Neuroinvasive Bacillus cereus Infection in Immunocompromised Hosts: Epidemiologic Investigation of 5 Patients With Acute Myeloid Leukemia.

Background: Bacillus cereus is a ubiquitous gram-positive rod-shaped bacterium that can cause sepsis and neuroinvasive disease in patients with acute leukemia or neutropenia. Methods: A single-center retrospective review was conducted to evaluate patients with acute leukemia, positive blood or cerebrospinal fluid test results for B cereus, and abnormal neuroradiographic findings between January 2018 and October 2022. Infection control practices were observed, environmental samples obtained, a dietary case-control study completed, and whole genome sequencing performed on environmental and clinical Bacillus isolates. Results: Five patients with B cereus neuroinvasive disease were identified. All patients had acute myeloid leukemia (AML), were receiving induction chemotherapy, and were neutropenic. Neurologic involvement included subarachnoid or intraparenchymal hemorrhage or brain abscess. All patients were treated with ciprofloxacin and survived with limited or no neurologic sequelae. B cereus was identified in 7 of 61 environmental samples and 1 of 19 dietary protein samples-these were unrelated to clinical isolates via sequencing. No point source was identified. Ciprofloxacin was added to the empiric antimicrobial regimen for patients with AML and prolonged or recurrent neutropenic fevers; no new cases were identified in the ensuing year. Conclusions: B cereus is ubiquitous in the hospital environment, at times leading to clusters with unrelated isolates. Fastidious infection control practices addressing a range of possible exposures are warranted, but their efficacy is unknown and they may not be sufficient to prevent all infections. Thus, including B cereus coverage in empiric regimens for patients with AML and persistent neutropenic fever may limit the morbidity of this pathogen.

18F-FDG PET/CT and radiolabeled leukocyte SPECT/CT imaging for the evaluation of cardiovascular infection in the multimodality context: ASNC Imaging Indications (ASNC I2) Series Expert Consensus Recommendations from ASNC, AATS, ACC, AHA, ASE, EANM, HRS, IDSA, SCCT, SNMMI, and STS.

This document on cardiovascular infection, including infective endocarditis, is the first in the American Society of Nuclear Cardiology Imaging Indications (ASNC I2) series to assess the role of radionuclide imaging in the multimodality context for the evaluation of complex systemic diseases with multi-societal involvement including pertinent disciplines. A rigorous modified Delphi approach was used to determine consensus clinical indications, diagnostic criteria, and an algorithmic approach to diagnosis of cardiovascular infection including infective endocarditis. Cardiovascular infection incidence is increasing and is associated with high morbidity and mortality. Current strategies based on clinical criteria and an initial echocardiographic imaging approach are effective but often insufficient in complicated cardiovascular infection. Radionuclide imaging with 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (CT) and single photon emission computed tomography/CT leukocyte scintigraphy can enhance the evaluation of suspected cardiovascular infection by increasing diagnostic accuracy, identifying extracardiac involvement, and assessing cardiac implanted device pockets, leads, and all portions of ventricular assist devices. This advanced imaging can aid in key medical and surgical considerations. Consensus diagnostic features include focal/multi-focal or diffuse heterogenous intense 18F-FDG uptake on valvular and prosthetic material, perivalvular areas, device pockets and leads, and ventricular assist device hardware persisting on non-attenuation corrected images. There are numerous clinical indications with a larger role in prosthetic valves, and cardiac devices particularly with possible infective endocarditis or in the setting of prior equivocal or non-diagnostic imaging. Illustrative cases incorporating these consensus recommendations provide additional clarification. Future research is necessary to refine application of these advanced imaging tools for surgical planning, to identify treatment response, and more.

18F-FDG PET/CT and Radiolabeled Leukocyte SPECT/CT Imaging for the Evaluation of Cardiovascular Infection in the Multimodality Context: ASNC Imaging Indications (ASNC I2) Series Expert Consensus Recommendations From ASNC, AATS, ACC, AHA, ASE, EANM, HRS, IDSA, SCCT, SNMMI, and STS.

This document on cardiovascular infection, including infective endocarditis, is the first in the American Society of Nuclear Cardiology Imaging Indications (ASNC I2) series to assess the role of radionuclide imaging in the multimodality context for the evaluation of complex systemic diseases with multi-societal involvement including pertinent disciplines. A rigorous modified Delphi approach was used to determine consensus clinical indications, diagnostic criteria, and an algorithmic approach to diagnosis of cardiovascular infection including infective endocarditis. Cardiovascular infection incidence is increasing and is associated with high morbidity and mortality. Current strategies based on clinical criteria and an initial echocardiographic imaging approach are effective but often insufficient in complicated cardiovascular infection. Radionuclide imaging with fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (CT) and single photon emission computed tomography/CT leukocyte scintigraphy can enhance the evaluation of suspected cardiovascular infection by increasing diagnostic accuracy, identifying extracardiac involvement, and assessing cardiac implanted device pockets, leads, and all portions of ventricular assist devices. This advanced imaging can aid in key medical and surgical considerations. Consensus diagnostic features include focal/multi-focal or diffuse heterogenous intense 18F-FDG uptake on valvular and prosthetic material, perivalvular areas, device pockets and leads, and ventricular assist device hardware persisting on non-attenuation corrected images. There are numerous clinical indications with a larger role in prosthetic valves, and cardiac devices particularly with possible infective endocarditis or in the setting of prior equivocal or non-diagnostic imaging. Illustrative cases incorporating these consensus recommendations provide additional clarification. Future research is necessary to refine application of these advanced imaging tools for surgical planning, to identify treatment response, and more.

18F-FDG PET/CT and radiolabeled leukocyte SPECT/CT imaging for the evaluation of cardiovascular infection in the multimodality context: ASNC Imaging Indications (ASNC I2) Series Expert Consensus Recommendations from ASNC, AATS, ACC, AHA, ASE, EANM, HRS, IDSA, SCCT, SNMMI, and STS.

This document on cardiovascular infection, including infective endocarditis, is the first in the American Society of Nuclear Cardiology Imaging Indications (ASNC I2) series to assess the role of radionuclide imaging in the multimodality context for the evaluation of complex systemic diseases with multi-societal involvement including pertinent disciplines. A rigorous modified Delphi approach was used to determine consensus clinical indications, diagnostic criteria, and an algorithmic approach to diagnosis of cardiovascular infection including infective endocarditis. Cardiovascular infection incidence is increasing and is associated with high morbidity and mortality. Current strategies based on clinical criteria and an initial echocardiographic imaging approach are effective but often insufficient in complicated cardiovascular infection. Radionuclide imaging with 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) and single photon emission computed tomography/CT leukocyte scintigraphy can enhance the evaluation of suspected cardiovascular infection by increasing diagnostic accuracy, identifying extracardiac involvement, and assessing cardiac implanted device pockets, leads, and all portions of ventricular assist devices. This advanced imaging can aid in key medical and surgical considerations. Consensus diagnostic features include focal/multi-focal or diffuse heterogenous intense 18F-FDG uptake on valvular and prosthetic material, perivalvular areas, device pockets and leads, and ventricular assist device hardware persisting on non-attenuation corrected images. There are numerous clinical indications with a larger role in prosthetic valves, and cardiac devices particularly with possible infective endocarditis or in the setting of prior equivocal or non-diagnostic imaging. Illustrative cases incorporating these consensus recommendations provide additional clarification. Future research is necessary to refine application of these advanced imaging tools for surgical planning, to identify treatment response, and more.

18F-FDG PET/CT and radiolabeled leukocyte SPECT/CT imaging for the evaluation of cardiovascular infection in the multimodality context: ASNC Imaging Indications (ASNC I2) Series Expert Consensus Recommendations from ASNC, AATS, ACC, AHA, ASE, EANM, HRS, IDSA, SCCT, SNMMI, and STS.

This document on cardiovascular infection, including infective endocarditis, is the first in the American Society of Nuclear Cardiology Imaging Indications (ASNC I2) series to assess the role of radionuclide imaging in the multimodality context for the evaluation of complex systemic diseases with multi-societal involvement including pertinent disciplines. A rigorous modified Delphi approach was used to determine consensus clinical indications, diagnostic criteria, and an algorithmic approach to diagnosis of cardiovascular infection including infective endocarditis. Cardiovascular infection incidence is increasing and is associated with high morbidity and mortality. Current strategies based on clinical criteria and an initial echocardiographic imaging approach are effective but often insufficient in complicated cardiovascular infection. Radionuclide imaging with 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (CT) and single photon emission computed tomography/CT leukocyte scintigraphy can enhance the evaluation of suspected cardiovascular infection by increasing diagnostic accuracy, identifying extracardiac involvement, and assessing cardiac implanted device pockets, leads, and all portions of ventricular assist devices. This advanced imaging can aid in key medical and surgical considerations. Consensus diagnostic features include focal/multi-focal or diffuse heterogenous intense 18F-FDG uptake on valvular and prosthetic material, perivalvular areas, device pockets and leads, and ventricular assist device hardware persisting on non-attenuation corrected images. There are numerous clinical indications with a larger role in prosthetic valves, and cardiac devices particularly with possible infective endocarditis or in the setting of prior equivocal or non-diagnostic imaging. Illustrative cases incorporating these consensus recommendations provide additional clarification. Future research is necessary to refine application of these advanced imaging tools for surgical planning, to identify treatment response, and more.

Infective Endocarditis Antibiotic Prophylaxis: Review of the Evidence and Guidelines.

PURPOSE OF REVIEW: The question of antibiotic prophylaxis and its role in prevention of infective endocarditis (IE) remains controversial, with differing recommendations from international societies. The aim of this review was to compare and contrast current recommendations on antibiotic prophylaxis for IE by the American Heart Association (AHA), the European Society of Cardiology (ESC), and the National Institute for Health and Care Excellence (NICE) and highlight the evidence supporting these recommendations. RECENT FINDINGS: International guidelines for administration of antibiotic prophylaxis for prevention of IE are largely unchanged since 2009. Studies on the impact of the more restrictive antibiotic prophylaxis recommendations are conflicting, with several studies suggesting lack of adherence to current guidance from the ESC (2015), NICE (2016), and AHA (2021). The question of antibiotic prophylaxis in patients with IE remains controversial, with differing recommendations from international societies. Despite the change in guidelines more than 15 years ago, lack of adherence to current guidelines persists. Due to the lack of high-quality evidence and the conflicting results from observational studies along with the lack of randomized clinical trials, the question of whether to recommend antibiotic prophylaxis or not in certain patient populations remains unanswered and remains largely based on expert consensus opinion.

Diagnostic TR-FRET assays for detection of antibodies in patient samples.

Serological assays are important diagnostic tools for surveying exposure to the pathogen, monitoring immune response post vaccination, and managing spread of the infectious agent among the population. Current serological laboratory assays are often limited because they require the use of specialized laboratory technology and/or work with a limited number of sample types. Here, we evaluate an alternative by developing time-resolved Förster resonance energy transfer (TR-FRET) homogeneous assays that exhibited exceptional versatility, scalability, and sensitivity and outperformed or matched currently used strategies in terms of sensitivity, specificity, and precision. We validated the performance of the assays measuring total immunoglobulin G (IgG) levels; antibodies against severe acute respiratory syndrome coronavirus (SARS-CoV) or Middle Eastern respiratory syndrome (MERS)-CoV spike (S) protein; and SARS-CoV-2 S and nucleocapsid (N) proteins and applied it to several large sample sets and real-world applications. We further established a TR-FRET-based ACE2-S competition assay to assess the neutralization propensity of the antibodies. Overall, these TR-FRET-based serological assays can be rapidly extended to other antigens and are compatible with commonly used plate readers.

Blastomycosis in New England: 5 Cases and a Review.

The geographic range of blastomycosis is thought to include New England, but documentation is sparse. We report 5 cases of infection with Blastomyces dermatitidis that were likely acquired in New England between 2011 and 2021. Our experience suggests that chart coding for the diagnosis of blastomycosis is imprecise and that mandatory reporting might help resolve uncertainties about the prevalence and extent of blastomycosis.

Transplant of organs from donors with positive SARS-CoV-2 nucleic acid testing: A report from the organ procurement and transplantation network ad hoc disease transmission advisory committee.

BACKGROUND: Decisions to transplant organs from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid test-positive (NAT+) donors must balance risk of donor-derived transmission events (DDTE) with the scarcity of available organs. METHODS: Organ Procurement and Transplantation Network (OPTN) data were used to compare organ utilization and recipient outcomes between SARS-CoV-2 NAT+ and NAT- donors. NAT+ was defined by either a positive upper or lower respiratory tract (LRT) sample within 21 days of procurement. Potential DDTE were adjudicated by OPTN Disease Transmission Advisory Committee. RESULTS: From May 27, 2021 (date of OTPN policy for required LRT testing of lung donors) to January 31, 2022, organs were recovered from 617 NAT+ donors from all OPTN regions and 53 of 57 (93%) organ procurement organizations. NAT+ donors were younger and had higher organ quality scores for kidney and liver. Organ utilization was lower for NAT+ donors compared to NAT- donors. A total of 1241 organs (776 kidneys, 316 livers, 106 hearts, 22 lungs, and 21 other) were transplanted from 514 NAT+ donors compared to 21 946 organs from 8853 NAT- donors. Medical urgency was lower for recipients of NAT+ liver and heart transplants. The median waitlist time was longer for liver recipients of NAT+ donors. The match run sequence number for final acceptor was higher for NAT+ donors for all organ types. Outcomes for hospital length of stay, 30-day mortality, and 30-day graft loss were similar for all organ types. No SARS-CoV-2 DDTE occurred in this interval. CONCLUSIONS: Transplantation of SARS-CoV-2 NAT+ donor organs appears safe for short-term outcomes of death and graft loss and ameliorates the organ shortage. Further study is required to assure comparable longer term outcomes.

Nirmatrelvir Plus Ritonavir for Early COVID-19 in a Large U.S. Health System : A Population-Based Cohort Study.

BACKGROUND: In the EPIC-HR (Evaluation of Protease Inhibition for Covid-19 in High-Risk Patients) trial, nirmatrelvir plus ritonavir led to an 89% reduction in hospitalization or death among unvaccinated outpatients with early COVID-19. The clinical impact of nirmatrelvir plus ritonavir among vaccinated populations is uncertain. OBJECTIVE: To assess whether nirmatrelvir plus ritonavir reduces risk for hospitalization or death among outpatients with early COVID-19 in the setting of prevalent SARS-CoV-2 immunity and immune-evasive SARS-CoV-2 lineages. DESIGN: Population-based cohort study analyzed to emulate a clinical trial using inverse probability-weighted models to account for anticipated bias in treatment. SETTING: A large health care system providing care for 1.5 million patients in Massachusetts and New Hampshire during the Omicron wave (1 January to 17 July 2022). PATIENTS: 44 551 nonhospitalized adults (90.3% with ≥3 vaccine doses) aged 50 years or older with COVID-19 and no contraindications for nirmatrelvir plus ritonavir. MEASUREMENTS: The primary outcome was a composite of hospitalization within 14 days or death within 28 days of a COVID-19 diagnosis. RESULTS: During the study period, 12 541 (28.1%) patients were prescribed nirmatrelvir plus ritonavir, and 32 010 (71.9%) were not. Patients prescribed nirmatrelvir plus ritonavir were more likely to be older, have more comorbidities, and be vaccinated. The composite outcome of hospitalization or death occurred in 69 (0.55%) patients who were prescribed nirmatrelvir plus ritonavir and 310 (0.97%) who were not (adjusted risk ratio, 0.56 [95% CI, 0.42 to 0.75]). Recipients of nirmatrelvir plus ritonavir had lower risk for hospitalization (adjusted risk ratio, 0.60 [CI, 0.44 to 0.81]) and death (adjusted risk ratio, 0.29 [CI, 0.12 to 0.71]). LIMITATION: Potential residual confounding due to differential access to COVID-19 vaccines, diagnostic tests, and treatment. CONCLUSION: The overall risk for hospitalization or death was already low (1%) after an outpatient diagnosis of COVID-19, but nirmatrelvir plus ritonavir reduced this risk further. PRIMARY FUNDING SOURCE: National Institutes of Health.

The Cost-effectiveness of Transplanting Hearts From Hepatitis C-infected Donors Into Uninfected Recipients.

BACKGROUND: The DONATE HCV trial demonstrated the safety and efficacy of transplanting hearts from hepatitis C viremic (HCV+) donors. In this report, we examine the cost-effectiveness and impact of universal HCV+ heart donor eligibility in the United States on transplant waitlist time and life expectancy. METHODS: We developed a microsimulation model to compare 2 waitlist strategies for heart transplant candidates in 2018: (1) status quo (SQ) and (2) SQ plus HCV+ donors (SQ + HCV). From the DONATE HCV trial and published national datasets, we modeled mean age (53 years), male sex (75%), probabilities of waitlist mortality (0.01-0.10/month) and transplant (0.03-0.21/month) stratified by medical urgency, and posttransplant mortality (0.003-0.052/month). We assumed a 23% increase in transplant volume with SQ + HCV compared with SQ. Costs (2018 United States dollar) included waitlist care ($2200-190 000/month), transplant ($213 400), 4-wk HCV treatment ($26 000), and posttransplant care ($2500-11 300/month). We projected waitlist time, quality-adjusted life-years (QALYs), lifetime costs, and incremental cost-effectiveness ratios (ICERs [$/QALY, discounted 3%/year]; threshold ≤$100 000/QALY). RESULTS: Compared with SQ, SQ + HCV decreased waitlist time from 8.7 to 6.7 months, increased undiscounted life expectancy from 8.9 to 9.2 QALYs, and increased discounted lifetime costs from $671 400/person to $690 000/person. Four-week HCV treatment comprised 0.5% of lifetime costs. The ICER of SQ + HCV compared with SQ was $74 100/QALY and remained ≤$100 000/QALY with up to 30% increases in transplant and posttransplant costs. CONCLUSIONS: Transplanting hearts from HCV-infected donors could decrease waitlist times, increase life expectancy, and be cost-effective. These findings were robust within the context of current high HCV treatment costs.

Thrombosis-Related Loss of Arterial Lines in the First Wave of COVID-19 and Non-COVID-19 Intensive Care Unit Patients.

BACKGROUND: Patients with coronavirus disease 2019 (COVID-19) can present with severe respiratory distress requiring intensive care unit (ICU)-level care. Such care often requires placement of an arterial line for monitoring of pulmonary disease progression, hemodynamics, and laboratory tests. During the first wave of the COVID-19 pandemic in March 2020, experienced physicians anecdotally reported multiple attempts, decreased insertion durations, and greater need for replacement of arterial lines in patients with COVID-19 due to persistent thrombosis. Because invasive procedures in patients with COVID-19 may increase the risk for caregiver infection, better defining difficulties in maintaining arterial lines in COVID-19 patients is important. We sought to explore the association between COVID-19 infection and arterial line thrombosis in critically ill patients. METHODS: In this primary exploratory analysis, a multivariable Fine-Gray subdistribution hazard model was used to retrospectively estimate the association between critically ill COVID-19 (versus sepsis/acute respiratory distress syndrome [ARDS]) patients and the risk of arterial line removal for thrombosis (with arterial line removal for any other reason treated as a competing risk). As a sensitivity analysis, we compared the number of arterial line clots per 1000 arterial line days between critically ill COVID-19 and sepsis/ARDS patients using multivariable negative binomial regression. RESULTS: We retrospectively identified 119 patients and 200 arterial line insertions in patients with COVID-19 and 54 patients and 68 arterial line insertions with non-COVID ARDS. Using a Fine-Gray subdistribution hazard model, we found the adjusted subdistribution hazard ratio (95% confidence interval [CI]) for arterial line clot to be 2.18 (1.06-4.46) for arterial lines placed in COVID-19 patients versus non-COVID-19 sepsis/ARDS patients ( P = .034). Patients with COVID-19 had 36.3 arterial line clots per 1000 arterial line days compared to 19.1 arterial line clots per 1000 arterial line days in patients without COVID-19 (adjusted incidence rate ratio [IRR] [95% CI], 1.78 [0.94-3.39]; P = .078). CONCLUSIONS: Our study suggests that arterial line complications due to thrombosis are more likely in COVID-19 patients and supports the need for further research on the association between COVID-19 and arterial line dysfunction requiring replacement.

At-home Testing and Risk Factors for Acquisition of SARS-CoV-2 Infection in a Major US Metropolitan Area.

Background: Unbiased assessment of the risks associated with acquisition of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is critical to informing mitigation efforts during pandemics. The objective of our study was to understand the risk factors for acquiring coronavirus disease 2019 (COVID-19) in a large prospective cohort of adult residents in a large US metropolitan area. Methods: We designed a fully remote longitudinal cohort study involving monthly at-home SARS-CoV-2 polymerase chain reaction (PCR) and serology self-testing and monthly surveys. Results: Between October 2020 and January 2021, we enrolled 10 289 adults reflective of the Boston metropolitan area census data. At study entry, 567 (5.5%) participants had evidence of current or prior SARS-CoV-2 infection. This increased to 13.4% by June 15, 2021. Compared with Whites, Black non-Hispanic participants had a 2.2-fold greater risk of acquiring COVID-19 (hazard ratio [HR], 2.19; 95% CI, 1.91-2.50; P < .001), and Hispanics had a 1.5-fold greater risk (HR, 1.52; 95% CI, 1.32-1.71; P < .016). Individuals aged 18-29, those who worked outside the home, and those living with other adults and children were at an increased risk. Individuals in the second and third lowest disadvantaged neighborhood communities were associated with an increased risk of acquiring COVID-19. Individuals with medical risk factors for severe disease were at a decreased risk of SARS-CoV-2 acquisition. Conclusions: These results demonstrate that race/ethnicity and socioeconomic status are the biggest determinants of acquisition of infection. This disparity is significantly underestimated if based on PCR data alone, as noted by the discrepancy in serology vs PCR detection for non-White participants, and points to persistent disparity in access to testing. Medical conditions and advanced age, which increase the risk for severity of SARS-CoV-2 disease, were associated with a lower risk of COVID-19 acquisition, suggesting the importance of behavior modifications. These findings highlight the need for mitigation programs that overcome challenges of structural racism in current and future pandemics.

Bebtelovimab for High-Risk Outpatients With Early COVID-19 in a Large US Health System.

There are limited data for the clinical efficacy of bebtelovimab in preventing severe coronavirus disease 2019. Among outpatients unable to take nirmatrelvir-ritonavir at a large health system, 10 of 377 (2.7%) patients who received bebtelovimab and 17 of 377 (4.5%) matched untreated patients were hospitalized or died. The 43% observed risk reduction with bebtelovimab was not statistically significant (P = 0.14).

Prior SARS-CoV-2 Infection Is Associated With Coronary Vasomotor Dysfunction as Assessed by Coronary Flow Reserve From Cardiac Positron Emission Tomography.

Background Cardiovascular complications from COVID-19 contribute to its high morbidity and mortality. The effect of COVID-19 infection on the coronary vasculature is not known. The objective of this study was to investigate the prevalence of coronary vasomotor dysfunction identified by coronary flow reserve from cardiac positron emission tomography in patients with previous COVID-19 infection. Methods and Results All patients who had polymerase chain reaction-confirmed SARS-CoV-2 infection referred for myocardial stress perfusion positron emission tomography imaging at Brigham and Women's Hospital from April 2020 to July 2021 were compared with a matched control group without prior SARS-CoV-2 infection imaged in the same period. The main outcome was the prevalence of coronary vasomotor dysfunction. Myocardial perfusion and myocardial blood flow reserve were quantified using N13-ammonia positron emission tomography imaging. Thirty-four patients with prior COVID-19 were identified and compared with 103 matched controls. The median time from polymerase chain reaction-confirmed SARS-CoV-2 to cardiac positron emission tomography was 4.6 months (interquartile range,1.2-5.6 months). There were 16 out of 34 (47%) patients previously hospitalized for COVID-19 infection. Baseline cardiac risk factors were common, and 18 (53%) patients in the COVID-19 group had abnormal myocardial perfusion. Myocardial blood flow reserve was abnormal (<2) in 44.0% of the patients with COVID-19 compared with 11.7% of matched controls (P<0.001). The mean myocardial blood flow reserve was 19.4% lower in patients with COVID-19 compared with control patients (2.00±0.45 versus 2.48±0.47, P<0.001). Conclusions Myocardial blood flow reserve was impaired in patients with prior COVID-19 infection compared with cardiovascular risk factor-matched controls, suggesting a relationship between SARS-CoV-2 infection and coronary vascular health. These data highlight the need to assess long-term consequences of COVID-19 on vascular health in future prospective studies.

Nirmatrelvir plus ritonavir for early COVID-19 and hospitalization in a large US health system.

Background: In the EPIC-HR trial, nirmatrelvir plus ritonavir led to an 88% reduction in hospitalization or death among unvaccinated outpatients with early COVID-19. Clinical impact of nirmatrelvir plus ritonavir among vaccinated populations is uncertain. Objective: To assess whether nirmatrelvir plus ritonavir reduces risk of hospitalization among outpatients with early COVID-19 in the setting of prevalent SARS-CoV-2 immunity and immune evasive SARS-CoV-2 lineages. Design: Population-based cohort study analyzed to emulate a clinical trial utilizing two-stage, inverse-probability weighted models to account for anticipated bias in testing and treatment. Setting: A large healthcare system providing care for 1.5 million patients in Massachusetts and New Hampshire during Omicron wave (January 1 to May 15, 2022) with staged access and capacity to prescribe nirmatrelvir plus ritonavir. Patients: 30,322 non-hospitalized adults (87.2% vaccinated) aged 50 and older with COVID-19 and without contraindications to nirmatrelvir plus ritonavir. Measurement: Primary outcome was hospitalization within 14 days of COVID-19 diagnosis. Results: During the study period, 6036 (19.9%) patients were prescribed nirmatrelvir plus ritonavir and 24,286 (80.1%) patients were not. Patients prescribed nirmatrelvir were more likely to be older, have more comorbidities, and be unvaccinated. Hospitalization occurred in 40 (0.66%) and 232 (0.96%) patients prescribed and not prescribed nirmatrelvir plus ritonavir, respectively. The adjusted risk ratio was 0.55 (95% confidence interval 0.38 to 0.80, p = 0.002). Observed risk reduction was greater among unvaccinated patients and obese patients. Limitations: Potential for residual confounding due to differential access and uptake of COVID-19 vaccines, diagnostics, and treatment. Conclusions: The overall risk of hospitalization was already low (<1%) following an outpatient diagnosis of COVID-19, but this risk was 45% lower among patients prescribed nirmatrelvir plus ritonavir. Funding: National Institutes of Health (P30 AI060354 and R01 CA236546).

Feasibility and lessons learned on remote trial implementation from TestBoston, a fully remote, longitudinal, large-scale COVID-19 surveillance study.

Longitudinal clinical studies traditionally require in-person study visits which are well documented to pose barriers to participation and contribute challenges to enrolling representative samples. Remote trial models may reduce barriers to research engagement, improve retention, and reach a more representative cohort. As remote trials become more common following the COVID-19 pandemic, a critical evaluation of this approach is imperative to optimize this paradigm shift in research. The TestBoston study was launched to understand prevalence and risk factors for COVID-19 infection in the greater Boston area through a fully remote home-testing model. Participants (adults, within 45 miles of Boston, MA) were recruited remotely from patient registries at Brigham and Women's Hospital and the general public. Participants were provided with monthly and "on-demand" at-home SARS-CoV-2 RT-PCR and antibody testing using nasal swab and dried blood spot self-collection kits and electronic surveys to assess symptoms and risk factors for COVID-19 via an online dashboard. Between October 2020 and January 2021, we enrolled 10,289 participants reflective of Massachusetts census data. Mean age was 47 years (range 18-93), 5855 (56.9%) were assigned female sex at birth, 7181(69.8%) reported being White non-Hispanic, 952 (9.3%) Hispanic/Latinx, 925 (9.0%) Black, 889 (8.6%) Asian, and 342 (3.3%) other and/or more than one race. Lower initial enrollment among Black and Hispanic/Latinx individuals required an adaptive approach to recruitment, leveraging connections to the medical system, coupled with community partnerships to ensure a representative cohort. Longitudinal retention was higher among participants who were White non-Hispanic, older, working remotely, and with lower socioeconomic vulnerability. Implementation highlighted key differences in remote trial models as participants independently navigate study milestones, requiring a dedicated participant support team and robust technology platforms, to reduce barriers to enrollment, promote retention, and ensure scientific rigor and data quality. Remote clinical trial models offer tremendous potential to engage representative cohorts, scale biomedical research, and promote accessibility by reducing barriers common in traditional trial design. Barriers and burdens within remote trials may be experienced disproportionately across demographic groups. To maximize engagement and retention, researchers should prioritize intensive participant support, investment in technologic infrastructure and an adaptive approach to maximize engagement and retention.