ABSTRACT Purpose The purpose of this study was to evaluate the incidence and risk factors for developing recurrent clinically significant cytomegalovirus infections (csCMVi) in heart transplant recipients. Methods We conducted a retrospective cohort study involving adult heart transplant recipients at three large transplant centers in the United States between January 2011 and March 2019. All patients with a history of csCMVi, defined as CMV disease or CMV infection requiring preemptive therapy, were followed from the date of treatment completion for the primary csCMVi episode. Outcomes of interest were recurrent csCMVi and all‐cause mortality. Results Among 98 heart transplant recipients with csCMVi, 22 (22.4%) episodes of recurrent csCMVi occurred. Median time‐to‐recurrent csCMVi was 31.5 (IQR 21.3–59.8) days following treatment completion. A preceding episode of CMV disease (versus infection) was associated with a lower risk of recurrent csCMVi (HR 0.29, 95% CI 0.08–0.98; p = 0.047). Patients with lymphopenia had higher rates of recurrent csCMVi without statistical significance (HR 2.13, 95% CI 0.88–5.13; p = 0.093). Seroconversion by the end‐of‐therapy among CMV D+/R− mismatched patients was associated with a reduced risk of csCMVi recurrence (HR 0.07, 95% CI 0.02–0.30; p < 0.001). Overall, 17 (17.3%) patients died during follow‐up, which was not significantly higher among those with recurrent csCMVi (HR 2.13, 95% CI 0.78–5.79; p = 0.141). Conclusions About one in five heart recipients with csCMVi developed post‐treatment recurrence. A preceding episode of CMV disease and seroconversion was protective against recurrence. Lymphopenia may be a practical biomarker to stratify recurrence risk. Overall, recurrent csCMVi was not significantly associated with mortality.
Left ventricular assist device (LVAD) thrombosis typically presents late and may have devastating consequences for patients. While LVAD pump thrombosis is uncommon with current pump designs, many patients worldwide remain supported with previous generations of LVADs, including the HeartWare device (HVAD). Researchers have focused on investigating the acoustic signatures of LVADs to enable earlier detection and treatment of this condition. This study explored the use of machine learning algorithms to predict thrombosis from harmonic power values determined from the acoustic signatures of a cohort of HVAD patients (n = 11). The current dataset was too small to develop a predictive model for new data, but exhaustive cross validation indicated that machine learning models using the first two or the first three harmonic power values both resulted in reasonable prediction accuracy of the thrombosis outcome. Furthermore, when principal component analysis (PCA) was applied to the harmonic power variables from these promising models, the use of the resulting PCA variables in machine learning models further increased the thrombosis outcome prediction accuracy. K-nearest neighbor (KNN) models gave the best predictive accuracy for this dataset. Future work with a larger HVAD recording dataset is necessary to develop a truly predictive model of HVAD thrombosis. Such a predictive model would provide clinicians with a marker to detect HVAD thrombosis based directly on pump performance, to be used along with current clinical markers.
P-709. Risk factors for hypoxia and mechanical ventilation in Respiratory Syncytial Virus (RSV) infections in hospitalized solid organ transplant recipients (SOTR)
Abstract Background RSV is a common respiratory infection that causes significant morbidity in SOTR. However, risk factors for complications such as hypoxic respiratory failure, mechanical ventilation, and secondary infections have not been well described. Methods This retrospective, international, multicenter cohort study is actively recruiting SOTR hospitalized with RSV. Here, we analyzed data from Mayo Clinic (Rochester, Florida, Arizona), Miami Transplant Institute, Cleveland Clinic, and Royal Melbourne Hospital between 2016 and 2019. Secondary infection was defined as culture positive infection within 90 days of RSV diagnosis. Whenever appropriate, logistic and Cox regression analysis were conducted to identify risk factors. Survival functions were estimated using the Kaplan-Meier method.Figure 1:Forest plots of multivariable logistic regression models for risk factors for A) hypoxia, B) secondary infections, C) mechanical ventilation. Note: all variables included are the ones statistically significant on univariate analysis. Abbreviations: CI, confidence interval; OR, Odds ratio; LRTI: lower respiratory tract infection. Results 233 SOTRs (58.8% male; median, 61 years), including 77 (49.1%) kidney, 23 (9.9%) liver, 79 (33.9%) lung, and 38 (16.3%) heart transplants (Table). Hypoxic respiratory failure, mechanical ventilation, and secondary infection were seen in 98 (42.1%), 23 (9.9%), and 58 (24.9%) patients, respectively. After multivariate analysis, age >60 years, symptoms and imaging evidence of lower respiratory tract infection (LRTI) were associated with oxygen requirement (Figure 1A); similar results were observed in an analysis of the lung transplant cohort only. Risk factors on multivariate analysis for secondary infection include a history of rejection within six months and mechanical ventilation (Figure 1B). Risk factors for mechanical ventilation included age >60 years and LRTI on imaging (Figure 1C) after multivariate analysis. Seventeen (7.3%) patients died within 90 days of diagnosis. Cox univariate analysis identified age >60 years and LRTI on imaging, secondary infections, mechanical ventilation and hypoxia on admission were associated with higher mortality (Figure 2 and 3).Figure 2:Forest plot with Cox proportional hazards models. Note: only univariate results shown, multivariate not done due to low number of events. Conclusion This multicenter study of SOTR hospitalized with RSV identified older age ( >60 years old) as a risk factor for hypoxic respiratory failure, mechanical ventilation and death. Mechanical ventilation and a history if rejection within six months of RSV were associated with increased risk of secondary infections, identifying them as high-risk that needs close surveillance for this complication.Figure 3:Effects of A) Age older than 60 years old and B) mechanical ventilation on 90 day probability of survival after RSV infection Disclosures Michelle Yong, MBBS, FRACP, MPH, PhD, MSD: Grant/Research Support|MSD: Honoraria|Takeda: Advisor/Consultant Yoichiro Natori, MD, Eurofin/Viracor: Honoraria|Nobel Pharma: Advisor/Consultant
Comparative Effectiveness of Outpatient COVID‐19 Therapies in Solid Organ Transplant Recipients
ABSTRACT Background Multiple outpatient therapies have been developed for COVID‐19 in high‐risk individuals, but solid organ transplant (SOT) recipients were not well represented in controlled clinical trials. To date, few comparative studies have evaluated outcomes between outpatient therapies in this population. Methods We performed a retrospective cohort study using de‐identified administrative claims data from OptumLabs Data Warehouse. Patients were included if they were age ≥ 18 years, diagnosed with COVID‐19 between January 2022 and December 2023, and underwent SOT prior to COVID‐19. The primary outcome was 30‐day hospitalization. Stabilized inverse probability of treatment weighting was used to account for potential confounding variables. Results 4192 SOT recipients with COVID‐19 were identified. 1403 received an outpatient COVID‐19 therapy, including anti‐spike monoclonal antibodies ( N = 748, 53.3%), molnupiravir ( N = 327, 23.3%), ritonavir‐boosted nirmatrelvir ( N = 217, 15.5%), or remdesivir ( N = 141, 10.0%). In weighted analysis compared to no treatment, anti‐spike monoclonal antibodies (hazard ratio [HR] 0.39, 95% confidence interval [CI] 0.28–0.55; p < 0.001), molnupiravir (HR 0.56, 95% CI 0.36–0.89; p = 0.013), and nirmatrelvir (HR 0.47, 95% CI 0.25–0.89; p = 0.020) were associated with reduced hospitalization risk, while remdesivir (HR 1.00, 95% CI 0.50–1.98; p = 0.992) was not. Hospitalization rates were similar between the treatment agents, apart from remdesivir showing a higher risk compared to anti‐spike monoclonal antibodies. Conclusions Outpatient COVID‐19 therapies were largely associated with improved outcomes among SOT recipients. These treatment agents showed similar rates of 30‐day hospitalization, except for remdesivir. The choice of outpatient COVID‐19 therapy in SOT recipients should primarily account for patients’ individual circumstances and drug‐drug interactions rather than differential therapeutic efficacy. image
Clinical utility of two-step hepatitis E virus IgM antibody testing in a low-prevalence setting: A 10-year retrospective multicenter study
Background: Diagnostic uncertainty caused by the low positive predictive value of HEV-specific IgM antibody (Ab) testing in a low-prevalence setting. We investigated the utility of a two-step HEV IgM Ab testing approach for diagnosing HEV infection. Methods: We retrospectively reviewed all adults who underwent HEV IgM Ab and/or HEV RNA testing from July 2013 through June 2023 at Mayo Clinic. Two-step HEV IgM testing involved initial testing using recomWell HEV IgM ELISA (Mikrogen, Neuried, Germany), with reflex to recomLine HEV IgM Strip (Mikrogen, Neuried, Germany) on all recomWell HEV IgM-reactive or IgM-equivocal specimens, as recomLine HEV IgM has higher specificity than recomWell HEV IgM but is more labor-intensive. Results: A total of 1640 patients had HEV IgM Ab or HEV RNA testing, including 1293 (79%) with only HEV IgM Ab testing, 213 (13%) with only HEV RNA testing, and 134 (8%) with both HEV IgM Ab and HEV RNA testing. Eighteen HEV infections were diagnosed with acute (N=16) and chronic (N=2) infections. Two-step IgM Ab testing did not identify 2 solid organ transplant recipients with chronic HEV infection. In acute HEV infection with HEV viremia, 3 out of 4 patients (2 solid organ transplant recipients and 1 patient with Guillain-Barre syndrome) were treated with ribavirin. Conclusions: A two-step HEV IgM Ab test may accurately diagnose acute HEV infection in immunocompetent persons. However, this approach fails to identify chronic HEV infection in immunocompromised individuals who need HEV RNA testing to establish the diagnosis.
Cytomegalovirus Infection After Solid Organ Transplantation: How I Use Cell-Mediated Immune Assays for Management
Introduction: The pathogenesis and outcome of cytomegalovirus (CMV) infection after solid organ transplantation (SOT) reflects the interplay between viral replication and CMV-specific immunity. Despite advances in its diagnosis and treatment, CMV continues to cause significant morbidity after SOT. Since CMV is an opportunistic pathogen that occurs as a result of impaired pathogen-specific immunity, laboratory assays that measure CMV-specific immune responses may be useful in assisting clinicians in its management. Methods and Results: The author summarizes the evolving and emerging data on the clinical utility of assays that quantify cell-mediated immune responses to CMV in SOT recipients. The majority of publications are observational studies that demonstrate that a lack or deficiency in CMV-specific cell-mediated immunity is correlated with a heightened risk of primary, reactivation, or recurrent CMV after transplantation. A few prospective interventional studies have utilized CMV-specific cell-mediated immune assays in guiding the duration of antiviral prophylaxis among CMV-seropositive SOT recipients. Likewise, CMV-specific cell-mediated immunity assays have been suggested to inform the need for secondary antiviral prophylaxis and immunologic optimization to prevent CMV relapse after treatment. Conclusions: CMV-specific cell-mediated immune assays are emerging to assist transplant clinicians in predicting a patient’s risk of CMV after transplantation, and these assays have been utilized to individualize the approach to CMV prevention and treatment. The author suggests the conduct of more interventional studies to further solidify the role of CMV-specific cell-mediated immune assays in routine clinical practice.
Shaping the Future of Infectious Diseases: The Journey to Promote Value, Opportunity, and Positive Messaging
Abstract The field of infectious diseases (ID) offers a rewarding career path and is widely viewed as an essential subspecialty in medicine. However, in recent years, these positive aspects have been overshadowed by concerns surrounding low fellowship match rates, undercompensation, and burnout. The Infectious Diseases Society of America Fellowship Training Program Directors Committee met in 2023, discussed the future of ID as a specialty, and sought to develop strategies to highlight the value and opportunities of ID for future generations, as well as underscore the importance of and provide tools for positive messaging to trainees about the subspecialty. This paper presents ideas generated at this meeting and is meant to serve as a reference for ID training program directors, as well as the wider ID community, in uplifting and shaping the future of the field.
Survey of Post‐Prophylaxis Delayed‐Onset Cytomegalovirus Management Strategies Among Transplant Providers
ABSTRACTBackgroundPreventive strategies for cytomegalovirus (CMV) in the posttransplant period have changed the pattern of CMV infections, now more commonly manifesting as late‐onset occurrences known as post‐prophylaxis delayed‐onset CMV disease (PPDOC). We conducted a survey to investigate provider practices in managing PPDOC.MethodsA web‐based provider survey on the management of PPDOC was developed using Research Electronic Data Capture (REDCap). It was distributed to the online forums of the American Society of Transplantation communities of practice (COP) for Infectious Diseases (IDCOP), Kidney and Pancreas (KPCOP), Liver and Intestinal (LICOP), and Thoracic and Critical Care (TCCOP). The survey was posted twice within a span of a month.ResultsFifty‐six respondents, comprising 50 (89%) transplant physicians and 6 (11%) transplant pharmacists, from 46 distinct transplant centers, completed the survey. Universal antiviral prophylaxis (UAP) was the predominant preventive approach for both high‐risk (85%) and moderate‐risk (85%) transplant recipients. Out of 56, 51 respondents completed the questions regarding management of PPDOC. Regular surveillance with nucleic acid amplification tests (NAAT) (88%) was the most commonly used approach in high‐risk recipients, while symptom monitoring (73%) was the most common strategy in moderate‐risk recipients. Immunologic monitoring was used only by a few respondents who found it moderately useful in high‐risk recipients.ConclusionManagement of PPDOC was highly variable among providers and strategies differed based on patient risk profile. These findings could help shape future studies and guidelines to harmonize CMV management.