Heart transplantation in patients from socioeconomically distressed communities.

BACKGROUND: Studies examining heart transplantation disparities have focused on individual factors such as race or insurance status. We characterized the impact of a composite community socioeconomic disadvantage index on heart transplantation outcomes. METHODS: From the Scientific Registry of Transplant Recipients (SRTR), we identified 49,340 primary, isolated adult heart transplant candidates and 32,494 recipients (2005-2020). Zip code-level socioeconomic disadvantage was characterized using the Distressed Community Index (DCI: 0-most prosperous, 100-most distressed) based on education, poverty, unemployment, housing vacancies, median income, and business growth. Patients from distressed communities (DCI ≥ 80) were compared to all others. RESULTS: Patients from distressed communities were more often non-white, less educated, and had public insurance (all p < 0.01). Distressed patients were more likely to require ventricular assist devices at listing (29.4 vs 27.1%) and before transplant (44.8 vs 42.0%, both p < 0.001), and they underwent transplants at lower-volume centers (23 vs 26 cases/year, p < 0.01). Distressed patients had higher 1-year waitlist mortality or deterioration (12.3% [95% confidence interval (CI) 11.6-13.0] vs 10.9% [95% CI 10.5-11.3]) and inferior 5-year survival (75.3% [95% CI 74.0-76.5] vs 79.5% [95% CI 79.0-80.0]) (both p < 0.001). After adjustment, living in a distressed community was independently associated with an increased risk of waitlist mortality or deterioration hazard ratio (HR 1.10, 95% CI 1.02-1.18) and post-transplant mortality (HR 1.13, 95% CI 1.06-1.20). CONCLUSIONS: Patients from socioeconomically distressed communities have worse waitlist and post-transplant mortality. These findings should not be used to limit access to heart transplantation, but rather highlight the need for further studies to elucidate mechanisms underlying the impact of community-level socioeconomic disparity.

Diagnosing heparin-induced thrombocytopenia in mechanical circulatory support device patients.

BACKGROUND: Mechanical circulatory support device (MCSD) patients with positive heparin-induced thrombocytopenia (HIT) screening pose a unique challenge, as clinicians must make rapid decisions about their anticoagulation and whether they can safely undergo cardiopulmonary bypass. We identified screening practices at our institution and other institutions nationwide that differed from American Society of Hematology (ASH) guidelines. This discovery prompted a data review to confirm the applicability of guidelines to this unique population and to highlight complications of "gestalt" screening. METHODS: Our study included MCSD patients with HIT testing from April 2014 to August 2020. We evaluated 510 PF4 IgG ELISA results. RESULTS: HIT was confirmed in 4.2% of patients. There was an increased prevalence of HIT in patients with nondurable (5.3%) vs durable devices (2.9%) or those in the preimplantation setting (1.3%), however this difference was not statistically significant (p = 0.26). None of the patients with a low probability 4T Score had HIT. All patients with a high probability 4T Score and PF4 immunoassay OD >2.0 had HIT. False positive results occurred in 22% of assays ordered for patients with a low probability 4T Score. Twelve patients with a low probability 4T Score and a false positive immunoassay were switched to a direct thrombin inhibitor (DTI) while awaiting confirmatory results. Two patients experienced clinically significant bleeding after conversion to a DTI. An organ was refused in one patient with false positive HIT screening. CONCLUSIONS: Our findings demonstrate that an opportunity exists to improve clinical outcomes by re-emphasizing the utility of established guidelines and highlighting their safe use in the MCSD patient population.

The effects of donor-specific antibody characteristics on cardiac allograft vasculopathy.

BACKGROUND: Cardiac allograft vasculopathy (CAV) causes late graft dysfunction and post-transplant mortality. Currently, the effects of different donor-specific antibodies (DSA) on the severity of CAV remain unclear. METHOD: We evaluated 526 adult heart transplant recipients at a single center between January 2010 and August 2015. Subjects were divided into those with DSA (n = 142) and those without DSA (n = 384, control). The DSA group was stratified into persistent DSA (n = 34), transient DSA (n = 105), 1:8 dilution DSA (n = 45), complement-binding (C1q) DSA (n = 36), Class I DSA (n = 37), and Class II DSA (n = 105). The primary outcome was the incidence of moderate-to-severe CAV (CAV 2/3) at 5-year follow-up. RESULTS: Subjects with persistent DSA, 1:8 dilution DSA, and C1q DSA had higher incidence of CAV 2/3 compared the control group (17.6%, 13.3%, and 16.7% vs. 3.1%, respectively; P≤ .001). The incidence of CAV 2/3 between subjects with transient DSA and the control group was similar (2.8% vs. 3.1%; P = .888). Subjects with Class II DSA also had higher incidence of CAV 2/3 (7.6% vs. 3.1%; P = .039). CONCLUSION: DSA that are persistent, 1:8 dilution positive, C1q positive, and Class II are associated with more severe grades of CAV. These DSA characteristics may prognosticate disease and warrant consideration for treatment.

Recipient and surgical factors trigger severe primary graft dysfunction after heart transplant.

BACKGROUND: Primary graft dysfunction (PGD) is a major cause of early mortality following heart transplant (HT). The International Society for Heart and Lung Transplantation (ISHLT) subdivides PGD into 3 grades of increasing severity. Most studies have assessed risk factors for PGD without distinguishing between PGD severity grade. We sought to identify recipient, donor and surgical risk factors specifically associated with mild/moderate or severe PGD. METHODS: We identified 734 heart transplant recipients at our institution transplanted between January 1, 2012 and December 31, 2018. PGD was defined according to modified ISHLT criteria. Recipient, donor and surgical variables were analyzed by multinomial logistic regression with mild/moderate or severe PGD as the response. Variables significant in single variable modeling were subject to multivariable analysis via penalized logistic regression. RESULTS: PGD occurred in 24% of the cohort (n = 178) of whom 6% (n = 44) had severe PGD. One-year survival was reduced in recipients with severe PGD but not in those with mild or moderate PGD. Multivariable analysis identified 3 recipient factors: prior cardiac surgery, recipient treatment with ACEI/ARB/ARNI plus MRA, recipient treatment with amiodarone plus beta-blocker, and 3 surgical factors: longer ischemic time, more red blood cell transfusions, and more platelet transfusions, that were associated with severe PGD. We developed a clinical risk score, ABCE, which provided acceptable discrimination and calibration for severe PGD. CONCLUSIONS: Risk factors for mild/moderate PGD were largely distinct from those for severe PGD, suggesting a differing pathophysiology involving several biological pathways. Further research into mechanisms underlying the development of PGD is urgently needed.

Hypothermia promotes mitochondrial elongation In cardiac cells via inhibition of Drp1.

Hypothermia is a valuable clinical tool in mitigating against the consequences of ischemia in surgery, stroke, cardiac arrest and organ preservation. Protection is afforded principally by a reduction of metabolism, manifesting as reduced rates of oxygen uptake, preservation of ATP levels, and a curtailing of ischemic calcium overload. The effects of non-ischemic hypothermic stress are relatively unknown. We sought to investigate the effects of clinically mild-to-severe hypothermia on mitochondrial morphology, oxygen consumption and protein expression in normoxic hearts and cardiac cells. Normoxic perfusion of rat hearts at 28-32 °C was associated with inhibition of mitochondrial fission, evidenced by a reduced abundance of the active phosphorylated form of the fission receptor Drp1 (pDrp1S616). Abundance of the same residue was reduced in H9c2 cells subjected to hypothermic culture (25-32 °C), in addition to a reduced abundance of the Drp1 receptor MFF. Hypothermia-treated H9c2 cardiomyocytes exhibited elongated mitochondria and depressed rates of mitochondrial-associated oxygen consumption, which persisted upon rewarming. Hypothermia also promoted a reduction in mRNA expression of the capsaicin receptor TRPV1 in H9c2 cells. When normothermic H9c2 cells were transfected with TRPV1 siRNA we observed reduced pDrp1S616 and MFF abundance, elongated mitochondria, and reduced rates of mitochondrial-associated oxygen consumption, mimicking the effects of hypothermic culture. In conclusion hypothermia promoted elongation of cardiac mitochondria via reduced pDrp1S616 abundance which was also associated with suppression of cellular oxygen consumption. Silencing of TRPV1 in H9c2 cardiomyocytes reproduced the morphological and respirometric phenotype of hypothermia. This report demonstrates a novel mechanism of cold-induced inhibition of mitochondrial fission.

Heart Transplantation for Giant Cell Myocarditis: A Case Series.

BACKGROUND: Giant cell myocarditis (GCM) has a poor prognosis without heart transplant, but post-transplant survival is unknown. PURPOSE: To describe the post-transplant survival of patients with GCM at a large transplant center. METHODS: Seven patients underwent heart transplant for histologically confirmed GCM of the explanted heart. The median age was 59 years, and 43% (3 of 7) were female. All patients had cardiogenic shock, multiorgan failure, elevated troponin, and recurrent ventricular tachycardia, and some required mechanical circulatory support. All patients received rabbit antithymocyte globulin (rATG) in the perioperative period at a dose of 1.5 mg/kg daily for 1 to 5 days and 4 received intravenous immunoglobulin 1 g/kg daily for 2 days after rATG. All patients had early initiation of tacrolimus by first to third postoperative day depending on renal function, early mycophenolate, and high dose steroid. All were maintained using tacrolimus, mycophenolate, and prednisone. RESULTS: One patient had asymptomatic recurrence of GCM at 3 months, managed by up-titration of tacrolimus, and had asymptomatic 2R cellular rejection at 4 months, managed with steroid bolus. No patient had high-grade rejection. One patient died at 267 days, possibly of GCM. Six of 7 (86%) remain alive at a median of 842 days (2.3 years) post transplant. CONCLUSIONS: Patients with GCM have excellent post-transplant survival with use of rATG and triple drug immunosuppressive therapy; however, some patients remain at risk for GCM recurrence after transplant, which may respond to augmented immunosuppression.

cBIN1 Score (CS) Identifies Ambulatory HFrEF Patients and Predicts Cardiovascular Events.

BACKGROUND: Cardiac Bridging Integrator 1 (cBIN1) is a membrane deformation protein that generates calcium microdomains at cardiomyocyte t-tubules, whose transcription is reduced in heart failure, and is released into blood. cBIN1 score (CS), an inverse index of plasma cBIN1, measures cellular myocardial remodeling. In patients with heart failure with preserved ejection fraction (HFpEF), CS diagnoses ambulatory heart failure and prognosticates hospitalization. The performance of CS has not been tested in patients with heart failure with reduced ejection fraction (HFrEF). METHODS AND RESULTS: CS was determined from plasma of patients recruited in a prospective study. Two comparative cohorts consisted of 158 ambulatory HFrEF patients (left ventricular ejection fraction (LVEF) ≤ 40%, 57 ± 10 years, 80% men) and 115 age and sex matched volunteers with no known history of HF. N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentrations were also analyzed for comparison. CS follows a normal distribution with a median of 0 in the controls, which increases to a median of 1.9 (p < 0.0001) in HFrEF patients. CS correlates with clinically assessed New York Heart Association Class (p = 0.007). During 1-year follow-up, a high CS (≥ 1.9) in patients predicts increased cardiovascular events (43% vs. 26%, p = 0.01, hazard ratio 1.9). Compared to a model with demographics, clinical risk factors, and NT-proBNP, adding CS to the model improved the overall continuous net reclassification improvement (NRI 0.64; 95% CI 0.18-1.10; p = 0.006). Although performance for diagnosis and prognosis was similar to CS, NT-proBNP did not prognosticate between patients whose NT-proBNP values were > 400 pg/ml. CONCLUSION: CS, which is mechanistically distinct from NT-proBNP, successfully differentiates myocardial health between patients with HFrEF and matched controls. A high CS reflects advanced NYHA stage, pathologic cardiac muscle remodeling, and predicts 1-year risk of cardiovascular events in ambulatory HFrEF patients. CS is a marker of myocardial remodeling in HFrEF patients, independent of volume status.

Successful Treatment of Severe COVID-19 Pneumonia With Clazakizumab in a Heart Transplant Recipient: A Case Report.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is characterized by an overwhelming cytokine response. Various treatment strategies have been attempted. METHODS AND RESULTS: A 61-year-old man with heart transplantation in 2017 presented with fever, cough, and dyspnea, and was confirmed positive for coronavirus disease 2019 (COVID-19). Laboratory tests showed significant elevations in C-reactive protein and interleukin-6 (IL-6). Echocardiogram showed left ventricular ejection fraction 58% (with ejection fraction 57% 6 months prior). Given the lack of clear management guidelines, the patient was initially managed symptomatically. However, the patient subsequently had a rapid respiratory deterioration with worsening inflammatory markers on day 5 of admission. Tocilizumab (anti-IL-6R) was in low supply in the hospital. The patient was offered clazakizumab (anti-IL-6) for compassionate use. Patient received 25 mg intravenously × 1 dose. Within 24 hours, he showed significant improvement in symptoms, oxygen requirements, radiological findings, and inflammatory markers. There was a transient leukopenia that improved in 4 days. He was discharged home on day 11, with negative nasopharyngeal SARS-CoV-2 PCR as an outpatient on day 35, development of positive serum COVID-19 IgG antibody, and he continued to do well on day 60, with no heart-related symptoms. CONCLUSION: Clazakizumab is a monoclonal antibody against human IL-6, which may be helpful in inhibiting the cytokine response to SARS-CoV-2 in COVID-19. Although not yet FDA approved, it is being investigated for treatment of renal antibody-mediated rejection. Clinical trials of clazakizumab for treatment of COVID-19 are underway worldwide.

Platelet Mapping by Thromboelastography and Whole Blood Aggregometry in Adult Patients Supported by Mechanical Circulatory Support Device on Aspirin Therapy.

Patients on mechanical circulatory support (MCS) devices are placed on aspirin and may require platelet function testing (PFT) to monitor the adequacy of therapy. Routine laboratory PFT is performed using whole blood aggregation (WBA) which typically has a long turnaround time (4-5 hours) and may not be readily available. By contrast, platelet mapping by thromboelastography (TPM) can provide results within 45 minutes. The objective of this study was to compare the results of TPM with WBA. We compared platelet mapping maximal amplitude (MA) by TPM with that of arachidonic acid (AA) to WBA with AA by impedance. We analyzed paired samples where both TPM and WBA were available. Of 45 paired samples, 34 were from 29 MCS patients and 11 were from non-MCS patients. When applying institutional interpretation guidelines with an MAActivator cutoff of ≤40 mm, WBAAA vs TPM MAAA in non-MCS and MCS patients correlated well with an accuracy of 100 and 94.4%, respectively. MAActivator >40 had poor correlation with an accuracy of 37.5%. Irrespective of MAActivator value, TPM AA inhibition expressed in percent of inhibition had poor accuracy. When used with proper guidelines for interpretation, specifically when MAActivator ≤ 40 mm, TPM is a suitable and reliable test to use for MCS patients on aspirin.

Myocardial hypothermia increases autophagic flux, mitochondrial mass and myocardial function after ischemia-reperfusion injury.

Animal studies have demonstrated beneficial effects of therapeutic hypothermia on myocardial function, yet exact mechanisms remain unclear. Impaired autophagy leads to heart failure and mitophagy is important for mitigating ischemia/reperfusion injury. This study aims to investigate whether the beneficial effects of therapeutic hypothermia are due to preserved autophagy and mitophagy. Under general anesthesia, the left anterior descending coronary artery of 19 female farm pigs was occluded for 90 minutes with consecutive reperfusion. 30 minutes after reperfusion, we performed pericardial irrigation with warm or cold saline for 60 minutes. Myocardial tissue analysis was performed one and four weeks after infarction. Therapeutic hypothermia induced a significant increase in autophagic flux, mitophagy, mitochondrial mass and function in the myocardium after infarction. Cell stress, apoptosis, inflammation as well as fibrosis were reduced, with significant preservation of systolic and diastolic function four weeks post infarction. We found similar biochemical changes in human samples undergoing open chest surgery under hypothermic conditions when compared to the warm. These results suggest that autophagic flux and mitophagy are important mechanisms implicated in cardiomyocyte recovery after myocardial infarction under hypothermic conditions. New therapeutic strategies targeting these pathways directly could lead to improvements in prevention of heart failure.

Controversies in the Postoperative Management of the Critically Ill Heart Transplant Patient.

Heart transplant recipients are susceptible to a number of complications in the immediate postoperative period. Despite advances in surgical techniques, mechanical circulatory support (MCS), and immunosuppression, evidence supporting optimal management strategies of the critically ill transplant patient is lacking on many fronts. This review identifies some of these controversies with the aim of stimulating further discussion and development into these gray areas.

Combined Heart and Kidney Transplantation: Clinical Experience in 100 Consecutive Patients.

Background Combined heart and kidney transplantation ( HKT x) is performed in patients with severe heart failure and advanced renal insufficiency. We analyzed the long-term survival after HKT x, the influence of age and dialysis status, the rates of cardiac rejection, and the influence of sensitization. Methods and Results From June 1992 to December 2016, we performed 100 HKT x procedures. We compared older (≥60 years, n=53) with younger (<60 years, n=47) recipients, and recipients on preoperative dialysis (n=49) and not on dialysis (n=51). We analyzed actuarial freedom from any cardiac rejection, acute cellular rejection, and antibody-mediated rejection, and survival rates by sensitized status with panel-reactive antibody levels <10%, 10% to 50%, and >50%, and compared these survival rates with those from the United Network for Organ Sharing database. There was no difference in 15-year survival between the 2 age groups (35±12.4% and 49±17.3%, ≥60 versus <60 years; P=0.45). There was no difference in 15-year survival between the dialysis and nondialysis groups (44±13.4% and 37±15.2%, P=0.95). Actuarial freedom from any cardiac rejection ( acute cellular rejection >0 or antibody-mediated rejection >0) was 92±2.8% and 84±3.8%, acute cellular rejection (≥2R/3A) 98±1.5% and 94±2.5%, and antibody-mediated rejection (≥1) 96±2.1% and 93±2.6% at 30 days and 1 year after HKT x. There was no difference in the 5-year survival among recipients by sensitization status with panel-reactive antibody levels <10%, 10% to 50%, and >50% (82±5.9%, 83±10.8%, and 92±8.0%; P=0.55). There was no difference in 15-year survival after HKT x between the United Network for Organ Sharing database and our center (38±3.2% and 40±10.1%, respectively; P=0.45). Conclusions HKT x is safe to perform in patients 60 years and older or younger than 60 years and with or without dialysis dependence, with excellent outcomes. The degree of panel-reactive antibody sensitization did not appear to affect survival after HKT x.

Predicted heart mass is the optimal metric for size match in heart transplantation.

BACKGROUND: Donor-recipient size match is traditionally assessed by body weight. We assessed the ability of 5 size match metrics-predicted heart mass (PHM), weight, height, body mass index (BMI) and body surface area (BSA)-to predict 1-year mortality after heart transplant and to assess the effect of size match on donor heart turn down for size. METHODS: The study cohort comprised 19,168 adult heart transplant recipients in the United Network for Organ Sharing registry between 2007 and 2016. Each size match metric was divided into 7 equally sized groups using the donor-recipient ratio for each metric. Single and multivariable Cox proportional hazard models for mortality 1 year after transplant were constructed. RESULTS: Recipients in the severely (donor-recipient PHM ratio 0.54-0.86) undersized group for PHM experienced increased mortality, with a hazard ratio of 1.34 (95% confidence interval, 1.13-1.59; p < 0.001). There was no increased risk of death at 1 year if donors were undersized for weight, height, BMI, or BSA. We found that 32% of heart offers turned down for donor size would be acceptable using a PHM threshold of 0.86 or greater and that 14% of offers accepted (most of which are female donor to male recipient) were below this threshold. CONCLUSIONS: PHM is the optimal donor-recipient size match metric for prediction of mortality after heart transplant. Many offers turned down for donor size were above the threshold for adequacy of size match by PHM identified, and thus, the use of PHM could improve donor heart utilization and post-transplant survival.

Association of a Novel Diagnostic Biomarker, the Plasma Cardiac Bridging Integrator 1 Score, With Heart Failure With Preserved Ejection Fraction and Cardiovascular Hospitalization.

Importance: Transverse tubule remodeling is a hallmark of heart failure. Cardiac bridging integrator 1 (cBIN1) is a circulating membrane scaffolding protein that is essential for transverse tubule health, and its plasma level declines with disease. Objective: To determine if a cBIN1-derived score can serve as a diagnostic biomarker of heart failure with preserved ejection fraction (HFpEF). Design, Setting, and Participants: In this cohort study, the cBIN1 score (CS) was determined from enzyme-linked immunoabsorbent assay-measured plasma cBIN1 concentrations from study participants in an ambulatory heart failure clinic at Cedars-Sinai Medical Center. Consecutive patients with a confirmed diagnosis of heart failure with preserved ejection fraction (HFpEF; defined by a left ventricular ejection fraction ≥50%) were recruited from July 2014 to November 2015 and compared with age-matched and sex-matched healthy volunteers with no known cardiovascular diagnoses and participants with risk factors for heart failure but no known HFpEF. Baseline characteristics and 1-year longitudinal clinical information were obtained through electronic medical records. Data analysis occurred from November 2016 to November 2017. Main Outcomes and Measures: The analysis examined the ability of the CS and N-terminal pro-B-type natriuretic peptide (NT-proBNP) results to differentiate among patients with HFpEF, healthy control participants, and control participants with risk factors for heart failure. We further explored the association of the CS with future cardiovascular hospitalizations. Results: A total of 52 consecutive patients with a confirmed diagnosis of HFpEF were enrolled (mean [SD] age, 57 [15] years; 33 [63%] male). The CS values are significantly higher in the patients with HFpEF (median [interquartile range (IQR)], 1.85 [1.51-2.28]) than in the 2 control cohorts (healthy control participants: median [IQR], -0.03 [-0.48 to 0.41]; control participants with risk factors only: median [IQR], -0.08 [-0.75 to 0.42]; P < .001). For patients with HFpEF, the CS outperforms NT-proBNP when the comparator group was either healthy control participants (CS: area under curve [AUC], 0.98 [95% CI, 0.96-1.00]; NT-proBNP level: AUC, 0.93 [95% CI, 0.88-0.99]; P < .001) or those with risk factors (CS: AUC, 0.98 [95% CI, 0.97-1.00]; NT-proBNP: AUC, 0.93 [95% CI, 0.88-0.99]; P < .001). Kaplan-Meier analysis of 1-year cardiovascular hospitalizations adjusted for age, sex, body mass index, and NT-proBNP levels reveals that patients with HFpEF with CS greater than or equal to 1.80 have a hazard ratio of 3.8 (95% CI, 1.3-11.2; P = .02) for hospitalizations compared with those with scores less than 1.80. Conclusions and Relevance: If further validated, the plasma CS, a marker of transverse tubule dysfunction, may serve as a biomarker of cardiomyocyte remodeling that has the potential to aide in the diagnosis of HFpEF.

High Molecular Weight von Willebrand Factor Multimer Loss and Bleeding in Patients with Short-Term Mechanical Circulatory Support Devices: A Case Series.

Acquired von Willebrand syndrome (VWS) due to loss of high-molecular-weight multimers (HMWMs) has been reported with longer term mechanical devices and is associated with mucosal bleeding, a primary hemostasis type of bleeding. However, little is known whether a similar defect occurs in patients with short-term mechanical circulatory support (STMCS) devices. We reviewed von Willebrand factor (VWF) profiles in patients with STMCS devices who underwent VWS workup from December 2015 to March 2017 at an academic quaternary care hospital. There were a total of 18 patients (57.0 ± 12.7 years old; 83.3% male) including nine with mucosal bleeding and nine with decreasing hemoglobin. The STMCS devices included Impella (n = 11), Impella and right ventricular assist device (n = 2), and an extracorporeal membrane oxygenator (n = 5). The mean HMWM by quantitative VWF multimer analysis was 3.6% ± 1.3% (normal cutoff: 18-34%). In all 10 cases in which VWF activity, fibrinogen, factor VIII, or VWF antigen level were obtained, they were either normal or elevated. All cases demonstrated high normal or elevated levels of low molecular weight multimers (LMWMs). These findings are consistent with type 2 VWS (qualitative defect). This is the first study that quantitatively describes STMCS device-associated HMWM loss, which may contribute to mucosal bleeding. This finding may have implications for intraoperative management during implantation of longer term devices or heart transplantation or other surgery while on STMCS.

Use of durable mechanical circulatory support on outcomes of heart-kidney transplantation.

OBJECTIVES: Previous studies have demonstrated that preheart transplant mechanical circulatory support (MCS) can lead to a small but significant increase in mortality. However, data on outcomes of patients with MCS who require simultaneous heart-kidney transplant are limited. METHODS: A retrospective review of simultaneous heart-kidney transplantations (HKTxs) performed at a single institution over a 5-year period was performed. Patients were divided based on the preoperative use of durable MCS. Renal graft-related end points were evaluated, including glomerular filtration rate following transplantation, prevalence of delayed renal graft function and freedom from antibody and cellular-mediated graft rejection. Patient-specific outcomes, including survival and frequency of non-fatal major adverse cardiac events at 1 year, were additionally assessed. RESULTS: During the study period, 50 HKTxs were performed, 14 of which had preoperative MCS. HKTx patients with and without MCS implantations had a similar prevalence of delayed graft function (57.1% vs 50.0%; P = 0.757). A numerical trend was observed towards a reduced glomerular filtration rate 1-month post-transplant in patients without an MCS device (81.2 ± 32.8 vs 64.4 ± 27.5; P = 0.072), but no significant difference was observed at 6 and 12 months. No significant difference was observed on the need for post-transplant renal replacement therapy, non-fatal major adverse cardiac events, freedom from graft rejection and overall survival at 1 year. CONCLUSIONS: The use of preoperative MCS in patients undergoing combined HKTx was not found to affect renal graft function post-transplantation and does not seem to be associated with increase in morbidity or mortality.

Interagency registry for mechanically assisted circulatory support report on the total artificial heart.

BACKGROUND: We sought to better understand the patient population who receive a temporary total artificial heart (TAH) as bridge to transplant or as bridge to decision by evaluating data from the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) database. METHODS: We examined data related to survival, adverse events, and competing outcomes from patients who received TAHs between June 2006 and April 2017 and used hazard function analysis to explore risk factors for mortality. RESULTS: Data from 450 patients (87% men; mean age, 50 years) were available in the INTERMACS database. The 2 most common diagnoses were dilated cardiomyopathy (50%) and ischemic cardiomyopathy (20%). Risk factors for right heart failure were present in 82% of patients. Most patients were INTERMACS Profile 1 (43%) or 2 (37%) at implantation. There were 266 patients who eventually underwent transplantation, and 162 died. Overall 3-, 6-, and 12-month actuarial survival rates were 73%, 62%, and 53%, respectively. Risk factors for death included older age (p = 0.001), need for pre-implantation dialysis (p = 0.006), higher creatinine (p = 0.008) and lower albumin (p < 0.001) levels, and implantation at a low-volume center (≤10 TAHs; p < 0.001). Competing-outcomes analysis showed 71% of patients in high-volume centers were alive on the device or had undergone transplantation at 12 months after TAH implantation vs 57% in low-volume centers (p = 0.003). CONCLUSIONS: Patients receiving TAHs have rapidly declining cardiac function and require prompt intervention. Experienced centers have better outcomes, likely related to patient selection, timing of implantation, patient care, and device management. Organized transfer of knowledge to low-volume centers could improve outcomes.

Combining Stem Cell Therapy for Advanced Heart Failure and Ventricular Assist Devices: A Review.

The use of stem cell therapy in combination with a left ventricular assist device (LVAD) for patients with advanced heart failure (HF) is an attractive concept with the potential to alter the natural history of HF. Cell therapy trials for HF have demonstrated excellent safety and encouraging results, but current rates of myocardial recovery after LVAD implantation are limited. Early trials combining these 2 therapies to increase the likelihood of recovery and to potentially obviate the need for subsequent transplantation appear promising. Additionally, the application of cell therapy to patients undergoing LVAD implantation as a bridge to cardiac transplantation creates an opportunity to examine cardiac tissue before and after treatment and to study the mechanism of benefit. Despite the promise, there is a paucity of data for the combination of stem cell therapy with LVAD insertion in patients with HF. Of 11 case series or clinical trials, the largest enrolled 30 patients. We highlight clinical trials using stem cell therapy for end-stage HF most relevant to an LVAD patient population and comprehensively review the preclinical and clinical studies of combined stem cell therapy and long-term mechanical circulatory support. Based on the available clinical trials, the combination of stem cell therapy and LVAD support is a promising approach but requires further clinical refinement, with additional clinical data and larger numbers of patients required to support its clinical application.

Characterizing Predictors and Severity of Vasoplegia Syndrome After Heart Transplantation.

BACKGROUND: Vasoplegia is characterized as a severe vasodilatory shock after cardiac surgery, and can be associated with substantial morbidity. Increased systemic inflammation and endothelial dysfunction, often related to prolonged cardiopulmonary bypass times, anesthesia, or mechanical circulatory support have been shown to be associated with the development of vasoplegia. We sought to identify risk factors and the impact of various degrees of vasoplegia after heart transplantation. METHODS: A retrospective review was conducted of 244 consecutive patients who underwent heart transplantation over a 3-year period. Patients were divided into three groups: no vasoplegia, mild vasoplegia (requiring one vasopressor), and moderate/severe vasoplegia (more than two vasopressors). One-year survival, freedom from rejection, and postoperative complication rates were assessed. Risk factors for vasoplegia subgroups were retrospectively identified. RESULTS: Vasoplegia syndrome was observed in 34.3% of patients after heart transplantation (mild, 74.1%; moderate/severe, 25.9%). Cardiopulmonary bypass time was significantly longer and pretransplant creatinine was significantly higher in the moderate/severe vasoplegia group. There was a strong trend toward greater use of mechanical circulatory support among moderate/severe vasoplegia patients compared with mild and no vasoplegia patients. After heart transplantation, 1-year survival, freedom from rejection, and need for hemodialysis were not significantly different between groups. CONCLUSIONS: Vasoplegia syndrome is common after heart transplantation. Risk factors for increased severity include longer cardiopulmonary bypass times and elevated preoperative creatinine. Although higher rates of mortality or graft rejection were not detected, vasoplegia was associated with prolonged intubation, greater blood product usage, and lengthened hospital stay. Further studies involving larger cohorts are warranted.

Left Ventricular Reconstruction for Postinfarction Left Ventricular Aneurysm: Review of Surgical Techniques.

Different surgical techniques, each with its own advantages and disadvantages, have been used to reverse adverse left ventricular remodeling due to postinfarction left ventricular aneurysm. The most appropriate surgical technique depends on the location and size of the aneurysm and the scarred tissue, the patient's preoperative characteristics, and surgeon preference. This review covers the reconstructive surgical techniques for postinfarction left ventricular aneurysm.