Conversion of fat to cellular fuel-Fatty acids ß-oxidation model.

ß-oxidation of fatty acids plays a significant role in the energy metabolism of the cell. This paper presents a ß-oxidation model of fatty acids based on queueing theory. It uses Michaelis-Menten enzyme kinetics, and literature data on metabolites' concentration and enzymatic constants. A genetic algorithm was used to optimize the parameters for the pathway reactions. The model enables real-time tracking of changes in the concentrations of metabolites with different carbon chain lengths. Another application of the presented model is to predict the changes caused by system disturbance, such as altered enzyme activity or abnormal fatty acid concentration. The model has been validated against experimental data. There are diseases that change the metabolism of fatty acids and the presented model can be used to understand the cause of these changes, analyze metabolites abnormalities, and determine the initial target of treatment.

Brief Report: Interruptions in HIV Prevention and Treatment During the COVID-19 Pandemic: A Cross-Sectional Study of Transgender and Gender Nonbinary Adults in the United States.

BACKGROUND: Transgender and gender nonbinary (TNB) people have been disproportionately affected by HIV and the COVID-19 pandemic. This study explored the prevalence of HIV prevention and treatment (HPT) interruptions during the pandemic and identified factors associated with these interruptions. SETTING: Data were drawn from LITE Connect, a US-based, nationwide, online, self-administered survey designed to examine the experiences of TNB adults during the COVID-19 pandemic. A convenience sample of 2134 participants were recruited between June 14, 2021, and May 1, 2022. METHODS: The analytic sample was restricted to participants taking antiretroviral medications to prevent or treat HIV before the onset of the pandemic (n = 153). We calculated descriptive statistics as well as Pearson χ 2 bivariate tests and multivariable models to identify factors associated with HPT interruptions during the pandemic. RESULTS: Thirty-nine percent of participants experienced an HPT interruption. We found a lower odds of HPT interruptions among participants living with HIV [adjusted odds ratios (aOR) 0.45; 95% Confidence Intervals (CI): 0.22, 0.92; P = 0.02] and essential workers [aOR 0.49; 95% CI: 0.23, 1.0; P = 0.06] and higher odds among people with chronic mental health conditions [aOR 2.6; 95% CI: 1.1, 6.2; P = 0.03]. When sex and education were included, we found a lower odds of interruptions among people with higher education. CI widened, but the magnitude and direction of effects did not change for the other variables. CONCLUSIONS: Focused strategies to address longstanding psychosocial and structural inequities are needed to mitigate HPT treatment interruptions in TNB people and prevent similar challenges during future pandemics.

Barriers to atrial fibrillation ablation during mitral valve surgery.

BACKGROUND: Nearly 40% of patients with atrial fibrillation (AF) undergoing mitral valve surgery do not receive concomitant ablation despite societal guidelines. We assessed barriers to implementation of this evidence-based practice through a survey of cardiac surgeons in 2 statewide quality collaboratives. METHODS: Adult cardiac surgeons across 2 statewide collaboratives were surveyed on their knowledge and practice regarding AF ablation. Questions concerning experience, clinical practice, case scenarios, and barriers to implementation were included. RESULTS: Among 66 respondents (66 of 135; 48.9%), the majority reported "very comfortable/frequently use" cryoablation (53 of 66; 80.3%) and radiofrequency (55 of 66; 83.3%). Only 12.1% (8/66) were not aware of the recommendations. Approximately one-half of the respondents reported learning AF ablation in fellowship (50.0%; 33 of 66) or attending courses (47.0%; 31 of 66). Responses to clinical scenarios demonstrated wide variability in practice patterns. One-half of the respondents reported no barriers; others cited increased cross-clamp time, excessive patient risk, and arrhythmia incidence as obstacles. Desired interventions included cardiology/electrophysiology support, protocols, pacemaker rate information, and education in the form of site visits, videos and proctors. CONCLUSIONS: Knowledge of evidence-based recommendations and practice patterns vary widely. These data identify several barriers to implementation of concomitant AF ablation and suggest specific interventions (mentorship/support, protocols, research, and education) to overcome these barriers.

Modeling an immune response to influenza A virus infection in alveolar epithelial cells.

Influenza A viruses (IAV) have been the cause of several influenza pandemics in history and are a significant threat for the next global pandemic. Hospitalized influenza patients often have excess interferon production and a dysregulated immune response to the IAV infection. Obtaining a better understanding of the mechanisms of IAV infection that induce these harmful effects would help drug developers and health professionals create more effective treatments for IAV infection and improve patient outcomes. IAV stimulates viral sensors and receptors expressed by alveolar epithelial cells, like RIG-I and toll-like receptor 3 (TLR3). These two pathways coordinate with one another to induce expression of type III interferons to combat the infection. Presented here is a queuing theory-based model of these pathways that was designed to analyze the timing and amount of interferons produced in response to IAV single stranded RNA and double-stranded RNA detection. The model accurately represents biological data showing the necessary coordination of the RIG-I and TLR3 pathways for effective interferon production. This model can serve as the framework for future studies of IAV infection and identify new targets for potential treatments.

SARS-CoV-2 Infection and Testing Experiences in a Nationwide Sample of Transgender and Gender-Diverse Adults, June-December 2021.

OBJECTIVES: COVID-19 surveillance data are rarely collected or disaggregated by gender identity in the United States. We quantified COVID-19 testing experiences and SARS-CoV-2 infection history among transgender and gender-diverse (TGD) people to inform testing strategies and public health responses. METHODS: From June 14 through December 16, 2021, TGD adults enrolled in a US nationwide online survey with optional SARS-CoV-2 antibody testing. We used multinomial regression analyses to identify correlates of suspected and confirmed SARS-CoV-2 infection (vs no known infection). We identified correlates of inability to access COVID-19 testing when needed using generalized linear models for binomial variables. RESULTS: Participants (N = 2092) reported trans masculine (30.5%), trans feminine (27.3%), and nonbinary (42.2%) gender identities. Ten percent of respondents had a confirmed history of SARS-CoV-2 infection, and 29.8% had a history of suspected SARS-CoV-2 infection. Nonbinary gender (adjusted prevalence ratio [aPR] = 1.68; 95% CI, 1.12-2.53), experiencing homelessness (aPR = 1.65; 95% CI, 1.05-2.60), and food insecurity (aPR = 1.45; 95% CI, 1.03-2.04) were associated with confirmed SARS-CoV-2 infection. Food insecurity (aPR = 1.38; 95% CI, 1.10-1.72), chronic physical health condition (aPR = 1.44; 95% CI, 1.15-1.80), chronic mental health condition (aPR = 3.65; 95% CI, 2.40-5.56), and increased anticipated discrimination scores (aPR = 1.03; 95% CI, 1.01-1.05) were associated with suspected SARS-CoV-2 infection. Thirty-four percent (n = 694 of 2024) of participants reported an inability to access COVID-19 testing when needed, which was associated with Latinx or Hispanic ethnicity, inconsistent telephone access, homelessness, disability, and transportation limitations. The majority (79.4%) reported a complete COVID-19 vaccine course at the time of participation. CONCLUSIONS: Inclusion of TGD people in public health surveillance and tailored public health strategies to address TGD communities' social and structural vulnerabilities may reduce barriers to COVID-19 testing.

Queueing theory model of mTOR complexes' impact on Akt-mediated adipocytes response to insulin.

A queueing theory based model of mTOR complexes impact on Akt-mediated cell response to insulin is presented in this paper. The model includes several aspects including the effect of insulin on the transport of glucose from the blood into the adipocytes with the participation of GLUT4, and the role of the GAPDH enzyme as a regulator of mTORC1 activity. A genetic algorithm was used to optimize the model parameters. It can be observed that mTORC1 activity is related to the amount of GLUT4 involved in glucose transport. The results show the relationship between the amount of GAPDH in the cell and mTORC1 activity. Moreover, obtained results suggest that mTORC1 inhibitors may be an effective agent in the fight against type 2 diabetes. However, these results are based on theoretical knowledge and appropriate experimental tests should be performed before making firm conclusions.

The impact of perioperative stroke and delirium on outcomes after surgical aortic valve replacement.

OBJECTIVE: The effects of stroke and delirium on postdischarge cognition and patient-centered health outcomes after surgical aortic valve replacement (SAVR) are not well characterized. Here, we assess the impact of postoperative stroke and delirium on these health outcomes in SAVR patients at 90 days. METHODS: Patients (N = 383) undergoing SAVR (41% received concomitant coronary artery bypass graft) enrolled in a randomized trial of embolic protection devices underwent serial neurologic and delirium evaluations at postoperative days 1, 3, and 7 and magnetic resonance imaging at day 7. Outcomes included 90-day functional status, neurocognitive decline from presurgical baseline, and quality of life. RESULTS: By postoperative day 7, 25 (6.6%) patients experienced clinical stroke and 103 (28.5%) manifested delirium. During index hospitalization, time to discharge was longer in patients experiencing stroke (hazard ratio, 0.62; 95% confidence interval [CI], 0.42-0.94; P = .02) and patients experiencing delirium (hazard ratio, 0.68; 95% CI, 0.54-0.86; P = .001). At day 90, patients experiencing stroke were more likely to have a modified Rankin score >2 (odds ratio [OR], 5.9; 95% CI, 1.7-20.1; P = .01), depression (OR, 5.3; 95% CI, 1.6-17.3; P = .006), a lower 12-Item Short Form Survey physical health score (adjusted mean difference -3.3 ± 1.9; P = .08), and neurocognitive decline (OR, 7.8; 95% CI, 2.3-26.4; P = .001). Delirium was associated with depression (OR, 2.2; 95% CI, 0.9-5.3; P = .08), lower 12-Item Short Form Survey physical health (adjusted mean difference -2.3 ± 1.1; P = .03), and neurocognitive decline (OR, 2.2; 95% CI, 1.2-4.0; P = .01). CONCLUSIONS: Stroke and delirium occur more frequently after SAVR than is commonly recognized, and these events are associated with disability, depression, cognitive decline, and poorer quality of life at 90 days postoperatively. These findings support the need for new interventions to reduce these events and improve patient-centered outcomes.

Queueing theory model of pentose phosphate pathway.

Due to its role in maintaining the proper functioning of the cell, the pentose phosphate pathway (PPP) is one of the most important metabolic pathways. It is responsible for regulating the concentration of simple sugars and provides precursors for the synthesis of amino acids and nucleotides. In addition, it plays a critical role in maintaining an adequate level of NADPH, which is necessary for the cell to fight oxidative stress. These reasons prompted the authors to develop a computational model, based on queueing theory, capable of simulating changes in PPP metabolites' concentrations. The model has been validated with empirical data from tumor cells. The obtained results prove the stability and accuracy of the model. By applying queueing theory, this model can be further expanded to include successive metabolic pathways. The use of the model may accelerate research on new drugs, reduce drug costs, and reduce the reliance on laboratory animals necessary for this type of research on which new methods are tested.

Concomitant Tricuspid Repair in Patients with Degenerative Mitral Regurgitation.

BACKGROUND: Tricuspid regurgitation is common in patients with severe degenerative mitral regurgitation. However, the evidence base is insufficient to inform a decision about whether to perform tricuspid-valve repair during mitral-valve surgery in patients who have moderate tricuspid regurgitation or less-than-moderate regurgitation with annular dilatation. METHODS: We randomly assigned 401 patients who were undergoing mitral-valve surgery for degenerative mitral regurgitation to receive a procedure with or without tricuspid annuloplasty (TA). The primary 2-year end point was a composite of reoperation for tricuspid regurgitation, progression of tricuspid regurgitation by two grades from baseline or the presence of severe tricuspid regurgitation, or death. RESULTS: Patients who underwent mitral-valve surgery plus TA had fewer primary-end-point events than those who underwent mitral-valve surgery alone (3.9% vs. 10.2%) (relative risk, 0.37; 95% confidence interval [CI], 0.16 to 0.86; P = 0.02). Two-year mortality was 3.2% in the surgery-plus-TA group and 4.5% in the surgery-alone group (relative risk, 0.69; 95% CI, 0.25 to 1.88). The 2-year prevalence of progression of tricuspid regurgitation was lower in the surgery-plus-TA group than in the surgery-alone group (0.6% vs. 6.1%; relative risk, 0.09; 95% CI, 0.01 to 0.69). The frequencies of major adverse cardiac and cerebrovascular events, functional status, and quality of life were similar in the two groups at 2 years, although the incidence of permanent pacemaker implantation was higher in the surgery-plus-TA group than in the surgery-alone group (14.1% vs. 2.5%; rate ratio, 5.75; 95% CI, 2.27 to 14.60). CONCLUSIONS: Among patients undergoing mitral-valve surgery, those who also received TA had a lower incidence of a primary-end-point event than those who underwent mitral-valve surgery alone at 2 years, a reduction that was driven by less frequent progression to severe tricuspid regurgitation. Tricuspid repair resulted in more frequent permanent pacemaker implantation. Whether reduced progression of tricuspid regurgitation results in long-term clinical benefit can be determined only with longer follow-up. (Funded by the National Heart, Lung, and Blood Institute and the German Center for Cardiovascular Research; ClinicalTrials.gov number, NCT02675244.).

Pacemaker implantation associated with tricuspid repair in the setting of mitral valve surgery: Insights from a Cardiothoracic Surgical Trials Network randomized trial.

OBJECTIVES: In a recent trial, tricuspid annuloplasty (TA) during mitral valve surgery (MVS) for degenerative mitral regurgitation and moderate or less tricuspid regurgitation (TR) reduced the composite rate of death, reoperation for TR, or TR progression at 2 years. However, this benefit was counterbalanced by an increase in implantation of permanent pacemakers (PPMs). In this study, we analyzed the timing, indications, and risk factors for these implantations. METHODS: We randomized 401 patients (MVS alone = 203; MVS + TA = 198). Potential risk factors for PPMs were assessed using multivariable time-to-event models with death and PPM implantation for heart failure indications as competing risks. RESULTS: A PPM was implanted in 36 patients (9.6; 95% CI, 6.8-13.0) within 2 years of randomization, with 30/187 (16.0%) in the MVS + TA and 6/188 (3.2%) in the MVS groups (rate ratio, 5.08; 95% CI, 2.16-11.94; P < .001). Most (29/36; 80.6%) implantations occurred within 30 days postoperatively. Independent risk factors for PPM implantation within 2 years were TA (hazard ratio [HR], 5.94; 95% CI, 2.27-15.53; P < .001), increasing age (5 years, HR, 1.23; 95% CI, 1.01-1.52; P = .04), and left ventricular ejection fraction (LVEF; HR, 0.96; 95% CI, 0.92-0.99; P = .02). In the subset of TA recipients (n = 197), age (5 years, HR, 1.05; 95% CI, 1.00-1.10; P = .04) and LVEF (HR, 0.95; 95% CI, 0.91-0.99; P = .01) were associated with PPM within 2 years. CONCLUSIONS: Concomitant TA, age, and baseline LVEF were risk factors for PPM implantation in patients who underwent MVS for degenerative mitral regurgitation. Although TA was effective in preventing progression of TR, innovation is needed to identify ways to decrease PPM implantation rates.

Progression of Tricuspid Regurgitation After Surgery for Ischemic Mitral Regurgitation.

BACKGROUND: Whether to repair nonsevere tricuspid regurgitation (TR) during surgery for ischemic mitral valve regurgitation (IMR) remains uncertain. OBJECTIVES: The goal of this study was to investigate the incidence, predictors, and clinical significance of TR progression and presence of ≥moderate TR after IMR surgery. METHODS: Patients (n = 492) with untreated nonsevere TR within 2 prospectively randomized IMR trials were included. Key outcomes were TR progression (either progression by ≥2 grades, surgery for TR, or severe TR at 2 years) and presence of ≥moderate TR at 2 years. RESULTS: Patients' mean age was 66 ± 10 years (67% male), and TR distribution was 60% ≤trace, 31% mild, and 9% moderate. Among 2-year survivors, TR progression occurred in 20 (6%) of 325 patients. Baseline tricuspid annular diameter (TAD) was not predictive of TR progression. At 2 years, 37 (11%) of 323 patients had ≥moderate TR. Baseline TR grade, indexed TAD, and surgical ablation for atrial fibrillation were independent predictors of ≥moderate TR. However, TAD alone had poor discrimination (area under the curve, ≤0.65). Presence of ≥moderate TR at 2 years was higher in patients with MR recurrence (20% vs. 9%; p = 0.02) and a permanent pacemaker/defibrillator (19% vs. 9%; p = 0.01). Clinical event rates (composite of ≥1 New York Heart Association functional class increase, heart failure hospitalization, mitral valve surgery, and stroke) were higher in patients with TR progression (55% vs. 23%; p = 0.003) and ≥moderate TR at 2 years (38% vs. 22%; p = 0.04). CONCLUSIONS: After IMR surgery, progression of unrepaired nonsevere TR is uncommon. Baseline TAD is not predictive of TR progression and is poorly discriminative of ≥moderate TR at 2 years. TR progression and presence of ≥moderate TR are associated with clinical events. (Comparing the Effectiveness of a Mitral Valve Repair Procedure in Combination With Coronary Artery Bypass Grafting [CABG] Versus CABG Alone in People With Moderate Ischemic Mitral Regurgitation, NCT00806988; Comparing the Effectiveness of Repairing Versus Replacing the Heart's Mitral Valve in People With Severe Chronic Ischemic Mitral Regurgitation, NCT00807040).

Motivational Interviewing to Promote the Effectiveness of Selective Prevention: an Integrated School-Based Approach.

School Mental Health prevention approaches that use multi-tiered systems are advancing rapidly. However, there is a relative shortage of effective selective prevention programs feasible to implement within the school context. To optimize the effectiveness of selective prevention in this context, a Motivational Interviewing (MI)-based prevention program for an adolescent student population was developed and tested. Footprints utilizes MI to increase engagement in modular Cognitive-Behavioral Therapy and to promote academic protective factors. In this study, forty-three adolescents were randomly assigned to Footprints or a treatment-as-usual waitlist control. Participants in the experimental condition demonstrated significant increases in behavioral and emotional functioning, self-efficacy to regulate behaviors, positive expectations for success, academic motivation, and grades in mathematics. Simultaneously, Footprints received high ratings for feasibility and acceptability within a dynamic school context. This exploratory efficacy evaluation provides initial support for MI's potential to promote the effectiveness of school-based prevention programs and warrants further study.

Risk for non-home discharge following surgery for ischemic mitral valve disease.

OBJECTIVES: To determine the frequency and risk factors for non-home discharge (NHD) and its association with clinical outcomes and quality of life (QOL) at 1 year following cardiac surgery in patients with ischemic mitral regurgitation (IMR). METHODS: Discharge disposition was evaluated in 552 patients enrolled in trials of severe or moderate IMR. Patient and in-hospital factors associated with NHD were identified using logistic regression. Subsequently, association of NHD with 1-year mortality, serious adverse events (SAEs), and QOL was assessed. RESULTS: NHD was observed in 30% (154/522) with 25% (n = 71/289) in moderate and 36% (n = 83/233) in patients with severe IMR (unadjusted P = .006), a difference not significant after including age (5-year change: adjusted odds ratio [adjOR], 1.52; 95% confidence interval [CI], 1.35-1.72; P < .001), diabetes (adjOR, 1.94; 95% CI, 1.27-2.94; P = .002), and previous heart failure (adjOR, 1.64; 95% CI, 1.06-2.52; P = .03). Odds of NHD were increased for patients with postoperative SAEs (adjOR, 1.85; 95% CI, 1.19-2.86; P = .01) but not based on type of cardiac surgery. Greater rates of death and SAEs were observed in NHD patients at 1 year: adjusted hazard ratio, 4.29 (95% CI, 2.14-8.59; P < .001) and adjusted rate ratio, 1.45 (95% CI, 1.03-2.02; P = .03), respectively. QOL did not differ significantly between groups. CONCLUSIONS: NHD is common following surgery for IMR, influenced by older age, diabetes, previous heart failure, and postoperative SAEs. These patients may be at greater risk of death and subsequent SAEs after discharge. Discussion of NHD with patients may have important implications for decision-making and guiding expectations following cardiac surgery.

Transcatheter mitral valve repair for functional mitral regurgitation: Evaluating the evidence.

OBJECTIVES: Two trials (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation Trial and Percutaneous Repair with the MitraClip Device for Severe Functional/Secondary Mitral Regurgitation Trial) were published in 2018 evaluating the effectiveness and safety of transcatheter repair for patients with heart failure with significant functional mitral regurgitation, which yielded different results. This article reviews the strength of the evidence, differences in trial designs, ethical and implementation implications, and delineates future research needs to help guide the appropriate dissemination of transcatheter repair for functional patients with mitral regurgitation. METHODS: The National Heart, Lung, and Blood Institute convened a workshop of interdisciplinary experts to address these objectives. RESULTS: Transcatheter repair of functional mitral regurgitation can provide significant benefits in terms of heart failure hospitalizations, survival, and quality of life when appropriate heart failure candidates with moderate to severe or severe mitral regurgitation while on optimal guideline-directed medical therapy can be identified. Key ingredients for success are preoperative evaluation and management and postoperative care by an interdisciplinary heart team. CONCLUSIONS: Given the discordance observed between trials, ongoing innovation in patient management, and potential expansion of indications for use, the evidence base must be expanded to optimize appropriate implementation of this complex therapy. This will require more complete capture of outcome data in real-world settings for all eligible candidates whether or not they receive this therapy. Inevitably, the indications for use of this therapy will expand, as will the devices and therapeutic approaches for this population, necessitating the study of comparative effectiveness through randomized trials or observational studies. Moreover, given the substantial variations in care delivery, conducting implementation research to delineate characteristics of the optimal care model would be of benefit.

Vulnerability to COVID-19-related Harms Among Transgender Women With and Without HIV Infection in the Eastern and Southern U.S.

BACKGROUND: COVID-19 is a new pandemic, and its impact by HIV status is unknown. National reporting does not include gender identity; therefore, data are absent on the impact of COVID-19 on transgender people, including those with HIV. Baseline data from the American Cohort to Study HIV Acquisition Among Transgender Women in High Risk Areas (LITE) Study provide an opportunity to examine pre-COVID factors that may increase vulnerability to COVID-19-related harms among transgender women. SETTING: Atlanta, Baltimore, Boston, Miami, New York City, Washington, DC. METHODS: Baseline data from LITE were analyzed for demographic, psychosocial, and material factors that may affect vulnerability to COVID-related harms. RESULTS: The 1020 participants had high rates of poverty, unemployment, food insecurity, homelessness, and sex work. Transgender women with HIV (n = 273) were older, more likely to be Black, had lower educational attainment, and were more likely to experience material hardship. Mental and behavioral health symptoms were common and did not differ by HIV status. Barriers to health care included being mistreated, provider discomfort serving transgender women, and past negative experiences; as well as material hardships, such as cost and transportation. However, most reported access to material and social support-demonstrating resilience. CONCLUSIONS: Transgender women with HIV may be particularly vulnerable to pandemic harms. Mitigating this harm would benefit everyone, given the highly infectious nature of this coronavirus. Collecting gender identity in COVID-19 data is crucial to inform an effective public health response. Transgender-led organizations' response to this crisis serve as an important model for effective community-led interventions.

COVID-19 Vulnerability of Transgender Women With and Without HIV Infection in the Eastern and Southern U.S.

BACKGROUND: COVID-19 is a new global pandemic and people with HIV may be particularly vulnerable. Gender identity is not reported, therefore data are absent on the impact of COVID-19 on transgender people, including transgender people with HIV. Baseline data from the American Cohort to Study HIV Acquisition Among Transgender Women in High Risk Areas (LITE) Study provide an opportunity to examine pre-COVID vulnerability among transgender women. SETTING: Atlanta, Baltimore, Boston, Miami, New York City, Washington, DC. METHODS: Baseline data from LITE were analysed for demographic, psychosocial, and material factors that may affect risk for COVID-related harms. RESULTS: The 1020 participants had high rates of poverty, unemployment, food insecurity, homelessness, and sex work. Transgender women with HIV (n=273) were older, more likely to be Black, had lower educational attainment, and were more likely to experience material hardship. Mental and behavioural health symptoms were common and did not differ by HIV status. Barriers to healthcare included being mistreated mistreatment, uncomfortable providers, and past negative experiences; as well as material hardships, such as cost and transportation. However, most reported access to material and social support - demonstrating resilience. CONCLUSIONS: Transgender women with HIV may be particularly vulnerable to pandemic harms. Mitigating this harm would have positive effects for everyone, given the highly infectious nature of this coronavirus. Collecting gender identity in COVID-19 data is crucial to inform an effective public health response. Transgender-led organizations' response to this crisis serve as an important model for effective community-led interventions.

Randomized Trials in Cardiac Surgery: JACC Review Topic of the Week.

Compared with randomized controlled trials (RCTs) in medical specialties, RCTs in cardiac surgery face specific issues. Individual and collective equipoise, rapid evolution of the surgical techniques, as well as difficulties in obtaining funding, and limited education in clinical epidemiology in the surgical community are among the most important challenges in the design phase of the trial. Use of complex interventions and learning curve effect, differences in individual operators' expertise, difficulties in blinding, and slow recruitment make the successful completion of cardiac surgery RCTs particularly challenging. In fact, over the course of the last 20 years, the number of cardiac surgery RCTs has declined significantly. In this review, a team of surgeons, trialists, and epidemiologists discusses the most important challenges faced by RCTs in cardiac surgery and provides a list of suggestions for the successful design and completion of cardiac surgery RCTs.

Strategies of Wait-listing for Heart Transplant vs Durable Mechanical Circulatory Support Alone for Patients With Advanced Heart Failure.

Importance: Given the shortage of donor hearts and improvement in outcomes with left ventricular assist device (LVAD) therapy, a relevant but, to date, unanswered question is whether select patients with advanced heart failure should receive LVAD destination therapy as an alternative to heart transplant. Objective: To determine whether a strategy of LVAD destination therapy is associated with similar survival benefit as wait-listing for heart transplant with or without LVAD therapy among patients with advanced heart failure. Design, Setting, and Participants: This retrospective propensity-matched cohort analysis used data on heart transplants from the United Network for Organ Sharing registry and LVAD implants from the Interagency Registry for Mechanically Assisted Circulatory Support from January 1, 2010, to December 31, 2014. The matched LVAD destination therapy cohort included 3411 patients. Data analysis for this study was conducted from December 22, 2017, to May 24, 2019. Main Outcomes and Measures: Survival at 5 years was analyzed using Cox proportional hazards models. Results: In total, 8281 patients had albumin level, creatinine level, and BMI data recorded and were included in the analysis. Despite propensity score matching, the 3411 patients receiving LVAD destination therapy still tended to be slightly older than the 3411 patients wait-listed for heart transplant (64.0 years [interquartile range, 55.0-70.0 years] vs 60.0 [interquartile range, 54.0-65.0 years]; P < .001), but there was no significant difference in sex (2701 men [79.2%] vs 2648 men [77.6%]; P = .13). After propensity score matching for age, sex, body mass index, renal function, and albumin level, 3411 patients were wait-listed for heart transplant. This included 1607 patients with bridge to transplant LVAD therapy and 1804 patients without LVAD. The strategy of wait-listing for heart transplant was associated with better 5-year survival than LVAD destination therapy (risk ratio, 0.42; 95% CI, 0.38-0.46) after matching and adjusting for key clinical factors. This survival advantage was associated with heart transplant (adjusted risk ratio for time-dependent transplant status, 0.27; 95% CI, 0.24-0.32). Conclusions and Relevance: The present analysis suggests that heart transplant with or without bridge to transplant LVAD therapy was associated with superior 5-year survival compared with LVAD destination therapy among patients matched on several relevant clinical factors. Continued improvement in LVAD technology, along with prospective comparative research, appears to be needed to amend this strategy.

Cost-effectiveness of coronary artery bypass grafting plus mitral valve repair versus coronary artery bypass grafting alone for moderate ischemic mitral regurgitation.

OBJECTIVE: The Cardiothoracic Surgical Trials Network reported that left ventricular reverse remodeling at 2 years did not differ between patients with moderate ischemic mitral regurgitation randomized to coronary artery bypass grafting plus mitral valve repair (n = 150) or coronary artery bypass grafting alone (n = 151). To address health resource use implications, we compared costs and quality-adjusted survival. METHODS: We used individual patient data from the Cardiothoracic Surgical Trials Network trial on survival, hospitalizations, quality of life, and US hospitalization costs to estimate cumulative costs and quality-adjusted life years. A microsimulation model was developed to extrapolate to 10 years. Bootstrap and deterministic sensitivity analyses were performed to address uncertainty. RESULTS: In-hospital costs were $59,745 for coronary artery bypass grafting plus mitral valve repair versus $51,326 for coronary artery bypass grafting alone (difference $8419; 95% uncertainty interval, 2259-18,757). Two-year costs were $81,263 versus $67,341 (difference 13,922 [2370 to 28,888]), and quality-adjusted life years were 1.35 versus 1.30 (difference 0.05; -0.04 to 0.14), resulting in an incremental cost-effectiveness ratio of $308,343/quality-adjusted life year for coronary artery bypass grafting plus mitral valve repair. At 10 years, its costs remained higher ($107,733 vs $88,583, difference 19,150 [-3866 to 56,826]) and quality-adjusted life years showed no difference (-0.92 to 0.87), with 5.08 versus 5.08. The likelihood that coronary artery bypass grafting plus mitral valve repair would be considered cost-effective at 10 years based on a cost-effectiveness threshold of $100K/quality-adjusted life year did not exceed 37%. Only when this procedure reduces the death rate by a relative 5% will the incremental cost-effectiveness ratio fall below $100K/quality-adjusted life year. CONCLUSIONS: The addition of mitral valve repair to coronary artery bypass grafting for patients with moderate ischemic mitral regurgitation is unlikely to be cost-effective. Only if late mortality benefits can be demonstrated will it meet commonly used cost-effectiveness criteria.

Portfolio Analysis of Research Grants in Data Science Funded by the National Heart, Lung, and Blood Institute.

Leveraging emerging opportunities in data science to open new frontiers in heart, lung, blood, and sleep research is one of the major strategic objectives of the National Heart, Lung, and Blood Institute (NHLBI), one of the 27 Institutes/Centers within the National Institutes of Health (NIH). To assess NHLBI's recent funding of research grants in data science and to identify its relative areas of focus within data science, a portfolio analysis from fiscal year 2008 to fiscal year 2017 was performed. In this portfolio analysis, an efficient and reliable methodology was used to identify data science research grants by utilizing several NIH databases and search technologies (iSearch, Query View Reporting system, and IN-SPIRE [Pacific Northwest National Laboratory, Richland, WA]). Six hundred thirty data science-focused extramural research grants supported by NHLBI were identified using keyword searches based primarily on NIH's working definitions of bioinformatics and computational biology. Further analysis characterized the distribution of these grants among the heart, lung, blood, and sleep disease areas as well as the subtypes of data science projects funded by NHLBI. Information was also collected for data science research grants funded by other NIH institutes/centers using the same search and analysis methodology. The funding comparison among different NIH institutes/centers highlighted relative data science areas of emphasis and further identified opportunities for potential data science areas in which NHLBI could foster research advances.