Algebraic topology-based machine learning using MRI predicts outcomes in primary sclerosing cholangitis.

BACKGROUND: Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease that can lead to cirrhosis and hepatic decompensation. However, predicting future outcomes in patients with PSC is challenging. Our aim was to extract magnetic resonance imaging (MRI) features that predict the development of hepatic decompensation by applying algebraic topology-based machine learning (ML). METHODS: We conducted a retrospective multicenter study among adults with large duct PSC who underwent MRI. A topological data analysis-inspired nonlinear framework was used to predict the risk of hepatic decompensation, which was motivated by algebraic topology theory-based ML. The topological representations (persistence images) were employed as input for classification to predict who developed early hepatic decompensation within one year after their baseline MRI. RESULTS: We reviewed 590 patients; 298 were excluded due to poor image quality or inadequate liver coverage, leaving 292 potentially eligible subjects, of which 169 subjects were included in the study. We trained our model using contrast-enhanced delayed phase T1-weighted images on a single center derivation cohort consisting of 54 patients (hepatic decompensation, n = 21; no hepatic decompensation, n = 33) and a multicenter independent validation cohort of 115 individuals (hepatic decompensation, n = 31; no hepatic decompensation, n = 84). When our model was applied in the independent validation cohort, it remained predictive of early hepatic decompensation (area under the receiver operating characteristic curve = 0.84). CONCLUSIONS: Algebraic topology-based ML is a methodological approach that can predict outcomes in patients with PSC and has the potential for application in other chronic liver diseases.

Rates of rebleeding, thrombosis and mortality associated with resumption of anticoagulant therapy after anticoagulant-related bleeding.

BACKGROUND: Data on resuming oral anticoagulants (OACs) after bleeding are primarily from studies involving patients given warfarin, with few data on direct OACs (DOACs). We aimed to characterize prescribing patterns for OACs after OAC-related bleeding and compare the rates of bleeding, thrombosis and mortality in patients who resumed either type of OAC with those who did not. METHODS: We conducted a population-based cohort study of adults aged 66 years or older who were admitted to hospital for bleeding while receiving OACs from Apr. 1, 2012, to Mar. 31, 2017, using linked administrative health databases from Ontario. We used competing risk methods to calculate cause-specific adjusted hazard ratios (HRs) for thrombosis, bleeding and mortality with resumption of OACs adjusted as a time-varying covariate. We determined time to OAC resumption using the Kaplan-Meier method. RESULTS: We included 6793 patients with gastrointestinal (n = 4297, 63.3%), intracranial (n = 805, 11.9%) or other bleeding (n = 1691, 25.0%). At cohort entry, 3874 patients (57.0%) were prescribed warfarin and 2919 patients (43.0%) were prescribed a DOAC. The most common indication for OAC was atrial fibrillation (n = 5557, 81.8%), followed by venous thromboembolism (n = 1367, 20.1%). Oral anticoagulants were resumed in 4792 patients (70.5%) within 365 days of the index bleed. The median time to resumption was 46 (interquartile range 6-550) days. We found that resuming OAC was associated with reduced rates of thrombosis (adjusted HR 0.60, 95% confidence interval [CI] 0.50-0.72) and mortality (adjusted HR 0.54, 95% CI 0.48-0.60), and an increased rate of rebleeding (adjusted HR 1.88, 95% CI 1.64-2.17). INTERPRETATION: We found that resuming OAC is associated with a reduction in thrombosis and mortality but an increase in bleeding. Randomized controlled trials that evaluate the net benefit of strategies for resumption of OAC after a bleeding event are warranted.

Management of antithrombotic therapy after gastrointestinal bleeding: A mixed methods study of health-care providers.

Essentials The factors influencing anticoagulation management after gastrointestinal bleeding are unclear. Focus groups and a discrete choice experiments survey of health-care providers were conducted. Re-bleeding risk and thrombosis risk were the most important factors influencing decision making. Preference variability exists with a minority most sensitive to the anticoagulation indication. ABSTRACT: Background Oral anticoagulants (OACs) are permanently discontinued in up to 50% of patients after gastrointestinal (GI) bleeding despite evidence of benefit to restarting. Objectives We aimed to identify factors influencing health-care provider decision making regarding resuming OAC after GI bleeding and to identify preference groups. Patients/Methods We conducted focus group discussions (FGDs) with health-care providers. Themes identified and ranked through a dot voting exercise became the attributes for a discrete choice experiment survey of health-care providers developed using Sawtooth (Sawtooth Software, Provo, UT, USA). Hierarchical Bayes analysis was used to estimate preference coefficients (utilities) for each attribute. Preference groups were identified using latent class analysis. Results We conducted four FGDs involving 29 participants. The five most important factors identified in the FGDs were included in the survey. There were 250 survey respondents (mean age 45 years, 53% male). The most important factor was re-bleeding risk followed by thrombosis risk, index bleed severity, indication for OAC, and patient characteristics. Two preference groups were identified, a majority group (87% of respondents) placed the highest utility on re-bleeding risk followed by thrombosis risk, while a minority group (13% of respondents) placed the highest utility on OAC indication. Conclusions Overall, the most important factor influencing provider decision making was re-bleeding risk followed closely by thrombosis risk, although the indication for OAC was most important for a minority of respondents. This highlights variability among providers in an area lacking high-quality data to guide practice. Further research is needed to determine absolute rates of outcomes and patient values and preferences.

Effectiveness of Dose De-escalation of Biologic Therapy in Inflammatory Bowel Disease: A Systematic Review.

INTRODUCTION: De-escalation of biologic therapy is a commonly encountered clinical scenario. Although biologic discontinuation has been associated with high rates of relapse, the effectiveness of dose de-escalation is unclear. This review was performed to determine the effectiveness of dose de-escalation of biologic therapy in inflammatory bowel disease. METHODS: We searched EMBASE, MEDLINE, and the Cochrane Central Register of Controlled Trials from inception to October 2019. Randomized controlled trials and observational studies involving dose de-escalation of biologic therapy in adults with inflammatory bowel disease in remission were included. Studies involving biologic discontinuation only and those lacking outcomes after dose de-escalation were excluded. Risk of bias was assessed using the Newcastle-Ottawa Scale. RESULTS: We identified 1,537 unique citations with 20 eligible studies after full-text review. A total of 995 patients were included from 18 observational studies (4 prospective and 14 retrospective), 1 nonrandomized controlled trial, and 1 subgroup analysis of a randomized controlled trial. Seven studies included patients with Crohn's disease, 1 included patients with ulcerative colitis, and 12 included both. Overall, clinical relapse occurred in 0%-54% of patients who dose de-escalated biologic therapy (17 studies). The 1-year rate of clinical relapse ranged from 7% to 50% (6 studies). Eighteen studies were considered at high risk of bias, mostly because of the lack of a control group. DISCUSSION: Dose de-escalation seems to be associated with high rates of clinical relapse; however, the quality of the evidence was very low. Additional controlled prospective studies are needed to clarify the effectiveness of biologic de-escalation and identify predictors of success.

Venous Thromboembolism in Patients with Liver Cirrhosis: Findings from the RIETE (Registro Informatizado de la Enfermedad TromboEmbolica) Registry.

Patients with cirrhosis are not only at an increased risk of bleeding but also at risk of venous thromboembolism (VTE). We sought to determine the clinical characteristics, management, and outcomes after VTE in patients with cirrhosis. We used the data from RIETE (Registro Informatizado de la Enfermedad TromboEmbolica), an international registry of patients with VTE, to compare the outcomes in patients with and without cirrhosis. Main outcomes included all-cause mortality, pulmonary embolism (PE)-related mortality, recurrent VTE, and bleeding. Among 43,611 patients with acute VTE, 187 (0.4%) had cirrhosis. Of these, 184 (98.4%) received anticoagulation for a median of 109 days (interquartile range [IQR]: 43-201 days), most commonly with enoxaparin (median dose: 1.77 [IQR: 1.38-2.00] mg/kg/day). Compared with patients without cirrhosis, those with cirrhosis had a higher rate of all-cause mortality (10.7 vs. 3.4%; odds ratio [OR]: 3.41; 95% confidence interval [CI]: 2.03-5.46) and fatal bleeding (2.1 vs. 0.2%; OR: 13.94; 95% CI: 3.65-37.90) but similar rates of fatal PE (0.5 vs. 0.5%; OR: 1.17; 95% CI: 0.03-6.70). Patients with cirrhosis had a higher rate of all-cause mortality per 100 patient-years of follow-up (58.9 vs. 16.0; hazard ratio [HR]: 3.70; 95% CI: 2.69-4.91). One-year hazard ratio of clinically relevant bleeding (HR: 2.86; 95% CI: 1.91-4.27), fatal bleeding (HR: 8.51; 95% CI: 3.5-20.7), or recurrent VTE (HR: 2.08; 95% CI: 1.00-4.36) was higher in patients with cirrhosis. Cirrhosis is a challenging comorbidity in patients with VTE. Most patients were treated with anticoagulation and had an elevated risk of recurrence, similar risk of fatal PE, and a very high risk of bleeding including fatal bleeds.

Spatial Convergence in Major Dissolved Ion Concentrations and Implications of Headwater Mining for Downstream Water Quality.

Spatial patterns in major dissolved solute concentrations were examined to better understand impact of surface coal mining in headwaters on downstream water chemistry. Sixty sites were sampled seasonally from 2012 to 2014 in an eastern Kentucky watershed. Watershed areas (WA) ranged from 1.6 to 400.5 km2 and were mostly forested (58%-95%), but some drained as much as 31% surface mining. Measures of total dissolved solutes and most component ions were positively correlated with mining. Analytes showed strong convergent spatial patterns with high variability in headwaters (<15 km2 WA) that stabilized downstream (WA > 75 km2), indicating hydrologic mixing primarily controls downstream values. Mean headwater solute concentrations were a good predictor of downstream values, with % differences ranging from 0.55% (Na+) to 28.78% (Mg2+). In a mined scenario where all headwaters had impacts, downstream solute concentrations roughly doubled. Alternatively, if mining impacts to headwaters were minimized, downstream solute concentrations better approximated the 300 µS/cm conductivity criterion deemed protective of aquatic life. Temporal variability also had convergent spatial patterns and mined streams were less variable due to unnaturally stable hydrology. The highly conserved nature of dissolved solutes from mining activities and lack of viable treatment options suggest forested, unmined watersheds would provide dilution that would be protective of downstream aquatic life.

The meaning of caring from the perspectives of patients undergoing physical therapy.

UNLABELLED: This research note describes a pilot study that examined the meaning of caring from the perspectives of patients undergoing physical therapy. METHODS: A phenomenological methodology was used to explore the essential meaning of caring behaviors from the experiences of patients undergoing physical therapy. Patients were asked to describe caring interactions they have experienced with their physical therapists. RESULTS: The responses of the participants were inductively analyzed for themes and sub-themes that explained physical therapy caring. Based on that analysis, a central theme of mindful caring emerged from participants' responses. The theme of mindful caring reflected the physical therapist and patient relationship. Further analysis uncovered four sub-themes that gave a clearer picture of caring behaviors experienced by the participants. These included personal values, patient empowerment, open communication and exceptional service. CONCLUSION: The results of this pilot study demonstrate the dimensions of caring in healthcare practice from the unique perspectives of patients.