Adenosine 2A Receptor Agonism Improves Survival in Extracorporeal Cardiopulmonary Resuscitation.

INTRODUCTION: Despite resuscitation advances including extracorporeal cardiopulmonary resuscitation (ECPR), freedom from neurologic and myocardial insult after cardiac arrest remains unlikely. We hypothesized that adenosine 2A receptor (A2AR) agonism, which attenuates reperfusion injury, would improve outcomes in a porcine model of ECPR. METHODS: Adult swine underwent 20 min of circulatory arrest followed by defibrillation and 6 h of ECPR. Animals were randomized to receive saline vehicle or A2AR agonist (ATL1223 or Regadenoson) infusion during extracorporeal membrane oxygenation. Animals were weaned off extracorporeal membrane oxygenation and monitored for 24 h. Clinical and biochemical end points were compared. RESULTS: The administration of A2AR agonists increased survival (P = 0.01) after cardiac arrest compared to vehicle. Markers of neurologic damage including S100 calcium binding protein B and glial fibrillary acidic protein were significantly lower with A2AR agonist treatment. CONCLUSIONS: In a model of cardiac arrest treated with ECPR, A2AR agonism increased survival at 24 h and reduced neurologic damage suggesting A2AR activation may be a promising therapeutic target after cardiac arrest.

Rodent Model of Cardiopulmonary Bypass Demonstrates Systemic Inflammation and NeuroMarker Changes.

INTRODUCTION: The physiologic derangements imposed by cardiopulmonary bypass (CPB) can result in complications such as postoperative delirium. We aim to validate a rodent survival model of CPB demonstrating a systemic inflammatory response and hypothesize that this contributes to post-CPB delirium. METHODS: Adult Sprague-Dawley rats were randomized to three groups: 1) Sham peripheral surgical cannulation, 2) CPB followed by acute phase harvest, or 3) CPB followed by 24-h survival. CPB was carried out for 60 min before decannulation and weaning from mechanical ventilation. Physiological and biochemical endpoints were compared between groups. Gene expression analysis of hippocampal tissue was performed using quantitative RT-PCR panels and protein expression levels were confirmed with Western blot. RESULTS: Sixteen animals underwent cannulation and were successfully decannulated without transfusion requirement or inotrope use with one procedure-related mortality. Serum acute phase proinflammatory chemokines cytokine-induced neutrophil chemoattractant 1, cytokine-induced neutrophil chemoattractant 3, fractalkine, and lipopolysaccharide-induced CXC chemokine as well as interleukin (IL)-10 were increased 1 h following CPB compared to sham (P < 0.05). Significant changes in hippocampal expression of biomarkers apolipoprotein 1, vascular epithelial growth factor A, and synapsin 1 were demonstrated following CPB. CONCLUSIONS: This study validated a model of CPB that captures the resultant systemic inflammatory response, and identified differentially expressed proteins that may be associated with brain injury. Modulation of the CPB-induced inflammatory response may be a promising therapeutic target to attenuate post-CPB delirium, and this survival rat model of CPB with low surgical attrition will allow for more comprehensive evaluations of the short- and long-term effects of both CPB and potential therapeutic interventions.

Machine Learning on 50,000 Manuscripts Shows Increased Clinical Research by Academic Cardiac Surgeons.

INTRODUCTION: Academic cardiac surgeons are productive researchers and innovators. We sought to perform a comprehensive machine learning (ML)-based characterization of cardiac surgery research over the past 40 y to identify trends in research pursuits. METHODS: US-based academic websites were queried for surgeon profiles. Publications since 1980 were obtained from Web of Science, and publication classifications (e.g., "human", "animal") were collected through the National Institutes of Health iCite tool. Publications were deemed "basic or translational" if >50% of their classification was under "animal" or "molecular or cell", and "clinical" if otherwise. ML-based clustering was performed on publication titles and Medical Subject Heading terms to identify research topics. RESULTS: A total of 944 cardiac surgeons accounted for 48,031 unique publications. Average citations per year have decreased since 1980 (P < 0.001). The percentage of basic or translational publications by cardiac surgeons has decreased over time (P < 0.001), comprising of only 8% of publications in 2022. Adult cardiac surgeons, those who received an F32, K08, or R01, and those with a PhD were more likely to publish basic or translational research. Top areas of basic or translational research were myocardial reperfusion, aortic aneurysms or remodeling, and transplant immunology. Major areas of clinical research included aortic disease, aortic valve disease, and mechanical circulatory support. Collaboration analysis revealed that 55% of publications were single-center, and the yearly percentage of these publications has decreased over time (P < 0.001). CONCLUSIONS: Cardiac surgeons are performing less basic or translational research relative to clinical research than ever before. The majority of publications over the past 40 y did not involve cross-center collaboration. Continued support for clinical research is needed, while also encouraging collaborative basic or translational science to foster innovation in patient care.

Postdoctoral National Institutes of Health F32 Grants: Broken Pipeline in the Development of Surgeon-Scientists.

OBJECTIVE: We examined trainees in surgery and internal medicine who received National Institutes of Health (NIH) F32 postdoctoral awards to determine their success rates in obtaining future NIH funding. BACKGROUND: Trainees participate in dedicated research years during residency (surgery) and fellowship (internal medicine). They can obtain an NIH F32 grant to fund their research time and have structured mentorship. METHODS: We collected NIH F32 grants (1992-2021) for Surgery Departments and Internal Medicine Departments from NIH RePORTER, an online database of NIH grants. Nonsurgeons and noninternal medicine physicians were excluded. We collected demographic information on each recipient, including gender, current specialty, leadership positions, graduate degrees, and any future NIH grants they received. A Mann-Whitney U test was used for continuous variables, and a χ 2 test was utilized to analyze categorical variables. An alpha value of 0.05 was used to determine significance. RESULTS: We identified 269 surgeons and 735 internal medicine trainees who received F32 grants. A total of 48 surgeons (17.8%) and 339 internal medicine trainees (50.2%) received future NIH funding ( P < 0.0001). Similarly, 24 surgeons (8.9%) and 145 internal medicine trainees (19.7%) received an R01 in the future ( P < 0.0001). Surgeons who received F32 grants were more likely to be department chair or division chiefs ( P =0.0055 and P < 0.0001). CONCLUSIONS: Surgery trainees who obtain NIH F32 grants during dedicated research years are less likely to receive any form of NIH funding in the future compared with their internal medicine colleagues who received F32 grants.

Pulmonary Hypertension and Operative Risk in Mitral Valve and Coronary Surgery.

INTRODUCTION: Pulmonary hypertension (PHT) is a known risk factor for coronary artery bypass grafting (CABG), though less well understood for valve operations. We hypothesized PHT is associated with lower risk during mitral valve operations compared to CABG. METHODS: Patients undergoing isolated mitral valve or CABG operations (2011-2019) in a regional Society of Thoracic Surgeons (STS) database were stratified by pulmonary artery systolic pressure (PASP). The association of PASP by procedure type was assessed by hierarchical regression modeling, adjusting for STS predicted risk scores. RESULTS: Of the 2542 mitral and 11,059 CABG patients, the mitral population had higher mean STS risk of mortality (3.6% versus 2.4%, P < 0.0001) and median PASP (42 mmHg versus 32 mmHg, P < 0.0001). PASP was independently associated with operative mortality and major morbidity in both mitral and CABG patients. However, for mitral patients a 10-mmHg increase in PASP was associated with lower odds of morbidity (odds ratio: 1.06 versus 1.13), mortality (odds ratio: 1.11 versus 1.18) and intensive care unit time (4.3 versus 7.6 h) compared with CABG patients (interaction terms P < 0.0001). Among mitral patients, median PASP was higher in stenotic versus regurgitant disease (57 mmHg versus 40 mmHg, P < 0.0001). However, there was no differential association of PASP on morbidity or mortality (interaction terms P > 0.05). CONCLUSIONS: Although mitral surgery patients tend to have higher preoperative pulmonary artery pressures, PHT was associated with a lower risk for mitral outcomes compared with CABG. Further research on the management and optimization of patients with PHT perioperatively is needed to improve care for these patients.

Temporal Cluster Analysis of Deep Sternal Wound Infection in a Regional Quality Collaborative.

INTRODUCTION: Deep sternal wound infection (DSWI) is a rare complication associated with high mortality. Seasonal variability in surgical site infections has been demonstrated, however, these patterns have not been applied to DSWI. The purpose of this study was to assess temporal clustering of DSWIs. METHODS: All cardiac surgery patients who underwent sternotomy were queried from a regional Society of Thoracic Surgeons database from 17 centers from 2001 to 2019. All patients with the diagnosis of DSWI were then identified. Cluster analysis was performed at varying time intervals (monthly, quarterly, and yearly) at the hospital and regional level. DSWI rates were calculated by year and month, and compared using mixed-effects negative binomial regression. RESULTS: A total of 134,959 patients underwent a sternotomy for cardiac surgery, of whom 469 (0.35%) developed a DSWI. Rates of DSWI per hospital across all years ranged from 0.12% to 0.69%. Collaborative-level rates of DSWIs were the greatest in September (0.44%) and the lowest in January (0.30%). Temporal clustering was not seen across seasonal quarters (high rate in preceeding quarter was not associated with a high rate in the next quarter) (P = 0.39). There were yearly differences across all institutions in the DSWI rates. A downward trend in DSWI rates was seen from 2001 to 2019 (P < 0.001). A difference among hospitals in the cohort was observed (P < 0.001). CONCLUSIONS: DSWI are a rare event within our region. Unlike other surgical site infection, there does not appear to be a seasonal pattern associated with DSWI.

Cerebrovascular Events in Patients With Centrifugal-Flow Left Ventricular Assist Devices: Propensity Score-Matched Analysis From the Intermacs Registry.

BACKGROUND: Ischemic and hemorrhagic cerebrovascular accidents remain common among patients with centrifugal-flow left ventricular assist devices, despite improvements in survival and device longevity. We compared the incidence of neurologic adverse events (NAEs) associated with 2 contemporary centrifugal-flow left ventricular assist devices: the Abbott HeartMate3 (HM3) and the Medtronic HeartWare HVAD (HVAD). METHODS: Using the Society of Thoracic Surgeons Interagency Registry for Mechanically Assisted Circulatory Support (Intermacs), we collected data on adult patients who received a centrifugal-flow left ventricular assist device as a primary isolated implant between January 1, 2017, and September 30, 2019. Major NAEs were defined as transient ischemic attack, ischemic cerebrovascular accident, or hemorrhagic cerebrovascular accident. The association of HVAD with risk of NAE in the first year after implant was evaluated using propensity score matching to balance for preimplant risk factors. After matching, freedom from first major NAE in the HM3 and HVAD cohorts was compared with Kaplan-Meier curves. A secondary analysis using multivariable multiphase hazard models was used to identify predictors of NAE, which uses a data-driven parametric fit of the early declining and constant phase hazards and the associations of risk factor with either phase. RESULTS: Of 6205 included patients, 3129 (50.4%) received the HM3 and 3076 (49.6%) received the HVAD. Median follow-up was 9 and 12 months (HM3 and HVAD, respectively). Patients receiving HVAD had more major NAEs (16.4% versus 6.4%, P<0.001) as well as each subtype (transient ischemic attack: 3.3% versus 1.0%, P<0.001; ischemic cerebrovascular accident: 7.7% versus 3.4%, P<0.001; hemorrhagic cerebrovascular accident: 7.2% versus 2.0%, P<0.001) than did patients receiving HM3. A propensity-matched cohort balanced for preimplant risk factors showed that HVAD was associated with higher probabilities of major NAEs (% freedom from NAE 82% versus 92%, P<0.001). Device type was not significantly associated with NAEs in the early hazard phase, but HVAD was associated with higher incidence of major NAEs during the constant hazard phase (hazard ratio, 5.71 [CI, 3.90-8.36]). CONCLUSIONS: HM3 is associated with lower hazard of major NAEs than is HVAD beyond the early postimplantation period and during the constant hazard phase. Defining the explanation for this observation will inform device selection for individual patients.

Cerebrovascular Events in Patients With Centrifugal-Flow Left Ventricular Assist Devices: Propensity Score-Matched Analysis From the Intermacs Registry.

BACKGROUND: Ischemic and hemorrhagic cerebrovascular accidents remain common among patients with centrifugal-flow left ventricular assist devices, despite improvements in survival and device longevity. We compared the incidence of neurologic adverse events (NAEs) associated with 2 contemporary centrifugal-flow left ventricular assist devices: the Abbott HeartMate3 (HM3) and the Medtronic HeartWare HVAD (HVAD). METHODS: Using the Society of Thoracic Surgeons Interagency Registry for Mechanically Assisted Circulatory Support (Intermacs), we collected data on adult patients who received a centrifugal-flow left ventricular assist device as a primary isolated implant between January 1, 2017, and September 30, 2019. Major NAEs were defined as transient ischemic attack, ischemic cerebrovascular accident, or hemorrhagic cerebrovascular accident. The association of HVAD with risk of NAE in the first year after implant was evaluated using propensity score matching to balance for preimplant risk factors. After matching, freedom from first major NAE in the HM3 and HVAD cohorts was compared with Kaplan-Meier curves. A secondary analysis using multivariable multiphase hazard models was used to identify predictors of NAE, which uses a data-driven parametric fit of the early declining and constant phase hazards and the associations of risk factor with either phase. RESULTS: Of 6205 included patients, 3129 (50.4%) received the HM3 and 3076 (49.6%) received the HVAD. Median follow-up was 9 and 12 months (HM3 and HVAD, respectively). Patients receiving HVAD had more major NAEs (16.4% versus 6.4%, P<0.001) as well as each subtype (transient ischemic attack: 3.3% versus 1.0%, P<0.001; ischemic cerebrovascular accident: 7.7% versus 3.4%, P<0.001; hemorrhagic cerebrovascular accident: 7.2% versus 2.0%, P<0.001) than did patients receiving HM3. A propensity-matched cohort balanced for preimplant risk factors showed that HVAD was associated with higher probabilities of major NAEs (% freedom from NAE 82% versus 92%, P<0.001). Device type was not significantly associated with NAEs in the early hazard phase, but HVAD was associated with higher incidence of major NAEs during the constant hazard phase (hazard ratio, 5.71 [CI, 3.90-8.36]). CONCLUSIONS: HM3 is associated with lower hazard of major NAEs than is HVAD beyond the early postimplantation period and during the constant hazard phase. Defining the explanation for this observation will inform device selection for individual patients.

Access to Left Ventricular Assist Device: Travel Time Does Not Tell The Whole Story.

BACKGROUND: Negative health effects of traveling longer distances for surgical services have been reported. Given the high complexity of multidisciplinary care required for management of Left Ventricular Assist Device (LVAD) implantation, only 4 of 18 centers in our state perform these operations. Given the limited access we hypothesized increased travel time would adversely affect postoperative outcomes and 30-d mortality. METHODS: A statewide Society of Thoracic Surgeons database was queried to identify patients undergoing Heartmate II/III and HVAD implantation, and 725 patients were identified. Travel time was calculated by zip code. Patients were stratified into regional and distant groups by the upper quartile of travel time (1-h). Preoperative variables and outcomes were compared between the groups. Multivariate analysis was performed to evaluate the impact of travel time in risk-adjusted models of 30-d mortality. RESULTS: Median patient travel time to their LVAD center in our state is 32 min (mean 53 ± 65 min, 46 ± 71 miles). Patients in the distant group (n = 191) had lower median incomes, higher self-pay status, higher rates of medical comorbid disease. Despite these differences there was no difference between the groups in ICU and/or hospital length of stay, readmission, postoperative complications, or 30-d mortality. Multivariate regression demonstrated insurance status, age, and prior surgery predicted 30-d mortality, but not travel time. CONCLUSIONS: Despite only four centers in the state performing LVAD implantation, travel time was strongly associated with preoperative risk, and socioeconomic status but not postoperative outcomes or 30-d mortality. Therefore, increasing access should focus on insurance, and patient characteristics not travel time.

Gastric Aspiration and Ventilator-Induced Model of Acute Respiratory Distress Syndrome in Swine.

INTRODUCTION: Mainstays of current treatment for acute respiratory distress syndrome (ARDS) focus on supportive care and rely on intrinsic organ recovery. Animal models of ARDS are often limited by systemic injury. We hypothesize that superimposing gastric aspiration and ventilator-induced injury will induce a lung-specific injury model of severe ARDS. MATERIALS AND METHODS: Adult swine (n = 8) were subject to a 12 h injury development period followed by 24 h of post-injury monitoring. Lung injury was induced with gastric secretions (3 cc/kg body weight/lung, pH 1-2) instilled to bilateral mainstem bronchi under direct bronchoscopic vision. Ventilator settings within the injury period contradicted baseline settings using high tidal volumes and low positive end-expiratory pressure. Baseline settings were restored following the injury period. Arterial oxygenation and lung compliance were monitored. RESULTS: At 12 h, PaO2/FiO2 ratio and static and dynamic compliance were significantly reduced from baseline (P < 0.05). During the postinjury period, animals showed no signs of recovery in PaO2/FiO2 ratio and lung compliance. Lung edema (wet/dry weight ratio) of injured lungs was significantly elevated versus noninjured lungs (8.5 ± 1.7 versus 5.6 ± 0.3, P = 0.009). Expression of proinflammatory cytokines IL-6 and IL-8 were significantly elevated in injured lungs (P < 0.05). CONCLUSIONS: Twelve hours of high tidal volume and low positive end-expiratory pressure in conjunction with low-pH gastric content instillation produces significant acute lung injury in swine. This large animal model may be useful for testing severe ARDS treatment strategies.

Contemporary prevalence and outcomes of rheumatic mitral valve surgery.

OBJECTIVE: Rheumatic mitral valve disease is often viewed as a historic disease in North America with limited contemporary data. We hypothesized that rheumatic pathology remains common and has worse short-term outcomes and higher resource utilization compared to other mitral valve pathologies. METHOD: All patients undergoing mitral valve repair or replacement (2011-2019) were extracted from a regional Society of Thoracic Surgeons database. Resource utilization metrics included inflation-adjusted hospital costs. Patients were stratified by mitral valve pathology for univariate analysis. RESULT: Out of the 6625 mitral valve procedures, 835 (12.6%) were from rheumatic disease, a proportion that incrementally increased over time (+0.39% per year, p = .032). Among 19 hospitals, there was high variability in number of rheumatic mitral operations (median: 22, interquartile range [IQR]: 5-80) and rate of rheumatic repairs (median: 3%, IQR: 0%-6%). Rheumatic patients were younger (62 vs. 65, p < .0001), more often female (75% vs. 43%, p < .001) and with greater burden of heart failure, multi-valve disease, and lung disease, but less coronary disease. There were no differences in operative mortality (5.2% vs. 5.0%, p = .85) or major morbidity (22.2% vs. 21.8%, p = .83). However, resource utilization was higher for rheumatic patients, including more frequent transfusions (43% vs. 39%, p = .012), longer ICU (73 vs. 64 h, p < .0001) and postoperative length of stay (8 vs. 7 days, p < .0001). CONCLUSIONS: Rheumatic mitral disease accounts for a meaningful (12%) and rising percentage of mitral valve operations in the region, with high variability among hospitals. Rheumatic mitral surgery yielded similar short-term outcomes compared to nonrheumatic pathology, but required greater resource utilization.

Aortic valve biologic protheses: A cohort comparison of premature valve failure.

BACKGROUND: Recent reports suggest an increased rate of early structural valve degeneration (SVD) in the Trifecta bioprosthesis (Abbott Cardiovascular). We sought to compare the intermediate-term outcomes of the Magna (Edwards Life Sciences) and Trifecta valves. METHODS: All surgical aortic valve replacements (SAVRs) with Trifecta or Magna/Magna Ease bioprostheses at an academic medical center were extracted from an institutional database. Patients who survived until after discharge (2011-2019) were included. The primary outcome was valve failure for any reason requiring reintervention or contributing to death, identified by reintervention or review of cause of death. Time to failure was estimated with Kaplan-Meier analysis and Cox Proportional Hazards Modeling. RESULTS: Out of 1444 patients, 521 (36%) underwent Trifecta and 923 (64%) underwent Magna implantation with a median follow-up of 27.6 months. Trifecta patients had larger median valve size (25 vs. 23 mm, p < .001) and lower median gradient (8.0 vs. 10.9 mmHg, p < .001). Trifecta patients had higher 48-month estimated failure rates (20.2 ± 7.6% vs. 2.6 ± 0.7%, p < .0001), with failure rates of 21.4 versus 9.2 failures per 1000 person-years (p < .001). After risk-adjustment, Trifecta patients had a 5.3 times hazard of failure (95% confidence interval: 2.78-12.34, p < .001) compared to Magna patients. Only Trifecta valves failed due to sudden aortic regurgitation, 8 out of 521 (1.5%). CONCLUSION: Despite lower postoperative mean gradients, the Trifecta bioprosthesis may have an increased risk of intermediate-term SVD. Further research is warranted to confirm the potential for sudden valve failure.

Meaningful Patient-centered Outcomes 1 Year Following Cardiac Surgery.

OBJECTIVE: To evaluate meaningful, patient-centered outcomes including alive-at-home status and patient-reported quality of life 1 year after cardiac surgery. BACKGROUND: Long-term patient-reported quality of life after cardiac surgery is not well understood. Current operative risk models and quality metrics focus on short-term outcomes. METHODS: In this combined retrospective/prospective study, cardiac surgery patients at an academic institution (2014-2015) were followed to obtain vital status, living location, and patient-reported outcomes (PROs) at 1 year using the NIH Patient-Reported Outcomes Measurement Information System (PROMIS). We assessed the impact of cardiac surgery, discharge location, and Society of Thoracic Surgeons perioperative predicted risk of morbidity or mortality on 1-year outcomes. RESULTS: A total of 782 patients were enrolled; 84.1% (658/782) were alive-at-home at 1 year. One-year PROMIS scores were global physical health (GPH) = 48.8 ±â€Š10.2, global mental health (GMH) = 51.2 ±â€Š9.6, and physical functioning (PF) = 45.5 ±â€Š10.2 (general population reference = 50 ±â€Š10). All 3 PROMIS domains at 1 year were significantly higher compared with preoperative scores (GPH: 41.7 ±â€Š8.5, GMH: 46.9 ±â€Š7.9, PF: 39.6 ±â€Š9.0; all P < 0.001). Eighty-two percent of patients discharged to a facility were alive-at-home at 1 year. These patients, however, had significantly lower 1-year scores (difference: GPH = -5.1, GMH = -5.1, PF = -7.9; all P < 0.001). Higher Society of Thoracic Surgeons perioperative predicted risk was associated with significantly lower PRO at 1 year (P < 0.001). CONCLUSIONS: Cardiac surgery results in improved PROMIS scores at 1 year, whereas discharge to a facility and increasing perioperative risk correlate with worse long-term PRO. One-year alive-at-home status and 1-year PRO are meaningful, patient-centered metrics that help define long-term quality and the benefit of cardiac surgery.

Early Versus Delayed Pacemaker for Heart Block After Valve Surgery: A Cost-Effectiveness Analysis.

BACKGROUND: A significant percentage of patients who acutely develop high-grade atrioventricular block after valve surgery will ultimately recover, yet the ability to predict recovery is limited. The purpose of this analysis was to evaluate the cost-effectiveness of two different management strategies for the timing of permanent pacemaker implantation for new heart block after valve surgery. METHODS: A cost-effectiveness model was developed using costs and probabilities of short- and long-term complications of pacemaker placement, short-term atrioventricular node recovery, intensive care unit stays, and long-term follow-up. We aggregated the total expected cost and utility of each option over a 20-y period. Quality-adjusted survival with a pacemaker was estimated from the literature and institutional patient-reported outcomes. Primary decision analysis was based on an expected recovery rate of 36.7% at 12 d with timing of pacemaker implantation: early placement (5 d) versus watchful waiting for 12 d. RESULTS: A strategy of watchful waiting was more costly ($171,798 ± $45,695 versus $165,436 ± $52,923; P < 0.0001) but had a higher utility (9.05 ± 1.36 versus 8.55 ± 1.33 quality-adjusted life years; P < 0.0001) than an early pacemaker implantation strategy. The incremental cost-effectiveness ratio of watchful waiting was $12,724 per quality-adjusted life year. The results are sensitive to differences in quality-adjusted survival and rates of recovery of atrioventricular node function. CONCLUSIONS: Watchful waiting for pacemaker insertion is a cost-effective management strategy compared with early placement for acute atrioventricular block after valve surgery. Although this is cost-effective from a population perspective, clinical risk scores predicting recovery will aid in personalized decision-making.

Valve-sparing aortic root replacement after neonatal arterial switch operation.

Arterial switch operations (ASO) are lifesaving procedures performed on neonates to treat transposition of the great arteries. However, future operations on the neoaorta may be required due to dilation. We present a case of a 25-year-old female who presented with dilation of her neoaorta and required a David procedure. Her previous ASO resulted in an anterior lie of the pulmonary artery in front of the neoaorta, with both coronary arteries coming off anteriorly. We describe our approach to performing a David procedure on this patient with this unique anatomy.

COVID-19 and cardiothoracic surgery: Effects on training and workforce utilization in a global pandemic.

BACKGROUND: The COVID-19 pandemic has disrupted all aspects of healthcare, including cardiothoracic surgery (CTS). We sought to determine the pandemic's impact on CTS trainees' educational experiences. METHODS: A survey was developed and distributed to members of the Thoracic Surgery Residents Association and other international CTS trainees. Trainees were asked to evaluate their cumulative experiences and share their overall perceptions of how CTS training had been impacted during the earliest months of the COVID-19 pandemic (i.e., since March 01, 2020). Surveys were distributed and responses were recorded June 25-August 05, 2020. In total, 748 surveys were distributed and 166 responses were received (overall response rate 22.2%). Of these, 126 of 166 responses (75.9%) met inclusion criteria for final analysis. RESULTS: Final responses analyzed included 45 of 126 (35.7%) United States (US) and 81 of 126 (64.3%) international trainees, including 101 of 126 (80.2%) senior and 25 of 126 (19.8%) junior trainees. Most respondents (76/126, 43.2%) lost over 1 week in the hospital due to the pandemic. Juniors (12/25, 48.0%) were more likely than seniors (20/101, 19.8%) to be reassigned to COVID-19-specific units (p < .01). Half of trainees (63/126) reported their case volumes were reduced by over 50%. US trainees (42/45, 93.3%) were more likely than international trainees (58/81, 71.6%) to report reduced operative case volumes (p < .01). Most trainees (104/126, 83%) believed their overall clinical acumen was not adversely impacted by the pandemic. CONCLUSIONS: CTS trainees in the United States and abroad have been significantly impacted by the COVID-19 pandemic, with time lost in the hospital, decreased operative experiences, less time on CTS services, and frequent reassignment to COVID-19-specific care settings.

SPECT imaging of lung ischemia-reperfusion injury using [99mTc]cFLFLF for molecular targeting of formyl peptide receptor 1.

Primary graft dysfunction after lung transplantation, a consequence of ischemia-reperfusion injury (IRI), is a major cause of morbidity and mortality. IRI involves acute inflammation and innate immune cell activation, leading to rapid infiltration of neutrophils. Formyl peptide receptor 1 (FPR1) expressed by phagocytic leukocytes plays an important role in neutrophil function. The cell surface expression of FPR1 is rapidly and robustly upregulated on neutrophils in response to inflammatory stimuli. Thus, we hypothesized that use of [99mTc]cFLFLF, a selective FPR1 peptide ligand, would permit in vivo neutrophil labeling and noninvasive imaging of IRI using single-photon emission computed tomography (SPECT). A murine model of left lung IRI was utilized. Lung function, neutrophil infiltration, and SPECT imaging were assessed after 1 h of ischemia and 2, 12, or 24 h of reperfusion. [99mTc]cFLFLF was injected 2 h before SPECT. Signal intensity by SPECT and total probe uptake by gamma counts were 3.9- and 2.3-fold higher, respectively, in left lungs after ischemia and 2 h of reperfusion versus sham. These values significantly decreased with longer reperfusion times, correlating with resolution of IRI as shown by improved lung function and decreased neutrophil infiltration. SPECT results were confirmed using Cy7-cFLFLF-based fluorescence imaging of lungs. Immunofluorescence microscopy confirmed cFLFLF binding primarily to activated neutrophils. These results demonstrate that [99mTc]cFLFLF SPECT enables noninvasive detection of lung IRI and permits monitoring of resolution of injury over time. Clinical application of [99mTc]cFLFLF SPECT may permit diagnosis of lung IRI for timely intervention to improve outcomes after transplantation.

Socioeconomic "Distressed Communities Index" Improves Surgical Risk-adjustment.

OBJECTIVE: We hypothesize the Distressed Communities Index (DCI), a composite socioeconomic ranking by ZIP code, will predict risk-adjusted outcomes after surgery. SUMMARY OF BACKGROUND DATA: Socioeconomic status affects surgical outcomes; however, the American College of Surgeons National Surgery Quality Improvement Program (ACS NSQIP) database does not account for these factors. METHODS: All ACS NSQIP patients (17,228) undergoing surgery (2005 to 2015) at a large academic institution were paired with the DCI, which accounts for unemployment, education level, poverty rate, median income, business growth, and housing vacancies. Developed by the Economic Innovation Group, DCI scores range from 0 (no distress) to 100 (severe distress). Multivariable regressions were used to evaluate ACS NSQIP predicted risk-adjusted effect of DCI on outcomes and inflation-adjusted hospital cost. RESULTS: A total of 4522 (26.2%) patients came from severely distressed communities (top quartile). These patients had higher rates of medical comorbidities, transfer from outside hospital, emergency status, and higher ACS NSQIP predicted risk scores (all P < 0.05). In addition, these patients had greater resource utilization, increased postoperative complications, and higher short- and long-term mortality (all P < 0.05). Risk-adjustment with multivariate regression demonstrated that DCI independently predicts postoperative complications (odds ratio 1.1, P = 0.01) even after accounting for ACS NSQIP predicted risk score. Furthermore, DCI independently predicted inflation-adjusted cost (+$978/quartile, P < 0.0001) after risk adjustment. CONCLUSIONS: The DCI, an established metric for socioeconomic distress, improves ACS NSQIP risk-adjustment to predict outcomes and hospital cost. These findings highlight the impact of socioeconomic status on surgical outcomes and should be integrated into ACS NSQIP risk models.

Diabetes Mellitus and Metformin Are Not Associated With Breast Cancer Pathologic Complete Response.

BACKGROUND: Metformin use has been linked to pathologic complete response (pCR) following neoadjuvant chemotherapy for several malignancies. We aimed to investigate the association of diabetes mellitus (DM) and metformin use with pCR in breast cancer. MATERIALS AND METHODS: All breast cancer patients who received neoadjuvant chemotherapy during June 2013-October 2016 at two academic medical centers were identified. A retrospective cohort study evaluated patients who did and did not achieve pCR. Multivariable logistic regression identified independent predictors of pCR, specifically looking at metformin use and DM. RESULTS: The study group included 351 breast cancer patients, with 90 (25.6%) achieving pCR after neoadjuvant chemotherapy. The rate of DM did not differ between those with and without pCR, nor did the rate of metformin use. Multivariable logistic regression identified HER2-positive tumors and smaller preoperative tumor size as predictors of pCR. The estrogen receptor (ER) positivity was associated with an absence of pCR. Importantly, neither DM nor metformin use was predictive of pCR. CONCLUSIONS: This study by the two institutions supports previous data of tumor-related factors known to be associated with pCR; however, the current analysis found neither DM nor metformin to be independently associated with pCR. Thus, additional prospective study is warranted prior to validating metformin as an antitumor agent.

Gastrointestinal Complications After Cardiac Surgery: Highly Morbid but Improving Over Time.

BACKGROUND: Gastrointestinal complications after cardiac surgery are associated with high morbidity and mortality. We sought to determine the granular impact of individual gastrointestinal complications after cardiac surgery and assess contemporary outcomes. MATERIALS AND METHODS: Patients undergoing cardiac surgery from 2010 to 2017 (6070 patients) were identified from an institutional Society of Thoracic Surgeons database. Records were paired with institutional data assessing gastrointestinal complications and cost. Patients were stratified by early (2010-2013) and current (2014-2017) eras. RESULTS: A total of 280 (4.6%) patients experienced gastrointestinal complications including Clostridiumdifficile infection (94, 33.6%), gastrointestinal bleed (86, 30.7%), hepatic failure (66, 23.6%), prolonged ileus (59, 21.1%), mesenteric ischemia (47, 16.8%), acute cholecystitis (17, 6.0%), and pancreatitis (14, 5.0%). Gastrointestinal complications were associated with higher rates of early postoperative major morbidity [206 (73.6%) versus 773 (13.4%), P < 0.0001], mortality [78 (27.9%) versus 161 (2.8%), P < 0.0001], length of stay (23 versus 6 d, P < 0.0001), and discharge to a facility [115 (41.1%) versus 1395 (24.1%), P < 0.0001]. Patients suffering gastrointestinal complications had worse risk-adjusted long-term survival (hazard ratio: 3.0, P < 0.0001) and higher adjusted cost ($9,173, P = 0.05). Between eras, there was no difference in incidence of gastrointestinal complications [139 (4.4%) versus 141 (4.8%), P = 0.51] or rate of specific complications (all P > 0.05). However, long-term survival increased in modern era (P < 0.0001). CONCLUSIONS: Although incidence of gastrointestinal complications after cardiac surgery has not changed over time, long-term survival has improved. Gastrointestinal complications remain associated with high resource utilization and major morbidity, but patients are now more likely to recover, highlighting the benefit of quality improvement efforts.