Research Spotlight

Fallahzadeh, M.A., Hansen, D.J., Trotter, J.F., Everson, G.T., Saracino, G., Rahimi, R.S., Helmke, S., Boutte, J. and Asrani, S.K. (2021). “Predicting clinical decompensation in patients with cirrhosis using the Hepquant-SHUNT test.” Aliment Pharmacol Ther 53(8): 928-938.

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BACKGROUND: Early identification of risk for decompensation in clinically stable cirrhotic patients helps specialists target early interventions and supports effective referrals from primary care providers to specialty centres. AIMS: To examine whether the HepQuant-SHUNT test (HepQuant LLC, Greenwood Village, Colorado, USA) predicts decompensation and the need for liver transplantation, hospitalisation or liver-related death. METHODS: Thirty-five compensated and 35 subjects with a previous episode of decompensation underwent the SHUNT Test and were followed for a median of 4.2 years. The disease severity index (DSI) (range 0-50) was examined for association with decompensation in compensated patients; and liver transplantation, liver-related death, and the number and days of liver related hospitalisations in all. DSI prediction of decompensation was also evaluated in 84 subjects with compensated cirrhosis from the Hepatitis C Antiviral Long-Term Treatment against Cirrhosis Trial (HALT-C) followed for a median of 5.8 years. RESULTS: At baseline, subjects with prior decompensation had significantly higher DSI than compensated subjects (32.6 vs 20.9, P < 0.001). DSI ≥24 distinguished the decompensated from the compensated patients and independently predicted adverse clinical outcomes (hazard ratio: 4.92, 95% confidence interval: 1.42-17.06). In the HALT-C cohort, 65% with baseline DSI ≥24 vs 19% with DSI <24 experienced adverse clinical outcomes (relative risk 3.45, P < 0.0001). CONCLUSIONS: The SHUNT test is a novel, noninvasive test that predicts risk of decompensation in previously compensated patients. DSI ≥24 is independently associated with risk for clinical decompensation, liver transplantation, death and hospitalisation.

Edwards, A.S., Kaplan, B. and Jie, T. (2021). “A Primer on Machine Learning.” Transplantation 105(4): 699-703.

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In transplant medicine, large collections of data from patients and various procedures have been stored and organized in registries and databases. With the increase in data volume, there has been a demand for tools that can handle the challenges presented by so-called “big data.” In recent years, mathematical and statistical tools such as machine learning are being utilized in an increasing number of analyses. In addition, machine learning has been utilized in various other domains in which a large amount of complex data needs to be interrogated (eg, genomics). Although the term “machine learning” has become a term commonly mentioned, the techniques, strengths, and limitations are often not fully understood by readers of transplant literature. This commentary will cover some of the history and basic concepts of machine learning. [No abstract; excerpt from article].

Doyle, J.D., Beacham, L., Martin, E.T., Talbot, H.K., Monto, A., Gaglani, M., Middleton, D.B., Silveira, F.P., Zimmerman, R.K., Alyanak, E., Smith, E.R., Flannery, B.L., Rolfes, M. and Ferdinands, J.M. (2021). “Relative and Absolute Effectiveness of High-Dose and Standard-Dose Influenza Vaccine Against Influenza-Related Hospitalization Among Older Adults-United States, 2015-2017.” Clin Infect Dis 72(6): 995-1003.

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BACKGROUND: Seasonal influenza causes substantial morbidity and mortality in older adults. High-dose inactivated influenza vaccine (HD-IIV), with increased antigen content compared to standard-dose influenza vaccines (SD-IIV), is licensed for use in people aged ≥65 years. We sought to evaluate the effectiveness of HD-IIV and SD-IIV for prevention of influenza-associated hospitalizations. METHODS: Hospitalized patients with acute respiratory illness were enrolled in an observational vaccine effectiveness study at 8 hospitals in the United States Hospitalized Adult Influenza Vaccine Effectiveness Network during the 2015-2016 and 2016-2017 influenza seasons. Enrolled patients were tested for influenza, and receipt of influenza vaccine by type was recorded. Effectiveness of SD-IIV and HD-IIV was estimated using a test-negative design (comparing odds of influenza among vaccinated and unvaccinated patients). Relative effectiveness of SD-IIV and HD-IIV was estimated using logistic regression. RESULTS: Among 1487 enrolled patients aged ≥65 years, 1107 (74%) were vaccinated; 622 (56%) received HD-IIV, and 485 (44%) received SD-IIV. Overall, 277 (19%) tested positive for influenza, including 98 (16%) who received HD-IIV, 87 (18%) who received SD-IIV, and 92 (24%) who were unvaccinated. After adjusting for confounding variables, effectiveness of SD-IIV was 6% (95% confidence interval [CI] -42%, 38%) and that of HD-IIV was 32% (95% CI -3%, 54%), for a relative effectiveness of HD-IIV versus SD-IIV of 27% (95% CI -1%, 48%). CONCLUSIONS: During 2 US influenza seasons, vaccine effectiveness was low to moderate for prevention of influenza hospitalization among adults aged ≥65 years. High-dose vaccine offered greater effectiveness. None of these findings were statistically significant.

Davis, A.P., Wilson, G.M., Erwin, J.P., 3rd, Michel, J.B., Banchs, J., Saeed, A. and Widmer, R.J. (2021). “Use of Web-Based Patient Portals in Patients With Atrial Fibrillation Is Associated With Higher Readmissions.” Ochsner J 21(1): 25-29.

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Background: The impact of web-based patient portals on patient outcomes-specifically hospital readmissions in patients with atrial fibrillation (AF)-remains understudied. Methods: This single-center retrospective cohort study investigated the use of an online portal system (MyChart) by patients hospitalized from January 1, 2014 to June 30, 2017 for AF. During the study period, 11,334 unique AF admissions were identified; 50.3% were MyChart users and 49.7% were non-MyChart users. Patients who experienced inpatient mortality were excluded. The study groups were analyzed for demographic variables, comorbidities, readmission rates, and the frequency of MyChart use during the 3.5-year time frame. Results: MyChart users were younger (median age, 74 years, interquartile range [IQR] 66-82 vs 77 years, IQR 68-85; P<0.0001) and more likely to be white (91.9% vs 84.6%; P<0.0001), but the sex distribution was similar between groups, with 51.8% males in the MyChart group vs 53.2% in the non-MyChart group. MyChart users had a significantly higher rate of readmission compared to non-MyChart users at 1 year (43.0% vs 32.0%, respectively; P<0.0001). MyChart users who were readmitted had a higher median number of logins to MyChart (121 [IQR 32-270.5]) than MyChart users who were not readmitted (91 [IQR 26-205]; P<0.0001). Multivariable regression analysis demonstrated that MyChart use was associated with readmission (odds ratio 1.57, 95% CI 1.49-1.70; P<0.0001). Conclusion: Among patients with AF, MyChart use was associated with higher readmissions in this single-center cohort. Use and benefit of bespoke portals require further study.

Davidson, C.J., Abramson, S., Smith, R.L., Kodali, S.K., Kipperman, R.M., Eleid, M.F., Reisman, M., Whisenant, B.K., Puthumana, J., Fowler, D., Grayburn, P.A., Hahn, R.T., Koulogiannis, K., Pislaru, S.V., Zwink, T., Minder, M., Deuschl, F., Feldman, T., Gray, W.A. and Lim, D.S. (2021). “Transcatheter Tricuspid Repair With the Use of 4-Dimensional Intracardiac Echocardiography.” JACC Cardiovasc Imaging Mar 10;S1936-878X(21)00153-4. [Epub ahead of print].

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We report the systematic use of 4-dimensional intracardiac echocardiography (4D-ICE) as an intraprocedural imaging modality in transcatheter annular repair therapies. Twenty-six patients enrolled in the U.S. Food and Drug Administration–approved early feasibility study were analyzed to compare 4D-ICE and TEE. Results showed that 4D-ICE was predominantly used in the lateral annulus (Figures 2 and 3) and improved visualization compared with TEE. [No abstract; excerpt from article].