Typical Clinical Scenarios Research Articles

In vivo assessment of catheter-tissue contact using tissue proximity indication and its impact on cardiac lesion formation in pulsed field ablation

BackgroundNo evidence exists regarding whether tissue proximity indication (TPI), an impedance-based contact indicator, can improve in vivo lesion formation and durability during pulsed field ablation (PFA). ObjectiveThis in vivo study investigated the relationship between catheter-tissue contact and lesion formation. MethodsIn 5 porcine subjects, PFA applications were delivered at 35 atrial target sites using the VARIPULSE variable-loop circular catheter with the CARTO 3 mapping system. We compared acute ablative low-voltage zones (LVZs; <0.5 mV), chronic LVZs, and pathologic lesions between no/minimum contact (TPI-negative/flickering TPI-positive status) and consistent tissue contact (consistent TPI-positive status) for typical clinical scenarios and tissue tenting (TPI-positive status with electrodes extensively away from the 3-dimensional mapping surface) for safety margin. Ultrasound imaging also confirmed contact category assessments. ResultsAcute and chronic LVZs were significantly larger with consistent contact compared with no/minimum contact, including pathologic lesion length (36.0 ± 12.5 mm vs 17.4 ± 15.2 mm; P = .002) and maximum width (10.3 ± 2.7 mm vs 5.7 ± 5.1 mm; P = .035); results with tenting (length: 34.6 ± 11.7; width: 11.3 ± 1.9 mm) were comparable to consistent contact. Lesion transmurality was achieved in all lesions with consistent contact or tissue tenting but only in 54.5% with no/minimum contact (P = .001 for each). The TPI-based electrode contact distance, measured as the cumulative length of the multielectrode catheter tip positive for TPI, significantly correlated with lesion length, maximum width, and transmurality. ConclusionConsistent TPI-based contact during PFA was strongly associated with distinct chronic transmural lesions, emphasizing the importance of tissue contact in optimizing circumferential lesion formation with circular PFA catheters.

Clinical Examples of the Additive Value of Absolute Quantification of Cell-Free DNA After Heart Transplantation.

Cell-free DNA (cfDNA) is used as a biomarker after transplantation to detect graft injury, relying on the donor fraction (DF). We have established a PCR-based approach allowing us to separately quantify absolute values of dd-cfDNA and recipient-derived cfDNA (rd-cfDNA). We aimed to present typical clinical scenarios after heart transplantation (HTx) to illustrate the advantages of absolute cfDNA values over DF. We used the cfDNA results of our cohort (509 samples of 52 patients followed during the first year after HTx) as background and determined the trajectories of cfDNA in specific clinical situations. We profiled an uncomplicated clinical course, viral and bacterial infections, acute and chronic rejection, and false-negative and false-positive rejections in six patients (five adults, one child). There was a substantial discrepancy between relative (DF) and absolute cfDNA-levels in several clinical situations. Rd- and dd-cfDNA were independently elevated during episodes of rejection and infection and were better suited to depict treatment response than DF alone. Absolute quantification of cfDNA may offer clinically relevant information additive to DF in various situations after HTx and could be helpful for more accurate monitoring of diagnosis and treatment of rejection.

(127) Is Artificial Intelligence Ready to Help Urologists?

Abstract Introduction ChatGPT is a language model developed by OpenAI. It's a variant of the GPT (Generative Pretrained Transformer) architecture, a transformer-based neural network used for natural language processing tasks. The model has been trained on a massive corpus of text data and can generate human-like responses to topics and questions. ChatGPT can be used for chatbots, conversation agents, and language translation. The integration of AI into urology has the potential to improve patient outcomes, increase efficiency, and reduce costs, ultimately leading to a better healthcare experience for patients. Objective The objective of this study is to assess the current state of artificial intelligence (AI) when it comes to urologic problems and to determine whether it is sufficiently developed and prepared to provide useful assistance to urologists in their clinical practice. This study aims to assess the accuracy, reliability, and potential benefits of one AI language model (ChatGPT) in efficiently answering common patient questions, providing patients with accurate educational information, minimizing patient harm, and guiding patients towards appropriate management. By exhibiting ChatGPT's capabilities and limitations in the context of urology, the study aims to demonstrate how AI can be helpful in everyday urological practices. Methods ChatGPT (chat.openai.com) was presented with typical clinical scenarios and patient questions. Results AI wrote the introduction answering “What is ChatGPT?” and “How can AI help urologists?”. For the conclusion, AI was prompted with “Is artificial intelligence ready to help urologists?”. Figures summarize the answers to common patient questions given by ChatGPT. Conclusions The use of AI in the field of urology is still in its early stages and more research is needed to determine its full potential. However, there have already been some promising developments and successful applications. For example, AI algorithms have been used to accurately diagnose prostate cancer, predict patient outcomes, and improve surgical planning. While AI has the potential to revolutionize the field of urology, it is important to note that AI is not a substitute for human expertise and judgment. AI algorithms can provide valuable insights and assistance, but the ultimate decision making and treatment planning should still be done by experienced urologists. Additionally, it is important to ensure that AI systems are developed and used in a way that respects patient privacy and data security, and that the outcomes of AI-assisted decision making are transparent and explainable. In summary, AI has the potential to greatly benefit the field of urology. Still, it is important to approach its use with caution and continue evaluating its impact as more research is conducted. Disclosure No.

A five-point scale for assessing the quality of life of patients with epilepsy

The main goal of epilepsy therapy is to improve the patient’s quality of life (QoL), which is a holistic indicator that reflects satisfaction with life in various areas. Currently existing questionnaires: QOLIE-89, QOLIE-31 and QOLIE-10 are adapted for use in Russia, but require a certain, sometimes considerable amount of time to complete them and then process. The five-point scale for assessing the QoL of epilepsy patients (SCALE 5) requires answering only one question: “Grade your general well-being on a five-point school scale at this moment?” and allows to get the necessary information in seconds, without using special forms and calculation formulas. The QoL is assessed by analogy with a Russian five-point school grading system, where 5 is an excellent grade, 4 is good etc. The resulting score serves as an immediate guideline for the doctor for further treatment of the patient: with a score of 3 (satisfactory), the cause of the reduced QoL should be identified and corrected (whether it is related to the illness, adverse events, anxiety/depression, etc.), and with scores of 2 and 1, immediate intervention is required: correction of therapy, consultation with a psychiatrist, possibly hospitalization. Here we present the results of more than 25 years of using SCALE 5. SCALE 5 is easy for patients to understand and for clinicians to use in the limited time of an outpatient appointment. The typical clinical scenarios and practical recommendations for determining the SCALE 5 score presented in the article are intended to facilitate the work of specialists in the fields of neurology, epileptology and psychiatry.

Investigating the effects of a temperature dependent photodynamic dose: A numerical study

SignificancePhotodynamic therapy (PDT) and photothermal therapy (PTT) show promise as cancer treatments, but challenges in generating large ablative volumes for deep-seated tumours persist. Using simulations, this study investigates combined PDT and PTT to increase treatment volumes, including the impact of a temperature-dependent PDT dose on the treatment volume radius. ApproachA finite-element model, using the open-source SfePy package, was developed to simulate combined interstitial photothermal and photodynamic treatments. Results compared an additive dose model to a temperature-dependent dose model with enhanced PDT dosimetry and examined typical clinical scenarios for possible synergistic effects. ResultsFindings revealed that the temperature-dependent dose model could significantly expand the damage radius compared to the additive model, depending on the tissue and drug properties. ConclusionsCharacterizing synergistic effects of PDT and PTT could enhance treatment planning. Future work is ongoing to implement additional variables, such as photosensitizer photobleaching, and spatial and temporally varying oxygenation.

Variations in intravenous fluid management for paediatric hypernatraemia in South Africa: A survey of junior and senior South African paediatric doctors

Background. Paediatric hypernatraemia is a severe and life-threatening electrolyte abnormality that is associated with considerable morbidity and mortality. Although intravenous (IV) fluid therapy is a crucial component of management, there are no management guidelines, and varying approaches to IV fluid therapy are commonplace in clinical practice. Objectives. To determine the variance in IV fluid therapy in the management of paediatric hypernatraemia among paediatric registrars and consultants in South Africa. Methods. A self-administered online survey was conducted from November 2020 to February 2021. The survey assessed paediatricians’ management of three typical clinical scenarios of community-acquired hypernatraemia seen in South Africa. Descriptive results were presented as proportions, frequencies and medians with interquartile ranges. Comparisons were done using contingency tables. Results. Responses from 119 participants were analysed. Most respondents worked in the state sector (69.8%), and were based mainly in Gauteng (46.2%) or Western Cape (25.2%) province. Most (60.2%) respondents considered a serum sodium level ≥146 mmol/L indicative of hypernatraemia, and 43.6% (n=51/117) reported seeing &gt;10 cases of paediatric hypernatraemia in 2019. For all three cases, at least eight different types of infusate (of varying sodium concentrations) were chosen as maintenance fluids. Fluid deficits were calculated using either the free water method or based on the perceived degree/percentage of clinical dehydration. Conclusion. There is considerable variability in the management of hypernatraemia among paediatricians in South Africa. There is an urgent need to develop a standardised guideline for the treatment of paediatric hypernatraemia.

Diagnosis and treatment of transthyretin amyloidosis cardiomyopathy: A position statement of the Polish Cardiac Society.

Considering the rare incidence of transthyretin amyloidosis cardiomyopathy (ATTR-CM) in Poland, patients encounter difficulties at the stages of diagnosis and treatment. For successful diagnosis, it is vital to raise the suspicion of ATTR-CM, that is, to identify typical clinical scenarios such as heart failure with preserved ejection fraction or the red flags of amyloidosis. In most cases, it is possible to establish the diagnosis on the basis of noninvasive tests. This article presents the recommended diagnostic algorithms including laboratory workup, imaging tests (in particular, isotope scanning), and genetic tests. Since ATTR-CM should be differentiated from light chain amyloidosis, we also discuss aspects related to hematological manifestations and invasive diagnosis. We describe neurological signs and symptoms in patients with amyloidosis and present therapeutic options, including the causative treatment of ATTR-CM with the only currently approved drug, tafamidis. We also discuss drugs that are being assessed in ongoing clinical trials. We outline differences in the symptomatic treatment of heart failure in ATTR-CM and recommendations for nonpharmacological treatment and monitoring of the disease. Finally, we underline the need for providing access to the causative treatment with tafamidis as part of a drug program, as in other rare diseases, so that patients with ATTR-CM can be treated according to the European Society of Cardiology guidelines on heart failure and cardiomyopathy.

A Japanese retrospective study of non-tuberculous mycobacterial infection in children, adolescents, and young adult patients with hematologic-oncologic diseases.

Non-tuberculous mycobacterial infection (NTM) is rare in healthy children, with lymphadenitis being the most common presentation. Immunocompromised populations are known to be at high risk, but the clinical picture of NTM infection in pediatric hematology/oncology patients is unclear. In this nationwide retrospective analysis of patients under the age of 40 treated in Japanese pediatric hematology/oncology departments who developed NTM infection between January 2010 and December 2020, 36 patients were identified: 21 patients with hematopoietic stem cell transplantation (HSCT) and 15 non-transplant patients. Post-transplant patients were infected with NTM at 24 sites, including the lungs (N=12), skin and soft tissues (N=6), bloodstream (N=4), and others (N=2). Nine of 12 patients with pulmonary NTM infection had a history of pulmonary graft-versus-host disease (GvHD), and rapid-growing mycobacteria (RGM) were isolated from 5 of them. In non-transplant patients, the primary diseases were acute lymphoblastic leukemia (ALL; N=5), inborn errors of immunity (IEI; N=6), and others (N=4). All cases of ALL had bloodstream infections with RGM, whereas all cases of IEI were infected with slow-growing mycobacteria (SGM). In summary, 3 typical clinical scenarios for pediatric hematology/oncology patients have been established: RGM-induced pulmonary disease in patients with pulmonary GvHD, RGM bloodstream infection in patients with ALL, and SGM infection in patients with IEI. Our findings suggest that NTM must be regarded as a pathogen for infections in these high-risk patients, especially those with pulmonary GvHD, who may require active screening for NTM.

Enhancing insulin supply chain resilience: A critical importance for diabetes management

Diabetes, a chronic metabolic disorder affecting millions worldwide, relies heavily on a stable and efficient supply chain for insulin, a life-saving hormone. However, the insulin supply chain faces multifaceted challenges that can disrupt access to this essential medication. In the realm of diabetes management, a novel and devastating occurrence has emerged—a severe shortage of insulin. This case report revolves around a singular clinical encounter that showcases a series of remarkable and uncommon aspects, which can enrich the knowledge of healthcare professionals. The patient’s condition presented several unique features, providing a learning opportunity that transcends the typical clinical scenarios seen in diabetes management. The findings surrounding the unavailability of insulin, the dire consequences it has on patients, and the clinical course and prognosis of an individual patient closely related to previous challenges. The shortage of insulin, though not a new challenge, has now reached unparalleled levels, resulting in life-threatening situations for those dependent on this vital hormone. This case report delves into a unique scenario where an individual patient’s health dramatically deteriorated due to the insulin scarcity, highlighting the urgency for comprehensive solutions and international cooperation to ensure access to this life-saving medication. This case report manuscript reviews the importance of enhancing the resistance and resilience of the insulin supply chain to ensure uninterrupted access to insulin for people with diabetes. We discuss the current challenges, their impact on diabetes management, and propose strategies to mitigate these issues. Strengthening the insulin supply chain is essential for the well-being of those living with diabetes, highlighting its significance for healthcare systems globally.

Accuracy of Electron Density Mapping of a Novel kVCBCT System Designed for Planning

A recently developed advanced kVCBCT system, designed for simulation and planning, includes improvements to the imaging panel and reconstruction technique, enabling more accurate electron density mapping than a typical CBCT. This study investigates the accuracy, limitations, and dosimetric impact of this new system. CBCT images were taken of both large (pelvis) and small (head) electron density phantoms with inserts ranging from lung (0.29) to cortical bone (1.69). Images were taken with several pre-set protocols with energies of 125 kVp and 140 kVp. The effects of longitudinal buildup (for scatter due to the cone-beam geometry) and blade position were also investigated. The HU values of each insert were measured over a small region of interest. Several electron density curves were generated - pelvis protocol on the large phantom, head protocol on the small phantom, and average - and imported into a treatment planning system. Dose calculation was performed using each curve and differences were observed. HU to electron density mapping was sensitive to the use of longitudinal buildup and blade position, with differences in the curves observed at both low and high electron densities, due to imager saturation effects not found in typical clinical scenarios. Subsequent studies used both longitudinal buildup and fully opened blades. Under these conditions, mapping was not sensitive to technique or phantom size at low electron densities. At higher values, the curves diverged, with the head protocol showing higher HU values and the pelvis protocol showing lower. The average curve matched very closely with the curve from our standard CT simulator. Dose calculation showed little dependence on the curve chosen, with max point dose differences of 1.2% between the pelvis and average scans, though most of the plan was <0.5% different. Results for the head protocol were similar. The system provides reliable HU values comparable to a CT simulator, though it is important to consider the effects of imager saturation by choosing appropriate scatter and collimation. The calibration is slightly sensitive to the choice of phantom size and beam energy, though these differences led to negligible (<0.5%) differences in dose calculation accuracy.

PATIENT PREFERENCES IN PHARMACEUTICAL AND DEVICE-BASED TREATMENTS FOR UNCONTROLLED HYPERTENSION

Objective: Radiofrequency renal denervation (RDN) safely reduces high blood pressure (BP) in hypertensive (HTN) patients. Patient preference regarding such a treatment over antihypertensive (AH) drugs for uncontrolled HTN is poorly understood. Design and method: A recent discrete choice experiment (DCE) study in patients with uncontrolled HTN identified the reduction in systolic BP as the most important driver of patient preference between interventional treatments (e.g. RDN) or drugs. Using a predictive model consisting of the preference weights for safety and efficacy attributes from the DCE study, we calculated patients’ treatment preferences in 3 typical clinical scenarios in HTN management. Each scenario presented a choice to either initiate/increase AH drugs, or to have interventional treatment such as RDN: (1) AH drug naïve: initiate AH drugs vs. interventional treatment (2) mild-moderate HTN, 1-3 AH drugs: increasing AH drugs vs. intervention with no drug changes, (3) severe HTN (systolic BP &gt;150mmHg, &gt;3 AH drugs): increasing AH drugs vs. intervention with no drug changes. In each scenario, the average predicted probability of choosing one treatment over the other was calculated based on a benefit-risk profile from the sum of preference-weighted treatment attributes (type of treatment, changes in AH drugs, office systolic BP reducing efficacy, effect duration, risk of drug side effects, interventional treatment adverse events). Values of the treatment attributes were derived from the literature, expert opinion, and published RDN studies (SPYRAL HTN OFF-MED, ON-MED, Global SYMPLICITY Registry). Results: In (1), 17% preferred interventional treatment without drugs vs 83% preferred initiation of drugs. In (2), 24% preferred interventional treatment without increasing drugs vs 76% preferred increasing drugs. In (3), 45% preferred interventional treatment without increasing drugs vs 55% preferred increasing drugs. Preference differences were driven by the magnitude of office systolic BP reductions with each treatment. Risks of treatment-related adverse events were less important to treatment choices. Conclusions: Preference for RDN ranged from one-fifth to one-half of patients depending on clinical scenario. The increase mirrored the extent of prior treatment with AH drugs and HTN severity on drugs. Patient preference was driven predominantly by efficacy and minimally by safety of treatment.

A survey study of the use of a subcutaneous implantable cardioverter-defibrillator in various clinical scenarios by expert electrophysiologists in Poland.

A subcutaneous implantable cardioverter-defibrillator (S-ICD) has become a recognized alternative to a traditional transvenous implantable cardioverter-defibrillator (T-ICD). Despite the growing evidence of non-inferiority of S-ICD, there are no clear clinical guidelines for selection of either of the two available systems. The aim of the study was to analyze the decisions made in predefined typical clinical scenarios by Polish cardiologists experienced in the use of both S-ICDs and T-ICDs. A group of 30 experts of cardiac electrotherapy experienced in the use of S-ICDs was recruited and invited to participate in a web-based anonymous survey. The survey questions regarded the proposed therapy in various but typical clinical scenarios. From the invited 30 experts representing 18 clinical centers, 25 completed the survey. 72% of them declared that the number of S-ICDs implanted at their center during the preceding 12 months exceeded 10, and 40% - that it was over 20. Rates of responders preferring S-ICD or T-ICD in various clinical scenarios are reported and discussed in detail. Significant divergence of opinion exists among Polish experts regarding the use of a subcutaneous cardioverter-defibrillator. It is especially pronounced on the issue of the use of the system in middle-age patients, in case of complications of the hitherto ICD therapy, or the need of upgrading the existing cardiac implantable electronic device.

Imaging of Central Nervous System Demyelinating Disorders

This article summarizes neuroimaging findings in demyelinating disease, the most common being multiple sclerosis. Revisions to criteria and treatment options have been ongoing, and MRI plays a pivotal role in diagnosis and disease monitoring. The common antibody-mediated demyelinating disorders with their respective classic imaging features are reviewed, as well as the differential diagnostic considerations on imaging. The clinical criteria of demyelinating disease rely heavily on imaging with MRI. With novel antibody detection, the range of clinical demyelinating syndromes has expanded, most recently with myelin oligodendrocyte glycoprotein-IgG antibodies. Imaging has improved our understanding of the pathophysiology of multiple sclerosis and disease progression, and further research is underway. The importance of increased detection of pathology outside of the classic lesions will have an important role as therapeutic options are expanding. MRI has a crucial role in the diagnostic criteria and differentiation among common demyelinating disorders and syndromes. This article reviews the typical imaging features and clinical scenarios that assist in accurate diagnosis, differentiation between demyelinating diseases and other white matter diseases, the importance of standardized MRI protocols in clinical practice, and novel imaging techniques.

Surgical treatment of brainstem cavernous malformations: an international Delphi consensus.

Indication for surgery in brainstem cavernous malformations (BSCMs) is based on many case series, few comparative studies, and no randomized controlled trials. The objective of this study was to seek consensus about surgical management aspects of BSCM. A total of 29 experts were invited to participate in a multistep Delphi consensus process on the surgical treatment of BSCM. Twenty-two (76%) of 29 experts participated in the consensus. Qualitative analysis (content analysis) of an initial open-ended question survey resulted in 99 statements regarding surgical treatment of BSCM. By using a multistep survey with 100% participation in each round, consensus was reached on 52 (53%) of 99 statements. These were grouped into 4 categories: 1) definitions and reporting standards (7/14, 50%); 2) general and patient-related aspects (11/16, 69%); 3) anatomical-, timing of surgery-, and BSCM-related aspects (22/37, 59%); and 4) clinical situation-based decision-making (12/32, 38%). Among other things, a consensus was reached for surgical timing, handling of associated developmental venous anomalies, handling of postoperative BSCM remnants, assessment of specific anatomical BSCM localizations, and treatment decisions in typical clinical BSCM scenarios. A summary of typical clinical scenarios and a catalog of various BSCM- and patient-related aspects that influence the surgical treatment decision have been defined, rated, and interpreted.

Superficial femoral artery stenting: Impact of stent design and overlapping on the local hemodynamics

BackgroundSuperficial femoral arteries (SFAs) treated with self-expanding stents are widely affected by in-stent restenosis (ISR), especially in case of long lesions and multiple overlapping devices. The altered hemodynamics provoked by the stent is considered as a promoting factor of ISR. In this context, this work aims to analyze the impact of stent design and stent overlapping on patient-specific SFA hemodynamics. MethodsThrough a morphing technique, single or multiple stents were virtually implanted within two patient-specific, post-operative SFA models reconstructed from computed tomography. The stented domains were used to perform computational fluid dynamics simulations, quantifying wall shear stress (WSS) based descriptors including time-averaged WSS (TAWSS), oscillatory shear index (OSI), transverse WSS (transWSS), and WSS ratio (WSSRATIO). Four stent designs (three laser-cut – EverFlex, Zilver and S.M.A.R.T. – and one prototype braided stent), and three typical clinical scenarios accounting for different order of stent implantation and overlapping length were compared. ResultsThe main hemodynamic differences were found between the two types of stent designs (i.e. laser-cut vs. braided stents). The braided stent presented lower median transWSS and higher median WSSRATIO than the laser-cut stents (p < 0.0001). The laser-cut stents presented comparable WSS-based descriptor values, except for the Zilver, exhibiting a median TAWSS ∼30% higher than the other stents. Stent overlapping provoked an abrupt alteration of the WSS-based descriptors. The overlapping length, rather than the order of stent implantation, highly and negatively impacted the hemodynamics. ConclusionThe proposed computational workflow compared different SFA stent designs and stent overlapping configurations, highlighting those providing the most favorable hemodynamic conditions.

Force decay of polyethylene terephthalate glycol aligner materials during simulation of typical clinical loading/unloading scenarios.

This invitro study investigated the effect of three distinct daily loading/unloading cycles on force delivery during orthodontic aligner therapy. The cycles were applied for 7days and were designed to reflect typical clinical aligner application scenarios. Flat polyethylene terephthalate glycol (PET-G) specimens (Duran®, Scheu Dental, Iserlohn, Germany) with thicknesses ranging between 0.4 and 0.75 mm were tested in athree-point-bending testing machine. Measurements comprised loading/unloading intervals of 12 h/12 h, 18 h/6 h, and 23 h/1 h, and specimens were exposed to bidistilled water during loading to simulate intraoral conditions. Avery large decay in force for the PET‑G specimens could already be observed after the first loading period, with significantly different residual force values of 24, 20, and 21% recorded for the 12 h/12 h, 18 h/6 h, and 23 h/1 h loading/unloading modes, respectively (Mann-Whitney U test, p < 0.01). In addition, further decays in force from the first to the last loading period at day7 of 13.5% (12 h/12 h), 9.7% (18 h/6 h), and 8.4% (23 h/1 h) differed significantly among the three distinct loading modes (Mann-Whitney U test, p < 0.01). Although the initial material stiffness of PET‑G is relatively high, the transmission of excessive forces is attenuated by the high material-related force decay already within afew hours after intraoral insertion.

Weighted pseudo-values for partly unobserved group membership in paediatric stem cell transplantation studies.

Generalised pseudo-values have been suggested to evaluate the impact of allogeneic stem cell transplantation on childhood leukaemia. The approach compares long-term survival of two cohorts defined by the availability or non-availability of suitable donors for stem cell transplantation. A patient's cohort membership becomes known only after completed donor search with or without an identified donor. If a patient suffers an event during donor search, stem cell transplantation will no longer be indicated. In such a case, donor search will be ceased and cohort membership will remain unknown. The generalised pseudo-values approach considers donor identification as binary time-dependent covariate and uses inverse-probability-of-censoring weighting to adjust for non-identified donors. The approach leads to time-consuming computations due to multiple redefinitions of the risk set for pseudo-value calculation and an explicit adjustment for waiting-time bias. Here, the problem is looked at from a different angle. By considering the probability that a donor would have been identified after ceasing of donor search, weights for common pseudo-values are defined. This leads to a faster alternative approach as only a single risk set is necessary. Extensive computer simulations show that both, the generalised and the new weighted pseudo-values approach, provide approximately unbiased estimates. Confidence interval coverage is satisfactory for typical clinical scenarios. In situations, where donor identification takes considerably longer than usual, the weighted pseudo-values approach is preferable. Both approaches complement each other as they have different potential in addressing further aspects of the underlying medical question.

The photoplethysmography dictionary: practical guidance on signal interpretation and clinical scenarios from TeleCheck-AF

Abstract Introduction During the coronavirus disease 2019 (COVID-19) pandemic, numerous centres in Europe used on-demand photoplethysmography (PPG) technology to remotely assess heart rate and rhythm in conjunction with teleconsultations within the TeleCheck-AF project. Purpose To develop an educational structured stepwise practical guide on how to interpret PPG signals and to study typical clinical scenarios how on-demand PPG was used in the TeleCheck-AF project. Methods During an online conference, the structured stepwise practical guide on how to interpret PPG signals was discussed and further refined during an internal review process. We provide the number of respective PPG recordings and number of patients managed within a clinical scenario during the TeleCheck-AF project. Results To interpret PPG recordings, we introduce a structured stepwise practical guide and provide representative PPG recordings. In the TeleCheck-AF project, 2522 subjects collected 90.616 recordings. The majority of these recordings was classified by the PPG algorithm as sinus rhythm (57.6%), followed by atrial fibrillation (AF) (23.6%). In 9.7% of recordings the quality was too low to interpret. Other observed rhythms were tachycardia (1.4%), extra systoles (4.7%), bigeminy episodes (1.8%), trigeminy episodes (0.6%) and atrial flutter (0.2%). The most frequent clinical scenario where PPG technology was used in the TeleCheck-AF project was follow-up after AF ablation (1110 patients) followed by heart rate and rhythm assessment around (tele)consultation (966 patients), sometimes including remote PPG-guided adaption of rate or rhythm control. 275 patients were followed around cardioversion, either (semi-)acute or elective. Other possible scenarios are assessment of palpitations, assessment of symptom-rhythm correlation and monitoring during up-titration of heart failure medication. Conclusion We introduce a newly developed structured stepwise practical guide on PPG signal interpretation developed based on presented experiences from TeleCheck-AF. The present clinical scenarios for the use of on-demand PPG technology derived from the TeleCheck-AF project will help to implement PPG technology in the management of arrhythmia patients. Funding Acknowledgement Type of funding sources: None. TeleCheck-AF clinical scenariosClassification of PPG recordings

Permanent stoma rates after anterior resection for rectal cancer: risk prediction scoring using preoperative variables.

A permanent stoma after anterior resection for rectal cancer is common. Preoperative counselling could be improved by providing individualized accurate prediction modelling. Patients who underwent anterior resection between 2007 and 2015 were identified from the Swedish Colorectal Cancer Registry. National Patient Registry data were added to determine presence of a stoma 2 years after surgery. A training set based on the years 2007-2013 was employed in an ensemble of prediction models. Judged by the area under the receiving operating characteristic curve (AUROC), data from the years 2014-2015 were used to evaluate the predictive ability of all models. The best performing model was subsequently implemented in typical clinical scenarios and in an online calculator to predict the permanent stoma risk. Patients in the training set (n = 3512) and the test set (n = 1136) had similar permanent stoma rates (13.6 and 15.2 per cent). The logistic regression model with a forward/backward procedure was the most parsimonious among several similarly performing models (AUROC 0.67, 95 per cent c.i. 0.63 to 0.72). Key predictors included co-morbidity, local tumour category, presence of metastasis, neoadjuvant therapy, defunctioning stoma use, tumour height, and hospital volume; the interaction between age and metastasis was also predictive. Using routinely available preoperative data, the stoma outcome at 2 years after anterior resection for rectal cancer can be predicted fairly accurately.

Perspectives on the Gamification of an Interactive Health Technology for Postoperative Rehabilitation of Pediatric Anterior Cruciate Ligament Reconstruction: User-Centered Design Approach.

BackgroundPediatric and adolescent athletes are a large demographic undergoing anterior cruciate ligament reconstruction (ACL-R). Postoperative rehabilitation is critical, requiring patients to complete home exercise programs (HEPs). To address obstacles to HEP adherence, we developed an interactive health technology, interACTION (iA), to monitor knee-specific rehabilitation. iA is a web-based platform that incorporates wearable motion sensors and a mobile app that provides feedback and allows remote monitoring. The Wheel of Sukr is a gamification mechanism that includes numerous behavioral elements. ObjectiveThis study aims to use a user-centered design process to incorporate behavioral change strategies derived from self-management theory into iA using the Wheel of Sukr, with the aim of influencing patient behavior.MethodsIn total, 10 athletes aged 10-18 years with a history of ACL-R were included in this study. Patients were between 4 weeks and 1 year post–ACL-R. Participants underwent a 60-minute triphasic interview. Phase 1 focused on elements of gaming that led to high participation and information regarding surgery and recovery. In phase 2, participants were asked to think aloud and rank cards representing the components of the Wheel of Sukr in order of interest. In phase 3, the patients reviewed the current version of iA. Interviews were recorded, transcribed, and checked for accuracy. Qualitative content analysis segmented the data and tagged meaningful codes until descriptive redundancy was achieved; next, 2 coders independently coded the data set. These elements were categorized according to the Wheel of Sukr framework. The mean age of participants was 12.8 (SD 1.32) years, and 70% (7/10) were female. Most participants (7/10, 70%) reported attending sessions twice weekly. All patients were prescribed home exercises. Self-reported HEP compliance was 75%-100% in 40% (4/10), 50%-75% in 40% (4/10), and 25%-50% of prescribed exercises in 20% (2/10) of the participants.ResultsThe participants responded positively to an app that could track home exercises. Desirable features included exercise demonstrations, motivational components, and convenience. The participants listed sports specificity, competition, notifications, reminders, rewards, and social aspects of gameplay as features to incorporate. In the Wheel of Sukr card sort exercise, motivation was ranked first; self-management, second; and growth, esteem, and fun tied for the third position. The recommended gameplay components closely followed the themes from the Wheel of Sukr card sort activity.ConclusionsThe participants believe iA is a helpful addition to recovery and want the app to include exercise movement tracking and encouragement. Despite the small number of participants, thematic saturation was reached, suggesting the sample was sufficient to obtain a representative range of perspectives. Future work will implement motivation; self-management; and growth, confidence, and fun in the iA user experience. Young athlete ACL-R patients will complete typical clinical scenarios using increasingly developed prototypes of the gamified iA in a controlled setting.