Citations

Abstract Background The use of irreversible electroporation (IRE) for cardiac ablation in the management of cardiac arrhythmias, known as Pulsed Field Ablation (PFA), has gained the attention of many researchers, physicians and companies. Despite the demonstrated efficacy and safety profiles of the technique, there are still many open questions. One of them deals with the effective electric field thresholds necessary for cardiac tissue ablation. Contrary to radiofrequency (RF) ablation, where the thermotemporal thresholds for tissue damage are well established, the electric field thresholds for effective IRE are uncertain and depend on the tissue type and the waveform characteristics of the delivered electric field. Purpose The use of numerical models to understand the electric field distribution and the corresponding lesion for a specific electrode geometry are widely used in IRE for cancer treatment. Models can predict ablation volumes when the field thresholds are known or can be used to estimate the field thresholds when the lesion geometry is established post-treatment. The goal of the present study was to build a subject-specific realistic 3D numerical model to assess the ability of modeling to predict PFA lesions. Methods PFA experiments were performed in male mongrel dogs following a protocol approved by the Mayo Clinic Institutional Animal Care and Use Committee. Briefly, animals were sedated and intubated, and two non-irrigated deflectable catheters with an 8-mm tip were positioned on both sides of the interventricular septum under fluoroscopy guidance. Submicrosecond pulses were delivered in a bipolar fashion across both catheters. Sequences of pulses of 300 ns duration (or other durations in that range) were repetitively applied with voltage levels in the kV range. 30 days after the procedure, MRI with late gadolinium enhancement (LGE) were acquired to assess the presence of ablation lesions in the treated tissue. Ventricular areas were segmented from MRI images and 3D volumes were created. The generated 3D geometries were imported into software COMSOL Multiphysics. Realistic 3D geometries of the catheters were placed in the same positions than during the experiments, fluoroscopy videos recorded during the procedures were used as a guidance. The computed electric field intensity distributions were compared to the LGE areas to extract the range of electric field thresholds where the predicted lesion size was compatible with the real size of the LGE areas for each application site and pulsing protocol. Results and conclusions Our results show how the numerical model is able to reproduce the shape of the LGE fibrotic lesion areas observed 30 days after the procedure. Additionally, the model clearly confirms the dose-dependent lesion sizes observed experimentally. This study supports that numerical modeling is a valuable tool for understanding PFA treatments and that it could be used as patient-specific treatment planning tool. Funding Acknowledgement Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie

Abstract Background Atrial fibrillation is associated with considerable morbidity and mortality. Real-world reports on the effect of early rhythm control on patient outcomes in patient with recent onset atrial fibrillation are limited. Purpose To assess the effect of early rhythm versus rate control on clinical outcomes in patients with newly diagnosed non-valvular atrial fibrillation. Method The Global Anticoagulant Registry in the FIELD-AF (GARFIELD-AF) is a non-interventional registry of adult (≥18 years) patients with newly diagnosed atrial fibrillation (≤ six weeks' duration) and at least one investigator determined risk factor for stroke. Patients were enrolled in 1317 participating sites in 35 countries between March 2010 and August 2016. Patients with permanent atrial fibrillation were excluded. Stratification to rhythm or rate control was based on treatment strategy initiated at baseline (≤48 days post enrolment). Rhythm control was defined as investigator reported initiation of rhythm control (antiarrhythmic drug(s), cardioversion, or ablation – alone or in combination with rate modifiers). Rate control was defined as investigator reported initiation of rate control and absence of rhythm control therapy. Overlap propensity weighting and Cox proportional-hazards models were used to evaluate effect on outcomes. Results Of 45,382 included patients, 23,858 (52.6%) received rhythm control and 21,524 (47.4%) rate control. Rates of rhythm control were similar throughout the study time period (52.7% in 2010/2011, 54.2% in 2015/2016). Patients in the rhythm control group were younger (median age (Q1; Q3) 68.0 (60.0; 76.0) versus 73.0 (65.0; 79.0)), had lower rates of prior stroke/transitory ischemic attack/systemic embolism (9.4% vs 13.0%), and a lower median GARFIELD death score (4.0 (2.3; 7.5) versus 5.1 (2.8; 9.2)). Median CHA2DS2-VASc Scores were 3.0 (2.0; 4.0) in both groups. Rate of anticoagulation treatment was similar in the rhythm and rate control group (66.0% versus 65.5%). After propensity score overlap weighting, patients of the two groups were well balanced on all observed characteristics. Event rates per 100 person-years (95% confidence interval [CI]) over two years follow-up in the rhythm and rate control group were 2.94 (2.78–3.10) versus 4.43 (4.22–4.64) for mortality, 0.84 (0.75–0.92) versus 1.16 (1.05–1.27) for non-haemorrhagic stroke/systemic embolism and 0.84 (0.76–0.93) versus 1.16 (1.06–1.27) for major bleeding. Adjusted hazard ratios (95% CI) for the same time period were 0.85 (0.79–0.92), 0.84 (0.72–0.97) and 0.9 (0.78–1.04). Conclusion In this large, internation registry, a rhythm control strategy was initiated at baseline in about half of the patients with newly diagnosed non-valvular atrial fibrillation. After adjustment for confounding factors, a significantly lower risk of all-cause mortality and non-haemorrhagic stroke/systemic embolism were observed for patients that received an early rhythm control strategy. Funding Acknowledgement Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): This work was supported by the Thrombosis Research Institute (London, UK).

Abstract Background Many patients with atrial fibrillation (AF) have comorbid vascular disease. The effects of oral anticoagulation (OAC) in AF patients with vascular disease, however, have not been widely studied. Purpose To investigate the impact of OAC in AF patients with (Vasc) or without (nVasc) concomitant vascular disease. Methods GARFIELD-AF is the largest multinational, prospective AF registry. The study comprised 51,574 GARFIELD-AF patients with newly diagnosed AF, 13,365 Vasc and 38,209 nVasc patients. All patients who reported coronary artery disease, aortic or peripheral artery disease, acute coronary syndromes, myocardial infarction, stenting, or coronary artery bypass graft were classified as having vascular disease. Adjusted hazard ratios were obtained via Cox proportional-hazards models to quantify the association of vascular disease with selected endpoints. Comparative effectiveness analyses were restricted to patients enrolled from April 2013-September 2016 (when NOACs became widely available) and who were eligible for anticoagulation (CHA2DS2-VASc ≥2 excl. gender). To evaluate the safety and efficacy of different anticoagulation strategies in Vasc and nVasc patients, propensity score using an overlap weighting scheme was applied. Weights were applied to Cox proportional-hazards models to estimate the effects of OAC vs No OAC and NOAC vs VKA. Results Vasc patients were older (median (Q1; Q3): 72.0 (65.0; 79.0) vs 70.0 (62.0; 78.0) and more often male (62.0 vs 53.6%). Vasc patients had a higher rate of comorbidities including heart failure, hypertension, and diabetes. Vasc patients received less OAC (62.8 vs 68.3%). NOACs were less common compared with nVasc patients (23.8% vs 28.7%) but a similar proportion of VKAs was observed in both (39.0% vs 39.6%). Antiplatelet monotherapy was more common in Vasc (31%) than nVasc (18%) patients. At 2-years, Vasc was associated with a higher risk of all-cause (HR [95% CI]: 1.30 [1.16–1.47]) and cardiovascular mortality (1.59 [1.28–1.97]). OACs significantly lowered the risk of all-cause mortality and stroke in nVasc patients (0.72 [0.63–0.82] and 0.64 [0.49–0.84], respectively), but not in nVasc patients. OACs led to a numerical increase in major bleeding in Vasc patients (1.32 [0.90–1.93]) and a significant increase in major bleeding in nVasc patients (1.40 [1.03–1.90]) (Figure 1). Compared with VKAs, NOACs did not significantly improve the risk of outcomes in nVasc patients. In Vasc patients however, NOACs significantly lowered the risk of all-cause mortality (0.74 [0.61–0.90]) and major bleeding (0.45 [0.29–0.70]) compared with VKAs (Figure 2). Conclusion AF patients with vascular disease have worse long-term outcomes than those without. They receive less often OAC, specifically NOAC, and more antiplatelet agents. The beneficial effects of NOAC over VKA are much more pronounced in patients with than in those without vascular disease. Funding Acknowledgement Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): This work was supported by the Thrombosis Research Institute (London, UK).

This selection from the NCCN Guidelines for Rectal Cancer focuses on management of malignant polyps and resectable nonmetastatic rectal cancer because important updates have been made to these guidelines. These recent updates include redrawing the algorithms for stage II and III disease to reflect new data supporting the increasingly prominent role of total neoadjuvant therapy, expanded recommendations for short-course radiation therapy techniques, and new recommendations for a “watch-and-wait” nonoperative management technique for patients with cancer that shows a complete response to neoadjuvant therapy. The complete version of the NCCN Guidelines for Rectal Cancer, available online at NCCN.org , covers additional topics including risk assessment, pathology and staging, management of metastatic disease, posttreatment surveillance, treatment of recurrent disease, and survivorship.

Background: Previous animal studies have shown no significant vascular injury from pulsed electrical field (PEF) ablation. We sought to assess the effect of PEF on swine coronary arteries. Methods: We performed intracoronary and epicardial (near the coronary artery) PEF ablations in swine pretreated with dual antiplatelet and antiarrhythmic therapy. Intracoronary PEF was delivered using MapiT catheters (Biotronik, Berlin), whereas epicardial PEF was delivered using EPT catheters (Boston Scientific, MA). PEF pulse duration was microseconds (Nanoknife 3.0, Angio Dynamics, NY) or nanoseconds (CellFX, Pulse Biosciences, CA). Results: We performed 39 intracoronary ablations in 10 swine and 20 epicardial-pericoronary ablations in 4 separate swine. Intracoronary PEF was delivered at higher energy compared with epicardial PEF (46 [interquartile range, IQR 20–85] J versus 10 [IQR 10–11] J, P < 0.01). Reversible coronary spasm occurred in 49% intracoronary ablations and 45% epicardial ablations ( P =0.80). At the end study, fixed coronary stenosis was demonstrated in 44% intracoronary ablations (80% for microsecond PEF and 18% for nanosecond PEF) and 0% epicardial ablations. Visible hemorrhagic and/or fibrotic myocardial lesions were observed at necropsy with similar frequency between intracoronary and epicardial PEF (45% versus 50%, P =0.70). Nanosecond PEF (49 ablations in 11 swine), when compared with microsecond PEF (10 intracoronary ablations in 3 swine), resulted in lower energy delivery (21 [IQR 10–46] J versus 129 [IQR 24–143] J, P =0.03) and less incidence of fixed coronary stenosis (18% versus 80%, P =0.04). Conclusions: In the swine model, intracoronary PEF resulted both in significant coronary spasm and fixed coronary stenosis. Epicardial PEF, delivered at lower energy, resulted in reversible spasm but no fixed coronary stenosis.

ImportanceThere is limited evidence for therapeutic options for pediatric COVID-19 outside of multisystem inflammatory syndrome in children (MIS-C).ObjectiveTo determine whether the use of steroids within 2 days of admission for non–MIS-C COVID-19 in children is associated with hospital length of stay (LOS). The secondary objective was to determine their association with intensive care unit (ICU) LOS, inflammation, and fever defervescence.Design, Setting, and ParticipantsThis cohort study analyzed data retrospectively for children (&amp;lt;18 years) who required hospitalization for non–MIS-C COVID-19. Data from March 2020 through September 2021 were provided by 58 hospitals in 7 countries who participate in the Society of Critical Care Medicine Discovery Viral Infection and Respiratory Illness Universal Study (VIRUS) COVID-19 registry.ExposureAdministration of steroids within 2 days of admission.Main Outcomes and MeasuresLength of stay in the hospital and ICU. Adjustment for confounders was done by mixed linear regression and propensity score matching.ResultsA total of 1163 patients met inclusion criteria and had a median (IQR) age of 7 years (0.9-14.3). Almost half of all patients (601/1163, 51.7%) were male, 33.8% (392/1163) were non-Hispanic White, and 27.9% (324/1163) were Hispanic. Of the study population, 184 patients (15.8%) received steroids within 2 days of admission, and 979 (84.2%) did not receive steroids within the first 2 days. Among 1163 patients, 658 (56.5%) required respiratory support during hospitalization. Overall, patients in the steroids group were older and had greater severity of illness, and a larger proportion required respiratory and vasoactive support. On multivariable linear regression, after controlling for treatment with remdesivir within 2 days, country, race and ethnicity, obesity and comorbidity, number of abnormal inflammatory mediators, age, bacterial or viral coinfection, and disease severity according to ICU admission within first 2 days or World Health Organization ordinal scale of 4 or higher on admission, with a random intercept for the site, early steroid treatment was not significantly associated with hospital LOS (exponentiated coefficient, 0.94; 95% CI, 0.81-1.09; P = .42). Separate analyses for patients with an LOS of 2 days or longer (n = 729), those receiving respiratory support at admission (n = 286), and propensity score–matched patients also showed no significant association between steroids and LOS. Early steroid treatment was not associated with ICU LOS, fever defervescence by day 3, or normalization of inflammatory mediators.Conclusions and RelevanceSteroid treatment within 2 days of hospital admission in a heterogeneous cohort of pediatric patients hospitalized for COVID-19 without MIS-C did not have a statistically significant association with hospital LOS.

Purpose. This randomized phase 2 study sought to assess the treatment effect of a finite duration of apalutamide with and without androgen deprivation therapy (ADT) in biochemically recurrent prostate cancer (BCR PC). Materials and Methods. Patients with BCR PC after primary definitive therapy and prostate-specific antigen (PSA) doubling time ≤12 months were randomized to open-label apalutamide (240 mg/d) alone, apalutamide plus ADT, or ADT alone (1 : 1:1 ratio) for 12 months followed by a 12-month observation period (NCT01790126). Mean changes from baseline in Functional Assessment of Cancer Therapy-Prostate (FACT-P) at 12 months (primary endpoint) and other prespecified assessments of health-related quality of life (HRQoL), PSA nadir, time to PSA progression, time to testosterone recovery, recovered testosterone >150 ng/dL without PSA progression at 24 months, and molecular markers were evaluated. Results. In 90 enrolled patients (apalutamide plus ADT (n = 31), apalutamide (n = 29), ADT (n = 30)), FACT-P at 12 months was not significantly different between apalutamide, ADT and apalutamide, and ADT groups. Addition of apalutamide to ADT prolonged time to PSA progression but this change did not reach statistical significance (hazard ratio (HR): 0.56, 95% confidence interval (CI): 0.23–1.36, P = 0.196 ); time to testosterone recovery was similar in the ADT-containing groups. In apalutamide plus ADT, apalutamide, and ADT groups, 37.9%, 37.0%, and 19.2% of patients, respectively, had testosterone >150 ng/dL at 24 months without confirmed PSA progression. Of the few biomarkers expressed in blood, EPHA3 was significantly associated with shorter time to PSA progression ( P = 0.02 ) in the overall population. Conclusions. HRQoL was similar in patients treated with apalutamide alone, ADT alone, or their combination, although apalutamide plus ADT did not demonstrate statistically significant noninferiority in change from baseline in overall HRQoL. The aggregated efficacy and safety outcomes support further evaluation of apalutamide plus ADT in BCR PC.

Abstract Among 1038 participants with pulmonary Mycobacterium avium complex and 120 with Mycobacterium abscessus enrolled in the US Bronchiectasis and NTM Research Registry, less than half received antibiotic therapy in the 24 months before registry enrollment, of which less than half were guideline based. Adverse effects occurred in 21% of therapy recipients, of whom 33% discontinued therapy.

Abstract We identified resistance mechanisms to abiraterone acetate/prednisone (AA/P) in patients with metastatic castration-resistant prostate cancer (mCRPC) in the Prostate Cancer Medically Optimized Genome-Enhanced Therapy (PROMOTE) study. We analyzed whole-exome sequencing (WES) and RNA-sequencing data from 83 patients with metastatic biopsies before (V1) and after 12 weeks of AA/P treatment (V2). Resistance was determined by time to treatment change (TTTC). At V2, 18 and 11 of 58 patients had either short-term (median 3.6 months; range 1.4–4.5) or long-term (median 29 months; range 23.5–41.7) responses, respectively. Nonresponders had low expression of TGFBR3 and increased activation of the Wnt pathway, cell cycle, upregulation of AR variants, both pre- and posttreatment, with further deletion of AR inhibitor CDK11B posttreatment. Deletion of androgen processing genes, HSD17B11, CYP19A1 were observed in nonresponders posttreatment. Genes involved in cell cycle, DNA repair, Wnt-signaling, and Aurora kinase pathways were differentially expressed between the responder and non-responder at V2. Activation of Wnt signaling in nonresponder and deactivation of MYC or its target genes in responders was detected via SCN loss, somatic mutations, and transcriptomics. Upregulation of genes in the AURKA pathway are consistent with the activation of MYC regulated genes in nonresponders. Several genes in the AKT1 axis had increased mutation rate in nonresponders. We also found evidence of resistance via PDCD1 overexpression in responders. Implications: Finally, we identified candidates drugs to reverse AA/P resistance: topoisomerase inhibitors and drugs targeting the cell cycle via the MYC/AURKA/AURKB/TOP2A and/or PI3K_AKT_MTOR pathways.