25 research outputs found
Beating versus arrested heart isolated tricuspid valve surgery: An 11-year experience in the current era
International audienceBACKGROUND AND AIM OF THE STUDY: Data about the beating heart (BH) technique for isolated tricuspid valve (TV) surgery compared to the arrested heart (AH) technique are sparse. We compared the outcomes of isolated TV surgery between BH and AH technique. METHODS: We performed an observational analysis of our database of isolated TV surgery. Patients were divided into two groups according to whether surgery was performed without (BH group) or with (AH group) aortic cross-clamping and cardioplegic arrest. The primary endpoint was survival to hospital discharge. Risk factors for in-hospital mortality were searched with multivariate analyses. We undertook further comparisons after propensity-score matching. RESULTS: From January 2007 to December 2017, we performed 82 isolated TV surgery (BH group, n = 47, 57.3%; AH group, n = 35, 42.7%). The mean age was 59.1 years, 56.1% were female. BH group patients were older (61.8 vs. 55.4 years; p = .035), had greater impaired renal function (glomerular filtration rate, 61.1 vs. 74.6 ml/min; p = .012), were more frequently operated for secondary TR (61.7 vs. 31.4%; p = .008), underwent more frequently a reoperation (53.2 vs. 28.6%; p = .042) and exhibited a higher surgical risk (EuroSCORE II, 3.92 vs. 2.50%; p = .013). In-hospital mortality was not different between both groups, either considering unmatched (BH = 10.6 vs. AH = 5.7%; OR = 1.96, 95% confidence interval [CI] = 0.36-10.77) or matched populations (BH = 10.6 vs. AH = 6.4%; OR = 1.89, 95% CI = 0.36-9.97). Age was the only predictor of in-hospital mortality. CONCLUSIONS: The BH technique showed comparable outcomes to the AH technique for isolated TV surgery despite a higher risk profile
Optical coherence tomography for the diagnosis and monitoring of idiopathic intracranial hypertension
The objectives of the study were to investigate the value of optical coherence tomography in detecting papilledema in patients with idiopathic intracranial hypertension (IIH), a disease which is difficult to monitor and which can lead to permanent visual deficits; to analyze retinal changes over time. In this non-interventional case-control study, spectral-domain optical coherence tomography (SD-OCT) was used to analyze the retinal and optic nerve head (ONH) morphology of 21 patients with IIH and 27 age- and sex-matched healthy controls over time. We analyzed the ONH volume using a custom-made algorithm and employed semi-automated segmentation of macular volume scans to assess the macular retinal nerve fiber layer (RNFL) and ganglion cell layer and inner plexiform layer complex as well as the total macular volume. In IIH patients, the ONH volume was increased and correlated with cerebrospinal fluid (CSF) pressure. The ONH volume decreased after the initiation of treatment with acetazolamide. The macular RNFL volume decreased by 5% in 3.5 months, and a stepwise multivariate regression analysis identified CSF pressure as the main influence on macular RNFL volume at diagnosis. The only factor predicting macular RNFL volume loss over time was ONH volume. SD-OCT can non-invasively monitor changes in retinal and ONH morphology in patients with IIH. Increased ONH volume leads to retinal atrophy in the form of macular RNFL volume loss, presumably due to mechanic jamming of the optic nerve at the disc and subsequent axonal loss
A Weber-like law for perceptual learning
What determines how much an organism can learn? One possibility is that the neural factors that limit sensory performance prior to learning, place an upper limit on the amount of learning that can take place. We tested this idea by comparing learning on a sensory task where performance is limited by cortical mechanisms, at two retinal eccentricities. Prior to learning, visual performance at the two eccentricities was either unmatched or equated in two different ways (through spatial scaling or visual crowding). The magnitude of learning was equivalent when initial levels of performance were matched regardless of how performance was equated. The magnitude of learning was a constant proportion of initial performance. This Weber-like law for perceptual learning demonstrates that it should be possible to predict the degree of perceptual improvement and the final level of performance that can be achieved via sensory training, regardless of what cortical constraint limits performance
Artificial intelligence extension of the OSCAR-IB criteria
Artificial intelligence (AI)-based diagnostic algorithms have achieved ambitious aims through automated image pattern recognition. For neurological disorders, this includes neurodegeneration and inflammation. Scalable imaging technology for big data in neurology is optical coherence tomography (OCT). We highlight that OCT changes observed in the retina, as a window to the brain, are small, requiring rigorous quality control pipelines. There are existing tools for this purpose. Firstly, there are human-led validated consensus quality control criteria (OSCAR-IB) for OCT. Secondly, these criteria are embedded into OCT reporting guidelines (APOSTEL). The use of the described annotation of failed OCT scans advances machine learning. This is illustrated through the present review of the advantages and disadvantages of AI-based applications to OCT data. The neurological conditions reviewed here for the use of big data include Alzheimer disease, stroke, multiple sclerosis (MS), Parkinson disease, and epilepsy. It is noted that while big data is relevant for AI, ownership is complex. For this reason, we also reached out to involve representatives from patient organizations and the public domain in addition to clinical and research centers. The evidence reviewed can be grouped in a five-point expansion of the OSCAR-IB criteria to embrace AI (OSCAR-AI). The review concludes by specific recommendations on how this can be achieved practically and in compliance with existing guidelines