A262 NEONATAL ACUTE LIVER FAILURE DUE TO PRESUMED GESTATIONAL ALLOIMMUNE LIVER DISEASE - A CASE REPORT

Background

Neonatal acute liver failure (NALF) is a rare disease that is distinct from acute liver failure seen in older children and adults. Gestational alloimmune liver disease (GALD) is the most frequent cause, is initiated in utero by sensitization of the maternal immune system to a fetal hepatocyte antigen and subsequent production of maternal immunoglobulin G antibodies that cross the placenta. Maternal IgG binds to a fetal hepatocyte antigen and initiates an innate immune response involving the terminal complement cascade and membrane attach complex. The understanding of the alloimmune origin has led to the use of intravenous immunoglobulin (IVIG) treatment and exchange transfusion, significantly increasing survival. However, approximately 25% of patients may not respond and require salvage liver transplantation. In spite of an increased rate of comorbidities, concern for technical difficulties and limited graft availability, young infants eligible for transplant have been shown to have similar overall patient and graft survival rates compared to older children with other indications for liver transplant.

Purpose

The primary aim of our study is to report a case of NALF with successful liver transplant.

Method

We present the case of a preterm girl with NALF due to GALD refractory to medical management, requiring liver transplantation.

Result(s)

This is a 35-week preterm girl, with scant pre-natal care, birth weight of 1.825 kg and Apgar 9/9. She is the seventh child of non-consanguineous parents, with healthy siblings. On day-of-life (DOL) 1 she presented with acute kidney injury, progressive worsening metabolic acidosis and hyperammonemia and was found to be profoundly coagulopathic (INR 6), with normal liver enzymes and liver failure was diagnosed. Initial investigation ruled out congenital infections, sepsis, neonatal hemophagocytic lymphohistiocytosis and metabolic diseases. Magnetic resonance imaging of the body demonstrated findings in keeping with iron deposition in the thyroid, liver and pancreas, suggestive of GALD. Completed double volume exchange transfusion and IVIG on DOL 9 and repeat IVIG on DOL 13 and 15, with partial improvement in INR. Due to persistent ascites, conjugated hyperbilirubinemia and hyperammonemia she was transferred for urgent liver transplant assessment. Persistent liver dysfunction in the form of hyperammonemia, hypoglycemia and progressive coagulopathy led to transplant listing on DOL 30. ABO incompatible deceased donor liver transplant was completed on DOL 62 (4.075 kg, estimated dry weight 3.5 kg). The procedure was uncomplicated, liver enzymes normalized, coagulopathy and hypoglycemia resolved. She was transferred to the ward on post-operative day (POD) 6. and weaned off sedatives and transitioned to oral feeds within 2 weeks of transplant, with complex abdominal wound closure on POD 29.

Conclusion(s)

Successful liver transplantation is possible in neonates with acute liver failure due to GALD refractory to medical management and weighing 4kg or less.

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Disclosure of Interest

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MICROBIOME & MICROBIAL THERAPY

Work-Related Dermatoses of the Feet in Professional Dancers: A Pilot Study

OBJECTIVE

The feet of professional dancers are exposed to high work-related stresses. To date, data from the professional dance sector concerning this matter are lacking. The aim of this exploratory project was to analyze and evaluate skin health in the foot area with regard to the prevalence of dermatoses, their locations, as well as gender-specific and load-specific differences.

METHODS

Professional classical and neo-classical ballet dancers were examined at two time points: in a phase with increased stress (T0: daily training sessions, rehearsals, and high performance frequency) (n=51, 35 females, 16 males) and after a 24-day rest phase (T1: n=35, 28 females, 7 males). In addition, gender-specific and load-specific (T0 and T1) differences were evaluated.

RESULTS

All professional dancers were affected by skin lesions of the feet at T0. Hyperkeratosis (96.1%), onychomycosis (27.5%), and subungual hematoma (11.8%) were the most frequent dermatoses of the feet of professional dancers. Onychomycosis affected the nails of the big toes in particular (right 15.7%; left 13.7%), and subungual hematomas were found exclusively on the nails of the first toe (right 7.8%; left 7.8%). Women tended to be more frequently affected by hyperkeratosis, men more frequently by onychomycosis. There were no load-specific differences between the stress and rest phases.

CONCLUSION

The prevalence of work-related dermatoses is equally high among female and male dancers. The results can be used for further research and serve as a basis for specific measures of behavioral and environmental prevention in dance.

[Frontal sinus anatomical scanographic study of transgender patients for feminization frontoorbitoplasty surgery]

INTRODUCTION

Little is known about the anatomical elements that allow safe and predictable performance of fronto orbital surgery for facial feminization. The primary objective of this study was to analyze the characteristics (dimensions, pneumatization rate, and anterior wall thickness) of the frontal sinus in MtF transgender patients. The secondary objective was to establish reproducible criteria for CT measurements that could guide preoperative planning of frontal impaction in feminization frontoplasty (FF).

MATERIALS

Fifty preoperative facial mass scans of FF surgery patients were included. The mean age of the operated patients was 34 years. The F line represented the ideal forehead tilt in the absence of a frontal hump.

RESULTS

The height, width, depth, and thickness of the anterior sinus wall were 26.6mm (±5.7), 49.5mm (±11.3), 10.9mm (±3.3), and 3mm (±0.7), respectively. The mean sinus width to skull width ratio was 0.73 (±0.12). Six percent of patients had bilateral frontal sinus agenesis. An osteotomy of the anterior wall of the frontal sinus was performed in the 64% of patients with frontal sinus projection anterior to the F-line. The emergence of the supraorbital nerves from the frontal bone was through a bony notch in 73.8% of cases.

CONCLUSIONS

Knowledge of the anatomy of the frontal sinus and preoperative study of the scans of the facial mass is essential for planning the FF. These characteristics guide the surgical technique of bone remodeling as well as the procedure for releasing the supraorbital nerves.

A multicentre, randomised, double-blind, phase II study to evaluate the tolerability of an induction dose escalation of everolimus in patients with metastatic breast cancer (DESIREE)

BACKGROUND

Stomatitis is one of the main reasons to discontinue everolimus in patients with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (mBC). To decrease stomatitis and subsequently early treatment discontinuations or dose reductions, the DESIREE trial investigated the use of a stepwise dose-escalation schedule of everolimus (EVE esc).

PATIENTS AND METHODS

DESIREE is a phase II, multicentre, randomised, double-blind, placebo-controlled trial in patients with HR+/HER2- mBC and progression/relapse after nonsteroidal aromatase inhibitor treatment. Patients were randomised to EVE esc (2.5 mg/day, week 1; 5 mg/day, week 2; 7.5 mg/day, week 3; 10 mg/day, weeks 4-24) or everolimus 10 mg/day (EVE 10mg) for 24 weeks plus exemestane. The primary endpoint was the incidence of stomatitis episodes grade ≥2 within 12 weeks of treatment. The secondary endpoints included toxicity, relative total dose intensity (RTDI) and quality of life (QoL).

RESULTS

A total of 160 patients were randomised and 156 started treatment (EVE esc: 80; EVE 10mg: 76). The median age of patients was 64 years (range 33-85), 56.3% patients in the EVE esc arm versus 42.1% in the EVE 10mg arm had liver metastasis (P = 0.081) and 62.5% versus 51.3% received over one metastatic therapy line (P = 0.196). Within 12 weeks, the incidence of stomatitis episodes grade ≥2 was significantly lower in the EVE esc arm compared with the EVE 10mg arm (28.8% versus 46.1%; odds ratio 0.47, 95% confidence interval 0.24-0.92; P = 0.026). Toxicity was in line with the known safety profile without new safety concerns. The median RTDI was 91.1% in the EVE esc arm versus 80.0% in the EVE 10mg arm (P = 0.329). Discontinuation rate in the first 3 weeks was 6.3% versus 15.8%, respectively (P = 0.073). QoL was comparable between the two treatment arms.

CONCLUSIONS

A dose-escalation schema of everolimus over 3 weeks can be successfully used to reduce the incidence of high-grade stomatitis in the first 12 weeks of treatment in patients with HR+/HER2- mBC.

TRIAL REGISTRATION

ClinicalTrials.govNCT02387099; https://clinicaltrials.gov/ct2/show/NCT02387099.

Home care provision and nursing home admission after myocardial infarction in relation to cardiogenic shock and out-of-hospital cardiac arrest status

Background

Autonomy is of great importance for quality of life. There is a paucity of data on autonomy for those who survive myocardial infarction (MI) with and without cardiogenic shock (CS) and out-of-hospital arrest (OHCA).

Purpose

To examine the association between CS, OHCA, and need for home care provision or nursing home admission as a proxy for impaired autonomy in a first-time MI population.

Methods

Danish nationwide registries were used to identify patients with first-time MI (2009–2019), who prior to the event were living at home without home care and discharged alive. The patients were stratified according to CS and OHCA status. We report 1-year cumulative incidence of a composite outcome of home care provision or nursing home admission with competing risk of death and as a secondary outcome all-cause mortality. Cause specific Cox regression models were used to estimate adjusted hazard ratios (HR) with patients without CS or OHCA as reference.

Results

We identified 61,451 patients in the period with MI (by groups: −OHCA/−CS: 59,316, −OHCA/+CS: 1,597, +OHCA/−CS: 913, and +OHCA/+CS: 669). The 1-year cumulative incidences of home care/nursing home were 6.9% for patients with −OHCA/−CS, 21.1% for −OHCA/+CS, 5.2% for +OHCA/−CS, and 8.1% for those with +OHCA/+CS. With the −OHCA/−CS as reference, the adjusted HRs for home care/nursing home were 3.12 (95% CI: 2.78–3.49) for patients with −OHCA/+CS, 1.27 (95% CI: 0.95–1.70) for +OHCA/−CS, and 2.31 (95% CI: 1.76–3.03) for +OHCA/+CS (Figure). The 1-year cumulative incidences of mortality were 4.8% for patients with −OHCA/−CS, 10.0% for −OHCA/+CS, 2.8% for +OHCA/−CS, and 3.7% for those with +OHCA/+CS (adjusted HRs: 2.81 (95% CI: 2.55–3.10), 1.09 (95% CI: 0.85–1.39) and 1.81 (95% CI: 1.42–2.30) (Figure 1).

Conclusion

In a selected cohort of patients with MI, without previous need for home care/nursing home and surviving until discharge date, patients with CS were independent of OHCA status associated with less autonomy after discharge with a more than two-fold higher 1-year incidence of home care provision or nursing home admission. Further, patients with CS were associated with a two-fold higher 1-year mortality compared with MI patients without CS independent of OHCA status.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): The work was supported by Rigshospitalets Research Foundation, Master cabinetmaker Sophus Jacobsen and Wife Astrid Jacobsen Foundation, and Director Jacob Madsen and Wife Olga Madsens Foundation. The funding source had no role in the design, conduct, analysis, or reporting of the study.

Dose-dependency of diclofenac's cardiovascular risks: a series of nationwide emulated trials

Background

The dose dependency of the adverse effects of diclofenac remains poorly understood.

Purpose

To examine the dose-related cardiovascular risks associated with diclofenac initiation

Methods

We used Danish nationwide health registries (1999–2018) to conduct a series of emulated trials (n=285). Eligible adults had no recent NSAID fillings, contraindications, or conditions with low adherence. Individuals eligible for inclusion were ≥18 years with (1) ≥90 days continuous prescription records prior to diclofenac initiation (baseline); (2) no NSAID prescriptions ≤90 days before enrollment, and (3) no exclusion criteria. Exclusion criteria reflected likelihood of low adherence to treatment (dementia, schizophrenia, or antipsychotic drug use) and labeled contraindications (ulcer disease/anti-ulcer drugs, gastrointestinal bleeding, inflammatory bowel disease, thrombocytopenia, or heart failure). Initiators of diclofenac were compared to healthcare-seeking non-initiators, but also head-to-head for initiators of high (≥75 mg pills as proxy for ≥150 mg/daily) vs. low dose (≤50 mg pills as proxy for <150 mg/daily). Cox proportional-hazards regression was used to compute the intention-to-treat hazard ratio, as measure of the incidence rate ratio (IRR), of major adverse cardiac and cerebrovascular events (MACCE) within 30 days from initiation.

Results

Among 3,177,484 diclofenac initiatiors, 31% used high and 69% used low dose. Compared with non-initiators, diclofenac initiatiors had a 70% increased rate for MACCE (IRR 1.70, 95% CI: 1.55–1.86), reflecting for the individual MACCE components an increased IRRs of 1.66 (95% CI: 1.54–1.79) for myocardial infaction, 1.32 (1.20–1.45) for ischemic stroke, and 1.69 (1.54–1.86) for cardiac death. The effect for MACCE did not differ between initiators of high (IRR 1.73, 95% CI: 1.51–1.97) and low dose (IRR 1.68, 95% CI: 1.52–1.86) (Figure 1). When comparing high and low dose diclofenac head-to-head, we found no meaningful difference in the IRR for MACCE (1.03, 95% CI: 0.89–1.19), MI (0.99, 0.87–1.11), ischemic stroke (0.95, 0.81–1.11) or cardiac death (1.04, 0.90–1.21) (Figure 2).

Conclusion

Initiation of low- and high-dose diclofenac was associated with a consistent and comparable increase in cardiovascular risk.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Novo Nordisk Foundation

The interaction effect of CHA2DS2-VASc components on ischemic stroke risk after atrial fibrillation: a population-based cohort study

Background

In the European Union, almost nine million individuals 55 years or older had atrial fibrillation in 2010. It is estimated that around a quarter of all ischemic stroke cases in individuals 80 to 89 years can be attributed to atrial fibrillation. The CHA2DS2-VASc is the most commonly used clinical tool to predict ischemic stroke and incorporates congestive heart failure, hypertension, age 75 years or older, diabetes mellitus, previous stroke/transient ischemic attack/systemic embolism, vascular disease, age 65 to 74 years, and female sex. It remains unknown whether the CHA2DS2-VASc components and atrial fibrillation interact biologically, i.e. whether the CHA2DS2-VASc components and atrial fibrillation increase ischemic stroke rate beyond their individual effects.

Purpose

We examined the interaction effect between CHA2DS2-VASc and atrial fibrillation and on ischemic stroke rate.

Methods

We conducted a population-based cohort study of all adult atrial fibrillation or flutter patients from 1996 through 2016 and a one-to-five comparison cohort from the general population. Members of the comparison cohort were matched on year of birth, sex, and the individual CHA2DS2-VASc components. We followed each individual from the index date (the date of atrial fibrillation or date of matching) until the first of ischemic stroke, death from any cause, loss-to follow-up, 10 years follow-up, or 31 December 2016. We calculated ischemic stroke rates per 1,000 person-years (PYs) and interaction contrasts, which is the proportion of the summed ischemic stroke rate of the CHA2DS2-VASc components and atrial fibrillation that is beyond their individual effects.

Results

After one-year follow-up, the ischemic stroke rate per 1,000 PY among individuals with CHA2DS2-VASc score zero was 5.69 (95% confidence interval [CI]: 4.68–6.69) in the atrial fibrillation cohort and 1.86 (95% CI: 1.60–2.12) in the comparison cohort. Among individuals with CHA2DS2-VASc score one, the mortality rate per 1,000 PY increased to 10.9 (95% CI: 9.75–12.0) in the atrial fibrillation cohort and 7.45 (95% CI: 7.01–7.88) in the comparison cohort. The interaction contrast in individuals with CHA2DS2-VASc score one was −0.41 (10.8 − 7.45 − 5.69 + 1.86) indicating that the ischemic stroke rate was not explained by interaction (−0.41 / 10.8 = −3.8%). The interaction effect was −2.75 in individuals with CHA2DS2-VASc score two and −2.79 in individuals with CHA2DS2-VASc score three or higher, again indicating no interaction. Interaction did not explain the ischemic stroke rate after one to five years follow-up either, but did explain 16% of the ischemic stroke rate in individuals with CHA2DS2-VASc score three or higher after five to 10 years follow-up.

Conclusion

Biological interaction between the CHA2DS2-VASc components and atrial fibrillation does not contribute substantially to the ischemic stroke risk.

Funding Acknowledgement

Type of funding sources: None.

Chronic thromboembolic pulmonary hypertension and mortality after venous thromboembolism: a nationwide population-based cohort study

Background

One of the ultimate long-term complications of venous thromboembolism (VTE) is chronic thromboembolic pulmonary hypertension (CTEPH). CTEPH is a condition defined as an increased mean pulmonary arterial pressure of at least 25 mmHg at rest and abnormal pulmonary artery resistance measured by right heart catheterization. To our knowledge, no study has compared mortality in VTE patients developing CTEPH to those who do not.

Purpose

We aimed to investigate the influence of CTEPH on long-term VTE mortality, by examining how receiving any pulmonary hypertension (PH) diagnosis following VTE influenced mortality.

Methods

We conducted a population-based cohort study of all adult Danish patients with an incident in or outpatient VTE diagnosis from 1995 through 2016. We excluded patients with a previous PH diagnosis. We defined CTEPH as receiving any PH diagnosis within two years following VTE. We categorized VTE by type (deep venous thrombosis [DVT] or pulmonary embolism [PE]) and provoking risk factors. We followed patients from two years after VTE until the first of death, emigration, or 31 December 2016. We calculated mortality rates and standardized mortality rate ratios (SMRs) of the association between PH and all-cause mortality and cause-specific mortality due to cancer and cardiovascular diseases. We also stratified the analyses by baseline presence of comorbidity (congestive heart failure, chronic pulmonary disease, and/or interstitial pulmonary disease).

Results

In 89,062 VTE patients alive two years after their VTE, 724 developed PH. The mortality rate per 1,000 person-years was 121 (95% confidence interval [CI]: 110–134) in patients with PH and 48 (95% CI: 47–48) in patients without PH. The SMR was 2.05 (95% CI: 1.77–2.37) for all VTE patients, 2.20 (95% CI: 1.53–3.16) for DVT patients, and 1.72 (95% CI: 1.47–2.01) for PE patients. The SMR was 1.79 (95% CI: 1.28–2.51) in VTE patients with a provoking VTE risk factor and 2.15 (95% CI: 1.83–2.53) in VTE patients without a provoking VTE risk factor. PH was associated with increased cause-specific mortality due to cardiovascular diseases (SMR=2.31, 95% CI: 1.75–3.06), but not cancer (SMR=0.94, 95% CI: 0.64–1.38). The SMR was 2.36 (95% CI: 2.06–2.71) in patients with comorbidity and 1.80 (95% CI: 1.45–2.24) in patients without comorbidity.

Conclusion

Development of PH, as a measure of CTEPH, within two years following incident VTE was associated with two-fold increased mortality in two-year VTE survivors. The increase in mortality was driven by cardiovascular causes.

Funding Acknowledgement

Type of funding sources: None.

Potential of comorbidity indices and CHA2DS2-VASc to predict ischemic stroke and mortality in patients with atrial fibrillation: a validation study

Background

Atrial fibrillation represents a large health burden and increases the risk of ischemic stroke and mortality. A large proportion of atrial fibrillation patients also has other comorbidities. It remains unknown whether comorbidity burden summarized as a comorbidity score can predict ischemic stroke and mortality after atrial fibrillation. In an aging population burdened with comorbidities, it thus has become increasingly important to understand the impact of comorbidity burden on the prognosis of atrial fibrillation.

Purpose

We examined the ability of the Danish Comorbidity Index for Acute Myocardial Infarction (DANCAMI), the Charlson Comorbidity Index (CCI), the Elixhauser Comorbidity Index (ECI), and the CHA2DS2-VASc to predict ischemic stroke and all-cause mortality within one year after atrial fibrillation or flutter.

Methods

We identified all patients with a first-time atrial fibrillation or flutter hospital diagnosis in Denmark from 2000 through 2015 (n=318,939). We identified all comorbidities in each index using hospital diagnoses in the 10 years before diagnosis of atrial fibrillation or flutter. For each comorbidity index, we calculated Harrell's C-Statistic to predict ischemic stroke, all-cause mortality, and cause-specific mortality due to cardiovascular diseases and cancer within one year after atrial fibrillation or flutter. We also calculated hazard ratios of the association of the DANCAMI comorbidities not included in the CCI with ischemic stroke and all-cause mortality within one year after atrial fibrillation or flutter, after conditioning on age, sex, and all CCI comorbidities.

Results

The C-Statistic to predict ischemic stroke was 0.64 (95% confidence interval [CI]: 0.63–0.64) for DANCAMI, 0.63 (95% CI: 0.63–0.64) for CCI, 0.63 (95% CI: 0.63–0.64) for ECI, and 0.64 (95% CI: 0.63–0.64) for CHA2DS2-VASc. The C-Statistic to predict all-cause mortality was 0.74 (95% CI: 0.74–0.75) for DANCAMI, 0.74 (95% CI: 0.73–0.74) for CCI, 0.73 (95% CI: 0.72–0.73) for ECI, and 0.69 (95% CI: 0.69–0.69) for CHA2DS2-VASc. Among the DANCAMI comorbidities not included in the CCI, five predicted increased risk of ischemic stroke (epilepsy, alcohol and drug abuse, schizophrenia, affective disorder, and chronic kidney disease) and eight predicted increased risk of all-cause mortality (coagulopathy, neurodegenerative disorder, epilepsy, alcohol and drug abuse, schizophrenia, affective disorder, chronic kidney disease, and chronic pancreatitis). Compared with all-cause mortality, DANCAMI was better at predicting mortality due to cardiovascular diseases (C-Statistic=0.79, 95% CI: 0.79–0.80) and cancer (C-Statistic=0.78, 95% CI: 95% CI: 0.76–0.80)

Conclusion

In patients with first-time atrial fibrillation or flutter, no comorbidity index predicted ischemic stroke well. However, DANCAMI predicted all-cause mortality on a par with the CCI and the ECI and better than CHA2DS2-VASc.

Funding Acknowledgement

Type of funding sources: None.

Overall survival in the OlympiA phase III trial of adjuvant olaparib in patients with germline pathogenic variants in BRCA1/2 and high risk, early breast cancer

BACKGROUND

The randomized, double-blind OlympiA trial compared 1 year of the oral poly(adenosine diphosphate-ribose) polymerase inhibitor, olaparib, to matching placebo as adjuvant therapy for patients with pathogenic or likely pathogenic variants in germline BRCA1 or BRCA2 (gBRCA1/2pv) and high-risk, human epidermal growth factor receptor 2-negative, early breast cancer (EBC). The first pre-specified interim analysis (IA) previously demonstrated statistically significant improvement in invasive disease-free survival (IDFS) and distant disease-free survival (DDFS). The olaparib group had fewer deaths than the placebo group, but the difference did not reach statistical significance for overall survival (OS). We now report the pre-specified second IA of OS with updates of IDFS, DDFS, and safety.

PATIENTS AND METHODS

One thousand eight hundred and thirty-six patients were randomly assigned to olaparib or placebo following (neo)adjuvant chemotherapy, surgery, and radiation therapy if indicated. Endocrine therapy was given concurrently with study medication for hormone receptor-positive cancers. Statistical significance for OS at this IA required P < 0.015.

RESULTS

With a median follow-up of 3.5 years, the second IA of OS demonstrated significant improvement in the olaparib group relative to the placebo group [hazard ratio 0.68; 98.5% confidence interval (CI) 0.47-0.97; P = 0.009]. Four-year OS was 89.8% in the olaparib group and 86.4% in the placebo group (Δ 3.4%, 95% CI -0.1% to 6.8%). Four-year IDFS for the olaparib group versus placebo group was 82.7% versus 75.4% (Δ 7.3%, 95% CI 3.0% to 11.5%) and 4-year DDFS was 86.5% versus 79.1% (Δ 7.4%, 95% CI 3.6% to 11.3%), respectively. Subset analyses for OS, IDFS, and DDFS demonstrated benefit across major subgroups. No new safety signals were identified including no new cases of acute myeloid leukemia or myelodysplastic syndrome.

CONCLUSION

With 3.5 years of median follow-up, OlympiA demonstrates statistically significant improvement in OS with adjuvant olaparib compared with placebo for gBRCA1/2pv-associated EBC and maintained improvements in the previously reported, statistically significant endpoints of IDFS and DDFS with no new safety signals.

Acute physical-activity related increases in interoceptive ability are not enhanced with simultaneous interoceptive attention

Interoception, the sense of the internal body, is proposed to support self-regulation, and consequently influence mental health. Researchers have therefore shown interest in improving the ability to accurately monitor internal signals (i.e., interoceptive accuracy, IAcc). Research suggests that cardiac IAcc is modifiable by both manipulations of interoceptive attention (guided attention towards the internal body), and interoceptive exposure (strategically inducing somatic signals e.g., via physical activity). Whilst successful in isolation, it is unclear whether a combined approach (i.e., directing attention towards the internal body when signals are more salient) could elicit greater benefits. In a 2 × 2 within-subject design, 48 healthy adults (M_age = 25.98 ± 4.73 years, 50% female) completed four 20-min conditions varying in both attentional focus (interoceptive vs exteroceptive) and physical activity (active vs rest), with cardiac IAcc measured immediately after. Results revealed a main effect for physical activity (p < 0.001), however, there was no effect for attentional focus (p = 0.397), and no interaction effect (p = 0.797). Differential analyses showed that a higher sporting background increased sensitivity to physical activity-related increases in cardiac IAcc (p = 0.031). Findings indicate that (irrespective of attentional focus) moderate-vigorous physical activity-based interventions have the potential to increase cardiac IAcc, with certain individuals potentially benefiting more.

Fully automated machine learning-based selection of optimal bSSFP frequency offset for artifact reduction in cardiac MRI

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Research Support from Siemens Healthineers GmbH.

Background

In bSSFP sequences commonly used for cardiac MRI, signal modulation (e.g. banding artifacts) due to B0 inhomogeneity is often observed, especially at higher field strengths. The spatial position of these artifacts can be shifted by a frequency offset to reduce artifacts in a region of interest (ROI), e.g. the heart. To this end, frequency scout (FS) scans are acquired to visually select the optimal frequency offset [1,2]. In this work, we propose a fully automated image-based system for selecting the optimal frequency offset on FS images based on machine learning.

Methods

The proposed prototype system consists of four main steps (Fig.1). First, a pre-trained deep-learning-based whole heart segmentation network is applied on a four chamber-view FS image to localize the ROI where artifacts should be reduced. Second, high frequency components within the ROI (for each frequency offset in the FS series) are extracted by successive processing of Fourier transformation, high-pass filtering, inverse Fourier transformation and subtraction over series. and N images with the lowest high-frequency content are selected. Third, an adaptive weighting map for each FS image is generated which penalizes signal deviations from a pixel-wise median that is calculated based on the selected images [3]. By averaging the maps and selecting the frame with maximum percentage, the optimal frequency offset is selected.

A total of 38 datasets, acquired on multiple clinical 3T MRI scanners (MAGNETOM Skyra, Vida, Prisma, Lumina; Siemens Healthcare, Erlangen, Germany), were used to evaluate the proposed system. All FS series were annotated manually and used to compare with the system output. The experts were allowed to select multiple possible optimal FS images within a FS series. In case of multiple annotations, the system output was labelled as correct when it selected one of the offsets chosen by the expert. Further, the generated weighting maps were visually evaluated.

Results

The proposed system achieved an accuracy of 92.1% compared to experts’ ground truth annotations. From the failed cases (n=3), the maximum difference was off by 2 frames. Based on the generated weighting maps, a reasonable decision on the selection of the optimal frequency offset is made. The algorithm successfully selects an FS image with minimized banding and flow artifacts within the ROI (Fig. 2a). Further, it reveals that the generated weighting map correctly suppress areas containing artifacts (Fig. 2b).

Conclusions

Initial results demonstrate the feasibility of the proposed system to automatically select the optimal frequency offset on FS scans. Therefore, it can improve the automation of a cardiac MRI workflow. An example of the result of each step