Research Spotlight

Flannery, B., J. R. Chung, A. S. Monto, E. T. Martin, E. A. Belongia, H. Q. McLean, M. Gaglani, K. Murthy, R. K. Zimmerman, M. P. Nowalk, M. L. Jackson, L. A. Jackson, M. A. Rolfes, S. Spencer and A. M. Fry (2019). “Influenza Vaccine Effectiveness in the United States During the 2016-2017 Season.” Clin Infect Dis 68(11): 1798-1806.

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BACKGROUND: In recent influenza seasons, the effectiveness of inactivated influenza vaccines against circulating A(H3N2) virus has been lower than against A(H1N1)pdm09 and B viruses, even when circulating viruses remained antigenically similar to vaccine components. METHODS: During the 2016-2017 influenza season, vaccine effectiveness (VE) across age groups and vaccine types was examined among outpatients with acute respiratory illness at 5 US sites using a test-negative design that compared the odds of vaccination among reverse transcription polymerase chain reaction-confirmed influenza positives and negatives. RESULTS: Among 7083 enrollees, 1342 (19%) tested positive for influenza A(H3N2), 648 (9%) were positive for influenza B (including B/Yamagata, n = 577), and 5040 (71%) were influenza negative. Vaccine effectiveness was 40% (95% confidence interval [CI], 32% to 46%) against any influenza virus, 33% (95% CI, 23% to 41%) against influenza A(H3N2) viruses, and 53% (95% CI, 43% to 61%) against influenza B viruses. CONCLUSIONS: The 2016-2017 influenza vaccines provided moderate protection against any influenza among outpatients but were less protective against influenza A(H3N2) viruses than B viruses. Approaches to improving effectiveness against A(H3N2) viruses are needed.

Fitzgerald, S., D. Dai, S. Wang, A. Douglas, R. Kadirvel, K. F. Layton, I. C. Thacker, M. J. Gounis, J. Y. Chueh, A. S. Puri, M. Almekhlafi, A. M. Demchuk, R. A. Hanel, E. Sauvageau, A. Aghaebrahim, A. J. Yoo, P. Kvamme, M. P. V, Y. Kayan, J. E. Delgado Almandoz, R. G. Nogueira, A. A. Rabinstein, D. F. Kallmes, K. M. Doyle and W. Brinjikji (2019). “Platelet-Rich Emboli in Cerebral Large Vessel Occlusion Are Associated With a Large Artery Atherosclerosis Source.” Stroke May 29. [Epub ahead of print].

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Background and Purpose. Nearly 30% of large vessel occlusion acute ischemic stroke clots are from an unknown source. We assessed histological clot composition in a series of patients with large vessel occlusion and investigated correlations between clot composition and stroke pathogenesis. Methods. As part of the multi-institutional STRIP registry (Stroke Thromboembolism Registry of Imaging and Pathology), consecutive emboli retrieved during mechanical thrombectomy were stained using Martius Scarlett Blue and analyzed using machine learning software. We assessed proportions of red blood cells, fibrin, platelets, and white blood cells. Correlations between clot components and stroke pathogenesis (large artery atherosclerosis, cardioembolism, and stroke of undetermined pathogenesis) were assessed using SPSS22. Results. One hundred five patients were included. The proportion of platelet-rich clots (55.0% versus 21.2%; P=0.005) and percentage of platelet content (22.1+/-4.2% versus 13.9+/-14.2%; P=0.03) was significantly higher in the large artery atherosclerosis group compared with the cardioembolic group. The proportion of platelet-rich clots (50.0% versus 21.2%; P=0.024) was also significantly higher in the cryptogenic group compared with cardioembolic cases. Large artery atherosclerosis and cryptogenic cases had a similar proportion of platelet-rich clots (55.0% versus 50.0%; P=0.636). There was no significant difference between stroke pathogenesis and the other major clot components. Conclusions. High platelet content of emboli is associated with a large artery atherosclerosis etiology of large vessel occlusion.

Feld, J. J., N. A. Terrault, H. S. Lin, S. H. Belle, R. T. Chung, N. Tsai, M. Khalili, R. Perrillo, S. L. Cooper, M. G. Ghany, H. L. A. Janssen and A. S. Lok (2019). “Entecavir and Peginterferon Alfa-2a in Adults With Hepatitis B e Antigen-Positive Immune-Tolerant Chronic Hepatitis B Virus Infection.” Hepatology 69(6): 2338-2348.

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Monotherapy with interferon or nucleoside analog is generally not recommended during the immune-tolerant (IT) phase of chronic hepatitis B virus (HBV) infection. Recognition that high HBV DNA levels are associated with hepatocellular carcinoma has increased interest in treating HBV in the IT phase. Small pediatric studies reported efficacy with combination nucleoside analog and interferon therapy. The aim of this study was to evaluate the safety and efficacy of the combination of entecavir and peginterferon in adults in the IT phase of chronic HBV infection. Hepatitis B e antigen (HBeAg)-positive adults with HBV DNA > 10(7) IU/mL and alanine aminotransferase (ALT) 5 times the ULN occurred in eight (29%) participants, and none were associated with icterus. Forty-eight weeks posttreatment, HBV DNA rebounded to baseline levels in all participants, including the participant who lost HBeAg, and ALT values returned to near baseline levels in all but four participants. Conclusion: A lead-in strategy of 8 weeks of entecavir followed by combination peginterferon and entecavir therapy for 40 weeks had limited efficacy in adults in the IT phase of chronic HBV infection and cannot be recommended.

Driver, S., S. Juengst, E. E. McShan, M. Bennett, K. Bell and R. Dubiel (2019). “A randomized controlled trial protocol for people with traumatic brain injury enrolled in a healthy lifestyle program (GLB-TBI).” Contemp Clin Trials Commun 14: 100328. eCollection 2019 June.

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Weight gain is prevalent among people with traumatic brain injury (TBI) and may be attributable to environmental or injury-specific factors such as mobility impairment, endocrine dysfunction, behavioral and emotional disorders, and sensory loss. Few weight management programs exist to meet the unique needs of this population. Researchers modified a nationally recognized, evidence-based weight-loss program, Group Lifestyle Balance (GLB), to address the needs of over-weight and obese people post TBI (GLB-TBI). This current randomized controlled trial (RCT) examines the efficacy of the GLB-TBI on weight and secondary outcomes compared to an attention control educational support group. Furthermore, researchers have developed a mobile technology app to further engage participants in the program. This RCT will enroll and randomize 66 participants over a two-year period. It is anticipated that findings from this current RCT will contribute to the knowledge and evidence for an effective weight-loss intervention among this underserved population, with a goal of achieving full recognition by the Centers for Disease Control and Prevention-National Diabetes Prevention Program and subsequent Center for Medicare and Medicaid Services reimbursement for participation.

DeRose, J. J., Jr., D. M. Mancini, H. L. Chang, M. Argenziano, F. Dagenais, G. Ailawadi, L. P. Perrault, M. K. Parides, W. C. Taddei-Peters, M. J. Mack, D. D. Glower, B. A. Yerokun, P. Atluri, J. C. Mullen, J. D. Puskas, K. O’Sullivan, N. M. Sledz, H. Tremblay, E. Moquete, B. S. Ferket, A. J. Moskowitz, A. Iribarne, A. C. Gelijns, P. T. O’Gara, E. H. Blackstone and A. M. Gillinov (2019). “Pacemaker Implantation After Mitral Valve Surgery With Atrial Fibrillation Ablation.” J Am Coll Cardiol 73(19): 2427-2435.

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BACKGROUND: The incidence of permanent pacemaker (PPM) implantation is higher following mitral valve surgery (MVS) with ablation for atrial fibrillation (AF) compared with MVS alone. OBJECTIVES: This study identified risk factors and outcomes associated with PPM implantation in a randomized trial that evaluated ablation for AF in patients who underwent MVS. METHODS: A total of 243 patients with AF and without previous PPM placement were randomly assigned to MVS alone (n = 117) or MVS + ablation (n = 126). Patients in the ablation group were further randomized to pulmonary vein isolation (PVI) (n = 62) or the biatrial maze procedure (n = 64). Using competing risk models, this study examined the association among PPM and baseline and operative risk factors, and the effect of PPM on time to discharge, readmissions, and 1-year mortality. RESULTS: Thirty-five patients received a PPM within the first year (14.4%), 29 (83%) underwent implantation during the index hospitalization. The frequency of PPM implantation was 7.7% in patients randomized to MVS alone, 16.1% in MVS + PVI, and 25% in MVS + biatrial maze. The indications for PPM were similar among patients who underwent MVS with and without ablation. Ablation, multivalve surgery, and New York Heart Association functional (NYHA) functional class III/IV were independent risk factors for PPM implantation. Length of stay post-surgery was longer in patients who received PPMs, but it was not significant when adjusted for randomization assignment (MVS vs. ablation) and age (hazard ratio [HR]: 0.81; 95% confidence interval [CI]: 0.61 to 1.08; p = 0.14). PPM implantation did not increase 30-day readmission rate (HR: 1.43; 95% CI: 0.50 to 4.05; p = 0.50). The need for PPM was associated with a higher risk of 1-year mortality (HR: 3.21; 95% CI: 1.01 to 10.17; p = 0.05) after adjustment for randomization assignment, age, and NYHA functional class. CONCLUSIONS: AF ablation, multivalve surgery, and NYHA functional class III/IV were associated with an increased risk for permanent pacing. PPM implantation following MVS was associated with a significant increase in 1-year mortality. (Surgical Ablation Versus No Surgical Ablation for Patients With Atrial Fibrillation Undergoing Mitral Valve Surgery; NCT00903370).