Hemodynamics and Wall Mechanics of Vascular Graft Failure.

Blood vessels are subjected to complex biomechanical loads, primarily from pressure-driven blood flow. Abnormal loading associated with vascular grafts, arising from altered hemodynamics or wall mechanics, can cause acute and progressive vascular failure and end-organ dysfunction. Perturbations to mechanobiological stimuli experienced by vascular cells contribute to remodeling of the vascular wall via activation of mechanosensitive signaling pathways and subsequent changes in gene expression and associated turnover of cells and extracellular matrix. In this review, we outline experimental and computational tools used to quantify metrics of biomechanical loading in vascular grafts and highlight those that show potential in predicting graft failure for diverse disease contexts. We include metrics derived from both fluid and solid mechanics that drive feedback loops between mechanobiological processes and changes in the biomechanical state that govern the natural history of vascular grafts. As illustrative examples, we consider application-specific coronary artery bypass grafts, peripheral vascular grafts, and tissue-engineered vascular grafts for congenital heart surgery as each of these involves unique circulatory environments, loading magnitudes, and graft materials.

Human Coronary Plaque T Cells Are Clonal and Cross-React to Virus and Self.

BACKGROUND: Coronary artery disease is an incurable, life-threatening disease that was once considered primarily a disorder of lipid deposition. Coronary artery disease is now also characterized by chronic inflammation' notable for the buildup of atherosclerotic plaques containing immune cells in various states of activation and differentiation. Understanding how these immune cells contribute to disease progression may lead to the development of novel therapeutic strategies. METHODS: We used single-cell technology and in vitro assays to interrogate the immune microenvironment of human coronary atherosclerotic plaque at different stages of maturity. RESULTS: In addition to macrophages, we found a high proportion of αß T cells in the coronary plaques. Most of these T cells lack high expression of CCR7 and L-selectin, indicating that they are primarily antigen-experienced memory cells. Notably, nearly one-third of these cells express the HLA-DRA surface marker, signifying activation through their TCRs (T-cell receptors). Consistent with this, TCR repertoire analysis confirmed the presence of activated αß T cells (CD4

A value-based approach to optimize red blood cell transfusion in patients receiving extracorporeal membrane oxygenation.

INTRODUCTION: The risk, cost, and adverse outcomes associated with packed red blood cell (RBC) transfusions in patients with cardiopulmonary failure requiring extracorporeal membrane oxygenation (ECMO) have raised concerns regarding the overutilization of RBC products. It is, therefore, necessary to establish optimal transfusion criteria and protocols for patients supported with ECMO. The goal of this study was to establish specific criteria for RBC transfusions in patients undergoing ECMO. METHODS: This was a retrospective cohort study conducted at Stanford University Hospital. Data on RBC utilization during the entire hospital stay were obtained, which included patients aged ≥18 years who received ECMO support between 1 January 2017, and 30 June 2020 (n = 281). The primary outcome was in-hospital mortality. RESULTS: Hemoglobin (HGB) levels >10 g/dL before transfusion did not improve in-hospital survival. Therefore, we revised the HGB threshold to ≤10 g/dL to guide transfusion in patients undergoing ECMO. To validate this intervention, we prospectively compared the pre- and post-intervention cohorts for in-hospital mortality. Post-intervention analyses found 100% compliance for all eligible records and a decrease in the requirement for RBC transfusion by 1.2 units per patient without affecting the mortality. CONCLUSIONS: As an institution-driven value-based approach to guide transfusion in patients undergoing ECMO, we lowered the threshold HGB level. Validation of this revised intervention demonstrated excellent compliance and reduced the need for RBC transfusion while maintaining the clinical outcome. Our findings can help reform value-based healthcare in this cohort while maintaining the outcome.

Integration of Reinforcement Learning in a Virtual Robotic Surgical Simulation.

Background. The revolutions in AI hold tremendous capacity to augment human achievements in surgery, but robust integration of deep learning algorithms with high-fidelity surgical simulation remains a challenge. We present a novel application of reinforcement learning (RL) for automating surgical maneuvers in a graphical simulation.Methods. In the Unity3D game engine, the Machine Learning-Agents package was integrated with the NVIDIA FleX particle simulator for developing autonomously behaving RL-trained scissors. Proximal Policy Optimization (PPO) was used to reward movements and desired behavior such as movement along desired trajectory and optimized cutting maneuvers along the deformable tissue-like object. Constant and proportional reward functions were tested, and TensorFlow analytics was used to informed hyperparameter tuning and evaluate performance.Results. RL-trained scissors reliably manipulated the rendered tissue that was simulated with soft-tissue properties. A desirable trajectory of the autonomously behaving scissors was achieved along 1 axis. Proportional rewards performed better compared to constant rewards. Cumulative reward and PPO metrics did not consistently improve across RL-trained scissors in the setting for movement across 2 axes (horizontal and depth).Conclusion. Game engines hold promising potential for the design and implementation of RL-based solutions to simulated surgical subtasks. Task completion was sufficiently achieved in one-dimensional movement in simulations with and without tissue-rendering. Further work is needed to optimize network architecture and parameter tuning for increasing complexity.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines.

AIM: This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients. METHODS: A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered. Structure: Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines.

AIM: This executive summary of the clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients. METHODS: A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered. Structure: Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. These guidelines present an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated and shared decision-making with patients is recommended.

Diminishing Basic Science Research Experience Among United States Cardiothoracic Surgery Trainees.

INTRODUCTION: There is growing concern regarding the attrition of surgeon-scientists. To understand the decline of basic science research (BSR), it is essential to examine trends in research conducted by trainees. We hypothesized that, over recent decades, cardiothoracic (CT) surgery trainees have published fewer BSR articles. MATERIALS AND METHODS: CT surgeons at United States training institutions in 2020 who completed training in the past three decades, excluding international trainees, were analyzed (1991-2000: n = 148; 2001-2010: n = 228; 2011-2020: n = 247). Publication records were obtained from Scopus. Articles with medical subject heading terms involving molecular/cellular or animal research were classified as BSR using the National Institutes of Health iCite Translation module. Data were analyzed using Fisher's exact test or the Wilcoxon rank-sum test. RESULTS: While the proportion of surgeons who published a first-author paper during training remained stable over the past two decades (178/228 [78.1%] versus 189/247 [76.5%], P = 0.7427), the proportion who published a first-author BSR paper decreased significantly (135/228 [59.2%] versus 96/247 [38.9%], P < 0.0001). Among surgeons who published a first-author paper in training, the total papers published by each trainee did not change over the past two decades (3.5 versus 3.3 first-author papers per 10 y of training, P = 0.8819). However, the number of BSR papers published during training decreased significantly (1.7 versus 0.8 first-author papers per 10 y of training, P < 0.0001). CONCLUSIONS: CT surgery trainees are publishing fewer BSR papers. Additional efforts are needed to increase exposure of trainees to BSR and reaffirm that BSR is a valuable and worthwhile pursuit for academic surgeons.

Analyzing the Scholarly Impact of Cardiothoracic Surgery Research Using the Relative Citation Ratio.

INTRODUCTION: The National Institutes of Health (NIH) recently developed the relative citation ratio (RCR), calculated as article citations benchmarked to NIH-funded publications in the same field. Here, we characterized the scholarly impact of academic cardiothoracic (CT) surgeons and their research using the RCR. MATERIALS AND METHODS: Using a database of 992 CT surgeons, we calculated the RCR for all articles published by each surgeon since 1980 using the NIH iCite database. All data were collected from publicly available online sources. Data are presented as median (interquartile range) or as odds ratios (ORs) for multivariable logistic regression analysis. RESULTS: Where RCR 1.00 indicates equal impact as an NIH-funded publication, the RCR among all 37,402 CT surgery articles was 0.84 (0.33-1.83) and the RCR among NIH-funded CT surgery articles was 1.07 (0.53-2.17). CT surgeons exhibited a career median RCR of 0.82 (0.54-1.13) and maximum RCR of 6.20 (3.04-13.57). Predictors of career median RCR >1.00 included female gender (OR 2.23, P = 0.001), thoracic subspecialization (OR 2.50, P < 0.001), full professor rank (OR 1.89, P = 0.001), and NIH funding (OR 1.75, P = 0.001). Predictors of career maximum RCR >50th percentile among CT surgeons included male gender (OR 1.87, P = 0.030), thoracic subspecialization (OR 2.05, P < 0.001), full professor rank (OR 4.89, P < 0.001), NIH funding (OR 3.17, P < 0.001), and career duration (OR 1.03, P = 0.002). CONCLUSIONS: We present the first assessment of the NIH-validated RCR for academic CT surgery. CT surgery research is highly impactful, although gender disparities persist with respect to the highest-impact research of our specialty.

Post-Transplant Extracorporeal Membrane Oxygenation for Severe Primary Graft Dysfunction to Support the Use of Marginal Donor Hearts.

Severe primary graft dysfunction (PGD) is the leading cause of early postoperative mortality following orthotopic heart transplantation (OHT). Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has been used as salvage therapy. This study aimed to evaluate the outcomes in adult OHT recipients who underwent VA-ECMO for severe PGD. We retrospectively reviewed 899 adult (≥18 years) patients who underwent primary OHT at our institution between 1997 and 2017. Recipients treated with VA-ECMO (19, 2.1%) exhibited a higher incidence of previous cardiac surgery (p = .0220), chronic obstructive pulmonary disease (p = .0352), and treatment with a calcium channel blocker (p = .0018) and amiodarone (p = .0148). Cardiopulmonary bypass (p = .0410) and aortic cross-clamp times (p = .0477) were longer in the VA-ECMO cohort and they were more likely to have received postoperative transfusion (p = .0013); intra-aortic balloon pump (IABP, p < .0001), and reoperation for bleeding or tamponade (p < .0001). The 30-day, 1-year, and overall survival after transplantation of non-ECMO patients were 95.9, 88.8, and 67.4%, respectively, compared to 73.7, 57.9, and 47.4%, respectively in the ECMO cohort. Fourteen (73.7%) of the ECMO patients were weaned after a median of 7 days following OHT (range: 1-12 days). Following OHT, VA-ECMO may be a useful salvage therapy for severe PGD and can potentially support the usage of marginal donor hearts.

Impact of PhD Degree Versus Non-PhD Research Fellowship on Future Research Productivity Among Academic Cardiothoracic Surgeons.

BACKGROUND: A PhD degree can offer significant research experience, but previous studies yielded conflicting conclusions on the relationship between a PhD degree and future research output. We compared the impact of a PhD degree versus research fellowship (RF) training on research productivity in cardiothoracic surgeons, hypothesizing that training pathways may influence potential associations. METHODS: CT surgeons practicing at all accredited United States CT surgery training programs in 2018 who pursued dedicated time for research (n = 597), including earning a PhD degree (n = 92) or completing a non-PhD RF (n = 505), were included. To control for training pathways, we performed subanalyses of U.S. medical school graduates (n = 466) and international medical school graduates (IMGs) (n = 131). Surgeon-specific data were obtained from publicly available sources (e.g., institutional webpages, Scopus). RESULTS: PhD surgeons published greater total papers (68.5 vs. 52.0, p = 0.0179) and total papers per year as an attending (4.6 vs. 3.0, p = 0.0150). For U.S. medical school graduates, there were 40 PhD surgeons and 426 non-PhD RF surgeons; both groups published a similar number of total papers (64.5 vs. 54.0, p = 0.3738) and total papers per year (3.2 vs. 3.0, p = 0.7909). For IMGs, there were 52 PhD surgeons and 79 non-PhD RF surgeons; the PhD surgeons published greater total papers (80.5 vs. 45.0, p = 0.0101) and total papers per year (5.7 vs. 2.7, p = 0.0037). CONCLUSION: CT surgeons with dedicated research training are highly academically productive. Although a PhD degree may be associated with enhanced career-long research productivity for IMGs, this association was not observed for U.S. medical school graduates.

Characterization of Cardiothoracic Surgeons Actively Leading Basic Science Research.

BACKGROUND: There is increasing concern regarding the attrition of surgeon-scientists in cardiothoracic (CT) surgery. However, the characteristics of CT surgeons who are actively leading basic science research (BSR) have not been examined. We hypothesized that early exposure to BSR during training and active grant funding are important factors that facilitate the pursuit of BSR among practicing CT surgeons. MATERIALS AND METHODS: We created a database of 992 CT surgeons listed as faculty at accredited United States CT surgery teaching hospitals in 2018. Data regarding each surgeon's training/professional history, publication record, and National Institutes of Health funding were acquired from publicly available online sources. Surgeons who published at least one first- or last-author paper in 2017-2018 were considered to be active, lead researchers. RESULTS: Of the 992 CT surgeons, 73 (7.4%) were actively leading BSR, and 599 (60.4%) were actively leading only non-BSR. Only 2 women were actively leading BSR. Surgeons actively leading BSR were more likely to have earned a PhD degree (20.5% versus 9.7%, P = 0.0049), and more likely to have published a first-author BSR paper during training (76.7% versus 40.9%, P< 0.0001). Surgeons actively leading BSR were also more likely to have an active National Institutes of Health grant (34.2% versus 5.8%, P< 0.0001), especially an R01 grant (21.9% versus 2.5%, P< 0.0001). CONCLUSIONS: A small minority of CT surgeons at academic training hospitals are actively leading BSR. In order to facilitate the development of surgeon-scientists, additional support must be given to trainees and junior faculty, especially women, to enable early engagement in BSR.

Career Research Productivity Correlates With Medical School Ranking Among Cardiothoracic Surgeons.

BACKGROUND: The foundation for a successful academic surgical career begins in medical school. We examined whether attending a top-ranked medical school is correlated with enhanced research productivity and faster career advancement among academic cardiothoracic (CT) surgeons. MATERIALS AND METHODS: Research profiles and professional histories were obtained from publicly available sources for all CT surgery faculty at accredited US CT surgery teaching hospitals in 2018 (n = 992). We focused on surgeons who completed medical school in the United States during or after 1990, the first-year US News & World Report released its annual medical school research rankings (n = 451). Subanalyses focused on surgeons who completed a research fellowship (n = 299) and those who did not (n = 152). RESULTS: A total of 124 surgeons (27.5%) attended a US News & World Report top 10 medical school, whereas 327 (72.5%) did not. Surgeons who studied at a top 10 medical school published more articles per year as an attending surgeon (3.2 versus 1.9; P < 0.0001), leading to more total publications (51.5 versus 27.0; P < 0.0001) and a higher H-index (16.0 versus 11.0; P < 0.0001) over a similar career duration (11.0 versus 10.0 y; P = 0.1294). These differences in career-long research productivity were statistically significant regardless of whether the surgeons completed a research fellowship or not. The surgeons in both groups, however, required a similar number of years to reach associate professor rank (P = 0.6993) and full professor rank (P = 0.7811) after starting their first attending job. CONCLUSIONS: Attending a top-ranked medical school is associated with enhanced future research productivity but not with faster career advancement in academic CT surgery.

The Use of Factor Eight Inhibitor Bypass Activity (FEIBA) for the Treatment of Perioperative Hemorrhage in Left Ventricular Assist Device Implantation.

OBJECTIVE: To test the hypothesis that factor eight inhibitor bypassing activity (FEIBA) can be used to control bleeding following left ventricular assist device (LVAD) implantation without increasing the 14-day composite thrombotic outcome of pump thrombus, ischemic cerebrovascular accidents, pulmonary embolism, and deep venous thrombosis. DESIGN: Retrospective cohort study. SETTING: Academic hospital. PARTICIPANTS: Three hundred nineteen consecutive patients who underwent LVAD implantation (December 1, 2009 to December 30, 2018). INTERVENTION: FEIBA administered to control perioperative hemorrhage. MEASUREMENTS AND MAIN RESULTS: The 82 patients (25.7%) in the FEIBA cohort had more risk factors for perioperative hemorrhage, such as lower preoperative platelet count (169 ± 66 v 194 ± 68 × 103/mL, p = 0.004), prior cardiac surgery (36.6% v 21.9%, p = 0.008), and longer cardiopulmonary bypass (CPB) time (100.3 v 75.2 minutes, p = 0.001) than the 237 controls. After 16.6 units (95% CI: 14.3-18.9) of blood products were given, 992 units (95% CI: 821-1163) of FEIBA were required to control bleeding in the FEIBA cohort. Compared to the controls, there were no differences in the 14-day composite thrombotic outcome (11.0% v 7.6%, p = 0.343) or mortality rate (3.7% v 1.3%, p = 0.179). Multivariate logistical regression identified preoperative international normalized ratio (odds ratio [OR]: 1.30, 95% CI: 1.04-1.62) and CPB time (OR: 1.11, 95% CI: 1.02-1.20) as risk factors for 14-day thrombotic events, but FEIBA usage was not associated with an increased risk. CONCLUSIONS: In this retrospective cohort study, the use of FEIBA (∼1,000 units, ∼13 units/kg) to control perioperative hemorrhage following LVAD implantation was not associated with increases in mortality or composite thrombotic outcome.

Evaluation of Risk Factors for Heart-Lung Transplant Recipient Outcome: An Analysis of the United Network for Organ Sharing Database.

BACKGROUND: Heart-lung transplantation (HLTx) is an effective treatment for patients with advanced cardiopulmonary failure. However, no large multicenter study has focused on the relationship between donor and recipient risk factors and post-HLTx outcomes. Thus, we investigated this issue using data from the United Network for Organ Sharing database. METHODS: All adult patients (age ≥18 years) registered in the United Network for Organ Sharing database who underwent HLTx between 1987 and 2017 were included (n=997). We stratified the cohort by patients who were alive without retransplant at 1 year (n=664) and patients who died or underwent retransplant within 1 year of HLTx (n=333). The primary outcome was the influence of donor and recipient characteristics on 1-year post-HLTx recipient death or retransplant. Kaplan-Meier curves were created to assess overall freedom from death or retransplant. To obtain a better effect estimation on hazard and survival time, the parametric Accelerated Failure Time model was chosen to perform time-to-event modeling analyses. RESULTS: Overall graft survival at 1-year post-HLTx was 66.6%. Of donors, 53% were male, and the mean age was 28.2 years. Univariable analysis showed advanced donor age, recipient male sex, recipient creatinine, recipient history of prior cardiac or lung surgery, recipient extracorporeal membrane oxygenation support, transplant year, and transplant center volume were associated with 1-year post-HLTx death or retransplant. On multivariable analysis, advanced donor age (hazard ratio [HR], 1.017; P=0.0007), recipient male sex (HR, 1.701; P=0.0002), recipient extracorporeal membrane oxygenation support (HR, 4.854; P<0.0001), transplant year (HR, 0.962; P<0.0001), and transplantation at low-volume (HR, 1.694) and medium-volume centers (HR, 1.455) in comparison with high-volume centers (P=0.0007) remained as significant predictors of death or retransplant. These predictors were incorporated into an equation capable of estimating the preliminary probability of graft survival at 1-year post-HLTx on the basis of preoperative factors alone. CONCLUSIONS: HLTx outcomes may be improved by considering the strong influence of donor age, recipient sex, recipient hemodynamic status, and transplant center volume. Marginal donors and recipients without significant factors contributing to poor post-HLTx outcomes may still be considered for transplantation, potentially with less impact on the risk of early postoperative death or retransplant.

Second Arterial Versus Venous Conduits for Multivessel Coronary Artery Bypass Surgery in California.

BACKGROUND: Whether a second arterial conduit improves outcomes after multivessel coronary artery bypass grafting remains unclear. Consequently, arterial conduits other than the left internal thoracic artery are seldom used in the United States. METHODS: Using a state-maintained clinical registry including all 126 nonfederal hospitals in California, we compared all-cause mortality and rates of stroke, myocardial infarction, repeat revascularization, and sternal wound infection between propensity score-matched cohorts who underwent primary, isolated multivessel coronary artery bypass grafting with the left internal thoracic artery, and who received a second arterial conduit (right internal thoracic artery or radial artery, n=5866) or a venous conduit (n=53 566) between 2006 and 2011. Propensity score matching using 34 preoperative characteristics yielded 5813 matched sets. A subgroup analysis compared outcomes between propensity score-matched recipients of a right internal thoracic artery (n=1576) or a radial artery (n=4290). RESULTS: Second arterial conduit use decreased from 10.7% in 2006 to 9.1% in 2011 (P<0.0001). However, receipt of a second arterial conduit was associated with significantly lower mortality (13.1% versus 10.6% at 7 years; hazard ratio, 0.79; 95% confidence interval [CI], 0.72-0.87), and lower risks of myocardial infarction (hazard ratio, 0.78; 95% CI, 0.70-0.87) and repeat revascularization (hazard ratio, 0.82; 95% CI, 0.76-0.88). In comparison with radial artery grafts, right internal thoracic artery grafts were associated with similar mortality rates (right internal thoracic artery 10.3% versus radial artery 10.7% at 7 years; hazard ratio, 1.10; 95% CI, 0.89-1.37) and individual risks of cardiovascular events, but the risk of sternal wound infection was increased (risk difference, 1.07%; 95% CI, 0.15-2.07). CONCLUSIONS: Second arterial conduit use in California is low and declining, but arterial grafts were associated with significantly lower mortality and fewer cardiovascular events. A right internal thoracic artery graft offered no benefit over that of a radial artery, but did increase risk of sternal wound infection. These findings suggest surgeons should consider lowering their threshold for using arterial grafts, and the radial artery may be the preferred second conduit.

Utilization of Del Nido Cardioplegia in Adult Coronary Artery Bypass Grafting　- A Retrospective Analysis.

BACKGROUND: Studies assessing the safety and effectiveness of Del Nido cardioplegia for adult cardiac surgery remain limited. We investigated early outcomes after coronary artery bypass grafting (CABG) using single-dose Del Nido cardioplegia vs. conventional multi-dose blood cardioplegia. Methods and Results: The 81 consecutive patients underwent isolated CABG performed by a single surgeon. The initial 27 patients received anterograde blood cardioplegia, while the subsequent 54 patients received anterograde Del Nido cardioplegia. There were no differences in the baseline characteristics of each group nor any differences in the 30-day incidences of myocardial infarction, all-cause death, and readmission following surgery. The use of Del Nido cardioplegia was associated with shorter cardiopulmonary bypass time (98 vs. 115 min, P=0.011), shorter cross-clamp time (74 vs. 87 min, P=0.006), and decreased need for intraoperative defibrillation (13.0% vs. 33.3%, P=0.030) compared with blood cardioplegia. To control for the difference in cross-clamp time, we performed propensity score matching with a logistical treatment model and confirmed that Del Nido cardioplegia provided similar outcomes as blood cardioplegia and also reduced the need for defibrillation independent of cross-clamp time. CONCLUSIONS: Compared with conventional blood cardioplegia, Del Nido cardioplegia provided excellent myocardial protection with reduced need for intraoperative defibrillation, shorter bypass and cross-clamp times, and comparable early clinical outcomes for adult patients undergoing CABG.

Methodological Standards for Meta-Analyses and Qualitative Systematic Reviews of Cardiac Prevention and Treatment Studies: A Scientific Statement From the American Heart Association.

Meta-analyses are becoming increasingly popular, especially in the fields of cardiovascular disease prevention and treatment. They are often considered to be a reliable source of evidence for making healthcare decisions. Unfortunately, problems among meta-analyses such as the misapplication and misinterpretation of statistical methods and tests are long-standing and widespread. The purposes of this statement are to review key steps in the development of a meta-analysis and to provide recommendations that will be useful for carrying out meta-analyses and for readers and journal editors, who must interpret the findings and gauge methodological quality. To make the statement practical and accessible, detailed descriptions of statistical methods have been omitted. Based on a survey of cardiovascular meta-analyses, published literature on methodology, expert consultation, and consensus among the writing group, key recommendations are provided. Recommendations reinforce several current practices, including protocol registration; comprehensive search strategies; methods for data extraction and abstraction; methods for identifying, measuring, and dealing with heterogeneity; and statistical methods for pooling results. Other practices should be discontinued, including the use of levels of evidence and evidence hierarchies to gauge the value and impact of different study designs (including meta-analyses) and the use of structured tools to assess the quality of studies to be included in a meta-analysis. We also recommend choosing a pooling model for conventional meta-analyses (fixed effect or random effects) on the basis of clinical and methodological similarities among studies to be included, rather than the results of a test for statistical heterogeneity.

Current status of domino heart transplantation.

Domino heart transplant, wherein the explanted heart from the recipient of an en-bloc heart-lung is utilized for a second recipient, represents a unique surgical strategy for patients with end-stage heart failure. With a better understanding of the potential advantages and disadvantages of this procedure, its selective use in the current era can improve and maximize organ allocation in the United States. In this report, we reviewed the current status of domino heart transplantation.

Salvage Extracorporeal Membrane Oxygenation Prior to "Bridge" Transcatheter Aortic Valve Replacement.

We describe a patient who presented in profound cardiogenic shock due to bioprosthetic aortic valve stenosis requiring salvage Extracorporeal Membrane Oxygenation followed by a "bridge" valve-in-valve transcatheter aortic valve replacement. doi: 10.1111/jocs.12750 (J Card Surg 2016;31:403-405).