Novel insights into diminished cardiac reserve in non-obstructive hypertrophic cardiomyopathy from four-dimensional flow cardiac magnetic resonance component analysis

AIMS

Hypertrophic cardiomyopathy (HCM) is characterized by hypercontractility and diastolic dysfunction, which alter blood flow haemodynamics and are linked with increased risk of adverse clinical events. Four-dimensional flow cardiac magnetic resonance (4D-flow CMR) enables comprehensive characterization of ventricular blood flow patterns. We characterized flow component changes in non-obstructive HCM and assessed their relationship with phenotypic severity and sudden cardiac death (SCD) risk.

METHODS AND RESULTS

Fifty-one participants (37 non-obstructive HCM and 14 matched controls) underwent 4D-flow CMR. Left-ventricular (LV) end-diastolic volume was separated into four components: direct flow (blood transiting the ventricle within one cycle), retained inflow (blood entering the ventricle and retained for one cycle), delayed ejection flow (retained ventricular blood ejected during systole), and residual volume (ventricular blood retained for >two cycles). Flow component distribution and component end-diastolic kinetic energy/mL were estimated. HCM patients demonstrated greater direct flow proportions compared with controls (47.9 ± 9% vs. 39.4 ± 6%, P = 0.002), with reduction in other components. Direct flow proportions correlated with LV mass index (r = 0.40, P = 0.004), end-diastolic volume index (r = -0.40, P = 0.017), and SCD risk (r = 0.34, P = 0.039). In contrast to controls, in HCM, stroke volume decreased with increasing direct flow proportions, indicating diminished volumetric reserve. There was no difference in component end-diastolic kinetic energy/mL.

CONCLUSION

Non-obstructive HCM possesses a distinctive flow component distribution pattern characterised by greater direct flow proportions, and direct flow-stroke volume uncoupling indicative of diminished cardiac reserve. The correlation of direct flow proportion with phenotypic severity and SCD risk highlight its potential as a novel and sensitive haemodynamic measure of cardiovascular risk in HCM.

Left atrial vorticity is independently associated with embolic brain infarcts and represents a promising imaging biomarker of cardioembolism in sinus rhythm and atrial fibrillation

Background

Atrial fibrillation (AF) is associated with embolic stroke, but risk scores such as CHA2DS2-VASc perform only modestly (C statistics 0.6–0.7). Meanwhile, up to 25% of embolic strokes in patients without AF have no identifiable cause, and occult left atrial (LA) thromboembolism may be a relevant mechanism in such cases.

Purpose

We hypothesised that imaging of left atrial blood flow could improve embolic risk prediction in patients with and without AF. We used 4D flow magnetic resonance imaging (MRI) to identify a biomarker that is: (a) independently associated with embolic brain infarction by brain MRI, (b) able to stratify blood flow characteristics both during AF and in sinus rhythm (SR), and (c) reproducible.

Methods

We recruited 3 patient cohorts to respectively address each aim. Firstly, to assess the association between LA flow parameters and embolic brain infarcts, we recruited cohort A, consisting of 134 patients (41% female; age 70±9 years) with a history of ischaemic stroke (N=44) or no history of stroke but with CHA2DS2VASc score ≥1 (N=90). Next, the sensitivity of 4D flow parameters to rhythm change was assessed in cohort B: 37 patients with persistent AF studied before and after cardioversion, whose results were compared with those of 23 healthy controls in SR [CHA2DS2-VASc = 0.0 (0.0–0.0)]. Finally, scan-rescan coefficients of variation (CV) and interval-scan CV at 30 days were determined in Cohort C (86 subjects; 64 in SR, 22 in AF). Brain MRI was used to identify large non-cortical or cortical brain infarcts (LNCCI) – i.e. infarcts likely to be embolic in origin.

Results

At least one LNCCI was present in 39 of 134 patients in cohort A. Lower LA vorticity was significantly associated with higher risk of prevalent LNCCIs (Figure 1), after adjustment for AF, age, and CHA2DS2VASc score [OR=2.10 (95% CI 1.12–3.92) per SD, P=0.02]. This association remained significant after further adjustment for other cardiac parameters (all P<0.05, Figure 1). By contrast, there was no significant association between peak velocity and LNCCIs (P=0.21).

LA vorticity was sensitive to rhythm change, improving significantly in patients in cohort B in SR at ≥4 weeks after cardioversion (CV) of persistent AF (Figure 2A, paired P<0.001 vs pre-CV), but remained impaired compared to healthy controls (Figure 2B, P<0.01).

Finally, reproducibility studies in cohort C showed that LA vorticity had a same-day scan-rescan CV of 7% without significant differences between SR and AF subjects (P>0.05), and also showed no significant temporal variability on interval scanning (P>0.05).

Conclusions

LA vorticity is reproducible, sensitive to changes in heart rhythm, and independently associated with embolic brain infarcts, suggesting a promising imaging biomarker of cardioembolism in SR and AF. LA blood flow imaging could improve stroke prediction and the personalisation of decisions about anticoagulation, regardless of heart rhythm.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Oxford BRC, BHF

Preparation of Polyfunctionalized Aromatic Nitriles from Aryl Oxazolines

A selective ortho,ortho’‐functionalization of readily available aryl oxazolines by two successive magnesiations with sBu₂Mg in toluene followed by trapping reactions with electrophiles, such as (hetero)aryl iodides or bromides, iodine, tosyl cyanide, ethyl cyanoformate or allylic bromides (39 examples, 62–99 % yield) is reported. Treatment of these aryl oxazolines with excess oxalyl chloride and catalytic amounts of DMF (50 °C, 4 h) provided the corresponding nitriles (36 examples, 73–99 % yield). Conversions of these nitriles to valuable heterocycles are reported, and a tentative mechanism is proposed.

Macrophage depletion impairs adequate cardiac repair in mouse models of myocardial infarction with variable transmurality - insights from multimodality molecular imaging

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Deutsche Forschungsgemeinschaft (DFG)

Introduction

Balanced myocardial tissue inflammation following acute myocardial infarction (MI) is needed for optimal cardiac repair. Macrophages contribute to wound healing, but may also be deleterious.

Purpose

We investigated the impact of macrophage depletion on early cardiac inflammation and later functional outcome in two models of MI with variable transmurality.

Methods

C57BL/6N mice received clodronate-liposomes for macrophage depletion (n = 49) or control PBS-liposomes (n = 23). After 24h, mice underwent permanent occlusion (PO) or transient ischemia-reperfusion (I/R, 60min) of the left coronary artery or sham surgery. Cardiac inflammation was assessed on MI + 1d, 3d, and 7d by CXCR4-targeted PET/CT using 68Ga-pentixafor. 99mTc-sestamibi SPECT/CT and cardiac magnetic resonance (CMR) calculated infarct sizes and left ventricular (LV) function at 1wk and 6wks. 18F-NaF PET/CT measured tissue microcalcification at 4wks. Imaging signals were validated by ex vivo autoradiography and immunohistochemistry.

Results

Clodronate macrophage depletion did not affect infarct size compared to PBS, but perfusion defects at 6wks were significantly larger after PO compared to I/R (%LV, 32 ± 11 vs 14 ± 10, p = 0.01). In both models, infarct CXCR4 expression was higher after macrophage depletion vs PBS at all timepoints (%injected dose (ID)/g; d3: PO: 1.4 ± 0.2 vs 0.9 ± 0.1; I/R: 1.4 ± 0.2 vs 1.0 ± 0.02; p < 0.05), and confirmed by ex vivo autoradiography. Immunostaining demonstrated fewer macrophages and higher neutrophil content within the myocardium after macrophage depletion vs PBS at 1d, 3d, and 7d post-MI. Acute LV rupture after PO was more frequent in macrophage-depleted than PBS mice (37% vs 17%). Conversely, surviving PO mice showed a similarly impaired ejection fraction (EF) after macrophage depletion vs PBS at 6wks (%, 32 ± 9 vs 32 ± 11, p = 0.84). No acute LV rupture was observed after I/R, but macrophage depletion led to worse EF (%, 42 ± 11 vs 54 ± 3, p = 0.1). Macrophage-depleted mice exhibited a dense intracavity thrombus adherent to the infarct wall after either injury, as visualized on CMR at 1wk. 18F-NaF PET identified active calcification localized to the thrombus region 4wks after MI, which was colocalized to CT opaque regions at 6wks.

Conclusion

Macrophage depletion impairs cardiac repair via several mechanisms including neutrophil-dominated inflammation, LV thrombus formation and tissue calcification. This observation underscores the requirement of macrophages for effective healing and may explain adverse response to broad anti-inflammatory therapy in myocardial ischemia.

Phase I clinical trial of an antithrombotic drug protocol combining apixaban and clopidogrel in dogs

INTRODUCTION

Combining an antiplatelet drug, clopidogrel, with the direct oral Factor Xa inhibitor, apixaban, could provide an effective antithrombotic strategy in dogs. Thus, a limited 3 + 3 phase I dose-escalation clinical trial in healthy dogs was conducted to evaluate bleeding (primary end-point) and pharmacodynamic (PD)/pharmacokinetic (PK) parameters (secondary end-point).

ANIMALS

Eleven beagle dogs, median body weight 10.2 kg (9.7-10.9 kg), were enrolled.

METHODS

Four doses of apixaban (three dogs/dose) administered for eight days. Clopidogrel dose was fixed at 18.75 mg per os (PO) q 24 h with escalation of apixaban dose at 5 mg PO q 12 h, 5 mg PO q 8 h, 10 mg PO q 12 h, and 10 mg PO q 8 h. Laboratory testing included fecal occult blood, coagulation parameters, Factor X activity, apixaban concentration, platelet aggregometry, and thromboelastography on days 1, 3, and 8.

RESULTS

Evidence of bleeding was not observed at any dosage. Dose-dependent changes in PD/PK parameters between baseline and 3 h post-medication were observed including a prolongation of prothrombin time, a prolongation of activated partial thromboplastin time, a decrease of Factor X activity level, and increased apixaban concentration.

CONCLUSIONS

The combination of apixaban at a dosage range of approximately 0.5 mg/kg PO q 12 h to 1 mg/kg PO q 8 h and clopidogrel at approximately 1.8 mg/kg PO q 24 h did not cause bleeding over a one-week period in healthy dogs. Clinically relevant changes in PD/PK data occur at all dosage levels. This study provides a starting point for longer-term clinical trials to determine safety and efficacy.

Molecular imaging in nuclear cardiology: Pathways to individual precision medicine

Growth of molecular imaging bears potential to transform nuclear cardiology from a primarily diagnostic method to a precision medicine tool. Molecular targets amenable for imaging and therapeutic intervention are particularly promising to facilitate risk stratification, patient selection and exquisite guidance of novel therapies, and interrogation of systems-based interorgan communication. Non-invasive visualization of pathobiology provides valuable insights into the progression of disease and response to treatment. Specifically, inflammation, fibrosis, and neurohormonal signaling, central to the progression of cardiovascular disease and emerging therapeutic strategies, have been investigated by molecular imaging. As the number of radioligands grows, careful investigation of the binding properties and added-value of imaging should be prioritized to identify high-potential probes and facilitate translation to clinical applications. In this review, we discuss the current state of molecular imaging in cardiovascular medicine, and the challenges and opportunities ahead for cardiovascular molecular imaging to navigate the path from diagnosis to prognosis to personalized medicine.

OP0117 LONGITUDINAL CHANGE IN THE CENTRAL NERVOUS SYSTEM PAIN RESPONSE AFTER TREATMENT WITH CERTOLIZUMAB OR PLACEBO. A POST-HOC ANALYSIS FROM THE PRECEPRA TRIAL

Background:

Tumor necrosis factor inhibitors have revolutionized the treatment of rheumatoid arthritis (RA). However, only about 50% of the patients respond well to TNF inhibitors. Therefore, markers that predict response to TNF inhibitors are valuable. Previously we demonstrated that central nervous system (CNS) response to nociceptive stimuli, measured by fMRI of the brain as blood oxygen level dependent (BOLD) signals, decreases already after 24 hours of anti-TNF administration a higher pre-treatment BOLD signal volume seems to predict clinical response to treatment with certolizumabpegol (CZP)1,2. We therefore hypothesized that the baseline volume of BOLD signal in the CNS could predict anti-TNF treatment response.

Objectives:

To perform a randomized placebo controlled trial in active RA patients to test the effect of TNF inhibition on arthritis induced pain activity in the brain and to test whether patients with high-level RA-related brain activation react differently to TNF-inhibitors than patients with low-level brain activation.

Methods:

Adult RA patients fulfilling the 2010 ACR/EULAR classification criteria with a DAS28>3.2 receiving stable DMARD treatment for at least 3 months were eligible. Patients underwent the first fMRI at screening measuring BOLD signal upon MCP joint compression and were stratified into low (< 700 units) and high (>700 units) voxel counts. Then patients were randomized to CZP or placebo with a 2:1 ratio. The second and third fMRI were performed after 12 and 24 weeks, respectively. Control stimulation was done by measuring brain activation after non-painful finger tapping.

Results:

156 RA patients with moderate-to-high disease activity participated in the study. In the finger tapping control, fMRI showed no significant changes in BOLD signal in the CZP-L and CZP-H arms, but a slight but significant decrease (p=0.043) was observed. After joint compression, the CZP-L group showed significant increase in the BOLD signal volume (p=0.043) in fMRI-2 as compared to fMRI-1 with no further significant changes. In contrast, in the CZP-H group, the BOLD signal volume significantly decreased (p=0.037) in fMRI-2 and continued to decrease further, p=0.007. No significant changes were observed in the placebo arm over time.

Conclusion:

TNF inhibition improves arthritis-related brain activity in the subgroup of RA patients with high baseline BOLD activity in the fMRI.

References:

[1]Hess, A.et al.PNAS (2011).

[2]Rech, J. et al. Arthritis & Rheumatism (2013).

Fig 1.

BOLD fMRI responses to painful stimulation

Acknowledgments:

The study was supported by an unrestricted grant of UCB Biopharma SPRL Brussels, Belgium

Disclosure of Interests:

Jürgen Rech Consultant of: BMS, Celgene, Novartis, Roche, Chugai, Speakers bureau: AbbVie, Biogen, BMS, Celgene, MSD, Novartis, Roche, Chugai, Pfizer, Lilly, Koray Tascilar: None declared, Hannah Schenker: None declared, Melanie Hagen: None declared, Marina Sergeeva: None declared, Mageshwar Selvakumar: None declared, Laura Konerth: None declared, Jutta Prade: None declared, Sandra Strobelt: None declared, Verena Schönau: None declared, Larissa Valor: None declared, Axel Hueber Grant/research support from: Novartis, Lilly, Pfizer, EIT Health, EU-IMI, DFG, Universität Erlangen (EFI), Consultant of: Abbvie, BMS, Celgene, Gilead, GSK, Lilly, Novartis, Speakers bureau: GSK, Lilly, Novartis, David Simon Grant/research support from: Else Kröner-Memorial Scholarship, Novartis, Consultant of: Novartis, Lilly, Arnd Kleyer Consultant of: Lilly, Gilead, Novartis, Abbvie, Speakers bureau: Novartis, Lilly, Frank Behrens Grant/research support from: Abbvie, Pfizer, Roche, Chugai, Janssen, Consultant of: Abbvie, Pfizer, Roche, Chugai, UCB, BMS, Celgene, MSD, Novartis, Biotest, Janssen, Genzyme, Lilly; Boehringer; Sandoz, Speakers bureau: Abbvie, Pfizer, Roche, Chugai, UCB, BMS, Celgene, MSD, Novartis, Biotest, Janssen, Genzyme, Lilly; Boehringer; Sandoz, Christoph Baerwald Consultant of: CGB received speaker or consulting fees from AbbVie, Paid instructor for: CGB received speaker or consulting fees from AbbVie, Speakers bureau: CGB received speaker or consulting fees from AbbVie, Stephanie Finzel: None declared, Reinhard Voll: None declared, Eugen Feist Consultant of: Novartis, Roche, Sobi, Lilly, Pfizer, Abbvie, BMS, MSD, Sanofi, Speakers bureau: Novartis, Roche, Sobi, Lilly, Pfizer, Abbvie, BMS, MSD, Sanofi, José Antonio P. da Silva Grant/research support from: Pfizer, Abbvie, Consultant of: Pfizer, AbbVie, Roche, Lilly, Novartis, Arnd Doerfler: None declared, Nemanja Damjanov Grant/research support from: from AbbVie, Pfizer, and Roche, Consultant of: AbbVie, Gedeon Richter, Merck, Novartis, Pfizer, and Roche, Speakers bureau: AbbVie, Gedeon Richter, Merck, Novartis, Pfizer, and Roche, Andreas Hess: None declared, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB

SAT0050 PREDICTION OF RESPONSE TO CERTOLIZUMAB PEGOL TREATMENT BY FUNCTIONAL MRI OF THE BRAIN: AN INTERNATIONAL, MULTI-CENTER, RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED TRIAL (PRECEPRA)

Background:

Personalization of RA treatment is not optimal due to lack of predictors. We previously demonstrated in RA patients that central nervous system (CNS) pain response to tender joint compression, measured by using functional MRI (fMRI) of the brain rapidly wanes after 24 hours of anti-TNF administration and that a higher pre-treatment BOLD signal volume seems to predict clinical response to treatment with certolizumab-pegol (CZP)1,2. We therefore hypothesized that the CNS pain response upon compression of a painful joint could predict subsequent anti-TNF treatment response.

Objectives:

To compare disease activity after 12-weeks of CZP treatment to that of placebo in DMARD-refractory RA patients based on pre-treatment baseline CNS pain response measured using BOLD fMRI.

Methods:

Adult RA patients fulfilling the 2010 ACR/EULAR classification criteria with a DAS28>3.2 under stable DMARD treatment for at least 3 months were eligible. Patients underwent fMRI scanning of the brain at screening for stratification by CNS pain response. Whole brain BOLD-signal-voxel-count of 700 units classifying between low and high, and were randomized to CZP or placebo (2:1) The primary outcome was low disease activity (LDA, DAS28 ≤3.2) after 12 weeks of treatment.

Results:

156 RA patients, inadequate responders to csDMARD, signed the informed consent. 139 patients (46/47, 46/49 and 42/43) (99 females, 71%) with moderate-high disease activity (mean (SD) DAS-28: 4.83 (1.03)) could be included respectively and completed the 12-week study treatment. Geometric mean (SD) numbers of baseline BOLD signal positive voxels were 559 (10), 81 (12) and 2498 (3) in the 3 arms respectively. The mean DAS28 (SD) scores after 12 weeks of study treatment were Placebo: 3.89 (1.29), CZP-L: 3.42 (1.06) and CZP-H: 3.06 (1.04). LDA was achieved in 12/47 patients (25.5 %) in placebo, 22/49 (44.9%) in the CZP-L, and 25/43, (58.1%) in the CZP-H arm. The linear effect term for the ordinal study group variable supported a linear trend of increasing CZP treatment effect with increasing baseline CNS pain response. RR (95% CI) for achieving LDA with each unit increase in treatment category over placebo was 1.79 (1.24 to 2.74, p=0.003).

Conclusion:

A higher pre-treatment brain activity in response to pain measured with fMRI predicts the chance of achieving low disease activity with CZP treatment.

References:

[1] Hess, A.et al.PNAS (2011)

[2] Rech, J.et al. Arthritis & Rheumatism(2013).

Acknowledgments :

The study was supported by an unrestricted grant from UCB Biopharma SPRL, Brussels, Belgium

Disclosure of Interests:

Jürgen Rech Consultant of: BMS, Celgene, Novartis, Roche, Chugai, Speakers bureau: AbbVie, Biogen, BMS, Celgene, MSD, Novartis, Roche, Chugai, Pfizer, Lilly, Koray Tascilar: None declared, Hannah Schenker: None declared, Marina Sergeeva: None declared, Mageshwar Selvakumar: None declared, Laura Konerth: None declared, Jutta Prade: None declared, Sandra Strobelt: None declared, Melanie Hagen: None declared, Verena Schönau: None declared, Larissa Valor: None declared, Axel Hueber Grant/research support from: Novartis, Lilly, Pfizer, EIT Health, EU-IMI, DFG, Universität Erlangen (EFI), Consultant of: Abbvie, BMS, Celgene, Gilead, GSK, Lilly, Novartis, Speakers bureau: GSK, Lilly, Novartis, David Simon Grant/research support from: Else Kröner-Memorial Scholarship, Novartis, Consultant of: Novartis, Lilly, Arnd Kleyer Consultant of: Lilly, Gilead, Novartis,Abbvie, Speakers bureau: Novartis, Lilly, Frank Behrens Grant/research support from: Abbvie, Pfizer, Roche, Chugai, Janssen, Consultant of: Abbvie, Pfizer, Roche, Chugai, UCB, BMS, Celgene, MSD, Novartis, Biotest, Janssen, Genzyme, Lilly; Boehringer; Sandoz, Speakers bureau: Abbvie, Pfizer, Roche, Chugai, UCB, BMS, Celgene, MSD, Novartis, Biotest, Janssen, Genzyme, Lilly; Boehringer; Sandoz, José Antonio P. da Silva Grant/research support from: Pfizer, Abbvie, Consultant of: Pfizer, AbbVie, Roche, Lilly, Novartis, Christoph Baerwald Consultant of: CGB received speaker or consulting fees from AbbVie, Paid instructor for: CGB received speaker or consulting fees from AbbVie, Speakers bureau: CGB received speaker or consulting fees from AbbVie, Stephanie Finzel: None declared, Reinhard Voll: None declared, Eugen Feist Consultant of: Novartis, Roche, Sobi, Lilly, Pfizer, Abbvie, BMS, MSD, Sanofi, Speakers bureau: Novartis, Roche, Sobi, Lilly, Pfizer, Abbvie, BMS, MSD, Sanofi, Arnd Doerfler: None declared, Nemanja Damjanov Grant/research support from: from AbbVie, Pfizer, and Roche, Consultant of: AbbVie, Gedeon Richter, Merck, Novartis, Pfizer, and Roche, Speakers bureau: AbbVie, Gedeon Richter, Merck, Novartis, Pfizer, and Roche, Andreas Hess: None declared, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB

OP0218 CENTRAL NERVOUS SYSTEM PAIN RESPONSE AND COMPONENTS OF DISEASE ACTIVITY IN RA PATIENTS AFTER TREATMENT WITH CERTOLIZUMAB OR PLACEBO: A POST-HOC ANALYSIS FROM THE PRECEPRA TRIAL

Background:

We have previously observed in RA patients that central nervous system (CNS) response to compression of a painful joint, measured using functional MRI (fMRI) of the brain as the number of blood oxygen level dependent (BOLD) signal positive voxels, is rapidly ameliorated, much earlier than any clinical response with anti-TNF treatment and a high baseline CNS pain response could predict better response to certolizumab pegol (CZP) treatment. Pre-CePRA was designed and conducted to test this effect in a randomized, placebo controlled trial of CZP and showed an incremental linear trend of DAS28 low disease activity (LDA) across study groups treated with placebo, and two CZP arms stratified as low or high pre-treatment CNS pain response.

Objectives:

To explore and describe pre-treatment CNS pain response associations with post treatment course of RA disease activity components and patient-physician discrepancy in global disease assessment.

Methods:

Patients fulfilling the 2010 ACR/EULAR classification criteria with moderate-severe disease activity (DAS-28>3.2) under stable DMARD treatment were recruited. Patients underwent an fMRI scan, stratified by a whole-brain BOLD positive voxel count threshold of 700 units and randomized to treatment with CZP or placebo in a 2:1 ratio. We descriptively assessed components of RA disease activity (Table 1 + 2). We summarized the mean results and 95% confidence intervals of these measurements at study timepoints and compared the 3 study groups at week 12 using one-way ANOVA and post-hoc Tukey tests.

Results:

156 eligible patients were screened and 139 (99 females, 71%) patients with moderate-high disease activity were randomized. ANOVA and pairwise comparisons showed that PGA-VAS improvement was larger in the CZP-H group whereas more similar to that in placebo in the CZP-L group. PhysGA-VAS however was similarly reduced in both CZP groups. Patients in the CZP-L group constantly rated their pain numerically higher than physicians whereas in the CZP-H group an initially higher discrepancy numerically reduced over time.

Conclusion:

These results suggest that improved patient global disease activity assessment could be the main driver of improved DAS-28 LDA rates with CZP treatment in patients with a high CNS pain response. Our findings indicate a potential role of fMRI imaging of the brain to further understand disease activity perception in RA patients.

Figure 1.

Course of disease activity components through trial timepoints. *indicates log-transformed y axis. *#x002A; Discrepancy equals Patient global minus physician global assessment.

Disclosure of Interests:

Hannah Schenker: None declared, Jürgen Rech Consultant of: BMS, Celgene, Novartis, Roche, Chugai, Speakers bureau: AbbVie, Biogen, BMS, Celgene, MSD, Novartis, Roche, Chugai, Pfizer, Lilly, Koray Tascilar: None declared, Melanie Hagen: None declared, Verena Schönau: None declared, Marina Sergeeva: None declared, Mageshwar Selvakumar: None declared, Laura Konerth: None declared, Jutta Prade: None declared, Sandra Strobelt: None declared, Larissa Valor: None declared, Axel Hueber Grant/research support from: Novartis, Lilly, Pfizer, EIT Health, EU-IMI, DFG, Universität Erlangen (EFI), Consultant of: Abbvie, BMS, Celgene, Gilead, GSK, Lilly, Novartis, Speakers bureau: GSK, Lilly, Novartis, David Simon Grant/research support from: Else Kröner-Memorial Scholarship, Novartis, Consultant of: Novartis, Lilly, Arnd Kleyer Consultant of: Lilly, Gilead, Novartis,Abbvie, Speakers bureau: Novartis, Lilly, Frank Behrens Grant/research support from: Abbvie, Pfizer, Roche, Chugai, Janssen, Consultant of: Abbvie, Pfizer, Roche, Chugai, UCB, BMS, Celgene, MSD, Novartis, Biotest, Janssen, Genzyme, Lilly; Boehringer; Sandoz, Speakers bureau: Abbvie, Pfizer, Roche, Chugai, UCB, BMS, Celgene, MSD, Novartis, Biotest, Janssen, Genzyme, Lilly; Boehringer; Sandoz, José Antonio P. da Silva Grant/research support from: Pfizer, Abbvie, Consultant of: Pfizer, AbbVie, Roche, Lilly, Novartis, Christoph Baerwald Consultant of: CGB received speaker or consulting fees from AbbVie, Paid instructor for: CGB received speaker or consulting fees from AbbVie, Speakers bureau: CGB received speaker or consulting fees from AbbVie, Stephanie Finzel: None declared, Reinhard Voll: None declared, Eugen Feist Consultant of: Novartis, Roche, Sobi, Lilly, Pfizer, Abbvie, BMS, MSD, Sanofi, Speakers bureau: Novartis, Roche, Sobi, Lilly, Pfizer, Abbvie, BMS, MSD, Sanofi, Arnd Doerfler: None declared, Nemanja Damjanov Grant/research support from: from AbbVie, Pfizer, and Roche, Consultant of: AbbVie, Gedeon Richter, Merck, Novartis, Pfizer, and Roche, Speakers bureau: AbbVie, Gedeon Richter, Merck, Novartis, Pfizer, and Roche, Andreas Hess: None declared, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB

Nix Pro Color Sensor Provides Comparable Color Measurements to Hunterlab Colorimeter

ObjectivesMeat color is the most important quality attribute that influences consumer purchase decisions. Monitoring color to maximize shelf life and consumer acceptability is routinely used in meat science research. The HunterLab MiniScan EZ (HunterLab) colorimeter is the widely used industry standard for objectively measuring meat color. This device can collect tristimulus values of CIE L* (lightness), a* (redness), and b* (yellowness) for color measurements based on the light reflectance from the meat surface. While the HunterLab colorimeter serves as an accurate measure of meat color, it is relatively expensive and bulky. The Nix Pro Color Sensor (Nix) colorimeter is a less expensive and smaller handheld device that can capture the CIE L*, a*, b* values which can be downloaded to a smartphone app. However, limited research has been performed to compare the efficiency of these colorimeters for measuring beef color. Therefore, the objective of this study was to investigate the capabilities of the Nix colorimeter as an additional resource for objective fresh beef color measurements.Materials and MethodsThe longissimus dorsi muscle from one side of A maturity beef carcasses (n = 200) were evaluated using the HunterLab and Nix colorimeters. Carcasses were allowed approximately 1 h to bloom after being ribbed (between the 12th and 13th rib) prior to color measurements. Three (technical replicate) scans were obtained using the HunterLab colorimeter (illuminant A and 10° standard observer) and the mean readings were recorded. A series of independent technical replication (3, 5, 7, and 9) scans were obtained using the Nix colorimeter with illuminant A and 10° standard observer as well. The differences in color measurements between colorimeters were analyzed by using the Bland Altman Limits of Agreement and CORR (correlation) procedure of SAS with α < 0.05.ResultsCorrelation between the HunterLab and Nix was highest for a* value (redness) with 3 scans (r = 0.85, P < 0.01), followed by 7, 5, and 9 scans (r = 0.84, 0.82, and 0.82, respectively; P < 0.01). Additionally, L* values (lightness) were highly correlated for all the scanning series (r = 0.79–0.81; P < 0.01). Similar to a* values, 3 scans with the Nix for b* values (yellowness) demonstrated the best correlation with HunterLab (r = 0.83; P < 0.01), whereas the 5, 7, and 9 scans were still highly correlated (r = 0.79–0.82; P < 0.01). The Bland Altman Limits of Agreement analysis indicated that the mean difference in a* values using 3 scans of both colorimeters was –1.68, whereas it was –0.91 for L* values and 0.25 for b* values. Moreover, the analysis indicated good agreement between the Nix and the Hunterlab colorimeters for all the color parameters.ConclusionThree replicate scans using the Nix was highly correlated with color measurements using the HunterLab colorimeter and can serve as an acceptable additional resource for objectively measuring beef color. The Nix provides an opportunity for a less expensive, more mobile, and multipurpose device. Although these colorimeters are not equivalent, the Nix could be an adequate method for objective beef color measurements and is comparable to the HunterLab.

Comparison between the effects of torsemide and furosemide on the renin-angiotensin-aldosterone system of normal dogs

INTRODUCTION/OBJECTIVES

We hypothesized that torsemide and furosemide, at approximately equipotent dosages (similar diuresis), would have comparable effects on the circulating renin-angiotensin-aldosterone system.

ANIMALS, MATERIALS AND METHODS

Six, healthy, middle-aged, male Beagles were randomized to receive torsemide (0.1 mg/kg PO q 12 h), furosemide (2.0 mg/kg PO q 12 h), or placebo for 10 days during three separate periods, separated by a 10-day washout period, in a crossover design. Blood was collected on days 1, 5, and 9 and 24-h urine collection ended on days 2, 6, and 10. After repeated measures analysis and Bonferonni correction, variables with an adjusted p<0.05 were investigated further, using Tukey's method.

RESULTS

Twenty-four-hour urine production differed significantly between the diuretics only on day 10, with torsemide causing a 38% greater diuresis than furosemide. There was, however, no significant difference in average 3-day diuresis. There were no significant differences between diuretics in the 24-h urinary excretion of sodium, chloride, or potassium, though furosemide caused less kaliuresis than torsemide. Serum renin, angiotensin II, and aldosterone and the urine aldosterone-to-creatinine ratio were significantly increased in the diuretic groups, as compared to placebo on days 5/6 and 9/10. There were no significant differences in these values between diuretics. Creatinine and blood urea nitrogen concentrations rose comparably in the diuretic groups, remaining within reference intervals in all dogs.

CONCLUSIONS

At approximately equipotent dosages (20:1), torsemide and furosemide produced comparable renin-angiotensin-aldosterone system activation. Torsemide's similar potassium excretion profile to furosemide decreases support for a hypothesized mineralocorticoid-receptor blocking capability.

2163Molecular imaging of cardiac and neuroinflammation early after myocardial infarction and in progressive heart failure

Background/Introduction

Myocardial infarction (MI) triggers local inflammation to support endogenous healing and repair. Recent imaging studies of the macrophage- and microglia-expressed mitochondrial translocator protein (TSPO) identified concurrent neuroinflammation after acute MI and in chronic heart failure. The source of this neuroinflammation and its relationship to cardiac function early and late after MI are unknown.

Purpose

We aimed to characterize the cellular basis of the TSPO PET signal by modulating early inflammation via clodronate-mediated macrophage depletion, and modifying late mitochondrial function using the TSPO inhibitor PK11195.

Methods

C57BL/6 mice underwent permanent coronary artery ligation (n=47) or sham surgery (n=9). Subgroups were treated 24h prior surgery with clodronate liposomes (n=18) to deplete peripheral macrophages or continuously with the cardioprotective TSPO inhibitor PK11195 (n=13). Cardiac and neuroinflammation were evaluated by whole-body PET using the TSPO ligand 18F-GE180 at 1wk, 4wk and 8wk after surgery. Cardiac function and perfusion were assessed by ECG-gated 99mTc-sestamibi SPECT.

Results

Untreated MI mice showed elevated TSPO signal in the infarct territory compared to sham at 1wk post-MI (ID/g, 10.5±2.9 vs 7.2±1.6, p<0.001), and elevated remote myocardial TSPO signal at 8wk (ID/g, 9±1.9 vs 7±1.6, p=0.003). TSPO signal in brain of MI mice was also increased compared to sham at 1wk (ID/g, 2.1±0.3 vs 1.8±0.2, p=0.006) and 8wk (ID/g, 2.0±0.3 vs 1.8±0.2, p=0.033), reflecting neuroinflammation. Clodronate macrophage depletion lowered the infarct territory TSPO signal at 1wk compared to untreated (ID/g, 4.9±1 vs 10.5±3, p<0.001), consistent with lack of peripheral macrophage recruitment. Conversely, brain TSPO remained elevated (ID/g, 2.7±0.3 vs 2.2±0.3, p<0.001), suggesting resident microglial activation as the source of cerebral PET signal. Late signal at 8wk was comparable between clodronate and untreated (p=NS). TSPO inhibition by PK11195 treatment did not affect acute TSPO signal in heart or brain compared to untreated (p=NS). At 8wk, remote myocardial signal was reduced (ID/g, 7.4±1 vs 9.0±2, p=0.040) in parallel with attenuated cardiac dysfunction in PK11195 treated mice (%EF, 49.8±6 vs 37.3±5, p<0.001). Late brain TSPO signal at 8wk was comparable between PK11195 treatment and untreated (p=NS). Consistently, cardiac and brain TSPO signal were proportional (r=0.637, p<0.001), and neuroinflammation was correlated to cardiac function at 8wk after MI (r=−0.345, p=0.005).

Conclusions

Cardiac TSPO signal reflects acute macrophage activity and chronic mitochondrial dysfunction in heart failure. Neuroinflammation derives from resident microglia, and is proportional to cardiac function at late stages. As such, TSPO PET provides insight into inflammation and mitochondrial dysfunction in progressive heart failure, and may guide novel therapies such as cardioprotection via TSPO inhibition.

Comparing the clinical success rate of the dorsolateral approach to the medial approach for injection of the centrodistal joint in the horse

BACKGROUND

Centrodistal joint injection is an important component of lameness evaluation and treatment. Successful injection is poor for the medial approach. The dorsolateral approach is an alternative but has not been validated with contrast medium. Radiograph-guidance has not been studied to determine its necessity or benefit for either approach.

OBJECTIVES

To determine if the dorsolateral approach to the centrodistal joint is more successful than the medial approach. To determine if radiograph-guidance is beneficial.

STUDY DESIGN

Prospective, randomised study.

METHODS

Three operators injected 98 centrodistal joints in total, each horse served as its own control. In Phase 1, injections were performed by standard technique. In the Phase 2, operators were allowed to use radiography to assist needle placement. Contrast deposition was evaluated by a single radiologist.

RESULTS

Without radiographic assistance, 10/25 (40%) joints were successfully injected using either the medial or dorsolateral approach. With radiographic assistance, 19/24 (79%) joints were successfully injected using the medial approach, 11/24 (46%) joints were successfully injected using the dorsolateral approach.

MAIN LIMITATIONS

The population consisted of aged horses representing a variety of breeds with existing osteoarthritis, and multiple operators were recruited.

CONCLUSIONS

The dorsolateral approach was equivalent to the medial approach when traditional injection techniques were used. Radiograph-guidance improved success of the medial approach, but not the dorsolateral approach. Many injections performed from the dorsolateral approach (32/49; 65%) resulted in extensive perivascular subcutaneous contrast deposition after infiltration into the tarsal canal. Further research is needed to improve injection success of the centrodistal joint when using the dorsolateral approach.

Identifying Environmental Risk Factors and Mapping the Distribution of West Nile Virus in an Endemic Region of North America

Understanding the geographic distribution of mosquito-borne disease and mapping disease risk are important for prevention and control efforts. Mosquito-borne viruses (arboviruses), such as West Nile virus (WNV), are highly dependent on environmental conditions. Therefore, the use of environmental data can help in making spatial predictions of disease distribution. We used geocoded human case data for 2004-2017 and population-weighted control points in combination with multiple geospatial environmental data sets to assess the environmental drivers of WNV cases and to map relative infection risk in South Dakota, USA. We compared the effectiveness of (1) land cover and physiography data, (2) climate data, and (3) spectral data for mapping the risk of WNV in South Dakota. A final model combining all data sets was used to predict spatial patterns of disease transmission and characterize the associations between environmental factors and WNV risk. We used a boosted regression tree model to identify the most important variables driving WNV risk and generated risk maps by applying this model across the entire state. We found that combining multiple sources of environmental data resulted in the most accurate predictions. Elevation, late-season humidity, and early-season surface moisture were the most important predictors of disease distribution. Indices that quantified interannual variability of climatic conditions and land surface moisture were better predictors than interannual means. We suggest that combining measures of interannual environmental variability with static land cover and physiography variables can help to improve spatial predictions of arbovirus transmission risk.

[Research consortium Neuroimmunology and pain in the research network musculoskeletal diseases]

BACKGROUND

The research consortium Neuroimmunology and Pain (Neuroimpa) explores the importance of the relationships between the immune system and the nervous system in musculoskeletal diseases for the generation of pain and for the course of fracture healing and arthritis.

MATERIAL AND METHODS

The spectrum of methods includes analyses at the single cell level, in vivo models of arthritis and fracture healing, imaging studies on brain function in animals and humans and analysis of data from patients.

RESULTS

Proinflammatory cytokines significantly contribute to the generation of joint pain through neuronal cytokine receptors. Immune cells release opioid peptides which activate opioid receptors at peripheral nociceptors and thereby evoke hypoalgesia. The formation of new bone after fractures is significantly supported by the nervous system. The sympathetic nervous system promotes the development of immune-mediated arthritis. The studies show a significant analgesic potential of the neutralization of proinflammatory cytokines and of opioids which selectively inhibit peripheral neurons. Furthermore, they show that the modulation of neuronal mechanisms can beneficially influence the course of musculoskeletal diseases.

DISCUSSION

Interventions in the interactions between the immune system and the nervous system hold a great therapeutic potential for the treatment of musculoskeletal diseases and pain.

Comparing brain activity patterns during spontaneous exploratory and cue-instructed learning using single photon-emission computed tomography (SPECT) imaging of regional cerebral blood flow in freely behaving rats

Learning can be categorized into cue-instructed and spontaneous learning types; however, so far, there is no detailed comparative analysis of specific brain pathways involved in these learning types. The aim of this study was to compare brain activity patterns during these learning tasks using the in vivo imaging technique of single photon-emission computed tomography (SPECT) of regional cerebral blood flow (rCBF). During spontaneous exploratory learning, higher levels of rCBF compared to cue-instructed learning were observed in motor control regions, including specific subregions of the motor cortex and the striatum, as well as in regions of sensory pathways including olfactory, somatosensory, and visual modalities. In addition, elevated activity was found in limbic areas, including specific subregions of the hippocampal formation, the amygdala, and the insula. The main difference between the two learning paradigms analyzed in this study was the higher rCBF observed in prefrontal cortical regions during cue-instructed learning when compared to spontaneous learning. Higher rCBF during cue-instructed learning was also observed in the anterior insular cortex and in limbic areas, including the ectorhinal and entorhinal cortexes, subregions of the hippocampus, subnuclei of the amygdala, and the septum. Many of the rCBF changes showed hemispheric lateralization. Taken together, our study is the first to compare partly lateralized brain activity patterns during two different types of learning.

Vergleich der Ergebnisse der Flimmerperimetrie (Prototyp versus kommerziellem Perimeter)

Hintergrund: Analyse der Vergleichbarkeit der Flimmerperimetrie mittels Pulsar-Prototyp vs. des neuen Octopus 600.

Methoden: Es wurde an beiden Augen von 20 Patienten mit einem primär chronischen Offenwinkelglaukom das 30°-Gesichtsfeld mittels Flimmerperimetrie (dynamische Strategie) an den Perimetern Pulsar und Octopus 600 (Haag-Streit) untersucht. Die Auswertung erfolgte anhand des mittleren Defekts (mean deviation = MD) und der Defekttiefe (square root of lost variance = sLV).

Ergebnisse: Im t-Test für verbundene Stichproben ergab die Pulsar-Perimetrie signifikant höhere MD-Werte verglichen mit der Octopus-600-Perimetrie: rechtes Auge MD 4,8 ± 3,6 src vs. 1,7 ± 2,9 src, p = 0,005; linkes Auge MD 3,9 ± 3,6 src vs. 1,4 ± 2,8 src, p = 0,018; beide Augen MD 4,35 ± 3,62 src vs. 1,55 ± 2,80 src, p = 0,002. Auch die sLV-Werte waren am Pulsar-Perimeter signifikant höher als am Octopus-600-Perimeter: rechtes Auge sLV 3,6 ± 1,6 src vs. 2,3 ± 1,3 src, p = 0,006; linkes Auge sLV 3,2 ± 0,8 src vs. 2,0 ± 0,8 src, p < 0,0001; beide Augen 3,37 ± 1,28 src vs. 2,12 ± 1,05 src, p < 0,0001. Die Signifikanzen blieben auch nach Bonferoni-Holm-Korrektur bestehen.

Schlussfolgerung: Die Untersuchungsergebnisse der Flimmerperimeter sind nicht vergleichbar, weil ein signifikanter Unterschied der MD und sLV vorliegt. Ursächlich sind unterschiedliche Leuchtdichten, Hintergrundhelligkeiten und Farbtemperaturen der Perimeter.

Genomewide association of piglet responses to infection with one of two porcine reproductive and respiratory syndrome virus isolates

Porcine reproductive and respiratory syndrome (PRRS) is a devastating disease in the swine industry. Identification of host genetic factors that enable selection for improved performance during PRRS virus (PRRSV) infection would reduce the impact of this disease on animal welfare and production efficiency. We conducted genomewide association study (GWAS) analyses of data from 13 trials of approximately 200 commercial crossbred nursery-age piglets that were experimentally infected with 1 of 2 type 2 isolates of PRRSV (NVSL 97-7985 [NVSL] and KS2006-72109 [KS06]). Phenotypes analyzed were viral load (VL) in blood during the first 21 d after infection (dpi) and weight gain (WG) from 0 to 42 dpi. We accounted for the previously identified QTL in the region on SSC4 in our models to increase power to identify additional regions. Many regions identified by single-SNP analyses were not identified using Bayes-B, but both analyses identified the same regions on SSC3 and SSC5 to be associated with VL in the KS06 trials and on SSC6 in the NVSL trials ( < 5 × 10); for WG, regions on SSC5 and SSC17 were associated in the NVSL trials ( < 3 × 10). No regions were identified with either method for WG in the KS06 trials. Except for the region on SSC4, which was associated with VL for both isolates (but only with WG for NVSL), identified regions did not overlap between the 2 PRRSV isolate data sets, despite high estimates of the genetic correlation between isolates for traits based on these data. We also identified genomic regions whose associations with VL or WG interacted with either PRRSV isolate or with genotype at the SSC4 QTL. Gene ontology (GO) annotation terms for genes located near moderately associated SNP ( < 0.003) were enriched for multiple immunologically (VL) and metabolism- (WG) related GO terms. The biological relevance of these regions suggests that, although it may increase the number of false positives, the use of single-SNP analyses and a relaxed threshold also increased the identification of true positives. In conclusion, although only the SSC4 QTL was associated with response to both PRRSV isolates, genes near associated SNP were enriched for the same GO terms across PRRSV isolates, suggesting that host responses to these 2 isolates are affected by the actions of many genes that function together in similar biological processes.

Contribution of magnetic resonance imaging in lung cancer imaging

Lung cancer is the leading cause of cancer death worldwide. Prognosis and treatment outcomes are known to be related to the disease stage at the time of diagnosis. Therefore, an accurate assessment of the extent of disease is critical to determine the most appropriate therapy. Currently available imaging modalities for diagnosis and follow-up consist of morphological and functional imaging. Morphological investigations are mainly performed with CT-scan and in some cases with MRI. In this review, we describe the contribution of MRI in lung cancer staging focusing on solid pulmonary nodule characterization and TNM staging assessment using chest and whole-body MRI examinations, detailing in each chapter current recommendations and future developments.

Effects of PTH(1-84) therapy on muscle function and quality of life in hypoparathyroidism: results from a randomized controlled trial

The effects of treatment with 100 μg parathyroid hormone (PTH) (1-84) or an identical placebo on muscle function and quality of life (QoL) was studied in hypoparathyroid patients. At baseline, we found reduced QoL but no myopathy in the patients. Six months of treatment did not improve QoL, and muscle strength decreased slightly.

INTRODUCTION

A reduced quality of life (QoL) and myopathy that may be due to the absence of PTH have been reported in patients with hypoparathyroidism (hypoPT).

METHODS

Sixty-two patients with chronic hypoPT were randomized to 6 months of treatment with either PTH(1-84) 100 μg/d s.c. or placebo, given as add-on therapy to conventional treatment. Muscle function and postural stability were investigated using a dynamometer chair, a stadiometer platform, the repeated chair stands test, the timed up and go test, and electromyography. QoL was assessed using the 36-item Short Form Health Survey and the WHO-5 Well-Being Index.

RESULTS

The mean age of the patients was 52 ± 11 years, and 85 % were females. At baseline, QoL was significantly reduced in comparison with norm-based scores. Compared with placebo, PTH did not improve QoL or muscle function. Rather, max force production decreased significantly by 30 % at elbow flexion in the PTH group compared with the placebo group. Moreover, there was a nonsignificant trend for muscle strength to decrease in the upper extremities and on knee extension in response to PTH. Treatment did not affect postural stability. Electromyography showed a slight decrease in the duration of motor unit potentials in the PTH group, indicating a tendency toward myopathy, which, however was not symptomatic.

CONCLUSIONS

Overall, our data do not support an immediate beneficial effect of PTH replacement therapy on muscle function or QoL. A high frequency of hypercalcemia among our patients may have compromised the potential beneficial effects of reversing the state of PTH insufficiency.

Clinical relevance of diffusion tensor imaging parameters in lumbar disco-radicular conflict

PURPOSE

To measure the fractional anisotropy (FA) and the mean diffusivity (MD) values of L4, L5 and S1 nerve roots using diffusion tensor imaging (DTI) and to correlate them with four different clinical patterns.

PATIENTS AND METHODS

Fifty-six human participants were prospectively included and divided between four groups: healthy subjects, patients with clinical symptomatic nerve root pain with and without anatomical discoradicular conflict and patients with incidental anatomical discoradicular conflict seen on magnetic resonance imaging (MRI). MRI protocol included anatomical sequences (sagittal T1- and T2-weighted, axial T2-weighted) and a 25 directions DTI sequence. FA and MD values were measured in consensus by two readers and compared between the four groups.

RESULTS

Mean FA and MD values were significantly different for patients with clinically symptomatic nerve root pain (n=27) both with (n=16) (FA=0.187±0.015; MD=510±40) and without (n=11) (FA=0.193±0.011; MD=490±30.5) anatomical discoradicular conflict compared to healthy subjects (n=29) (FA=0.221±0.011; MD=460.9±35.5) including 2 subjects with incidental anatomical discoradicular conflict (FA=0.211±0.013; MD=450.8±41.2) on MRI (P=0.003).

CONCLUSION

Measurement of FA and MD values of L4, L5 and S1 nerve roots using DTI could be useful in lumbar nerve root pain assessment. Further studies with different image processing methods are needed.

Brain MRI findings in neurologically asymptomatic patients with infective endocarditis

BACKGROUND AND PURPOSE

Neurologic complications in infective endocarditis are frequent and affect patient prognosis negatively. Additionally, detection of asymptomatic lesions by MR imaging could help early management of this condition. The objective of our study was to describe MR imaging characteristics of cerebral lesions in a neurologically asymptomatic population with infective endocarditis.

MATERIALS AND METHODS

One hundred nine patients at the acute phase of a definite or possible infective endocarditis according to the Duke modified criteria and without neurologic manifestations according to the NIHSS were prospectively included. Each patient underwent cerebral MR imaging and MRA within 7 days of admission.

RESULTS

MR imaging showed abnormalities in 78 patients (71.5%). Acute ischemic lesions (40 patients, 37%) and cerebral microbleeds (62 patients, 57%) were the most frequent lesions. Eight patients had an acute SAH, 3 patients had brain microabscesses, 3 had a small cortical hemorrhage, and 3 had a mycotic aneurysm. Acute ischemic lesions mostly appeared as multiple small infarcts disseminated in watershed territories (25/40, 62.5%) and as lesions of different ages (21/40, 52.5%). Cerebral microbleeds were preferentially distributed in cortical areas (362/539 cerebral microbleeds, 67%). No significant correlation was found among lesions, in particular between acute ischemia and cerebral microbleeds.

CONCLUSIONS

Occult cerebral lesions, in particular cerebral microbleeds and acute ischemic lesions, are frequent in infective endocarditis. The MR imaging pattern of acute small infarcts of different ages predominating in watershed territories and cortical cerebral microbleeds may represent a surrogate imaging marker of infective endocarditis.

An assessment of opinion of Indian physicians about emergency medicine in India

BACKGROUND

Emergency medicine (EM) has recently been recognized as a specialty in India and formal training programmes are yet to be developed.

METHODS

A survey was devised to elicit the opinion of recently graduated physicians in Chennai, India about EM as well as about the current state of EM in India. A convenience sample of 130 respondents filled out a 21-question survey.

RESULTS

Ninety-four per cent of respondents stated that EM was essential for providing quality healthcare; 94% of respondents felt there needs to be a change in emergency departments in India, with only 20% stating they were proud of the emergency departments in India. Seventy-six per cent of respondents were more likely to consider EM if the specialty was recognized by the Medical Council of India and 76% were inclined to pursue the specialty if there were more training programmes.

CONCLUSION

Recently graduated physicians found flaws in the current state of emergency care in India; however, overall they remain interested in the field of EM.

Noninvasive magnetic resonance imaging of vessels affected by transplant arteriosclerosis in an experimental mouse aortic allograft model

BACKGROUND

Transplant arteriosclerosis is still the leading cause of late mortality after heart transplantation despite advances in immunosuppression regimes. Experimental mouse models have substantially contributed to a better understanding of the multifactorial pathogenesis, but the major limitation of these studies is the difficulty in monitoring progression of transplant arteriosclerosis over time. Therefore, the aim of this study was to investigate whether MR measurements are sensitive enough to detect characteristic vascular lesions in a small animal transplantation model.

METHODS

For this purpose we investigated 22 iso- and allogeneic aortic graft transplanted mice in vivo with a 4.7 T MR scanner using a 2D-RARE technique, 3D time-of-flight angiography and 3D phase contrast angiography as well as a special snake-based reconstruction algorithm. The MR lumen values of patency from native images and from 3D vessel reconstructions of the respective methods were correlated with conventional histological analysis.

RESULTS

A comparison of the different techniques showed that angiographic MR modalities correlated well with histological measurements. 2D-RARE sequences were inferior to the sequences obtained by other ones. Superior correlations and the most accurate results were found for vessel reconstruction based on 3D angiographic time-of-flight data.

CONCLUSION

These data demonstrate that mouse in vivo MR imaging is sensitive enough to detect and quantify vascular changes caused by transplant arteriosclerosis.