Brain Imaging Research Articles

Tidying up white matter: Neuroplastic transformations in sensorimotor tracts following slackline skill acquisition

AbstractThis study investigated changes in white matter (WM) morphology following complex motor learning, that is, the learning to walk a slackline. A sample of young adults from the general population underwent brain imaging before the slackline intervention, after successful learning, and after a subsequent follow‐up period by applying state‐of‐the‐art measures for the assessment of micro‐ and macrostructural characteristics of WM fiber tracts (voxel‐based and fixel‐based). A randomly assigned control group (CG) was scanned at the same time points of assessment but received no intervention over the study period. Learning to walk a slackline resulted in manifold changes in WM morphology: (1) Whole brain fixel‐based analyses revealed robust increases in the fiber cross‐section in bundles closely associated with sensorimotor functions (e.g., superior longitudinal fasciculi, corticospinal tract); (2) The neurite orientation dispersion and density imaging (NODDI) parameters showed widespread decreases in overlapping fiber bundles. In the CG, no time‐related WM changes were apparent at all. This well‐controlled longitudinal intervention study provides substantial new evidence that learning a complex motor skill modulates fiber organization and fiber density in sensorimotor tracts.

Working memory related functional connectivity in adult ADHD and its amenability to training: A randomized controlled trial

BackgroundWorking memory (WM) deficits are among the most prominent cognitive impairments in attention deficit hyperactivity disorder (ADHD). While functional connectivity is a prevailing approach in brain imaging of ADHD, alterations in WM-related functional brain networks and their malleability by cognitive training are not well known. We examined whole-brain functional connectivity differences between adults with and without ADHD during n-back WM tasks and rest at pretest, as well as the effects of WM training on functional and structural brain connectivity in the ADHD group. MethodsForty-two adults with ADHD and 36 neurotypical controls performed visuospatial and verbal n-back tasks during functional magnetic resonance imaging (fMRI). In addition, seven-minute resting state fMRI data and diffusion-weighted MR images were collected from all participants. The adults with ADHD continued into a 5-week randomized controlled WM training trial (experimental group training on a dual n-back task, n = 21; active control group training on Bejeweled II video game, n = 21), followed by a posttraining MRI. Brain connectivity was examined with Network-Based Statistic. ResultsAt the pretest, adults with ADHD had decreased functional connectivity compared with the neurotypical controls during both n-back tasks in networks encompassing fronto-parietal, temporal, occipital, cerebellar, and subcortical brain regions. Furthermore, WM-related connectivity in widespread networks was associated with performance accuracy in a continuous performance test. Regarding resting state connectivity, no group differences or associations with task performance were observed. WM training did not modulate functional or structural connectivity compared with the active controls. ConclusionOur results indicate large-scale abnormalities in functional brain networks underlying deficits in verbal and visuospatial WM commonly faced in ADHD. Training-induced plasticity in these networks may be limited

Que peut nous apprendre l’étude du métabolisme cérébral en TEP au 18F-FDG du syndrome de Lance-Adams ?

Lance-Adams syndrome, also known as “chronic post-anoxic myoclonus”, is a rare syndrome characterised by intention and action myoclonus following cerebral anoxia, leading to major disability. The cortical or subcortical origin of the myoclonus is still debated. Answering this question would open up new avenues of translational research to gain a better understanding of the pathophysiology of this syndrome and better guide the therapeutic management of patients. In addition to a neurological examination, the initial diagnostic work-up includes a biological work-up, electrophysiological investigations and brain imaging to rule out diGerential diagnoses. Cerebral MRI is the reference imaging technique. In the literature, more than a third of patients have a normal MRI. MRI is used to rule out a vascular cause and to look for atrophy or neuronal damage. Few data are available in the literature on the role of nuclear medicine. To date, 13 cases have been published using 18F-FDG PET and 4 using cerebral perfusion scintigraphy. Abnormalities of cortical and/or subcortical perfusion or metabolism are reported in 65% of cases; they are limited to the neocortex in 23% and aGect the cerebellum in 12% of cases. In this article, we present three patients who underwent cerebral 18F-FDG PET scans for Lance-Adams syndrome with normal MRI. The results of these examinations are discussed and compared with the data found in the literature.

Pushing the limits of MRI brain imaging.

Pushing the limits of MRI brain imaging.

An array of paired folded-end dipoles for whole-brain imaging at 9.4 T

PurposeTo improve transmit B1+ field homogeneity and longitudinal coverage of a human head RF array coil, we developed a novel eight-element transceiver (TxRx) array using composite elements based on paired folded-end dipoles. MethodsThe developed array consisted of eight pairs of coupled folded-end dipoles. Only one dipole in each pair was driven during transmission, while the other was passively coupled with the active one. The distribution of the transmit B1+ field was numerically optimized by changing the overlap between the dipoles and the value of the reactive lumped element placed in the middle of the passive dipole. ResultsThe proposed array of paired folded-end dipoles substantially improved the B1+ homogeneity and longitudinal coverage over the entire brain including the brain stem compared to a single-row folded-end dipole array. The improved whole brain coverage was demonstrated both numerically and experimentally. ConclusionAs a proof of concept, we developed and characterized both numerically and experimentally a prototype of a single-row eight-element 9.4 T array for human brain imaging consisting of composite array elements based on paired passively-coupled folded-end dipoles. The array improved the transmit magnetic field distribution due to the laterally elongated field pattern created by one active and one passive dipole per channel. As a result, the provided coverage was substantially better than that of an 8-element dipole array consisting of long folded-end dipoles. For the first time, an image of the entire human brain at 9.4 T, covering the brain stem up to the fourth vertebra, was obtained using a simple single row eight-element array.

Optimal timing of anticoagulation after acute ischaemic stroke with atrial fibrillation (OPTIMAS): a multicentre, blinded-endpoint, phase 4, randomised controlled trial

The optimal timing of anticoagulation for patients with acute ischaemic stoke with atrial fibrillation is uncertain. We investigated the efficacy and safety of early compared with delayed initiation of direct oral anticoagulants (DOACs) in patients with acute ischaemic stroke associated with atrial fibrillation. We performed a multicentre, open-label, blinded-endpoint, parallel-group, phase 4, randomised controlled trial at 100 UK hospitals. Adults with atrial fibrillation and a clinical diagnosis of acute ischaemic stroke and whose physician was uncertain of the optimal timing for DOAC initiation were eligible for inclusion in the study. We randomly assigned participants (1:1) to early (ie, ≤4 days from stroke symptom onset) or delayed (ie, 7-14 days) anticoagulation initiation with any DOAC, using an independent online randomisation service with random permuted blocks and varying block length, stratified by stroke severity at randomisation. Participants and treating clinicians were not masked to treatment assignment, but all outcomes were adjudicated by a masked independent external adjudication committee using all available clinical records, brain imaging reports, and source images. The primary outcome was a composite of recurrent ischaemic stroke, symptomatic intracranial haemorrhage, unclassifiable stroke, or systemic embolism incidence at 90 days in a modified intention-to-treat population. We used a gatekeeper approach by sequentially testing for a non-inferiority margin of 2 percentage points, followed by testing for superiority. OPTIMAS is registered with ISRCTN (ISRCTN17896007) and ClinicalTrials.gov (NCT03759938), and the trial is ongoing. Between July 5, 2019, and Jan 31, 2024, 3648 patients were randomly assigned to early or delayed DOAC initiation. 27 participants did not fulfil the eligibility criteria or withdrew consent to include their data, leaving 3621 patients (1814 in the early group and 1807 in the delayed group; 1981 men and 1640 women) in the modified intention-to-treat analysis. The primary outcome occurred in 59 (3·3%) of 1814 participants in the early DOAC initiation group compared with 59 (3·3%) of 1807 participants in the delayed DOAC initiation group (adjusted risk difference [RD] 0·000, 95% CI -0·011 to 0·012). The upper limit of the 95% CI for the adjusted RD was less than the non-inferiority margin of 2 percentage points (pnon-inferiority=0·0003). Superiority was not identified (psuperiority=0·96). Symptomatic intracranial haemorrhage occurred in 11 (0·6%) participants allocated to the early DOAC initiation group compared with 12 (0·7%) participants allocated to the delayed DOAC initiation group (adjusted RD 0·001, -0·004 to 0·006; p=0·78). Early DOAC initiation within 4 days after ischaemic stroke associated with atrial fibrillation was non-inferior to delayed initiation for the composite outcome of ischaemic stroke, intracranial haemorrhage, unclassifiable stroke, or systemic embolism at 90 days. Our findings do not support the current common and guideline-supported practice of delaying DOAC initiation after ischaemic stroke with atrial fibrillation. British Heart Foundation.

Functional brain imaging and population-level visits to urban spaces

Functional brain imaging and population-level visits to urban spaces

Headaches in SLE patients: a cross-sectional analysis of clinical, immunological, and Radiological Correlations.

Systemic Lupus Erythematosus (SLE) is a multifaceted autoimmune disorder characterized by diverse clinical manifestations, including a significant prevalence of headaches. This cross-sectional study aimed to thoroughly explore the relationship between SLE and headaches by analysing their prevalence, types, and associated clinical, immunological, and radiological factors. A comparative analysis was conducted on 179 SLE patients, who were categorized into two groups: those with headaches and those without. Data collection encompassed demographic details, disease activity levels, neurological assessments, immunological profiles, and brain imaging results. Headaches were diagnosed and classified following the International Classification of Headache Disorders (ICHD-3). Disease activity was measured using the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). Statistical analyses were performed to identify significant associations and correlations. Headaches were observed in 55% of the SLE patients, predominantly presenting as tension-type headaches (65%) and migraines (27%). Notably, no patients met the criteria for a lupus-specific headache. The Headache Group exhibited significantly higher disease activity (SLEDAI scores). Tension-type and migraine headaches were particularly associated with increased muco-cutaneous manifestations. The presence of antiphospholipid (aPL) antibodies was significantly linked to migraines and cluster headaches. While neurological disorders such as ischemic stroke and venous sinus thrombosis were more prevalent in the Headache Group, these findings were not statistically significant. Brain MRI abnormalities were detected in 9.4% of patients with headaches, including venous sinus thrombosis (2.3%), ischemic stroke (5.8%), and white matter hyperintensities (1.1%). This study underscore es the complex relationship between SLE and headaches, suggesting that headaches may serve as an indicator of heightened SLE disease activity. Immunological factors, particularly aPL antibodies, show a strong association with specific headache types. MRI abnormalities further emphasize the intricate neurobiological aspects in SLE patients experiencing headaches. Continued research is essential to better understand biomarkers, genetic factors, and effective treatment strategies for managing headaches in SLE patients.

Comparative Study on Different Clinical Decision-Making Tools in Pediatric Head Injury Cases

Objective: To carry out a comparative study on effective clinical decision-making tools between Canadian Assessment of Tomography for Childhood Head injury, Pediatric Emergency Care Applied Research Network (PECARN) and Children's Head injury Algorithm for the prediction of Important Clinical Events in pediatrics head trauma cases. Study Design: Validation study. Place and Duration of Study: Department of Surgery, Saif Shaheed Hospital, Haveli Kahota, Azad Kashmir, Pakistan, from Oct 2021 to Nov 2022. Methodology: One hundred and fifty paediatric patients suffering from minor head injury were evaluated on clinical intervention decisions as per emergency procedures during the period of study. Sensitivity, Specificity, Positive Predictive Value and Negative Predictive Value of the selected diagnostic tests was checked. Results: Based on the head CT positivity, PECARN was found to be 81.8% sensitive and 61.9% specific. Canadian Assessment of Tomography for Childhood show sensitivity of 90.9 % and specificity of 65.5%. CHALICE had sensitivity and specificity of 63.6% and 61.5% respectively. CHALICE was unable to identify a pathological CT result with statistical significance (p=0.17) however PECARN and CATCH rule proved significant (p<0.05). CATCH rule show highest positive predictive score of 17.2% and negative predictive score of 98.8%. Conclusion: PECARN, CATCH, and CHALICE criteria are effective in deciding whether or not to perform Computerized Brain Tomography (CBT) scans on children with MHT, leading us to believe that employing these criteria could prevent unnecessary CBT scans.

Update on the Neurobiology of Borderline Personality Disorder: A Review of Structural, Resting-State and Task-Based Brain Imaging Studies.

This review summarizes recent advances in research on the neurobiology of borderline personality disorder (BPD) according to structural brain imaging investigations and resting-state and task-based functional brain activation studies. Extending established findings on differences in regional brain volumes and cortical thickness between BPD and healthy controls, recent research illuminates shared and distinct brain structural characteristics compared to other psychiatric diagnoses, and uncovers relations of these brain structures with transdiagnostic symptoms and clinical features. Resting-state functional brain imaging studies reveal disruptions among adolescents and adults with BPD in frontolimbic and default-mode networks, which primarily underlie affect regulation and self-referential processes, respectively. Recent task-based functional brain imaging research builds on existing neurobiological understanding of emotion and cognition in BPD by revealing novel intersections with interpersonal- and stress-related processes. Studies of psychological and pharmacological interventions suggest possible effects on neural regions underlying emotion processing and behavioral control.

Brain Tumor Detection and Size Estimation using Microwave Imaging

This project focuses on developing an antenna that utilising microwave imaging technology for visualising, detecting, and estimating the size of human tumors using simulation approach. A rectangular microstrip patch antenna is chosen for its advantages of low cost, convenience, efficiency, and compactness, offering a non-ionised alternative. To meet the antenna specifications, rectangular slots are incorporated into the design. The antenna performs effectively at 7.5 GHz, exhibiting a return loss of -24.20383 dB, well below the -10 dB threshold. Placing the antenna 15 mm away from the human brain model results in a specific absorption rate (SAR) value of 0.2 W/kg for 10g, indicating its safety for brain imaging. By scanning a human head phantom with and without a tumor, the antenna captures reflected signals from different locations, enabling the generation of tumour images. A 10-mm-radius tumor is introduced to the phantom, and the unique reflected signal serves as an indicator for tumor detection, using the signal without a tumor as a reference. MATLAB software is employed for image processing, allowing the generation of tumour images and the estimation of tumor size. The simulation results demonstrate 63% accuracy in tumor size estimation. In conclusion, the antenna proves to be a safe and effective brain imaging system for tumor detection.

Altered resting-state connectivity of the auditory cortex in congenital amusia: A functional magnetic resonance imaging study in Mandarin speakers.

Brain imaging studies have reported that the neural deficits of congenital amusia in non-tonal language speakers are mainly in the connectivity between the auditory cortex and the inferior frontal gyrus (IFG) in the right hemisphere. However, the relationship between the functional connectivity (FC) in these regions and the music perception ability of amusia in tonal language speakers remains unclear. In this study, we investigated the FC characteristics of amusia in Mandarin speakers in resting-state functional magnetic resonance imaging data by voxel-wise connectivity analyses with seeds in left and right Heschl's gyri (HG) and region of interest (ROI)-to-ROI connectivity analyses. Our findings indicate increased connectivity between right HG and bilateral posterior superior temporal gyrus, as determined by voxel-wise connectivity analyses in amusia. Conversely, reduced connectivity was observed between bilateral HG and bilateral IFG (orbital part) as assessed through ROI-to-ROI connectivity analyses in amusia when compared to controls. Moreover, the music perception scores of amusia in Mandarin speakers were associated with diminished connectivity between the left HG and the right IFG. This study furnishes direct evidence for the link between music perception deficits and the aberrant frontotemporal connectivity of congenital amusia in tonal language speakers in resting state.

Optimizing Strategies to Prevent Cognitive Decline With 20-Year Brain Imaging

Optimizing Strategies to Prevent Cognitive Decline With 20-Year Brain Imaging

Acceleration of Brain Atrophy and Progression From Normal Cognition to Mild Cognitive Impairment

It remains unclear which risk factors accelerate brain atrophy along with a progression from normal cognition to mild cognitive impairment (MCI). To examine risk factors associated with the acceleration of brain atrophy and progression from normal cognition to MCI based on long-term longitudinal data for middle-aged and older adults. Data for this cohort study were extracted from the Biomarkers for Older Controls at Risk for Dementia (BIOCARD) cohort, initiated at the National Institutes of Health from January 1, 1995, to December 31, 2005, and continued at Johns Hopkins University from January 1, 2015, to October 31, 2023. All participants were cognitively normal at baseline. The participants whose structural magnetic brain imaging (MRI) of the brain and cerebrospinal fluid (CSF) measures were available for over 10 years were included. Longitudinal structural MRI of the brain and measurement of CSF biomarkers for Alzheimer disease pathology (ratio of amyloid β peptide 42 [Aβ42] to Aβ40, tau phosphorylated at threonine 181, and total tau). Annual change rates of segmental brain volumes, Kaplan-Meier survival curves plotting time to event for progression to MCI symptom onset, and hazard ratios (HRs) determined by Cox proportional hazards regression models. A total of 185 participants (mean [SD] age, 55.4 [8.4] years; 116 women [63%]) were included and followed up for a maximum of 27 years (median, 20 [IQR, 18-22] years). The groups with high levels of atrophy in the white matter and enlargement in the ventricles had an earlier progression from normal cognition to MCI symptom onset (HR for white matter, 1.86 [95% CI, 1.24-2.49]; P = .001; HR for ventricles, 1.71 [95% CI, 1.19-2.24]; P = .009). Diabetes was associated with progression to MCI (HR, 1.41 [95% CI, 1.06-1.76]; P = .04), as was a low CSF Aβ42:Aβ40 ratio (HR, 1.48 [95% CI, 1.09-1.88]; P = .04), and their combination had a higher HR of 1.55 (95% CI, 1.13-1.98]; P = .03), indicating a synergic association of diabetes and amyloid pathology with MCI progression. In this cohort study of middle-aged and older adults, higher rates of volume change in the white matter and ventricles, along with the presence of diabetes and a low CSF Aβ42:Aβ40 ratio, were identified as important risk factors for the progression to MCI. These results support the importance of identifying individuals who have accelerated brain atrophy to optimize preventive strategies for progression to MCI.

Linking the evolution of two prefrontal brain regions to social and foraging challenges in primates.

The diversity of cognitive skills across primates remains both a fascinating and a controversial issue. Recent comparative studies provided conflicting results regarding the contribution of social vs ecological constraints to the evolution of cognition. Here, we used an interdisciplinary approach combining comparative cognitive neurosciences and behavioral ecology. Using brain imaging data from 16 primate species, we measured the size of two prefrontal brain regions, the frontal pole (FP) and the dorso-lateral prefrontal cortex (DLPFC), respectively, involved in metacognition and working memory, and examined their relation to a combination of socio-ecological variables. The size of these prefrontal regions, as well as the whole brain, was best explained by three variables: body mass, daily traveled distance (an index of ecological constraints), and population density (an index of social constraints). The strong influence of ecological constraints on FP and DLPFC volumes suggests that both metacognition and working memory are critical for foraging in primates. Interestingly, FP volume was much more sensitive to social constraints than DLPFC volume, in line with laboratory studies showing an implication of FP in complex social interactions. Thus, our data highlights the relative weight of social vs ecological constraints on the evolution of specific prefrontal brain regions and their associated cognitive operations in primates.

Assessing the metabolism of the olfactory circuit by use of 18F-FDG PET-CT imaging in patients suspected of suffering from Alzheimer’s disease or frontotemporal dementia

PurposeThe loss of olfactory function is known to occur in patients suffering from (behavioral variant) frontotemporal dementia ((bv)FTD) and Alzheimer’s disease (AD), although different pathophysiological mechanisms underpin this clinical symptom in both disorders. This study assessed whether brain metabolism of the olfactory circuit as assessed by positron emission tomography (PET) imaging with 2-[fluorine-18]fluoro-2-deoxy-d-glucose ([18F]-FDG) can distinguish these entities in different subsets of patients.MethodsPatients presenting with cognitive decline were included from a prospectively kept database: (1) bvFTD patients, (2) AD patients and (3) patients with logopenic primary progressive aphasia (PPA). Metabolic rates were calculated for different regions of the olfactory circuit for each subgroup and compared with a cohort of subjects with normal brain metabolism. Additionally, in patients with a logopenic PPA pattern on PET-imaging, statistical parametric mapping (SPM) analysis was performed.ResultsThe metabolism of subdivisions of the olfactory circuit as assessed by [18F]-FDG PET brain imaging to bvFTD and AD from control subjects resulted in sensitivity/specificity rates of 95/87.5% and 80/83.3%, respectively. A sensitivity/specificity rate of 100/87.5% was achieved when used to differentiate AD from bvFTD. In patients with the PPA pattern on imaging, the underlying cause (either FTD or AD) could be determined with a sensitivity/specificity rate of 88/82%. SPM analysis concurred that different regions of the olfactory circuit were affected in patients suffering from AD PPA or bvFTD PPA.ConclusionMetabolic dysfunction in the olfactory circuit is different in various neurodegenerative disorders. Further investigation of the correlations between the cerebral metabolism and the mechanisms which drive olfactory dysfunction is needed.

Linking the evolution of two prefrontal brain regions to social and foraging challenges in primates

The diversity of cognitive skills across primates remains both a fascinating and a controversial issue. Recent comparative studies provided conflicting results regarding the contribution of social vs ecological constraints to the evolution of cognition. Here, we used an interdisciplinary approach combining comparative cognitive neurosciences and behavioral ecology. Using brain imaging data from 16 primate species, we measured the size of two prefrontal brain regions, the frontal pole (FP) and the dorso-lateral prefrontal cortex (DLPFC), respectively, involved in metacognition and working memory, and examined their relation to a combination of socio-ecological variables. The size of these prefrontal regions, as well as the whole brain, was best explained by three variables: body mass, daily traveled distance (an index of ecological constraints), and population density (an index of social constraints). The strong influence of ecological constraints on FP and DLPFC volumes suggests that both metacognition and working memory are critical for foraging in primates. Interestingly, FP volume was much more sensitive to social constraints than DLPFC volume, in line with laboratory studies showing an implication of FP in complex social interactions. Thus, our data highlights the relative weight of social vs ecological constraints on the evolution of specific prefrontal brain regions and their associated cognitive operations in primates.

Ex vivo magnetic resonance imaging of the human fetal brain.

The fetal brain undergoes a dynamic process of development during gestation, marked by well-orchestrated events such as neuronal proliferation, migration, axonal outgrowth, and dendritic arborization, mainly elucidated through histological studies. Ex vivo magnetic resonance imaging (MRI) has emerged as a useful tool for 3D visualization of the developing fetal brain, serving as a complementary tool to traditional histology. In this review, we summarized the commonly employed ex vivo MRI techniques and their advances in fetal brain imaging, as well as a standard protocol for postmortem fetal brain specimen collection and fixation. We then provided an overview of ex vivo MRI-based studies on the fetal brain. According to our review, ex vivo T1- or T2-weighted structural MRI has contributed to the characterization of the anatomy of transient neuronal proliferative zones, the basal ganglia, and the cortex. Diffusion MRI related techniques, such as diffusion tensor imaging and tractography, have helped to investigate the microstructural patterns of fetal brain tissue, as well as the early emergence and development of neuronal migration pathways and white matter bundles. Ex vivo MRI findings have shown strong histological correlations, supporting the potential of MRI in evaluating the developmental events in the fetal brain. Postmortem MRI examinations have also demonstrated comparable, and in certain cases, superior performance to traditional autopsy in revealing fetal brain abnormalities. In conclusion, ex vivo fetal brain MRI is an invaluable tool that provides unique insights into the early stages of brain development.

Relative contribution of imaging techniques for the contemporary diagnosis of infective endocarditis: a single-center experience

Abstract Introduction In developed countries, the incidence of infective endocarditis (IE) is up to 6 cases per 100,000 individuals and in-hospital mortality rates are reported to reach 30%. The diagnostic recommendations for IE have been revised in the new ESC guidelines emphasizing the use of transesophageal echocardiography (TEE) and advanced imaging techniques (computed tomography [CT], magnetic resonance [MR], positron emission tomography [PET] and white blood cell scintigraphy [WBC-SPECT]). Aims This research aims to investigate the practical applicability of established clinical guidelines in a real-world population with suspected IE. Methods We reviewed the hospital database from 06/2021 to 06/2023 using the international classification of disease codification (ICD-10) for IE. Only patients admitted to Cardiology or Cardiac Surgery departments were included. Diagnosis of IE was defined according to the modified Duke criteria. Firstly, we identified individuals in whom diagnosis was performed by clinical presentation, blood cultures and transthoracic echocardiogram (TTE). Subsequently, we identified those who required further imaging diagnostic investigation. Results A total of 63 patients were included [mean age 64 ±14 years; 76% male (n=48)]. Native IE was diagnosed in 53 (84%) patients, prosthetic IE in 7 (11%) and cardiac implantable electronic devices-related IE in 3 (5%). A total of 26 (41%) patients had at least one predisposing risk factor, 48 (76%) presented with fever, 24 (38%) suffered an embolic event and 1 (2%) had an immunological phenomenon. Out of 49 positive blood cultures (78%), typical microorganisms consistent with IE were isolated in 25 (78%) of samples: 13 (34%) staphylococcus aureus, 10 (26%) oral streptococci, 9 (24%) enterococcus faecalis, 5 (13%) streptococcus gallolyticus and 1 (3%) HACEK group. Overall, in 22 (34%) patients, a definitive diagnosis of IE was established by means of clinical presentation, blood cultures and TTE. In the remaining, TEE was performed in 86% (n=36). Of those, a definite diagnosis was established in 52% (n=22). Brain and whole-body imaging upgraded the diagnosis from possible to definite in 3 (5%) patients. In the one patient in which a comprehensive clinical evaluation including TTE and TEE rejected IE, the diagnosis was ultimately established by means of PET. The median time from admission to the definite/possible diagnosis of IE was 6 (IQR 2-17) days. A total of 47 (75%) patients underwent surgery, with the most frequent indications being heart failure 46% (n=21) and uncontrolled infection 28% (n=13). Time from diagnosis to surgery was 10 (2-19) days, hospital length of stay was 45 (35-70) days and in-hospital mortality 21%. Conclusion Clinical presentation, blood cultures and TTE plus TEE established the definite or possible diagnosis of IE in most patients with suspected IE. Advanced imaging techniques allowed the establishment of definite diagnosis in only 6% of patients.

Long-term outcomes after transcatheter aortic valve implantation: derivation and validation of the long-TAVI prediction model

Abstract Background Identification of high-risk individuals after transcatheter aortic valve implantation (TAVI) is essential to personalized care. Established risk models require a plethora of variables, fail to account for biomarker dynamics and imaging parameters, mostly focus on the short term, and offer limited predictive performance. Purpose We aimed to develop an easily applicable prediction model for long-term mortality or heart failure (HF) admission following TAVI. Methods Patients undergoing TAVI at a high-volume university centre in the United Kingdom (n = 990) were recruited into a prospective cohort study. Enrolled patients were divided into a development cohort (07/2007 – 12/2016) and a validation cohort (01/2017 – 11/2018) and followed for up to 15.1 (median 5.3, interquartile range [IQR] 2.8 – 7.4) years. Patient characteristics along with pre- and post-procedural imaging results and brain natriuretic peptide (BNP) levels before the procedure and at 3 months were recorded. A clinical risk score for long-term mortality and HF admission (i.e., Long-TAVI risk score) was derived using Cox regression and evaluated using time-dependent area under the receiver operating characteristics curve (AUC). Results Age at presentation was 79.8 (standard deviation [SD] 8.9) years, 961 (99.0%) patients had signs of heart failure, left ventricular ejection fraction was 52 (SD 11.2), and pre-TAVI BNP levels were 298.0 (interquartile range [IQR] 159.0 – 571.5) pg/mL. High BNP levels at presentation (higher vs. lower than 400 pg/mL: HR 1.50, 95% CI 1.17 – 1.92, P < 0.001) and dynamic changes in BNP with the first 3 months (low/high vs. low/low: 2.61, 95% CI 1.17 – 5.86, P = 0.020; high/high vs. low/low: 2.41, 95% CI 1.26 – 4.64, P = 0.008) were independent predictors mortality or HF admission. The simple 8-item Long-TAVI score accounts for periprocedural BNP dynamics and shows good discrimination (AUC 0.76, 95% CI 0.72 – 0.79) and calibration in the development cohort performing similarly well in the external validation cohort (AUC 0.70, 95% CI 0.63 – 0.77). Long-TAVI significantly outperformed the logistic EURO score (AUC 0.56, 95% CI 0.52 – 0.59, P < 0.001). Conclusion Both pre-TAVI BNP levels and periprocedural BNP trajectories are independently associated with long-term outcomes after TAVI. Accounting for clinical characteristics, imaging parameters, and circulating BNP levels, the newly developed Long-TAVI risk score achieves high performance and provides the first prediction model for long-term mortality or HF admission. Long-TAVI represents a novel tool for personalized risk assessment in patients undergoing TAVI.Correlation at baseline A) and FUP B)Score performance A) and risk groups B)