Impact of age over 70 years in the new allocation system on the outcomes of heart transplantation in the US.

BACKGROUND: United Network for Organ Sharing (UNOS) allocation criteria changed in 2018 to accommodate the increased prevalence of patients on a ventricular assist device as a bridge to heart transplant and prioritize sicker people in anticipation of a heart graft. We aimed to assess the impact of patient age in the new allocation policy on mortality following heart transplantation. Secondary outcomes included the effect of age ≥70 on post-transplant events, including stroke, dialysis, pacemaker, and rejection requiring treatment. METHODS: The UNOS Registry was queried to identify patients who underwent heart transplants alone in the US between 2000 and 2021. Patients were divided into groups according to their age (over 70 and under 70 years old). RESULTS: Patients aged over 70 were more likely to require dialysis during follow-up, but less likely to experience rejection requiring treatment, compared with patients aged <70. Age ≥70 in the new allocation system was a significant predictor of 1-year mortality (adjusted HR: 1.41; 95% CI: 1.05-1.91; p = .024), but its effect on 5-year mortality was not significant after adjusting for potential confounders (adjusted HR: 1.27; 95% CI:.97-1.66; p = .077). Undergoing transplantation under the new allocation policy vs the old allocation policy was not a significant predictor of mortality in patients over 70 years old. CONCLUSIONS: Age ≥70 is a significant predictor of 1-year mortality following heart transplantation, but not at 5 and 10 years; however, the new allocation does not seem to have changed the outcomes for this group of patients.

Nationwide hospitalizations of patients with down syndrome and congenital heart disease over a 15-year period.

Down syndrome is one of the most common genetic diseases, generally associated with an increased probability of congenital heart diseases. This increased risk contributes to escalated levels of morbidity and mortality. In this study, we sought to analyze nationwide data of pediatric and adult patients with Down syndrome and congenital heart disease over a 15-year period. Data obtained from the hospital discharge form between 2001 and 2016 of patients diagnosed with Down syndrome in Italy and at least one congenital heart disease were included. Information on 12362 admissions of 6527 patients were included. Age at first admission was 6.2 ± 12.8 years and was a predictor of mortality (HR = 1.51, 95% CI 1.13-2.03, p = 0.006). 3923 (60.1%) patients underwent only one admission, while 2604 (39.9%) underwent multiple (> 1) admissions. There were 5846 (47.3%) admissions for cardiac related symptoms. Multiple admissions (SHR: 3.13; 95% CI: 2.99, 3.27; P < 0.01) and cardiac admissions (SHR: 2.00; 95% CI: 1.92, 2.09; P < 0.01) were associated with an increased risk of additional potential readmissions. There was an increased risk of mortality for patients who had cardiac admissions (HR = 1.45, 95% CI: 1.08-1.94, p = 0.012), and for those who underwent at least 1 cardiac surgical procedure (HR = 1.51, 95% CI 1.13-2.03, p = 0.006). CONCLUSIONS: A younger age at first admission is a predictor for mortality in patients with Down syndrome and congenital heart disease. If patients undergo more than one admission, the risk of further readmissions increases. There is a pivotal role for heart disease in influencing the hospitalization rate and subsequent mortality. WHAT IS KNOWN: • Down syndrome individuals often face an increased risk of congenital heart diseases. • Congenital heart diseases contribute significantly to morbidity and mortality in Down syndrome patients. WHAT IS NEW: • This study analyzes nationwide data covering a 15-year period of pediatric and adult patients in Italy with Down syndrome and congenital heart disease. • It identifies a younger age at first admission as a predictor for mortality in these patients, emphasizing the criticality of early intervention. • Demonstrates a correlation between multiple admissions, particularly those related to cardiac issues, and an increased risk of further readmissions, providing insights into the ongoing healthcare needs of these individuals.

Prognostic implications of inactive status in highest urgency categories among heart transplantation recipients in the new donor heart allocation system.

BACKGROUND: Patients on the waiting list for heart transplantation (HT) can become inactive or made status seven because of medical reasons, such adverse events, complications, or psychosocial circumstances. If the condition that caused the inactivation is resolved, patients are re- activated. Information about the prognostic implications of Status 7 in the new donor heart allocation system has not been described. To bridge this knowledge gap, we performed an analysis of the United Network of Organ Sharing (UNOS) registry. METHODS: Data on adult patients who underwent HT between October 18th, 2018 and October 2021, were queried from the UNOS registry. The main outcomes were post- transplant all-cause mortality, 1-year all-cause mortality and treated acute rejection. Since re-transplantation is a competing event for all-cause mortality, we performed competing risk survival analysis and reported sub distribution hazard ratios (SHR) from the Fine and Gray model to examine the relationship between inactive status and all-cause mortality. RESULTS: A total of 5267 adult patients underwent HT and were previously listed as Status 1 or Status 2 in the new allocation system. We identified 946 HT recipients temporarily inactivated while on HT list (18%). The number of temporarily inactive patients remained stable since the implementation of the new donor allocation system (p = .37). Approximately, two-thirds of temporarily inactive patients (65.9%) were inactivated for being too sick, whereas other frequent justifications for inactivity included left ventricular assist device implantation (7.8%) and insurance related issues (4.8%). Temporarily inactive HT recipients were more likely to be African Americans, males, have a higher body mass index (BMI) and significantly longer waiting time (391.6 ± 600 vs. 72.3 ± 223 days, p < .001) compared with never inactivated patients. In the unadjusted analyses 30-day mortality did not differ between groups, but both 1-year and overall all-cause mortality was significantly higher in temporarily inactive patients (1-year: SHR: 1.3; 95% confidence intervals [CI]: 1.03, 1.64; p = .028, overall mortality SHR: 1.31; 95% CI: 1.06, 1.64; p = .014). After adjustment for donor and recipient characteristics, a trend towards higher 1-year and overall mortality remained (1-year: SHR 1.32; 95% CI .99, 1.76, p = .006, overall mortality SHR: 1.29; 95% CI: .98-1.68, p = .065). No differences in treated acute allograft rejection at 1 year were found between groups. CONCLUSIONS: Temporary inactive status while waiting for HT occurs in approximately one in five HT recipients listed in higher urgency categories after the implementation of the new allocation system. A signal of adverse long-term outcomes was found, and this could be explained by differences in recipient characteristics. Further research is required to elucidate pathways involved and possible implications for clinical practice.

Impact of new allocation system on length of stay following heart transplantation in the United States.

BACKGROUND: United Network for Organ Sharing (UNOS) allocation criteria changed in 2018 to accommodate the increased prevalence of ventricular assist device use as a bridge to heart transplant, which consequently prioritized sicker patients. We aimed to assess the impact of this new allocation policy on the length of stay following heart transplantation. Secondary outcomes include other risk factors for prolonged hospitalization and its effect on mortality and postoperative complications. METHODS: The UNOS Registry was queried to identify patients who underwent isolated heart transplants in the United States between 2001 and 2023. Patients were divided into quartiles according to their respective length of stay. RESULTS: A total of 57 020 patients were included, 15 357 of which were allocated with the new system. The median hospital length of stay was 15 days (mean 22.7 days). Length of stay was longer in the new allocation era (25 ± 30 vs. 22 ± 27 days, p < .001). The longer length of stay was associated with increased 5-year mortality in the new allocation system (aHR: 1.18; 95% CI: 1.15, 1.20; p-value: < .001). CONCLUSION: Longer hospital stays and associated observed increased risk for mortality in the era after the allocation criteria change reflect the rationale of this shift which was to prioritize heart transplants for sicker patients. Further studies are needed to track the progress of surgical and perioperative management of these studies over time.

Machine learning-based prediction of mortality after heart transplantation in adults with congenital heart disease: A UNOS database analysis.

BACKGROUND: Machine learning (ML) is increasingly being applied in Cardiology to predict outcomes and assist in clinical decision-making. We sought to develop and validate an ML model for the prediction of mortality after heart transplantation (HT) in adults with congenital heart disease (ACHD). METHODS: The United Network for Organ Sharing (UNOS) database was queried from 2000 to 2020 for ACHD patients who underwent isolated HT. The study cohort was randomly split into derivation (70%) and validation (30%) datasets that were used to train and test a CatBoost ML model. Feature selection was performed using SHapley Additive exPlanations (SHAP). Recipient, donor, procedural, and post-transplant characteristics were tested for their ability to predict mortality. We additionally used SHAP for explainability analysis, as well as individualized mortality risk assessment. RESULTS: The study cohort included 1033 recipients (median age 34 years, 61% male). At 1 year after HT, there were 205 deaths (19.9%). Out of a total of 49 variables, 10 were selected as highly predictive of 1-year mortality and were used to train the ML model. Area under the curve (AUC) and predictive accuracy for the 1-year ML model were .80 and 75.2%, respectively, and .69 and 74.2% for the 3-year model, respectively. Based on SHAP analysis, hemodialysis of the recipient post-HT had overall the strongest relative impact on 1-year mortality after HΤ, followed by recipient-estimated glomerular filtration rate, age and ischemic time. CONCLUSIONS: ML models showed satisfactory predictive accuracy of mortality after HT in ACHD and allowed for individualized mortality risk assessment.

Sex mismatch following heart transplantation in the United States: Characteristics and impact on outcomes.

BACKGROUND: Available literature indicates the possible detrimental effect of sex mismatching on mortality in patients undergoing heart transplantation. Our objective was to examine the role of sex and heart mass (predicted heart mass [PHM]) mismatch on mortality and graft rejection in patients undergoing heart transplantation in the US. METHODS: Data on adult patients who underwent heart transplantation between January 2015 and October 2021 were queried from the United Network of Organ Sharing (UNOS) registry. The main outcomes were all-cause mortality, 1-year all-cause mortality and treated acute rejection. RESULTS: A total of 19 805 adult patients underwent heart transplant during the study period. 92.2% of the patients in the female graft to male group had a PHM mismatch <25%, while only 38.5% had such a mismatch in the male graft to female group. In male to male and female to female groups, 79% and 76% of the patients had a PHM mismatch <25% (p = .122). Proportion of PHM mismatch was similar throughout the study period. Unadjusted analysis showed that male recipients of female grafts had increased risk for all-cause mortality (hazard ratio [HR]: 1.13; 95% confidence intervals [CI]: 1.02, 1.27; p = .026) and 1-year mortality (HR: 1.26; 95% CI: 1.09, 1.45; p = .002) compared to male recipients of male grafts. Graft failure incidence was also higher (HR: 1.12; 95% CI: 1.01, 1.25; p = .041). However, all these associations were non- significant after risk factor adjustment. CONCLUSIONS: Sex mismatching is associated with post-transplant mortality with transplantation of female donor grafts to male recipients demonstrating worse outcomes, although this association disappears after risk factor adjustment. Further research is required to elucidate the need for potential changes in clinical practice.

Characteristics and outcomes of left ventricular assist device recipients transplanted before and after the new donor heart allocation system.

BACKGROUND: Concerns about the impact of the new donor heart allocation system on posttransplant outcomes have emerged after its implementation. We sought to evaluate the characteristics and outcomes of left ventricular assist device (LVAD) recipients transplanted before and after the implantation of the new policy on October 18, 2018. METHODS: Data on bridge to transplantation of adult patients with LVAD between January 2015 and October 2021, with durable LVAD as a (BTT), was queried from the United Network of Organ Sharing (UNOS) registry. The main outcomes were 30-day all-cause mortality, 30-day fatal graft failure, 1-year all-cause mortality, treated acute rejection at 1 year and renal replacement therapy (RRT) for acute renal failure. RESULTS: In our study, 7096 patients met the inclusion criteria including 2435 in the new allocation system. The transplanted patients in the new allocation system era had older donor age, longer ischemic time, and higher proportion of newer generation LVADs. Adjusted 30-day all-cause mortality was significantly lower for LVAD recipients in the new allocation system era (2.5% vs. 3.6%; sub-hazard ratio [SHR] 0.36, 95% Confidence intervals [CI] 0.27-0.48, p < 0.001) without differences in the risk of fatal graft failure and 1-year mortality (7.8% vs. 9.6%). Significantly lower adjusted 30-day mortality with HVAD and HM3 devices than HM2 in the new allocation system era was found, without differences in 1-year mortality. Acute allograft rejection requiring treatment was significantly lower (Odds Ratio 0.78, 95% CI 0.65-0.94, p = 0.01), whereas a trend toward higher risk of renal failure requiring RRT was identified. CONCLUSIONS: Despite changing donor characteristics and longer ischemic times, posttransplant outcomes in LVAD recipients have not worsened with the implementation of the new allocation system and this finding is related to the use of newer generation continuous flow LVADs.

Pericardiectomy and Pericardial Window for the Treatment of Pericardial Disease in the Contemporary Era.

PURPOSE OF REVIEW: To summarize the contemporary practice of pericardiectomy and pericardial window. We discuss the indications, preoperative planning, procedural aspects, postprocedural management, and outcomes of each procedure. RECENT FINDINGS: Surgical approaches for the treatment of pericardial disease have been around even before the emergence of cardiopulmonary bypass. Since the forthcoming of cardiopulmonary bypass, there have been significant changes in the epidemiology and diagnostic approach of pericardial diseases as well as advancements in the surgical techniques and perioperative management used in the care of these patients. Pericardiectomy has an average mortality of almost 7% and is typically performed in patients with advanced symptoms from constrictive pericarditis and relatively few comorbidities. Pericardial window is a safe procedure for the treatment of pericardial effusion that can be performed with different approaches.

Percutaneous coronary intervention versus coronary artery bypass graft surgery in dialysis-dependent patients: A pooled meta-analysis of reconstructed time-to-event data.

OBJECTIVE: Το perform a systematic review with meta-analysis of published data comparing outcomes between a percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) in dialysis-dependent patients. METHODS: We searched PubMed, Scopus, and Cochrane databases for studies including dialysis-dependent patients who underwent either CABG or PCI. This meta-analysis follows the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. We conducted one-stage and two-stage meta-analysis with Kaplan-Meier-derived individual patient data for overall survival and meta-analysis with the random-effects model for the in-hospital mortality and repeat revascularization. RESULTS: Twelve studies met our eligibility criteria, including 13,651 and 28,493 patients were identified in the CABG and PCI arms, respectively. Patients who underwent CABG had overall improved survival compared with those who underwent PCI at the one-stage meta-analysis (hazard ratio [HR]: 1.12, 95% confidence interval [CI]: 1.09-1.16, p < .0001) and the two-stage meta-analysis (HR: 1.15, 95% CI: 1.08-1.23, p < .001, I2 = 30.0%). Landmark analysis suggested that PCI offers better survival before the 8.5 months of follow-up (HR: 0.96, 95% CI: 0.92-0.99, p = .043), while CABG offers an advantage after this timepoint (HR: 1.3, 95% CI: 1.22-1.32, p < .001). CABG was associated with increased odds for in-hospital mortality (odds ratio [OR]: 1.70, 95% CI: 1.50-1.92, p < .001, I2 = 0.0%) and decreased odds for repeat revascularization (OR: 0.22, 95% CI: 0.14-0.34, p < .001, I2 = 58.08%). CONCLUSIONS: In dialysis-dependent patients, CABG was associated with long-term survival but a higher risk for early mortality. The risk for repeat revascularization was higher with PCI.

Effect of Hepatitis C donor status on heart transplantation outcomes in the United States.

BACKGROUND: Recent studies demonstrated safety and efficacy of heart transplantation (HT) from hepatitis C virus (HCV)-positive donors. We sought to evaluate the impact of HCV donor status on the outcomes of patients undergoing HT in the United States. METHODS: We analyzed a retrospective cohort of adult patients from the United Network for Organ Sharing (UNOS) database who underwent isolated HT from 2015 until present. Primary outcomes were 30-day and 1-year overall mortality. Secondary outcomes included risk for graft failure and overall survival, incident stroke and need for dialysis during the available follow-up period. All end points were evaluated according to HCV status. RESULTS: All-cause 30-day and 1-year mortality was similar between the two groups (3.4% vs 3.2%, P = .973 and 6.9% vs 7.8%, P = .769, respectively, for patients receiving heart grafts from HCV+ vs. HCV- donors). Graft failure was 12.8% (95% CI: 8%-19%) and 15.2% (95 CI: 15%-16%) in the HCV+ and HCV- groups, respectively (P = .92 and P = .68). Competing risk regression analysis for re-operation showed a non-significant trend for higher risk for re-transplantation in the HCV+ group (HR: 2.71; 95% CI: 0.83, 8.80, P = .097). CONCLUSION: HCV donor status does not seem to negatively affect the outcomes of HT in the U.S population.

State-of-the-art machine learning algorithms for the prediction of outcomes after contemporary heart transplantation: Results from the UNOS database.

PURPOSE: We sought to develop and validate machine learning (ML) models to increase the predictive accuracy of mortality after heart transplantation (HT). METHODS AND RESULTS: We included adult HT recipients from the United Network for Organ Sharing (UNOS) database between 2010 and 2018 using solely pre-transplant variables. The study cohort comprised 18 625 patients (53 ± 13 years, 73% males) and was randomly split into a derivation and a validation cohort with a 3:1 ratio. At 1-year after HT, there were 2334 (12.5%) deaths. Out of a total of 134 pre-transplant variables, 39 were selected as highly predictive of 1-year mortality via feature selection algorithm and were used to train five ML models. AUC for the prediction of 1-year survival was .689, .642, .649, .637, .526 for the Adaboost, Logistic Regression, Decision Tree, Support Vector Machine, and K-nearest neighbor models, respectively, whereas the Index for Mortality Prediction after Cardiac Transplantation (IMPACT) score had an AUC of .569. Local interpretable model-agnostic explanations (LIME) analysis was used in the best performing model to identify the relative impact of key predictors. ML models for 3- and 5-year survival as well as acute rejection were also developed in a secondary analysis and yielded AUCs of .629, .609, and .610 using 27, 31, and 91 selected variables respectively. CONCLUSION: Machine learning models showed good predictive accuracy of outcomes after heart transplantation.

Impact of induction therapy on outcomes after heart transplantation.

BACKGROUND: Approximately 50% of heart transplant (HT) programs utilize induction therapy (IT) with interleukin-2 receptor antagonists (IL2RA) or polyclonal anti-thymocyte antibodies (ATG). METHODS: Adult HT recipients were identified in the UNOS Registry between 2010 and 2020. We compared mortality between IT strategies with competing risk analysis. RESULTS: A total of 28 634 HT recipients were included in the study (50.1% no IT, 21.3% ATG, 27.9% IL2RA, .7% alemtuzumab, .01% OKT3). Adjusted all-cause, 30 day and 1 year mortality were lower among those treated with IT than no IT (sub-hazard ratio [SHR] .87, 95% CI .79-.96, SHR .86, .76-.97, SHR .76, .63-.93, P = .007, respectively). In propensity score matching analysis IT was associated with lower 30-day and 1-year mortality. IL2RA had higher all-cause and 1-year mortality than ATG (SHR 1.41, 95% CI 1.23-1.69 and 1.55, 95% CI 1.29-1.88, respectively). Utilization of IT was associated with significantly lower risk of treated rejection at 1 year after HT compared with no IT (relative risk ratio [RRR] .79) and similarly ATG compared with IL2RA (RRR .51). CONCLUSION: IT was associated with lower mortality and treated rejection episodes than no IT. IL2RA is the most used IT approach but ATG has lower risk of treated rejection and mortality.

Repeat Coronary Artery Bypass Grafting: A Meta-Analysis of Off-Pump versus On-Pump Techniques in a Large Cohort of Patients.

BACKGROUND: Redo coronary artery bypass grafting (CABG) can be performed with either the off-pump (OPCAB) or the on-pump (ONCAB) technique. METHOD: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), this meta-analysis compared the safety and efficacy of OPCAB versus ONCAB redo CABG. RESULTS: Twenty-three (23) eligible studies were included (OPCAB, n=2,085; ONCAB, n=3,245). Off-pump CABG significantly reduced the risk of perioperative death (defined as in-hospital or 30-day death rate), myocardial infarction, atrial fibrillation, and acute kidney injury. The two treatment approaches were comparable regarding 30-day stroke and late all-cause mortality. CONCLUSIONS: Off-pump redo CABG resulted in lower perioperative death and periprocedural complication rates. No difference was observed in perioperative stroke rates and long-term survival between the two techniques.

Mitochondrial transplantation by intra-arterial injection for acute kidney injury.

Acute kidney injury is a common clinical disorder and one of the major causes of morbidity and mortality in the postoperative period. In this study, the safety and efficacy of autologous mitochondrial transplantation by intra-arterial injection for renal protection in a swine model of bilateral renal ischemia-reperfusion injury were investigated. Female Yorkshire pigs underwent percutaneous bilateral temporary occlusion of the renal arteries with balloon catheters. Following 60 min of ischemia, the balloon catheters were deflated and animals received either autologous mitochondria suspended in vehicle or vehicle alone, delivered as a single bolus to the renal arteries. The injected mitochondria were rapidly taken up by the kidney and were distributed throughout the tubular epithelium of the cortex and medulla. There were no safety-related issues detected with mitochondrial transplantation. Following 24 h of reperfusion, estimated glomerular filtration rate and urine output were significantly increased while serum creatinine and blood urea nitrogen were significantly decreased in swine that received mitochondria compared with those that received vehicle. Gross anatomy, histopathological analysis, acute tubular necrosis scoring, and transmission electron microscopy showed that the renal cortex of the vehicle-treated group had extensive coagulative necrosis of primarily proximal tubules, while the mitochondrial transplanted kidney showed only patchy mild acute tubular injury. Renal cortex IL-6 expression was significantly increased in vehicle-treated kidneys compared with the kidneys that received mitochondrial transplantation. These results demonstrate that mitochondrial transplantation by intra-arterial injection provides renal protection from ischemia-reperfusion injury, significantly enhancing renal function and reducing renal damage.

Mitochondrial transplantation enhances murine lung viability and recovery after ischemia-reperfusion injury.

The most common cause of acute lung injury is ischemia-reperfusion injury (IRI), during which mitochondrial damage occurs. We have previously demonstrated that mitochondrial transplantation is an efficacious therapy to replace or augment mitochondria damaged by IRI, allowing for enhanced muscle viability and function in cardiac tissue. Here, we investigate the efficacy of mitochondrial transplantation in a murine lung IRI model using male C57BL/6J mice. Transient ischemia was induced by applying a microvascular clamp on the left hilum for 2 h. Upon reperfusion mice received either vehicle or vehicle-containing mitochondria either by vascular delivery (Mito V) through the pulmonary artery or by aerosol delivery (Mito Neb) via the trachea (nebulization). Sham control mice underwent thoracotomy without hilar clamping and were ventilated for 2 h before returning to the cage. After 24 h recovery, lung mechanics were assessed and lungs were collected for analysis. Our results demonstrated that at 24 h of reperfusion, dynamic compliance and inspiratory capacity were significantly increased and resistance, tissue damping, elastance, and peak inspiratory pressure (Mito V only) were significantly decreased (P < 0.05) in Mito groups as compared with their respective vehicle groups. Neutrophil infiltration, interstitial edema, and apoptosis were significantly decreased (P < 0.05) in Mito groups as compared with vehicles. No significant differences in cytokines and chemokines between groups were shown. All lung mechanics results in Mito groups except peak inspiratory pressure in Mito Neb showed no significant differences (P > 0.05) as compared with Sham. These results conclude that mitochondrial transplantation by vascular delivery or nebulization improves lung mechanics and decreases lung tissue injury.

Mitochondrial transplantation ameliorates acute limb ischemia.

OBJECTIVE: Acute limb ischemia (ALI), the most challenging form of ischemia-reperfusion injury (IRI) in skeletal muscle tissue, leads to decreased skeletal muscle viability and limb function. Mitochondrial injury has been shown to play a key role in skeletal muscle IRI. In previous studies, we have demonstrated that mitochondrial transplantation (MT) is an efficacious therapeutic strategy to replace or to augment mitochondria damaged by IRI, allowing enhanced muscle viability and function in cardiac tissue. In this study, we investigated the efficacy of MT in a murine ALI model. METHODS: C57BL/6J mice (male, 10-12 weeks) were used in a model of ALI. Ischemia was induced by applying a tourniquet on the left hindlimb. After 2 hours of ischemia, the tourniquet was released, and reperfusion of the hindlimb was re-established; either vehicle alone (n = 15) or vehicle containing mitochondria (n = 33) was injected directly into all the muscles of the hindlimb. Mitochondria were delivered at concentrations of 1 × 106 to 1 × 109 per gram wet weight to each muscle, and the animals were allowed to recover. Sham mice received no ischemia or injections but were anesthetized for 2 hours and allowed to recover. After 24 hours of recovery, limb function was assessed by DigiGait (Mouse Specifics Inc, Boston, Mass), and animals were euthanized; the gastrocnemius, soleus, and vastus medialis muscles were collected for analysis. RESULTS: After 24 hours of hindlimb reperfusion, infarct size (percentage of total mass) and apoptosis were significantly decreased (P < .001, each) in the gastrocnemius, soleus, and vastus medialis muscles in MT mice compared with vehicle mice for all mitochondrial concentrations (1 × 106 to 1 × 109 per gram wet weight). DigiGait analysis at 24 hours of reperfusion showed that percentage shared stance time was significantly increased (P < .001) and stance factor was significantly decreased (P = .001) in vehicle compared with MT and sham mice. No significant differences in percentage shared stance time (P = .160) or stance factor (P = .545) were observed between MT and sham mice. CONCLUSIONS: MT ameliorates skeletal muscle injury and enhances hindlimb function in the murine model of ALI.

Short Leukocyte Telomere Length Precedes Clinical Expression of Atherosclerosis: The Blood-and-Muscle Model.

RATIONALE: Short telomere length (TL) in leukocytes is associated with atherosclerotic cardiovascular disease (ASCVD). It is unknown whether this relationship stems from having inherently short leukocyte TL (LTL) at birth or a faster LTL attrition thereafter. LTL represents TL in the highly proliferative hematopoietic system, whereas TL in skeletal muscle represents a minimally replicative tissue. OBJECTIVE: We measured LTL and muscle TL (MTL) in the same individuals with a view to obtain comparative metrics for lifelong LTL attrition and learn about the temporal association of LTL with ASCVD. METHODS AND RESULTS: Our Discovery Cohort comprised 259 individuals aged 63±14 years (mean±SD), undergoing surgery with (n=131) or without (n=128) clinical manifestation of ASCVD. In all subjects, MTL adjusted for muscle biopsy site (MTLA) was longer than LTL and the LTL-MTLA gap similarly widened with age in ASCVD patients and controls. Age- and sex-adjusted LTL (P=0.005), but not MTLA (P=0.90), was shorter in patients with ASCVD than controls. The TL gap between leukocytes and muscle (LTL-MTLA) was wider (P=0.0003), and the TL ratio between leukocytes and muscle (LTL/MTLA) was smaller (P=0.0001) in ASCVD than in controls. Findings were replicated in a cohort comprising 143 individuals. CONCLUSIONS: This first study to apply the blood-and-muscle TL model shows more pronounced LTL attrition in ASCVD patients than controls. The difference in LTL attrition was not associated with age during adulthood suggesting that increased attrition in early life is more likely to be a major explanation of the shorter LTL in ASCVD patients. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02176941.

A Multi-Mode System for Myocardial Functional and Physiological Assessment during Ex Situ Heart Perfusion.

Ex situ heart perfusion (ESHP) has proven to be an important and valuable step toward better preservation of donor hearts for heart transplantation. Currently, few ESHP systems allow for a convenient functional and physiological evaluation of the heart. We sought to establish a simple system that provides functional and physiological assessment of the heart during ESHP. The ESHP circuit consists of an oxygenator, a heart-lung machine, a heater-cooler unit, an anesthesia gas blender, and a collection funnel. Female Yorkshire pig hearts (n = 10) had del Nido cardioplegia (4°C) administered, excised, and attached to the perfusion system. Hearts were perfused retrogradely into the aortic root for 2 hours before converting the system to an isovolumic mode or a working mode for further 2 hours. Blood samples were analyzed to measure metabolic parameters. During the isovolumic mode (n = 5), a balloon inserted in the left ventricular (LV) cavity was inflated so that an end-diastolic pressure of 6-8 mmHg was reached. During the working mode (n = 5), perfusion in the aortic root was redirected into left atrium (LA) using a compliance chamber which maintained an LA pressure of 6-8 mmHg. Another compliance chamber was used to provide an afterload of 40-50 mmHg. Hemodynamic and metabolic conditions remained stable and consistent for a period of 4 hours of ESHP in both isovolumic mode (LV developed pressure: 101.0 ± 3.5 vs. 99.7 ± 6.8 mmHg, p = .979, at 2 and 4 hours, respectively) and working mode (LV developed pressure: 91.0 ± 2.6 vs. 90.7 ± 2.5 mmHg, p = .942, at 2 and 4 hours, respectively). The present study proposed a novel ESHP system that enables comprehensive functional and metabolic assessment of large mammalian hearts. This system allowed for stable myocardial function for up to 4 hours of perfusion, which would offer great potential for the development of translational therapeutic protocols to improve dysfunctional donated hearts.

Visceral white adipose tissue and serum proteomic alternations in metabolically healthy obese patients undergoing bariatric surgery.

Metabolically healthy obesity is characterized as a comorbidity-free obesity status, however the exact pathogenetic mechanisms implicated in its transition to unhealthy obesity have not yet been unveiled. Our aim was to investigate the effect of metabolic health on the proteomic profile both in serum and visceral fat of morbidly obese subjects. 28 patients undergoing bariatric surgery were prospectively enrolled. They were divided into two groups: metabolically healthy (MHO, n = 18) and unhealthy (MUO, n = 10) obese patients. 30 biomarkers were measured in serum and visceral adipose tissue with the use of targeted proteomic analysis (Luminex assays). TNF weak inducer of apoptosis (TWEAK) (p = 0.043), TNF related apoptosis inducing ligand (TRAIL) (p = 0.037), Growth differentiation factor-15 (GDF-15) (p = 0.04), Resistin (RETN) (p = 0.047), Matrix metalloproteinase-9 (MMP-9) (p = 0.011) and C-terminal telopeptide (ICTP) (p = 0.022) were up-regulated in the MUO group in the visceral white adipose tissue. Moreover, C-C motif ligand-3 (CCL-3) (p = 0.056), Interleukin-20 (IL-20) (p = 0.04), Prokineticin-1 (PROK-1) (p = 0.028) and TWEAK (p = 0.016) were found to be suppressed in the serum of MHO group. Significant correlations between serum and adipose tissue levels of certain cytokines were also observed, while 16 biomarkers were associated with BMI. Our results indicate metabolic health substantially attenuates the expression of TWEAK, TRAIL, GDF-15, RETN, MMP-9 and ICTP expression locally, in the visceral white adipose tissue, and the expression of CCL-3, IL-20, PROK-1 and TWEAK in the peripheral blood. Intriguingly, different cytokines -except for TWEAK- are up-regulated in each site, suggesting that obesity is not a homogenous but a multi-dimensional disease.

A single center's experience with total arterial revascularization and spiral aneurysmorrhaphy for ischemic cardiac disease.

The restoration of left ventricular (LV) geometry in combination with coronary artery bypass grafting for the treatment of ischemic cardiac disease remains controversial. We hereby present the experience of our center with total arterial myocardial revascularization (TAMR) and spiral aneurysmorrhaphy for ischemic heart disease. A retrospective analysis of 101 patients with advanced cardiovascular disease who underwent TAMR and spiral aneurysmorrhaphy was performed. Spiral aneurysmorrhaphy is a modification of the linear aneurysmorrhaphy and was applied to patients who had a LV aneurysm with a diameter of less than 5 cm. Peri-operative and in-hospital data were retrieved. The majority of the patients were male (87.13%) with a mean age of 63.1 years. Mean pre-operative ejection fraction (EF) was 35.7% ranging between 20 and 65%. An average of 3.23 grafts was required per patient. Early mortality was 6.93% (one intra-operative and six in-hospital deaths). Addition of concomitant valve surgery was associated with prolonged total operative, cardiopulmonary bypass and cross-clamp time (p < 0.001), increased need for blood (p = 0.012) and plasma (p = 0.038), longer intensive care unit (ICU) stay (p = 0.045) and higher rate of post-operative cerebrovascular accident (p = 0.011). Furthermore, patients with a pre-operative EF between 30 and 50% had a shorter ICU stay (p = 0.045) and LoS (p = 0.029) compared with patients with EF <30%. Early mortality and post-operative complication rates following this combined procedure are in consistency with the relevant available data suggesting its feasibility regardless of the EF or addition of concomitant surgeries. Data from the follow-up of these patients are required to examine the long-term efficacy of this surgical modality.