Impact of catheter ablation versus medical therapy on cognitive function in atrial fibrillation: a systematic review

PURPOSE: Atrial fibrillation is associated with an increased risk of cognitive impairment. It is unclear whether the restoration of sinus rhythm with catheter ablation may modify this risk. We conducted a systematic review of studies comparing cognitive outcomes following catheter ablation with medical therapy (rate and/or rhythm control) in atrial fibrillation. METHODS: Searches were performed on the following databases from their inception to 17 October 2021: PubMed, OVID Medline, Embase and Cochrane Library. The inclusion criteria comprised studies comparing catheter ablation against medical therapy (rate and/or rhythm control in conjunction with anticoagulation where appropriate) which included cognitive assessment and/or a diagnosis of dementia as an outcome. RESULTS: A total of 599 records were screened. Ten studies including 15,886 patients treated with catheter ablation and 42,684 patients treated with medical therapy were included. Studies which compared the impact of catheter ablation versus medical therapy on quantitative assessments of cognitive function yielded conflicting results. In studies, examining new onset dementia during follow-up, catheter ablation was associated with a lower risk of subsequent dementia diagnosis compared to medical therapy (hazard ratio: 0.60 (95% confidence interval 0.42–0.88, p < 0.05)). CONCLUSION: The accumulating evidence linking atrial fibrillation with cognitive impairment warrants the design of atrial fibrillation treatment strategies aimed at minimising cognitive decline. However, the impact of catheter ablation and atrial fibrillation medical therapy on cognitive decline is currently uncertain. Future studies investigating atrial fibrillation treatment strategies should include cognitive outcomes as important clinical endpoints. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10840-022-01196-y

Evaluation of an open-source pipeline to create patient-specific left atrial models: A reproducibility study

This work presents an open-source software pipeline to create patient-specific left atrial models with fibre orientations and a fibrDEFAULTosis map, suitable for electrophysiology simulations, and quantifies the intra and inter observer reproducibility of the model creation. The semi-automatic pipeline takes as input a contrast enhanced magnetic resonance angiogram, and a late gadolinium enhanced (LGE) contrast magnetic resonance (CMR). Five operators were allocated 20 cases each from a set of 50 CMR datasets to create a total of 100 models to evaluate inter and intra-operator variability. Each output model consisted of: (1) a labelled surface mesh open at the pulmonary veins and mitral valve, (2) fibre orientations mapped from a diffusion tensor MRI (DTMRI) human atlas, (3) fibrosis map extracted from the LGE-CMR scan, and (4) simulation of local activation time (LAT) and phase singularity (PS) mapping. Reproducibility in our pipeline was evaluated by comparing agreement in shape of the output meshes, fibrosis distribution in the left atrial body, and fibre orientations. Reproducibility in simulations outputs was evaluated in the LAT maps by comparing the total activation times, and the mean conduction velocity (CV). PS maps were compared with the structural similarity index measure (SSIM). The users processed in total 60 cases for inter and 40 cases for intra-operator variability. Our workflow allows a single model to be created in 16.72 ± 12.25 min. Similarity was measured with shape, percentage of fibres oriented in the same direction, and intra-class correlation coefficient (ICC) for the fibrosis calculation. Shape differed noticeably only with users' selection of the mitral valve and the length of the pulmonary veins from the ostia to the distal end; fibrosis agreement was high, with ICC of 0.909 (inter) and 0.999 (intra); fibre orientation agreement was high with 60.63% (inter) and 71.77% (intra). The LAT showed good agreement, where the median ± IQR of the absolute difference of the total activation times was 2.02 ± 2.45 ms for inter, and 1.37 ± 2.45 ms for intra. Also, the average ± sd of the mean CV difference was -0.00404 ± 0.0155 m/s for inter, and 0.0021 ± 0.0115 m/s for intra. Finally, the PS maps showed a moderately good agreement in SSIM for inter and intra, where the mean ± sd SSIM for inter and intra were 0.648 ± 0.21 and 0.608 ± 0.15, respectively. Although we found notable differences in the models, as a consequence of user input, our tests show that the uncertainty caused by both inter and intra-operator variability is comparable with uncertainty due to estimated fibres, and image resolution accuracy of segmentation tools

Atrial Fibrillation and In-Hospital Mortality in Covid-19 patients

BACKGROUND: There are conflicting data on whether new-onset atrial fibrillation (AF) is independently associated with poor outcomes in COVID-19 patients. This study represents the largest dataset curated by manual chart review comparing clinical outcomes between patients with sinus rhythm, pre-existing AF, and new-onset AF. OBJECTIVE: The primary aim of this study was to assess patient outcomes in COVID-19 patients with sinus rhythm, pre-existing AF, and new-onset AF. The secondary aim was to evaluate predictors of new-onset AF in patients with COVID-19 infection. METHODS: This was a single-center retrospective study of patients with a confirmed diagnosis of COVID-19 admitted between March and September 2020. Patient demographic data, medical history, and clinical outcome data were manually collected. Adjusted comparisons were performed following propensity score matching between those with pre-existing or new-onset AF and those without AF. RESULTS: The study population comprised of 1241 patients. A total of 94 (7.6%) patients had pre-existing AF and 42 (3.4%) patients developed new-onset AF. New-onset AF was associated with increased in-hospital mortality before (odds ratio [OR] 3.58, 95% confidence interval [CI] 1.78-7.06, P < .005) and after (OR 2.80, 95% CI 1.01-7.77, P < .005) propensity score matching compared with the no-AF group. However, pre-existing AF was not independently associated with in-hospital mortality compared with patients with no AF (postmatching OR: 1.13, 95% CI 0.57-2.21, P = .732). CONCLUSION: New-onset AF, but not pre-existing AF, was independently associated with elevated mortality in patients hospitalised with COVID-19. This observation highlights the need for careful monitoring of COVID-19 patients with new-onset AF. Further research is needed to explain the mechanistic relationship between new-onset AF and clinical outcomes in COVID-19 patients

High prevalence of new clinically significant findings in patients with embolic stroke of unknown source evaluated by cardiac magnetic resonance imaging

Background: Embolic stroke of unknown source (ESUS) accounts for one in six ischaemic strokes. Current guidelines do not recommend routine cardiac magnetic resonance (CMR) imaging in ESUS and, beyond the identification of cardio-embolic sources, there are no data assessing new clinical findings from CMR in ESUS. This study aimed to assess the prevalence of new cardiac and non-cardiac findings and to determine their impact on clinical care in patients with ESUS.Methods and Results: In this prospective, multicentre, observational study, CMR was performed within 3-months of ESUS. All scans were reported according to standard clinical practice. A new clinical finding was defined as one not previously identified through prior clinical evaluation. A clinically significant finding was defined as one resulting in further investigation, follow-up or treatment. A change in patient care was defined as initiation of medical, interventional, surgical or palliative care. From 102 patients recruited, 96 underwent CMR. One or more new clinical findings were observed in 59 patients (61%). New findings were clinically significant in 48 (81%) of these patients. Of 40 patients with a new clinically significant cardiac finding, 21 (53%) experienced a change in care (medical therapy, n=15; interventional/surgical procedure, n=6). In 12 patients with a new clinically significant extra-cardiac finding, 6 (50%) experienced a change in care (medical therapy, n=4; palliative care, n=2). Conclusions: CMR imaging identifies new clinically significant cardiac and non-cardiac findings in half of patients with recent ESUS. Advanced cardiovascular screening should be considered in patients with ESUS.<br/

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe