that can mimic ischaemic or dilated cardiomyopathies (eg, cardiac sarcoidosis (CS) and iron overload cardiomyopathy). Echocardiography is the first modality of choice for the evaluation of cardiomyopathies in either category, and the differential can be narrowed using cardiac magnetic resonance (CMR) and nuclear imaging techniques. The diagnosis of cardiac amyloidosis is supported with key findings seen on echocardiography, CMR and nuclear imaging, whereas AFD can be suggested by unique features on CMR. CMR and nuclear imaging are also important modalities for the diagnosis of CS, while iron overload cardiomyopathy is mostly diagnosed using tissue characterisation on CMR. Overall, multimodality imaging is necessary for the accurate non-invasive diagnosis of infiltrative cardiomyopathies, which is important to ensure appropriate treatment and prognostication.