Safety of same day discharge after atrial fibrillation ablation

Background

Atrial fibrillation (AF) ablation is an outpatient procedure with traditionally an overnight hospital observation (OHO). Recently, there has been a trend towards same day discharge (SDD).

Purpose

Compare AF ablation procedure safety outcomes with SDD vs. OHO.

Methods

We reviewed consecutive AF procedures performed from January 2013 to June 2021 at a single academic center. Patients underwent OHO until June 2020, after which patients had SDD whenever feasible. Adverse events were assessed at three months, which included pericardial effusion, pericarditis, post-procedure hypotension, embolic events, and vascular complications. We also assessed emergency department (ED) visits and procedure-related hospital admissions.

Results

There were 1254 patients who underwent 1575 AF ablations. 1440 patients underwent OHO and 135 had SDD. Mean age was 62.2 years, BMI 33 kg/m2, 65% were male, and 27.6% had persistent AF, without significant differences in baseline characteristics between OHO and SDD. We found that SDD was not associated with increased complications (OHO 0.20% v. SDD 0.49%; p>0.05), ED visits, or hospital admissions (2% v. 5%; p>0.05) (Figure 1, 2). There were no gender or age-related disparities in all outcomes (p>0.05).

Conclusion

SDD protocol after AF ablation is feasible and not associated with higher incidence of complications, ED visits, and procedure-related hospitalizations.

Funding Acknowledgement

Type of funding sources: None.

Race disparities in atrial fibrillation detection using implantable loop recorder for cryptogenic stroke

Background

Cryptogenic stroke represents about 25–30% of all ischemic strokes. Continuous electrocardiographic monitoring using implantable loop recorder (ILR) can detect asymptomatic and undiagnosed atrial fibrillation (AF).

Purpose

To assess patient-specific factors in ILR implantation and AF detection in patients with cryptogenic strokes.

Methods

We retrospectively reviewed 379 patients with cryptogenic stroke indicated for ILR implantation, from January 2017 to June 2021 at our university hospital. We evaluated patient demographic and clinical characteristics to assess the risk factors associated with higher incidence of AF detection, using logistic regression models.

Results

Of the 379 ILRs implanted, 60.4% were males with 71.2% Caucasian, mean age 67.6 years, and mean BMI 28.5. The mean CHADSVASC score of 3.9 at the time of ischemic stroke. These patients had prior diagnosis of diabetes mellitus (27.4%), hypertension (65.7%), chronic kidney disease (19.5%), coronary artery disease (20%) and congestive heart failure (2%). Of the entire cohort, AF was diagnosed in 16% of patients with 14 months mean follow up. There were more females diagnosed with AF on ILR (20% v. 18.7%, p>0.05). Caucasians were more likely to have AF detected compared to non-Caucasians (OR 2.3, 95% CI, p<0.02). There were 52 patients with mobile cardiac outpatient telemetry (MCOT) before having ILR implantation. AF was not detected on MCOT, but 15% were diagnosed with AF with ILR monitoring. In univariate analysis, increasing age is strongly associated with the detection of AF (p=0.03).

Conclusions

There continues to exist race disparities in ILR implantation and eventual AF detection, leading to further socioeconomic health disparities. ILR should be considered especially in elderly with cryptogenic stroke given the higher incidence of AF detection.

Funding Acknowledgement

Type of funding sources: None.

Cardiovascular structure and function assessed by MRI in healthy South Asians compared to White Europeans: a UK Biobank study

Background

There is limited data on ethnic specific comparisons for measures of cardiovascular structure and function in healthy cohorts. Echocardiographic data indicate South Asian's (SAs) have smaller mass and evidence of more concentric remodelling compared to White Europeans (WEs). Furthermore, there is no data published for strain or strain rates.

Purpose

To compare Cardiac Magnetic Resonance (CMR) derived measures of structure and function between age and sex matched healthy SAs and WEs from the UK biobank cohort.

Methods

South Asian and WE participants from the UK Biobank who underwent CMR imaging were included. Individuals with a history of cardiovascular disease, hypertension, obesity (BMI ≥30 kg/m2 in WEs and ≥27 kg/m2 in SAs) and diabetes were excluded. Ethnic groups were matched according to age and sex at recruitment. Cine images (bSSFP) were analysed blinded to participant details using commercially available software. Left ventricular (LV) mass, LV volumes, global longitudinal and circumferential systolic strain (GLS and GCS), together with peak early diastolic strain rates (PEDSR), were obtained. Data distributions were assessed and T-Test or Man Whitney U conducted as appropriate.

Results

Datasets from the UK biobank were screened (n=45000). After applying exclusion criteria, 111 pairs of matched SAs and WEs were available for analysis (n=69 male and n=42 female matched pairs). Mean age of the entire cohort was 58±8 years. Data has been corrected according to body surface area (BSA),(males: WE 2.0±0.1 vs SA 1.8±0.1 m2, p≤0.001; females: WE 1.7±0.2 vs SA 1.6±0.1 m2, p≤0.001). There was no difference in heart rate (males: WE 64.5±9.3 vs SA 65.8±9.6 bpm, p=0.113; females: WE 66.2±7.8 vs SA 69.5±10.3 bpm, p=0.125). Results by sex and ethnicity are displayed in table 1. In males there was no difference in ejection fraction (EF) or indexed LV end diastolic volume (LVEDV). However indexed mass and mass/volume ratio were significantly lower in SAs, and GLS but not GCS was significantly higher than in SAs. Longitudinal PEDSR were significantly higher in SAs than in WE. By contrast, SA females had significantly lower EF with no difference in indexed LVEDV compared to WE females. However, as seen with the males SA females had significantly lower indexed LV mass and mass/volume ratio compared to WE females. Finally, both GLS and GCS were significantly higher in SAs compared to WE females, whereas there was no difference in longitudinal PEDSR.

Conclusion

Substantial differences in cardiovascular structure and function exist between SA and WE ethnic groups, in both men and women. Contrary to previous echocardiographic studies, LV volumes were similar between ethnicities and SA have less, not increased, concentric remodelling than WE. These findings highlight the need for ethnicity and sex-specific healthy reference ranges derived from CMR.

Funding Acknowledgement

Type of funding sources: None.

Effect of defibrillator on long term all-cause mortality in patients with chronic kidney disease: an updated meta-analysis

Background

The beneficial role of implantable defibrillator (ICD) in patients with chronic kidney disease (CKD) is less understood as this population is often not well represented in clinical trials.

Purpose

Evaluate the effect of ICD use in patients with CKD on long term outcomes.

Methods

Literature search was conducted for studies reporting the effect of ICD on all-cause mortality in patients with CKD, which is defined as glomerular filtration rate (GFR) <60 mL/min. The search was not restricted to time or publication status. The search included the following databases: Ovid MEDLINE, EMBASE, Scopus, Web of Science, Google Scholar, and EBSCO CINAHL. The minimum duration of follow-up required for inclusion was one year.

Results

The literature search identified 834 studies, of which 14 studies with 70,661 patients were included. Mean follow up was 39 months (12–81 months). For all patients with CKD, ICD was associated with lower all-cause mortality (log HR −0.247, SE 0.101, p=0.015); Heterogeneity: df=13 (P<0.01), I2=97.057; Test for overall effect: Z=−2.431 (Figure 1). When further stratified based on dialysis, CKD patients without the need for dialysis had favorable outcome (log HR −0.211, SE 0.095, p=0.026); Heterogeneity: df=6 (P<0.01), I2=70.146; Test for overall effect: Z=−2.225, whereas ICD implantation in CKD patients requiring dialysis was not associated with mortality benefit (log HR −0.262, SE 0.134, p=0.051) (Figure 2A, B).

Conclusion

ICD implantation is associated with mortality benefit in patients with CKD, but this association is not present for patients requiring dialysis.

Funding Acknowledgement

Type of funding sources: None.

Association of late-gadolinium enhancement in cardiac magnetic resonance with ventricular arrhythmias and mortality in patients with non-ischemic cardiomyopathy

Background

Late-gadolinium enhancement (LGE) in cardiac magnetic resonance (CMR) is a predictor of adverse events such as cardiovascular mortality, cardiovascular related hospitalization and defibrillation shocks in patients with non-ischemic cardiomyopathy (NICM). The correlation between LGE and ventricular arrhythmia and mortality has not been completely established.

Purpose

This meta-analysis assessed the relationship between LGE in CMR with ventricular arrhythmias: sustained, non-sustained and ICD therapy; and mortality in patients with NICM.

Methods

Databases were queried for studies reporting the association between LGE in CMR in NICM and ventricular arrhythmias and mortality, including Ovid MEDLINE, EMBASE, Web of Science, and Google Scholar. The search was not restricted to time or publication status. The minimal follow up duration was one year.

Results

A total of 46 studies and 10,548 patients (4,610 with LGE vs 5,938 without LGE) were included; mean follow up was 3 years (ranging between 13 to 71 months) and mean left ventricular ejection fraction 33%. LGE in NICM was associated with increased risk of ventricular arrhythmias and sudden cardiac death (odds ratio 4.595, 95% confidence interval 3.54–5.97; P<0.01) and mortality (odds ratio 2.949, 95% confidence interval 2.285–3.806; P<0.01). Heterogeneity is low to moderate: χ2=82.2, df =45 (P=0.001), I2=45% (Figures 1, 2).

Conclusions

Our results suggest that LGE is associated with increased risk of ventricular arrhythmias, sudden cardiac death and mortality in long-term follow up. These results further substantiate the need for larger prospective randomized trials using LGE to decide ICD indication regardless of EF. There are two ongoing trials testing this indication: CMR-ICD and CMR-GUIDE.

Funding Acknowledgement

Type of funding sources: None.

Does body mass index affect atrial fibrillation ablation outcomes

Background

There are conflicting reports in the literature regarding whether body-mass index (BMI) influences the success and procedural complication rates of atrial fibrillation (AF) ablation.

Purpose

To determine if differences in BMI affect AF ablation outcomes

Methods

At a single academic center, AF ablation procedures were reviewed from 2013 to 2021. Primary outcomes were AF recurrence (after a 90 day blanking period), procedure-related complications, emergency department visits or hospital admission (ED/HOSP). Patients had a minimum of 6 months follow-up

Results

We analyzed 1569 AF ablation consecutive procedures (1093 de novo, 476 repeat ablation) using either radiofrequency or cryoablation. The study population was 65% male with a mean age 62 years, with 28% persistent AF. BMI was separated into three cohorts: <25 kg/m2 (N=218), 25–30 kg/m2 (N=547), and >30 kg/m2 (N=804). There were no significant differences in the type of AF, left atrial diameter, or left ventricular ejection fraction in the BMI subgroups. There was a direct relationship between the prevalence of co-morbid conditions and increasing BMI: hypertension (49.1%, 59.9%, 60.2%; p 0.04), diabetes (6.4%, 13.5%, 21.3%; p 0.01), and obstructive sleep apnea (5.5%, 10.8%, 26.7%; p<0.01). There were no significant differences in AF recurrence, procedural complications or ED/HOSP among the BMI cohorts (p>0.05) (Figure 1). No gender related disparities were noted in outcomes (p>0.05).

Conclusion

Higher BMI was not associated with AF recurrence, complications, or ED/HOSP after AF ablation despite a higher prevalence of comorbid medical conditions

Funding Acknowledgement

Type of funding sources: None.

Inter-field strength agreement of cardiovascular magnetic resonance cine-derived strain and strain rate measures: a randomised study

Background

Left ventricular (LV) strain and strain rate measurements can be derived from routinely acquired cardiovascular magnetic resonance (CMR) cine images by feature tracking techniques. However, the inter-field strength agreement of strain measurements derived from these techniques is not known. We hypothesised that there would be excellent inter-field strength agreement (between 1.5 and 3 Tesla [T]) for the measurement of global strain and strain rate derived from cine imaging.

Methods

Prospective, randomised cross-over observational study. Healthy volunteers each underwent CMR scans at 1.5T and 3T within 30 minutes on the same day in a randomised order. Retrospectively ECG gated, short and long-axis balanced steady state free precession cine images were obtained using standardised acquisition parameters at both field strengths. Two software packages were used to derive LV global longitudinal, circumferential and long and short axis radial systolic strain, peak systolic, early diastolic and late diastolic strain rates. All strain values are expressed as positive numbers.

Results

Twenty-two subjects (mean age 36±12 years; 45% male) were studied. No differences in heart rate and blood pressure measurements during scanning were observed between field strengths. The abstract figure shows an example of strain analysis and Bland-Altman plots for global longitudinal and circumferential strain. Minimal bias was seen in all strain and strain rate measurements between field strengths using the first software package. Strain and strain rate values derived from long axis images (longitudinal and long axis radial) showed poor to fair agreement (intraclass correlation co-efficient (ICC) range 0.39–0.71), whereas measures derived from short axis images (circumferential and short axis radial) showed good to excellent agreement between field strengths (ICC range 0.78–0.91). Similar results were observed with the second software package, though the differences in agreement between long and short axis derived measures were less pronounced.

Conclusion

Longitudinal strain and strain rate measures derived from CMR feature tracking have poor inter-field strength agreement between 1.5T and 3T. By contrast, agreement of circumferential and short axis radial strain and strain rate measurements at 1.5T and 3T is good. These results need to be considered when assessing strain at different field strengths.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): United Kingdom National Institute for Health Research

Impaired myocardial calcium handling in people with type 2 diabetes: an in vivo manganese-enhanced magnetic resonance imaging study

Background

There is a high prevalence of subclinical cardiac dysfunction in people with type 2 diabetes (T2D) which is associated with subsequent development of heart failure. Dysregulated myocardial calcium handling has been demonstrated in animal models of T2D and may be a key mechanism driving the development of heart failure. Manganese-enhanced cardiac magnetic resonance imaging (MEMRI) provides a unique method to assess in vivo myocardial calcium handling.

Purpose

To determine whether myocardial calcium handling is perturbed in people with T2D with no history of cardiovascular disease. We hypothesised that myocardial manganese uptake would be reduced in people with T2D compared with healthy volunteers.

Methods

Cross-sectional case-control study, adults with (n=20) and without (n=9) T2D underwent both gadolinium-enhanced MRI and MEMRI. Standard gadolinium-enhanced MRI was used to assess cardiac structure, function and tissue characteristics. MEMRI scans were performed within two weeks of the initial scan. Native T1 maps were obtained in the mid-short axis slice position using a Modified Look-Locker Inversion recovery sequence. An intravenous infusion of manganese dipyridoxyl diphosphate (5 μmol/kg (0.1 mL/kg) at 1 mL/min) was administered and T1 maps at the same location were repetitively acquired every 2.5 min for 30 min. Regions of interest were drawn in the inferoseptal segment and blood pool for all T1 maps from 0 to 30 min by a single observer. The primary outcome was the rate of manganese uptake which was assessed by Patlak modelling as a measure of myocardial calcium handling. Manganese uptake constants were compared using analysis of co-variance, with age, sex and body mass index as co-variates.

Results

Subjects with T2D were older (62±7 vs. 57±5 years, p=0.046) but body mass index (29.0±4.5 vs. 26.2±3.4 kg/m2, p=0.106), systolic (135±16 vs. 134±17 mmHg, p=0.809) and diastolic (81±10 vs. 83±9 mmHg, p=0.736) blood pressures were similar. Compared to control subjects, participants with T2D had normal systolic function but more concentric left ventricular remodelling (mass/volume ratio 0.90±0.14 vs. 0.71±0.06 g/mL, p<0.001) and reduced peak early diastolic strain rate (0.64±0.17 vs. 0.91±0.26 s–1, p=0.002). Myocardial manganese uptake was substantially reduced in people with T2D compared with controls (6.51±1.46 vs. 8.45±2.52 ml/100 g of tissue/min, p=0.003) (Figure 1).

Conclusions

For the first time, we have demonstrated in vivo that despite no history of cardiovascular disease and normal systolic function, patients with T2D have marked impairment of myocardial calcium handling. This has potential major implications for the pathogenesis, diagnosis and treatment of diabetic cardiomyopathy.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): British Heart Foundation and National Institute for Health Research

The influence of anastomotic techniques on postoperative anastomotic complications: Results of the Oesophago-Gastric Anastomosis Audit

BACKGROUND

The optimal anastomotic techniques in esophagectomy to minimize rates of anastomotic leakage and conduit necrosis are not known. The aim of this study was to assess whether the anastomotic technique was associated with anastomotic failure after esophagectomy in the international Oesophago-Gastric Anastomosis Audit cohort.

METHODS

This prospective observational multicenter cohort study included patients undergoing esophagectomy for esophageal cancer over 9 months during 2018. The primary exposure was the anastomotic technique, classified as handsewn, linear stapled, or circular stapled. The primary outcome was anastomotic failure, namely a composite of anastomotic leakage and conduit necrosis, as defined by the Esophageal Complications Consensus Group. Multivariable logistic regression modeling was used to identify the association between anastomotic techniques and anastomotic failure, after adjustment for confounders.

RESULTS

Of the 2238 esophagectomies, the anastomosis was handsewn in 27.1%, linear stapled in 21.0%, and circular stapled in 51.9%. Anastomotic techniques differed significantly by the anastomosis sites (P < .001), with the majority of neck anastomoses being handsewn (69.9%), whereas most chest anastomoses were stapled (66.3% circular stapled and 19.3% linear stapled). Rates of anastomotic failure differed significantly among the anastomotic techniques (P < .001), from 19.3% in handsewn anastomoses, to 14.0% in linear stapled anastomoses, and 12.1% in circular stapled anastomoses. This effect remained significant after adjustment for confounding factors on multivariable analysis, with an odds ratio of 0.63 (95% CI, 0.46-0.86; P = .004) for circular stapled versus handsewn anastomosis. However, subgroup analysis by anastomosis site suggested that this effect was predominantly present in neck anastomoses, with anastomotic failure rates of 23.2% versus 14.6% versus 5.9% for handsewn versus linear stapled anastomoses versus circular stapled neck anastomoses, compared with 13.7% versus 13.8% versus 12.2% for chest anastomoses.

CONCLUSIONS

Handsewn anastomoses appear to be independently associated with higher rates of anastomotic failure compared with stapled anastomoses. However, this effect seems to be largely confined to neck anastomoses, with minimal differences between techniques observed for chest anastomoses. Further research into standardization of anastomotic approach and techniques may further improve outcomes.

Response to Chemical Pleurodesis in Children with Frequent Relapsing Nephrotic Syndrome Having Refractory Unilateral Pleural Effusion

Idiopathic nephrotic syndrome is one of the most common chronic renal disorders in children. Associated bilateral pleural effusion is common due to the transudative process as a result of hypoalbuminemia. However, unilateral pleural effusion is a rare phenomenon and at times, unresponsive even when the patients are in remission. Here, we report two cases of frequent relapse nephrotic syndrome presented as persistent unilateral pleural effusion responsive to chemical pleurodesis, which was done with bleomycin along with normal saline.

Oral health status and absence from school among 12 year olds

OBJECTIVE

To assess dental caries, periodontal status, malocclusion and absenteeism from school among 12-year-olds in Bhopal district, Central India.

MATERIALS AND METHODS

Two-stage random sample of 1238 school children. Decayed missing filled teeth (DMFT), Significant caries index (SiC), community periodontal index (CPI) and dental aesthetic index (DAI) were used to record dental caries, periodontal status and malocclusion. Information on absence from school in the previous year due to pain/discomfort in the teeth or mouth was collected via interviews. Generalized structural equation modelling (GSEM) examined the direct and indirect predictors of absence from school.

RESULTS

A total of 39.1%, 17.3% and 23.9% of children had dental caries, calculus and gingival bleeding respectively. Mean DMFT and SiC scores were 1.82± 1.36 and 3.15 ± 1.47. 5,127 school hours were missed due to oral health problems per 1,000 children. None of the studied variables predicted absence from school. Utilization of dental care was associated directly with gender and malocclusion (p⟨ 0.001). Periodontal status was associated with male gender, nuclear families, tobacco consumption, and malocclusion (p⟨ 0.001). Higher DMFT was associated with male gender, malocclusion and experience of pain/discomfort (p⟨ 0.001).

CONCLUSIONS

Poor oral health and a high prevalence of untreated dental caries were noted. Despite a considerable number of missed school hours reported due to dental conditions, none of the studied variables predicted absence from school.

Burden of osteoarthritis in India and its states, 1990-2019: findings from the Global Burden of disease study 2019

OBJECTIVE

To describe the burden of osteoarthritis (OA) in India from 1990 to 2019.

DESIGN

Data from Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 were used. The burden of OA -knee OA, hip OA, hand OA, and other OA- was estimated for India and its states from 1990 to 2019 through a systematic analysis of prevalence, incidence, years lived with disability (YLD), and disability-adjusted life years (DALY) using methods reported in GBD 2019 study.

RESULT

Around 23.46 million individuals in India had OA in 1990; this increased to 62.35 million in 2019. The age-standardised prevalence of OA increased from 4,895 (95% uncertainty interval (UI):4,420-5,447) in 1990-5313 (95%UI:4,799-5,898) in 2019, per 100,000 persons. Similarly, DALYs due to OA increased from 0.79 million (95%UI:0.40-1.55) to 2.12 million (95%UI:1.07-4.23); while age-standardised DALYs increased from 164 (95%UI:83-325) to 180 (95%UI:91-361) per 100,000 persons from 1990 to 2019. OA was the 20^th most common cause of YLDs in India in 2019, accounting for 1.48% (95%UI:0.88-2.78) of all YLDs; increasing from 23rd most common cause in 1990 (1.25%(95%UI:0.74-2.34)). Knee OA was the most common form of OA, followed by hand OA. The prevalence, incidence, and DALYs for OA and knee OA were consistently higher in females than males.

CONCLUSION

The burden and impact of OA in India are substantial and is increasing. Adopting suitable control and preventive community measures to reduce modifiable risk factors (obesity, injuries, occupational stress) are needed to reduce the current and future burden of OA in India.

Primary pulmonary synovial sarcoma: A clinicopathological study of 22 cases

INTRODUCTION

Primary pulmonary synovial sarcoma (PPSS) is a rare mesenchymal tumour with characteristic translocation SS18-SSX1/2/rarely 4 fusion transcripts, and presents most often in adolescents and young adults. According to the World Health Organization (WHO) classification, synovial sarcoma is a malignant tumour of uncertain differentiation.

AIMS

To present a case series of PPSS with clinical, pathological and molecular analysis at a rare primary site.

SETTING AND DESIGN

Retrospective study conducted in a tertiary care hospital.

MATERIALS AND METHODS

Twenty-two cases of PPSSs were retrieved from electronic database between January 2009 to December 2018. Metastatic tumours from soft tissue primaries were excluded. Immunohistochemistry (IHC) and reverse transcription polymerase chain reaction (RT-PCR) were performed. Statistical analysis was performed using Mann-Whitney non-parametric test.

RESULTS

Among 22 patients, the male-female ratio was 3.4:1 and the median age was 31.5 years. The tumours were classified as monophasic (90.9%) and biphasic (9.1%) subtypes and graded as grade 2(77.3%) and grade 3(22.7%). IHC demonstrated expression of TLE1 (17/17 cases), Bcl-2 (7/8 cases), focal EMA (16/17 cases), CD99 (10/11 cases), focal pancytokeratin (8/12 cases) and CD56 (14/14 cases). The fusion transcripts included SYT-SSX1(4/11, 36.4%) and SYT-SSX2 (2/11, 18.2%). The remaining five cases were negative for SS18 rearrangement by RT-PCR. Only 8 patients had localised tumour. Surgical excision was performed in 5 patients. The median follow-up period was 6 months and 21 days.

CONCLUSIONS

Monophasic SS was the most common subtype. Small core biopsies pose a diagnostic challenge, in such a scenario, a combination of clinical, histomorphological, immunomarkers and genetic studies help confirm the diagnosis of PPSS.

Search for Resonances Decaying to Three W Bosons in Proton-Proton Collisions at sqrt[s]=13 TeV

A search for resonances decaying into a W boson and a radion, where the radion decays into two W bosons, is presented. The data analyzed correspond to an integrated luminosity of 138  fb^{-1} recorded in proton-proton collisions with the CMS detector at sqrt[s]=13  TeV. One isolated charged lepton is required, together with missing transverse momentum and one or two massive large-radius jets, containing the decay products of either two or one W bosons, respectively. No excess over the background estimation is observed. The results are combined with those from a complementary channel with an all-hadronic final state, described in an accompanying paper. Limits are set on parameters of an extended warped extra-dimensional model. These searches are the first of their kind at the LHC.

Probing Charm Quark Dynamics via Multiparticle Correlations in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

Multiparticle azimuthal correlations of prompt D^{0} mesons are measured in Pb-Pb collisions at a nucleon-nucleon center-of-mass energy of sqrt[s_{NN}]=5.02  TeV. For the first time, a four-particle cumulant method is used to extract the second Fourier coefficient of the azimuthal distribution (v_{2}) of D^{0} mesons as a function of event centrality and the D^{0} transverse momentum. The ratios of the four-particle v_{2} values to previously measured two-particle cumulant results provide direct experimental access to event-by-event fluctuations of charm quark azimuthal anisotropies. These ratios are also found to be comparable to those of inclusive charged particles in the event. However, hints of deviations are seen in the most central and peripheral collisions. To investigate the origin of flow fluctuations in the charm sector, these measurements are compared to a model implementing fluctuations of charm quark energy loss via collisional or radiative processes in the quark-gluon plasma. These models cannot quantitatively describe the data over the full transverse momentum and centrality ranges, although the calculations with collisional energy loss provide a better description of the data.

Vessel wall magnetic resonance and arterial spin labelling imaging in the management of presumed inflammatory intracranial arterial vasculopathy

Optimal criteria for diagnosing and monitoring response to treatment for infectious and inflammatory medium–large vessel intracranial vasculitis presenting with stroke are lacking. We integrated intracranial vessel wall MRI with arterial spin labelling into our routine clinical stroke pathway to detect presumed inflammatory intracranial arterial vasculopathy, and monitor disease activity, in patients with clinical stroke syndromes. We used predefined standardized radiological criteria to define vessel wall enhancement, and all imaging findings were rated blinded to clinical details. Between 2017 and 2018, stroke or transient ischaemic attack patients were first screened in our vascular radiology meeting and followed up in a dedicated specialist stroke clinic if a diagnosis of medium–large inflammatory intracranial arterial vasculopathy was radiologically confirmed. Treatment was determined and monitored by a multi-disciplinary team. In this case series, 11 patients were managed in this period from the cohort of young stroke presenters (<55 years). The median age was 36 years (interquartile range: 33,50), of which 8 of 11 (73%) were female. Two of 11 (18%) had herpes virus infection confirmed by viral nucleic acid in the cerebrospinal fluid. We showed improvement in cerebral perfusion at 1 year using an arterial spin labelling sequence in patients taking immunosuppressive therapy for >4 weeks compared with those not receiving therapy [6 (100%) versus 2 (40%) P = 0.026]. Our findings demonstrate the potential utility of vessel wall magnetic resonance with arterial spin labelling imaging in detecting and monitoring medium–large inflammatory intracranial arterial vasculopathy activity for patients presenting with stroke symptoms, limiting the need to progress to brain biopsy. Further systematic studies in unselected populations of stroke patients are needed to confirm our findings and establish the prevalence of medium–large artery wall inflammation.

A Comparative Study of Rapid SARS-Cov-2 Antigen Detection Assay against RT-PCR Assay for Diagnosis of COVID-19 in a Tertiary Hospital of Kathmandu

Background The Coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus (SARS-CoV-2) has spread worldwide since its first recorded case in the city of Wuhan, China, in December 2019. SARS-CoV-2 infection causes asymptomatic to sever pneumonia. Severe cases may develop acute respiratory disease symdrome (ARDS), with an average mortality rate of 6.9%. Real Time Reverse Transcriptase Polymerase Chain Reaction (rRT-PCR) assay is the current reference standard laboratory method for the diagnosis of SARS-CoV-2 infection. However, it takes around 6-8 hours to get the result and is time consuming. Therefore, rapid and accurate tests for SARS-CoV-2 screening are essential to expedite disease prevention and control. Lateral flow immunoassay using monoclonal anti SARS-CoV-2 antibodies which target for SARS-CoV-2 antigen can be complimentary screening test if their accuracy were comparable to that of the real time reverse transcriptionpolymerase chain reaction (RT-PCR) assay. Objective To find the sensitivity and specificity of a rapid antigentest kit in comparison to reverse transcription-polymerase chain reaction (RT-PCR). Method A cross-sectional hospital based study was carried out at Shree Birendra Army Hospital, Kathmandu for a period of four months. Result Our finding shows sensitivity and specificity of rapid diagnostic tests (RDT) Ag kit as 60.6% and 96.4% respectively. Positive and negative predictive value was 83.7% and 89.0%. Likewise, positive and negative likelihood ratio was 17.0 and 0.4. The overall accuracy of the antigen kit was 88.1% in comparison to reverse transcriptionpolymerase chain reaction (RT-PCR) as the gold standard. Conclusion Our study concluded the use of rapid antigen kit is mainly useful for screening purposes.