Prevalence of transthyretin cardiac amyloidosis in patients with high-degree AV block

OBJECTIVE

Transthyretin amyloid cardiomyopathy (ATTR-CM) is an infiltrative cardiac disorder caused by deposition of wild type or mutated transthyretin. As ATTR-CM is associated with conduction disease, we sought to determine its prevalence in patients with idiopathic high-degree atrioventricular (AV) block requiring permanent pacemaker (PPM) implantation.

METHODS

Consecutive patients aged 70-85 years undergoing PPM implantation for idiopathic high-degree AV block between November 2019 and November 2021 were offered a 3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) scan. Demographics, comorbidities, electrocardiographic and imaging data from the time of device implantation were retrospectively collected.

RESULTS

39 patients (79.5% male, mean (SD) age at device implantation 76.2 (2.9) years) had a DPD scan. 3/39 (7.7%, all male) had a result consistent with ATTR-CM (Perugini grade 2 or 3). Mean (SD) maximum wall thickness of those with a positive DPD scan was 19.0 mm (3.6 mm) vs 11.4 mm (2.7 mm) in those with a negative scan (p=0.06). All patients diagnosed with ATTR-CM had spinal canal stenosis and two had carpal tunnel syndrome.

CONCLUSIONS

ATTR-CM should be considered in older patients requiring permanent pacing for high-degree AV block, particularly in the presence of left ventricular hypertrophy, carpal tunnel syndrome or spinal canal stenosis.

Cardiac Computed Tomography: Application in Valvular Heart Disease

The incidence and prevalence of valvular heart disease (VHD) is increasing and has been described as the next cardiac epidemic. Advances in imaging and therapeutics have revolutionized how we assess and treat patients with VHD. Although echocardiography continues to be the first-line imaging modality to assess the severity and the effects of VHD, advances in cardiac computed tomography (CT) now provide novel insights into VHD. Transcatheter valvular interventions rely heavily on CT guidance for procedural planning, predicting and detecting complications, and monitoring prosthesis. This review focuses on the current role and future prospects of CT in the assessment of aortic and mitral valves for transcatheter interventions, prosthetic valve complications such as thrombosis and endocarditis, and assessment of the myocardium.

Impact of afterload and infiltration on coexisting aortic stenosis and transthyretin amyloidosis

OBJECTIVE

The coexistence of wild-type transthyretin cardiac amyloidosis (ATTR) is common in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI). However, the impact of ATTR and AS on the resultant AS-ATTR is unclear and poses diagnostic and management challenges. We therefore used a multicohort approach to evaluate myocardial structure, function, stress and damage by assessing age-related, afterload-related and amyloid-related remodelling on the resultant AS-ATTR phenotype.

METHODS

We compared four samples (n=583): 359 patients with AS, 107 with ATTR (97% Perugini grade 2), 36 with AS-ATTR (92% Perugini grade 2) and 81 age-matched and ethnicity-matched controls. 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) scintigraphy was used to diagnose amyloidosis (Perugini grade 1 was excluded). The primary end-point was NT-pro Brain Natriuretic Peptide (BNP) and secondary end-points related to myocardial structure, function and damage.

RESULTS

Compared with older age controls, the three disease cohorts had greater cardiac remodelling, worse function and elevated NT-proBNP/high-sensitivity Troponin-T (hsTnT). NT-proBNP was higher in AS-ATTR (2844 (1745, 4635) ng/dL) compared with AS (1294 (1077, 1554)ng/dL; p=0.002) and not significantly different to ATTR (3272 (2552, 4197) ng/dL; p=0.63). Diastology, hsTnT and prevalence of carpal tunnel syndrome were statistically similar between AS-ATTR and ATTR and higher than AS. The left ventricular mass indexed in AS-ATTR was lower than ATTR (139 (112, 167) vs 180 (167, 194) g; p=0.013) and non-significantly different to AS (120 (109, 130) g; p=0.179).

CONCLUSIONS

The AS-ATTR phenotype likely reflects an early stage of amyloid infiltration, but the combined insult resembles ATTR. Even after treatment of AS, ATTR-specific therapy is therefore likely to be beneficial.

Impact of COVID-19 Pandemic on Cardiovascular Testing in Asia

Background

The coronavirus disease-2019 (COVID-19) pandemic significantly affected management of cardiovascular disease around the world. The effect of the pandemic on volume of cardiovascular diagnostic procedures is not known.

Objectives

This study sought to evaluate the effects of the early phase of the COVID-19 pandemic on cardiovascular diagnostic procedures and safety practices in Asia.

Methods

The International Atomic Energy Agency conducted a worldwide survey to assess changes in cardiovascular procedure volume and safety practices caused by COVID-19. Testing volumes were reported for March 2020 and April 2020 and were compared to those from March 2019. Data from 180 centers across 33 Asian countries were grouped into 4 subregions for comparison.

Results

Procedure volumes decreased by 47% from March 2019 to March 2020, showing recovery from March 2020 to April 2020 in Eastern Asia, particularly in China. The majority of centers cancelled outpatient activities and increased time per study. Practice changes included implementing physical distancing and restricting visitors. Although COVID testing was not commonly performed, it was conducted in one-third of facilities in Eastern Asia. The most severe reductions in procedure volumes were observed in lower-income countries, where volumes decreased 81% from March 2019 to April 2020.

Conclusions

The COVID-19 pandemic in Asia caused significant reductions in cardiovascular diagnostic procedures, particularly in low-income countries. Further studies on effects of COVID-19 on cardiovascular outcomes and changes in care delivery are warranted.

Comprehensive mechanical & metabolic imaging of abdominal aortic aneurysm with 4D flow/ FDG PET on an integrated PETMRI: a feasibility study

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): NIHR Biomedical Research Centre, University College London Hospitals.

Background

A number of non-invasive imaging derived parameters have been implicated in the development and progression of abdominal aortic aneurysm, although the mechanism, and relationships of many of these are yet to be precisely determined.  Mechanical parameters can now be studied using 4D phase contrast magnetic resonance (PCMR), and inflammatory cellular activity can be detected with FDG PET.

Purpose

It may be postulated that inflammation of the aortic wall may be the intermediary at the tissue level linking mechanical wall shear stress (WSS) to aneurysm progression. It may be feasible to study 4D PCMR and FDG PET at the same patient visit on a PETMRI platform, with the potential to enhance temporal and spatial co-registration and improving the understanding of any relationship between these two parameters.  Our study aims to assess feasibility of studying these on an integrated PETMRI system.

Methods

7 patients with known aortic aneurysm were recruited in a vascular ultrasound screening follow up clinic.  During a single visit following 6 hours fasting, all patients underwent FDG injection and 60 minutes uptake period.  With quiet breathing, list mode PET acquisition and concurrent 4D PCMR was acquired using stacks of spiral acquisition, with ECG trace information for retrospective gating.  Images from the 4D PCMR and FDG PET were assessed qualitatively for image quality and visual matching.

Results

All 7 patients completed the study.  Overall image quality was adequate to good.  There is qualitatively a good concordance with impression of positive correlation between wall shear stress and inflammatory signal (see attached image).

Conclusion

We have demonstrated feasibility of combined assessment of mechanical and metabolic imaging parameters using an integrated PETMRI system.  Initial findings show there to be a broad concordance of wall shear stress and inflammatory signal in the abdominal aneurysm.

18F-FDGPET/CT improves diagnostic certainty over the modified Duke Criteria in blood culture negative infective endocarditis

Funding Acknowledgements

Type of funding sources: None.

Introduction

Diagnosis of blood culture negative infective endocarditis (BCNIE) is challenging, with positive microbiology key in the modified Duke Criteria (mDC). ESC IE Guidelines (2015) recommend the use of 18F-FDG PET/CT (PET) in cases where transoesophageal echocardiography (TOE) is equivocal and where cardiac implantable device-related IE (CIDRE) is suspected. We explored the role of PET to improve diagnostic certainty in the challenging cohort of BCNIE.

Methods

Retrospective review of all suspected BCNIE patients undergoing PET (10/2015 to 01/2021). Myocardial suppression technique was used in all cases, and studies were assessed for valve/device avidity. Patients were classified as definite/possible/rejected IE by mDC pre- and post-PET, with incremental benefit assessed by net reclassification index (NRI) versus actual diagnosis. Actual diagnosis was defined by Endocarditis Team consensus or surgical specimen (where available) at a minimum of 2-months following index admission.

Results

PET was performed in 110/807 (13.6%) cases overall. BCNIE prevalence was 18% across the total cohort, with 25/110 (22.7%) PET studies in BCNIE patients (male = 17, mean age 65). (p = 0.16 for PET in BCNIE compared to overall). PET was undertaken in 8 CIDRE, 9 native IE (NVE) and 10 prosthetic IE (PVE); 2-patients had suspected CIDRE + PVE. TOE was performed in all cases, and surgery was required in 8/25 patients. IE was confirmed in 44% of cases.

PET sensitivity, specificity, positive and negative predictive values were 73%, 93%, 89% and 81%, respectively. Addition of PET to the mDC improved re-classification to definite or rejected IE, with NRI 0.633 (positive NRI 0.3; negative 0.333), and added weight to the original mDC classification in 14/25 (56%) of cases.

Conclusion

PET improves diagnostic certainty when combined with mDC in the evaluation of patients with BCNIE across NVE, PVE and CIDRE.

Evolution of 18F-FDG-PET/CT findings in patients following COVID-19 pneumonia: An Initial Investigation

The aim of this study was to assess the temporal evolution of pulmonary ¹⁸F-FDG uptake in patients with coronavirus disease 2019 (COVID-19) and post–COVID-19 lung disease (PCLD). Methods: Using our hospital’s clinical electronic records, we retrospectively identified 23 acute COVID-19, 18 PCLD, and 9 completely recovered ¹⁸F-FDG PET/CT patients during the 2 peaks of the U.K. pandemic. Pulmonary ¹⁸F-FDG uptake was measured as a lung target-to-background ratio (TBR_lung = SUV_max/SUV_min) and compared with temporal stage. Results: In acute COVID-19, less than 3 wk after infection, TBR_lung was strongly correlated with time after infection (r_s = 0.81, P < 0.001) and was significantly higher in the late stage than in the early stage (P = 0.001). In PCLD, TBR_lung was lower in patients treated with high-dose steroids (P = 0.003) and in asymptomatic patients (P < 0.001). Conclusion: Pulmonary ¹⁸F-FDG uptake in COVID-19 increases with time after infection. In PCLD, pulmonary ¹⁸F-FDG uptake rises despite viral clearance, suggesting ongoing inflammation. There was lower pulmonary ¹⁸F-FDG uptake in PCLD patients treated with steroids.

Nuclear cardiology: state of the art

Radionuclide imaging remains an essential component of modern cardiology. There is overlap with the information from other imaging techniques, but no technique is static and new developments have expanded its role. This review focuses on ischaemic heart disease, heart failure, infection and inflammation. Radiopharmaceutical development includes the wider availability of positron emission tomography (PET) tracers such as rubidium-82, which allows myocardial perfusion to be quantified in absolute terms. Compared with alternative techniques, myocardial perfusion scintigraphy PET and single photon emission computed tomography (SPECT) have the advantages of being widely applicable using exercise or pharmacological stress, full coverage of the myocardium and a measure of ischaemic burden, which helps to triage patients between medical therapy and revascularisation. Disadvantages include the availability of expertise in some cardiac centres and the lack of simple SPECT quantification, meaning that global abnormalities can be underestimated. In patients with heart failure, despite the findings of the STICH (Surgical Treatment for Ischemic Heart Failure) trial, there are still data to support the assessment of myocardial hibernation in predicting when abolition of ischaemia might lead to improvement in ventricular function. Imaging of sympathetic innervation is well validated, but simpler markers of prognosis mean that it has not been widely adopted. There are insufficient data to support its use in predicting the need for implanted devices, but non-randomised studies are promising. Other areas where radionuclide imaging is uniquely valuable are detection and monitoring of endocarditis, device infection, myocardial inflammation in sarcoidosis, myocarditis and so on, and reliable detection of deposition in suspected transthyretin-related amyloidosis.

Computed tomography coronary angiogram in left main stem disease: how does it fare against invasive coronary angiography?

Funding Acknowledgements

Type of funding sources: None.

Background

Computed Tomography Coronary Angiography (CTCA) is increasingly being used to detect and exclude the presence of coronary artery stenosis. Published studies to date comparing CTCA to invasive coronary angiography (ICA) have focused on epicardial vessels other than the left main stem (LMS) (1 - 4). Despite the diagnostic accuracy of CTCA specifically for LMS disease being unknown, it has been used in a recent multi-centre trial (5).

Purpose

To evaluate the diagnostic performance of CTCA compared with ICA for the detection and visual grading of native Left Main Stem lesions. 

Methods

Retrospective study of patients who underwent CTCA and ICA within 12 months as part of a Quality Improvement project, with no prior coronary intervention. CTCA LMS lesions were graded by consensus of 3 independent blinded reviewers using the Coronary Artery Disease - Reporting and Data System (CAD-RADS) (none, minimal, mild, moderate and severe) and ICAs were similarly evaluated by consensus of 2 independent, blinded reviewers. Moderate and severe LMS lesions were considered clinically significant.

Results

A total of 53 subjects underwent both CTCA and ICA (70% male, mean age: 62). 66% of LMS lesions were found to be significant on ICA. Compared to ICA, CT angiography has a sensitivity of 83% and a specificity of 89% for detecting a significant LMS stenosis of 50% or more, with a positive predictive value of and a negative predictive value of 94% and 73% respectively. CTCA for detecting a significant LMS stenosis has a AUC of 0.88.  In stenosis grading, CTCA correlated with ICA at the same CAD-RADS level in 53% of cases, with over-estimation in 19% and under-estimation in 28% of cases. 

Conclusion

In this retrospective single centre study of patients with native coronary vessels, CTCA is shown to be accurate in identifying significant LMS lesions detected on ICA. However, at a level of stenosis grading, there is significant inter-modality discrepancy with CTCA associated with over- and under-estimation of LMS lesion severities compared with ICA.

Diagnostic Performance of CTCA vs ICA Significant LMS lesion ICA positive ICA negative CTCA positive 29 2 CTCA negative 6 16 Diagnostic Performance of CTCA vs ICA in significant LMS lesions Abstract Figure. Significant LMS lesions:CTCA performance

AS-amyloidosis. Dual pathology or novel disease? A multimodality, multi-centre assessment across health and disease

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): British Heart Foundation

onbehalf

AS-Amyloidosis consortium

Background

The coexistence of severe aortic stenosis (lone AS) and transthyretin cardiac amyloidosis (lone amyloidosis) is common, but the resultant AS-amyloidosis phenotype is unclear.

Purpose

We characterised AS-amyloidosis, hypothesizing that the dual insult of AS-amyloidosis results is a severe phenotype.

Methods

We compared four cohorts with deep phenotyping: 81 older age controls, 359 lone AS, 36 AS-amyloidosis (Perugini grade 2 and 3) and 107 lone amyloidosis (Perugini grade 2 and 3).

Results

AS-amyloidosis was similar to lone AS with respect to left ventricular mass and LVEF (57 (45, 64)%). It was similar to lone amyloidosis with respect to lateral S" (0.04 (0.03, 0.06) m/s), NT-proBNP (4149 (1449, 6459) ng/L) and troponin T (56 (34, 100) ng/L). Whilst, prevalence of carpal tunnel syndrome (CTS) (17%) and diastolic function (E/A ratio 1.1 (0.8, 2.8)) were intermediate.

Conclusion

AS-amyloidosis is not a double insult from AS and amyloidosis, but a mixed phenotype with features similar to lone amyloidosis (cardiac biomarkers), lone AS (remodelling and LVEF) or intermediate (diastology and CTS).

Characteristics across all 4 groups Variable Older age controls (n = 81) Lone AS (n = 359) AS-amyloidosis (n = 36) Lone amyloidosis (n = 107) P value Age (years) 82 (80, 84)*†‡ 85 (80, 88)§∞ 88 (85, 92)# 80 (75, 84) &lt;0.005 Sex (% male) 69 *‡ 49 ∞ 61 # 94 &lt;0.005 Carpal tunnel syndrome (%) 0 2 § 17 # 38 &lt;0.005 Voltage/mass ratio 0.22 (0.14, 0.27)‡ 0.18 (0.13, 0.28)∞ 0.18 (0.09, 0.21)# 0.07 (0.05, 0.10) &lt;0.005 NT-ProBNP (ng/L) 131 (66, 221)*†‡ 1629 (639, 3941)§∞ 4149 (1449, 6459) 2888 (1755, 5483) &lt;0.005 hsTnT (ng/L) 12 (8, 17)*†‡ 24 (15, 40)§∞ 56 (34, 100) 62 (41, 82) &lt;0.005 Inferolateral wall thickness (cm) 0.9 (0.8, 1.0)*†‡ 1.1 (0.9, 1.3)∞ 1.3 (1.1, 1.5)# 1.7 (1.6, 1.9) &lt;0.005 Anteroseptal wall thickness (cm) 1.0 (0.9, 1.2)*†‡ 1.4 (1.2, 1.6)§∞ 1.5 (1.3, 1.8) 1.7 (1.6, 1.9) &lt;0.005 Indexed LV mass (g/m2) 79 (66, 102)*†‡ 128 (99, 152)∞ 126 (116, 140)# 174 (159, 200) &lt;0.005 LVEF (%) 59 (54, 63)‡ 59 (50, 65)∞ 57 (45, 64)# 39 (31, 48) &lt;0.005 Lateral S" (m/s) 0.08 (0.07, 0.09)*†‡ 0.07 (0.05, 0.08)§∞ 0.05 (0.04, 0.07) 0.05 (0.04, 0.06) &lt;0.005 Septal S" (m/s) 0.06 (0.06, 0.08)*†‡ 0.05 (0.04, 0.06)∞ 0.04 (0.03, 0.06) 0.04 (0.03, 0.05) &lt;0.005 E/A 0.7 (0.6, 0.8)*†‡ 0.8 (0.7, 1.3)§∞ 1.1 (0.8, 2.8)# 2.4 (1.8, 3.3) &lt;0.005 RV Wall thickness (cm) 0.4 (0.3, 0.4)*†‡ 0.4 (0.4, 0.6)∞ 0.6 (0.4, 0.7)# 0.8 (0.7, 1.0) &lt;0.005 TAPSE (cm) 2.4 (2.0, 2.7)*†‡ 2.1 (1.6, 2.5)∞ 1.9 (1.5, 2.1)# 1.4 (1.2, 1.9) &lt;0.005 Classical LFLG AS (%) 9 13 0.472 * p &lt; 0.05, Old age control vs Lone AS † p &lt; 0.05, Old age control vs AS-amyloidosis ‡ p &lt; 0.05, Old age control vs Lone amyloidosis § p &lt; 0.05, Lone AS vs AS-amyloidosis ∞ p &lt; 0.05, Lone AS vs Lone amyloidosis # p &lt; 0.05, AS-amyloidosis vs Lone amyloidosis Abstract Figure. AS-amyloidosis compared to other cohorts

The impact of frailty in an endocarditis cohort: association with length of stay and mortality

Introduction

Predictors of poor outcome are well established in Endocarditis (IE). “Frailty” refers to a syndrome of physiological decline associated with adverse health outcomes. Gilbert et al.(Lancet, 2018) developed a Hospital Frailty Risk Score (HFRS) that predicts 30-day mortality and length of stay (LOS).

Aim

Identify impact of an abbreviated HFRS (aHFRS) on in-hospital survival and LOS in IE given high morbidity and mortality.

Methods

Retrospective analysis of prospectively collected cases (Jan 2018–date). aHFRS score was calculated with key IE, cardiac, respiratory, oncology & frailty diagnoses. Univariate regression was applied overall and in key “cohorts” (native & prosthetic IE, medical & surgical management) for survival and LOS.

Results

Of 334 cases, LOS data were available in 317; mean age 57.8y (range 17–91, male 74%). Table 1 describes key cohorts. Mortality was 10.1% (medical, 11.9%; surgical, 8.3%). Mean LOS was 31.2 days (range 0–224).

Mean aHFRS was 5.38diagnoses (SD 2.61, range 0–14); 1.65 pre-IE and 3.73 attributed to IE alone, consistent across cohorts. Regression analyses highlight increasing LOS with increasing aHFRS (r2=0.06, Figure 1). Table 1 summarises the modest impact of aHFRS on LOS, and a trend to worse outcome in medical management (r2=0.02).

Discussion

Higher aHFRS is associated with longer LOS and a trend to higher mortality in medically managed IE. IE itself is associated with a number of frailty diagnoses. To improve outlook and provide holistic care, the IE Team may need to include experts in frailty. Satisfactory outcomes may require intensive post-IE rehabilitation.

Funding Acknowledgement

Type of funding source: None

1174Characterization of disease hot-phases using 18f-fluorodeoxyglucose positron emission tomography in arrhythmogenic cardiomyopathy caused by desmosomal gene mutations

Introduction

Mutations in the genes encoding for desmosomal proteins are associated with Arrhythmogenic Cardiomyopathy (AC), a condition in which “hot-phases” reminiscent of myocarditis can develop and which represent active disease progression. Detection of hot-phase disease can offer novel treatment opportunities.

Purpose

We used 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) to determine the prevalence of myocardial inflammation during clinical hot phases in AC.

Methods

Nineteen (12 male; age 38±14 years) symptomatic desmosomal gene mutation carriers (PKP-2, n=6; DSG-2, n=3; DSC-2, n=1; DSP, n=9) underwent FDG-PET and cardiac magnetic resonance (CMR). AC was diagnosed according to the 2010 Task Force diagnostic criteria. The indication for FDG-PET was presentation with clinically suspected myocarditis in 10 (53%), increase in arrhythmic burden in 4 (21%), deteriorating left ventricular (LV) systolic function in 3 (16%) and as part of a diagnostic workup in 2. We compared regional distribution of FDG uptake and late gadolinium enhancement (LGE) on CMR using a standard 16-segment model. Concordance between the two tests was defined as >50% of segment overlap and partial concordance as 1- 50%. Cohen's κ was used to evaluate the inter-method agreement between FDG and LGE.

Results

Nine (47%) patients (5 male) had LV heterogeneous FDG uptake. RV uptake was never observed. Eight of these cases had a definite and 1 had a borderline diagnosis of AC. FDG uptake associated with the presence of DSP gene mutations (7/9, 78% vs 2/10, 20%, p=0.02) and older age (44±12 vs 33±15 years, p=0.05). Concurrent CMR study was available in 15 patients, including all nine with a positive FDG-PET. RV LGE was present in 6 (40%) and LV LGE in 14 cases (93%). All nine (100%) patients with FDG uptake had LV LGE. The commonest segments with FDG-uptake were the basal-anterior, mid-inferolateral and mid-anterolateral (5 cases, 56%), whereas LGE was most commonly present in the mid-anteroseptal (8 cases, 89%) followed by the basal- and mid-inferior segments (6 cases, 67%). Concordance of FDG uptake and LGE was present in 2 cases (22%). There was no concordance in 1 case (11%). Partial concordance was present in 6 (67%). There was poor inter-method topographical agreement between FDG-PET and CMR, κ = 0.04, p=0.64.

Conclusion

Up to 50% of desmosomal gene positive AC patients, and especially those with DSP mutations, and clinical “hot phases” have evidence for myocarditis on FDG-PET. The topographical variation between PET and CMR highlight the underlying pathophysiological stage of disease (inflammation versus scar) and suggest that the imaging modalities provide complementary information on tissue characterisation in AC.

Acknowledgement/Funding

Alexandros Protonotarios is funded by a BHF Clinical Research Training Fellowship no. FS/18/82/34024

P2764Medical management of Staphylococcus aureus infective endocarditis: unexpectedly favourable outcomes in an aggressive disease

Introduction

Early surgical intervention (ESI) for infective endocarditis (IE) is associated with improved outcomes. Staphylococcus aureus endocarditis (SAE) is associated with particularly high rates of tissue destruction, morbidity and mortality. However, the question as to whether ESI is mandated in all SAE continues to be debated, in both native (NVE) and prosthetic (PVE) endocarditis.

Methods

Retrospective review of all IE cases presenting to our institution from October 2015 to January 2019. IE was diagnosed following imaging and microbiological protocols as per ESC guidance, and data were extracted for those with SAE. Patients with isolated cardiac implantable electronic device IE or bacteraemia secondary to indwelling long-term venous catheter infection were excluded (non-valvular IE).

Results

Valvular IE was diagnosed in 411 patients overall; NVE in 286 (69.6%) and PVE in 125 (30.4%). S aureus was isolated in 111 patients (28.1%), of whom 5 had a Methicillin-resistant strain. SAE was confirmed in a similar proportion of NVE and PVE cases [83/111 (74.8%) and 28/111 (25.2%), respectively]. Surgical intervention was mandated in 35/83 with NVE (42.2%) and 11/28 (39.3%) with PVE, lower than in our overall cohort (55.9% and 48.8%, respectively).

In-hospital SAE mortality was 16.2% overall (18.4% medical vs 13.0% surgical), and contributes a significant proportion to overall mortality (29% to medical & 26% to surgical mortality). Figure 1 identifies the cause of death per mode of treatment, highlighting the aggressive nature of S aureus infection (abscess, disseminated infection and septic shock; n=8), the importance of advanced non-cardiac comorbidity precluding intervention (n=3) and ongoing intravenous drug use in those with PVE (n=4). However, medical management was successful in 57.8% (38/83) of NVE and 60.7% (17/28) of PVE cases, both in hospital and to a minimum follow-up of 3-months.

Conclusion

Staphylococcus aureus is virulent and highly pathogenic, driving severe sepsis and advanced tissue destruction in SAE. Despite this, medical management can be successful when following international guidance, but requires co-ordinated care driven by a multidisciplinary IE team at a cardiothoracic centre.

Hybrid cardiac imaging using PET/MRI: a joint position statement by the European Society of Cardiovascular Radiology (ESCR) and the European Association of Nuclear Medicine (EANM)

Positron emission tomography (PET) and magnetic resonance imaging (MRI) have both been used for decades in cardiovascular imaging. Since 2010, hybrid PET/MRI using sequential and integrated scanner platforms has been available, with hybrid cardiac PET/MR imaging protocols increasingly incorporated into clinical workflows. Given the range of complementary information provided by each method, the use of hybrid PET/MRI may be justified and beneficial in particular clinical settings for the evaluation of different disease entities. In the present joint position statement, we critically review the role and value of integrated PET/MRI in cardiovascular imaging, provide a technical overview of cardiac PET/MRI and practical advice related to the cardiac PET/MRI workflow, identify cardiovascular applications that can potentially benefit from hybrid PET/MRI, and describe the needs for future development and research. In order to encourage its wide dissemination, this article is freely accessible on the European Radiology and European Journal of Hybrid Imaging web sites.

KEY POINTS

• Studies and case-reports indicate that PET/MRI is a feasible and robust technology. • Promising fields of application include a variety of cardiac conditions. • Larger studies are required to demonstrate its incremental and cost-effective value. • The translation of novel radiopharmaceuticals and MR-sequences will provide exciting new opportunities.

An overview of PET/MR, focused on clinical applications

Hybrid PET/MR scanners are innovative imaging devices that simultaneously or sequentially acquire and fuse anatomical and functional data from magnetic resonance (MR) with metabolic information from positron emission tomography (PET) (Delso et al. in J Nucl Med 52:1914-1922, 2011; Zaidi et al. in Phys Med Biol 56:3091-3106, 2011). Hybrid PET/MR scanners have the potential to greatly impact not only on medical research but also, and more importantly, on patient management. Although their clinical applications are still under investigation, the increased worldwide availability of PET/MR scanners, and the growing published literature are important determinants in their rising utilization for primarily clinical applications. In this manuscript, we provide a summary of the physical features of PET/MR, including its limitations, which are most relevant to clinical PET/MR implementation and to interpretation. Thereafter, we discuss the most important current and emergent clinical applications of such hybrid technology in the abdomen and pelvis, both in the field of oncologic and non-oncologic imaging, and we provide, when possible, a comparison with clinically consolidated imaging techniques, like for example PET/CT.

PET/CT Imaging of Unstable Carotid Plaque with 68Ga-Labeled Somatostatin Receptor Ligand

⁶⁸Ga-labeled somatostatin receptor ligand PET imaging has recently been shown in preclinical and early human studies to have a potential role in the evaluation of vulnerable arterial plaques. We prospectively evaluated carotid plaque ⁶⁸Ga-DOTATATE uptake in patients with recent carotid events, assessed inter- and intraobserver variability of such measurements, and explored the mechanism of any plaque DOTATATE activity with immunohistochemistry in resected specimens. Methods: Twenty consecutively consenting patients with recent symptomatic carotid events (transient ischemic attack, stroke, or amaurosis fugax), due for carotid endarterectomy, were prospectively recruited. ⁶⁸Ga-DOTATATE PET/CT of the neck was performed before surgery. ⁶⁸Ga-DOTATATE uptake was measured by drawing regions of interest along the carotid plaques and contralateral plaques/carotid arteries by an experienced radionuclide radiologist and radiographer. Two PET quantification methods with inter- and intraobserver variability were assessed. Resected carotid plaques were retrieved for somatostatin receptor subtype-2 (sst2) immunohistochemical staining. Results: The median time delay between research PET and surgery was 2 d. SUVs and target-to-background ratios for the symptomatic plaques and the asymptomatic contralateral carotid arteries/plaques showed no significant difference (n = 19, P > 0.10), regardless of quantification method. The intraclass correlation coefficient was greater than 0.8 in all measures of carotid artery/plaque uptake (SUV) and greater than 0.6 in almost all measures of target-to-background ratio. None of the excised plaques was shown to contain cells (macrophages, lymphocytes, vessel-associated cells) expressing sst2 on their cell membrane. Conclusion:⁶⁸Ga-DOTATATE activity on PET in recently symptomatic carotid plaques is not significantly different from contralateral carotids/plaques. Any activity seen on PET is not shown to be from specific sst2 receptor-mediated uptake in vitro. It is therefore unlikely that sst2 PET/CT imaging will have a role in the detection and characterization of symptomatic carotid plaques.

Quantifying the Area at Risk in Reperfused ST-Segment-Elevation Myocardial Infarction Patients Using Hybrid Cardiac Positron Emission Tomography-Magnetic Resonance Imaging

BACKGROUND

Hybrid positron emission tomography and magnetic resonance allows the advantages of magnetic resonance in tissue characterizing the myocardium to be combined with the unique metabolic insights of positron emission tomography. We hypothesized that the area of reduced myocardial glucose uptake would closely match the area at risk delineated by T2 mapping in ST-segment-elevation myocardial infarction patients.

METHODS AND RESULTS

Hybrid positron emission tomography and magnetic resonance using (18)F-fluorodeoxyglucose (FDG) for glucose uptake was performed in 21 ST-segment-elevation myocardial infarction patients at a median of 5 days. Follow-up scans were performed in a subset of patients 12 months later. The area of reduced FDG uptake was significantly larger than the infarct size quantified by late gadolinium enhancement (37.2±11.6% versus 22.3±11.7%; P<0.001) and closely matched the area at risk by T2 mapping (37.2±11.6% versus 36.3±12.2%; P=0.10, R=0.98, bias 0.9±4.4%). On the follow-up scans, the area of reduced FDG uptake was significantly smaller in size when compared with the acute scans (19.5 [6.3%-31.8%] versus 44.0 [21.3%-55.3%]; P=0.002) and closely correlated with the areas of late gadolinium enhancement (R 0.98) with a small bias of 2.0±5.6%. An FDG uptake of ≥45% on the acute scans could predict viable myocardium on the follow-up scan. Both transmural extent of late gadolinium enhancement and FDG uptake on the acute scan performed equally well to predict segmental wall motion recovery.

CONCLUSIONS

Hybrid positron emission tomography and magnetic resonance in the reperfused ST-segment-elevation myocardial infarction patients showed reduced myocardial glucose uptake within the area at risk and closely matched the area at risk delineated by T2 mapping. FDG uptake, as well as transmural extent of late gadolinium enhancement, acutely can identify viable myocardial segments.

T1 mapping and T2 mapping at 3T for quantifying the area-at-risk in reperfused STEMI patients

BACKGROUND

Whether T1-mapping cardiovascular magnetic resonance (CMR) can accurately quantify the area-at-risk (AAR) as delineated by T2 mapping and assess myocardial salvage at 3T in reperfused ST-segment elevation myocardial infarction (STEMI) patients is not known and was investigated in this study.

METHODS

18 STEMI patients underwent CMR at 3T (Siemens Bio-graph mMR) at a median of 5 (4-6) days post primary percutaneous coronary intervention using native T1 (MOLLI) and T2 mapping (WIP #699; Siemens Healthcare, UK). Matching short-axis T1 and T2 maps covering the entire left ventricle (LV) were assessed by two independent observers using manual, Otsu and 2 standard deviation thresholds. Inter- and intra-observer variability, correlation and agreement between the T1 and T2 mapping techniques on a per-slice and per patient basis were assessed.

RESULTS

A total of 125 matching T1 and T2 mapping short-axis slices were available for analysis from 18 patients. The acquisition times were identical for the T1 maps and T2 maps. 18 slices were excluded due to suboptimal image quality. Both mapping sequences were equally prone to susceptibility artifacts in the lateral wall and were equally likely to be affected by microvascular obstruction requiring manual correction. The Otsu thresholding technique performed best in terms of inter- and intra-observer variability for both T1 and T2 mapping CMR. The mean myocardial infarct size was 18.8 ± 9.4 % of the LV. There was no difference in either the mean AAR (32.3 ± 11.5 % of the LV versus 31.6 ± 11.2 % of the LV, P = 0.25) or myocardial salvage index (0.40 ± 0.26 versus 0.39 ± 0.27, P = 0.20) between the T1 and T2 mapping techniques. On a per-slice analysis, there was an excellent correlation between T1 mapping and T2 mapping in the quantification of the AAR with an R(2) of 0.95 (P < 0.001), with no bias (mean ± 2SD: bias 0.0 ± 9.6 %). On a per-patient analysis, the correlation and agreement remained excellent with no bias (R(2) 0.95, P < 0.0001, bias 0.7 ± 5.1 %).

CONCLUSIONS

T1 mapping CMR at 3T performed as well as T2 mapping in quantifying the AAR and assessing myocardial salvage in reperfused STEMI patients, thereby providing an alternative CMR measure of the the AAR.

Non-small-cell lung cancer resectability: diagnostic value of PET/MR

PURPOSE

To assess the diagnostic performance of PET/MR in patients with non-small-cell lung cancer.

METHODS

Fifty consecutive consenting patients who underwent routine (18)F-FDG PET/CT for potentially radically treatable lung cancer following a staging CT scan were recruited for PET/MR imaging on the same day. Two experienced readers, unaware of the results with the other modalities, interpreted the PET/MR images independently. Discordances were resolved in consensus. PET/MR TNM staging was compared to surgical staging from thoracotomy as the reference standard in 33 patients. In the remaining 17 nonsurgical patients, TNM was determined based on histology from biopsy, imaging results (CT and PET/CT) and follow-up. ROC curve analysis was used to assess accuracy, sensitivity and specificity of the PET/MR in assessing the surgical resectability of primary tumour. The kappa statistic was used to assess interobserver agreement in the PET/MR TNM staging. Two different readers, without knowledge of the PET/MR findings, subsequently separately reviewed the PET/CT images for TNM staging. The generalized kappa statistic was used to determine intermodality agreement between PET/CT and PET/MR for TNM staging.

RESULTS

ROC curve analysis showed that PET/MR had a specificity of 92.3 % and a sensitivity of 97.3 % in the determination of resectability with an AUC of 0.95. Interobserver agreement in PET/MR reading ranged from substantial to perfect between the two readers (Cohen's kappa 0.646 - 1) for T stage, N stage and M stage. Intermodality agreement between PET/CT and PET/MR ranged from substantial to almost perfect for T stage, N stage and M stage (Cohen's kappa 0.627 - 0.823).

CONCLUSION

In lung cancer patients PET/MR appears to be a robust technique for preoperative staging.

Nipple-sparing mastectomy: Evaluation of oncologic safety and aesthetic outcomes in 94 patients

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Background: The surgical treatment of breast cancer has evolved from radical mastectomy to breast conservation therapy. Today we have another therapeutic dilemma: how to manage the nipple-areolar complex (NAC) in mastectomy offering patients better aesthetic results with oncologic safety.

Methods: We analyzed data on 125 consecutive nipple- or skin-sparing mastectomies (SSM) with immediate reconstruction with tissue expander, prosthesis or autologous tissue performed in 94 patients from 2003 to 2010 in a tertiary referral hospital. Nipple-sparing mastectomy (NSM) was performed for treatment disease (n= 94) and prophylaxis of contralateral breast or symmetrization in selected cases (n= 31).

Results: Mean patients age was 46.8 years (range 27 to 69 years) and mean follow-up time was 27.2 months (range 2 weeks to 81 months). Twelve patients were stage 0, 41 stage I, 35 stage II A and B and 7 stage III. There were 125 nipple- or areola-sparing mastectomies (31 bilateral and 94 unilateral), including 112 NSM and 13 SSM. On pathologic review, 12 breasts had carcinoma in situ, 83 invasive carcinoma, and 31 breasts were cancer free. Thirteen nipples (13.8%) were compromised by tumor on subareolar biopsy and were removed. The location and type of incision was variable according to the tumor site and previous patient scar. Periareolar incision with prolongation along the inferior pole of breast was the preferred method. Patients with positive axillary node (27.5%) received adjuvant radiotherapy. There was no nipple necrosis. One patient presented local relapse in the skin-sparing group within 24 months.

Conclusions: These data demonstrate that NSM is oncologically safe and can be performed with all types of breast reconstruction.

Adolescent Kawasaki disease: usefulness of 64-slice CT coronary angiography for follow-up investigation

BACKGROUND

Kawasaki disease (KD) is a systemic vasculitis that mainly affects coronary arteries in children, and requires regular follow-up from the time of diagnosis.

OBJECTIVE

To evaluate the feasibility of 64-slice CT angiography (CTA) for follow-up of patients with KD using previously performed invasive catheter coronary angiography (CCA) as reference standard.

MATERIALS AND METHODS

The study group comprised 12 patients (age 17.6 ± 2.9 years, mean ± SD) with a diagnosis of KD and a previously performed CCA (interval, 32.6 ± 13.5 months) who underwent 64-slice cardiac CTA. The quality of the images for establishing the presence of coronary abnormalities was determined by two observers. The CTA findings were compared with those from the prior CCA.

RESULTS

Adequate image quality was obtained in all patients. Mean effective dose for CTA was 6.56 ± 0.95 mSv. CTA allowed accurate identification, characterization and measurement of all coronary aneurysms (n = 32), stenoses (n = 3) and occlusions (n = 9) previously demonstrated by CCA. One patient with disease progression went on to have percutaneous coronary intervention.

CONCLUSION

Coronary lesions were reliably evaluated by 64-slice CTA in the follow-up of compliant patients with KD, reducing the need for repeated diagnostic invasive CCA. Hence, in an adequately selected patient population, the role of CCA could be limited almost only to therapeutic procedures.

The impact of 18F-FDG PET/CT in patients with liver metastases

PURPOSE

The aim of this study was to assess the performance of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) versus dedicated contrast-enhanced CT (CECT) in the detection of metastatic liver disease.

METHODS

All patients that presented to our Institution with suspected metastatic liver disease who underwent (18)F-FDG PET/CT and CECT within 6 weeks of each other, were retrospectively analyzed, covering a 5-year period. One hundred and thirty-one patients (67 men, 64 women; mean age 62) were identified. Seventy-five had colorectal carcinoma and 56 had other malignancies. The performance of CECT and that of (18)F-FDG-PET/CT in detecting liver metastases were compared. The ability of each to detect local recurrence, extrahepatic metastases and to alter patient management was recorded. The final diagnosis was based on histology, clinical and radiological follow-up (mean 23 months).

RESULTS

In detecting hepatic metastases, (18)F-FDG-PET/CT yielded 96% sensitivity and 75% specificity, whilst CECT showed 88% sensitivity and 25% specificity. (18)F-FDG-PET/CT and CECT were concordant in 102 out of 131 patients (78%). In the colorectal group (18)F-FDG-PET/CT showed 94% sensitivity and 75% specificity, whilst CECT had 91% sensitivity and 25% specificity. In the noncolorectal group (18)F-FDG-PET/CT showed 98% sensitivity and 75% specificity whilst CECT had 85% sensitivity and 25% specificity. Overall, (18)F-FDG-PET/CT altered patient management over CECT in 25% of patients. CECT did not alter patient management over (18)F-FDG-PET/CT alone in any patients.

CONCLUSION

(18)F-FDG-PET/CT performed better in detecting metastatic liver disease than CECT in both colorectal and noncolorectal malignancies, and frequently altered patient management. The future role of CECT in these patients may need to be re-evaluated to avoid potentially unnecessary duplication of investigation where (18)F-PET/CT is readily available.

Ultrasound-guided core biopsy for the diagnosis of lumps in the neck: results in 82 patients

Ultrasound-guided core biopsy of nodes (n = 78) and other lumps (n = 4) in the neck allowed a firm histological diagnosis in 76 of 82 patients (93%). Of the remaining six patients, histological examination was equivocal in four and valueless in two. Of 18 patients with a diagnosis of lymphoma only 3 required excision of the node to provide additional information for the planning of treatment.

An outbreak of shigellosis in a child care institution in Queluz, Portugal - 1995

The introduction of shigella into a child care centre carries a high risk of secondary spread from person to person within the centre. We report an outbreak of shigellosis in early 1995 that affected 99 children, 17 of their relations, and seven workers i

Pentose synthesis in glucose-grown cells of Lactobacillus casei

The pathway of pentose synthesis in glucose-grown cells of Lactobacillus casei was ascertained. Glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase were present in glucose-grown cells, while transaldolase and transketolase were present only in traces. This suggested that only the oxidative arm of this pathway was operative in glucose-grown cells. On the other hand, in ribose-grown cells, transaldolase was induced with a concomitant suppression of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase. These results were confirmed by the detection of labelled CO2 produced by L. casei grown on [1-14C]glucose. The activities of the enzymes of the oxidative pentose phosphate pathway as also the rate of CO2 formation were higher in the exponential phase of growth as compared to the stationary phase, when the requirement of the cells for pentoses for the formation of DNA and RNA was higher.

Glucose 6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase from Lactobacillus casei: responses with different modulators

Glucose 6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD) were separated and partially purified from glucose-grown cells of Lactobacillus casei. The enzymes had similar pH optima, thermosensitivity and molecular weights. They had different net charges and their pI values were 5.38 and 4.52, respectively. Histidine, arginine, lysine and cysteine residues were essential for the activity of G6PD, and all the above amino acids with the exception of lysine were required for 6PGD activity. Mg2+ activated 6PGD up to 15 mM concentration, above which it was inhibitory. It had no effect on G6PD activity. G6PD was specific for NADP+, but 6PGD showed some activity with NAD+ as the cofactor, although it was essentially NADP(+)-preferring. Both the enzymes, were inhibited by NADPH. 6PGD was also inhibited by its product, ribulose 5-phosphate. ATP inhibited 6PGD only at subsaturating concentrations of NADP+. The inhibition was sigmoidal in the absence of Mg2+ and hyperbolic in its presence.

Absence of the septum pellucidum with porencephalia. A neuroradiologic syndrome with variable clinical expression

We studied 12 patients with absence of the septum pellucidum associated with porencephalies. Seven patients had bilateral and five apparently unilateral defects of the cerebral mantle. The clinical manifestations were relatively mild in half of the patients and limited to isolated partial seizures in one. In one case, extensive calcification was present adjacent to the defects. In two cases, the presence of a cleft was demonstrated only by magnetic resonance imaging, although it had been suspected by computed tomography in one.

Ethanol metabolism in liver cirrhosis and chronic alcoholism

Ethanol metabolism and its influence on serum lactate/pyruvate ratio was studied after intravenous infusion of ethanol in 17 patients: 4 controls, 5 alcoholics with cirrhosis, 4 non-alcoholic cirrhotics and 4 alcoholics without liver disease. All refrained from the use of alcohol and drugs 4 weeks prior to the experiment. After maximal ethanol blood levels were achieved at the end of the infusion, ethanol removal occurred at two different rates. This was probably due to the fact that different volumes of ethanol were distributed with time: a fast period (30 to 60 min) and a slow period (60 to 180 min). The rates of disappearence in the two periods were similar in all groups which suggests that liver cirrhosis, independent of clinical severity and/or chronic alcoholism with previous abstinence from alcohol, does not modify ethanol metabolic rates in the liver. The relation lactate/pyruvate doubled in all cases but it occurred within 30 minutes in the groups without liver disease and within 60 minutes in the cirrhotics. This could account for the decreased liability of cirrhotic patients to alcohol hypoglycemia.