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Mycobacterium tuberculosis (Mtb) is the leading infectious disease killer worldwide. We discovered that intracellular Mtb fails to grow in macrophages in which fatty acid β-oxidation (FAO) is blocked. Macrophages treated with FAO inhibitors rapidly generate a burst of mitochondria-derived reactive oxygen species, which promotes NADPH oxidase recruitment and autophagy to limit the growth of Mtb. Furthermore, we demonstrate the ability of trimetazidine to reduce pathogen burden in mice infected with Mtb. These studies will add to the knowledge of how host metabolism modulates Mtb infection outcomes., Macrophage activation involves metabolic reprogramming to support antimicrobial cellular functions. How these metabolic shifts influence the outcome of infection by intracellular pathogens remains incompletely understood. Mycobacterium tuberculosis (Mtb) modulates host metabolic pathways and utilizes host nutrients, including cholesterol and fatty acids, to survive within macrophages. We found that intracellular growth of Mtb depends on host fatty acid catabolism: when host fatty acid β-oxidation (FAO) was blocked chemically with trimetazidine, a compound in clinical use, or genetically by deletion of the mitochondrial fatty acid transporter carnitine palmitoyltransferase 2 (CPT2), Mtb failed to grow in macrophages, and its growth was attenuated in mice. Mechanistic studies support a model in which inhibition of FAO generates mitochondrial reactive oxygen species, which enhance macrophage NADPH oxidase and xenophagy activity to better control Mtb infection. Thus, FAO inhibition promotes key antimicrobial functions of macrophages and overcomes immune evasion mechanisms of Mtb.

High protein diets are commonly utilized for weight loss, yet have been reported to raise cardiovascular risk. The mechanisms underlying this risk are unknown. Here, we show that dietary protein drives atherosclerosis and lesion complexity. Protein ingestion acutely elevates amino acid levels in blood and atherosclerotic plaques, stimulating macrophage mTOR signaling. This is causal in plaque progression as the effects of dietary protein are abrogated in macrophage-specific Raptor-null mice. Mechanistically, we find amino acids exacerbate macrophage apoptosis induced by atherogenic lipids, a process that involves mTORC1-dependent inhibition of mitophagy, accumulation of dysfunctional mitochondria, and mitochondrial apoptosis. Using macrophage-specific mTORC1- and autophagy-deficient mice we confirm this amino acid-mTORC1-autophagy signaling axis in vivo. Our data provide the first insights into the deleterious impact of excessive protein ingestion on macrophages and atherosclerotic progression. Incorporation of these concepts in clinical studies will be important to define the vascular effects of protein-based weight loss regimens.

An amendment to this paper has been published and can be accessed via a link at the top of the paper. © 2020, The Author(s).

Objective Left ventricular assist device (LVAD) implantation has been shown to increase allosensitization before orthotopic heart transplantation, but the influence of LVAD support on posttransplant rejection is controversial. This study examines the postoperative incidence of acute cellular rejection (ACR) in patients bridged with continuous flow LVAD (CF-LVAD) relative to primary transplant (Primary Tx). Methods All patients who underwent orthotopic heart transplantation at our institution between July 2006 and March 2019 were retrospectively reviewed (n = 395). Patients were classified into Primary Tx (n = 145) and CF-LVAD (n = 207) groups. Propensity score matching on 13 covariates implemented a 0.1 caliper logistic model with nearest neighbor 1:1 matching. Development of moderate to severe (ie, 2R/3R) rejection was evaluated using a competing risks model. Potential predictors of 2R/3R ACR were evaluated using Fine-Gray regression on the marginal subdistribution hazard. Results Propensity score matching yielded 122 patients in each group (n = 244). At 12 and 24 months, the cumulative incidence of 2R/3R ACR was 17% and 23% for the CF-LVAD group and 26% and 31%, respectively, for the Primary Tx group (P = .170). CF-LVAD was not predictive of 2R/3R rejection on multivariable Fine-Gray regression (subdistribution hazard ratio, 0.73; 95% confidence interval, 0.40-1.33; P = .301). There was no difference in the 5-year incidence of antibody mediated rejection (10% [n = 12] vs 9% [n = 11]; P = .827). Conclusions After adjusting for covariates, CF-LVAD was not associated with an increased risk of moderate to severe ACR during the 24 months after cardiac transplantation. Further investigation is warranted with larger cohorts, but CF-LVAD may have minimal influence on posttransplant ACR.

Die risikoadaptierte Dickdarmkrebsvorsorge fuhrt dazu, dass die ergriffenen Masnahmen wesentlich haufiger mit pathologischen Befunden verbunden sind und somit weniger gesunde Menschen im Rahmen der Vorsorge invasiv untersucht werden mussen. Dies wiederum wirkt sich auf Kosten und die Komplikationsrate der Vorsorgemasnahmen aus und gestaltet Vorsorge letztlich attraktiver. Bis dato wurde zur Risikoadaptation vor allem das familiare Risiko identifiziert. Klare Regeln, wie dieses Risiko flachendeckend evaluiert werden kann, gibt es nicht. Leitlinienempfehlungen besagen einen Start mit invasiven Vorsorgemasnahmen 10 Jahre vor Erkrankung der Indexperson. Der Tatsache, dass Manner fruher an Darmkrebs erkranken als Frauen, tragt der Beschluss des Gemeinsamen Bundesausschusses insofern Rechnung, als das Startalter fur die erste von 2 Vorsorgekoloskopien bei Mannern auf das 50. Lebensjahr vorgezogen wurde. Neuere strukturierte epidemiologische Untersuchungen zeigen, dass eine Risikoadaptation sehr viel differenzierter und letztlich auch aussagekraftiger funktionieren konnte. Hierzu bedarf es strukturierter Erhebungen bei den infrage kommenden Personengruppen (z. B. beim Check-up mit 35 Jahren). Die logische Konsequenz aus einer differenzierten Risikostratifikation ist ein unterschiedlicher Beginn der invasiven Untersuchungen und auf jeden Fall der Einsatz invasiver diagnostischer Methoden (Vorsorgekoloskopie) bei erhohtem Risiko.

Obesity and diabetes modulate macrophage activation, often leading to prolonged inflammation and dysfunctional tissue repair. Increasing evidence suggests that the NLRP3 inflammasome plays an important role in obesity-associated inflammation. We have previously shown that activation of the lipotoxic inflammasome by excess fatty acids in macrophages occurs via a lysosome-dependent pathway. However, the mechanisms that link cellular lipid metabolism to altered inflammation remain poorly understood. PPARγ is a nuclear receptor transcription factor expressed by macrophages that is known to alter lipid handling, mitochondrial function, and inflammatory cytokine expression. To undercover novel links between metabolic signaling and lipotoxic inflammasome activation, we investigated mouse primary macrophages deficient in PPARγ. Contrary to our expectation, PPARγ knockout (KO) macrophages released significantly less IL-1β and IL-1α in response to lipotoxic stimulation. The suppression occurred at the transcriptional level and was apparent for multiple activators of the NLRP3 inflammasome. RNA sequencing revealed upregulation of IFN-β in activated PPARγKO macrophages, and this was confirmed at the protein level. A blocking Ab against the type 1 IFNR restored the release of IL-1β to wild type levels in PPARγKO cells, confirming the mechanistic link between these events. Conversely, PPARγ activation with rosiglitazone selectively suppressed IFN-β expression in activated macrophages. Loss of PPARγ also resulted in diminished expression of genes involved in sterol biosynthesis, a pathway known to influence IFN production. Together, these findings demonstrate a cross-talk pathway that influences the interplay between metabolism and inflammation in macrophages.

Osteoclasts are mitochondria-rich cells, but the role of these energy-producing organelles in bone resorption is poorly defined. To this end, we conditionally deleted the mitochondria-inducing co-activator, PGC1β, in myeloid lineage cells to generate PGC1βLysM mice. In contrast to previous reports, PGC1β-deficient macrophages differentiate normally into osteoclasts albeit with impaired resorptive function due to cytoskeletal disorganization. Consequently, bone mass of PGC1βLysM mice is double that of wild type. Mitochondrial biogenesis and function are diminished in PGC1βLysM osteoclasts. All abnormalities are normalized by PGC1β transduction. Furthermore, OXPHOS inhibitors reproduce the phenotype of PGC1β deletion. PGC1β's organization of the osteoclast cytoskeleton is mediated by expression of GIT1, which also promotes mitochondrial biogenesis. Thus, osteoclast mitochondria regulate the cell's resorptive activity by promoting cytoskeletal organization. © 2018 American Society for Bone and Mineral Research.

Despite evidence that pharmacogenetics can improve tamoxifen pharmacotherapy, there are few studies with American Indian and Alaska Native (AIAN) people. We examined variation in cytochrome P450 (CYP) genes (CYP2D6, CYP3A4, CYP3A5, and CYP2C9) and tamoxifen biotransformation in AIAN patients with breast cancer (n = 42) from the Southcentral Foundation in Alaska and the Confederated Salish and Kootenai Tribes in Montana. We tested for associations between CYP diplotypes and plasma concentrations of tamoxifen and metabolites. Only the CYP2D6 variation was significantly associated with concentrations of endoxifen (P = 0.0008) and 4-hydroxytamoxifen (P = 0.0074), tamoxifen's principal active metabolites, as well as key metabolic ratios. The CYP2D6 was also the most significant predictor of active metabolites and metabolic ratios in a multivariate regression model, including all four genes as predictors, with minor roles for other CYP genes. In AIAN populations, CYP2D6 is the largest contributor to tamoxifen bioactivation, illustrating the importance of validating pharmacogenetic testing for therapy optimization in an understudied population.

Macrophages specialize in removing lipids and debris present in the atherosclerotic plaque. However, plaque progression renders macrophages unable to degrade exogenous atherogenic material and endogenous cargo including dysfunctional proteins and organelles. Here we show that a decline in the autophagy–lysosome system contributes to this as evidenced by a derangement in key autophagy markers in both mouse and human atherosclerotic plaques. By augmenting macrophage TFEB, the master transcriptional regulator of autophagy–lysosomal biogenesis, we can reverse the autophagy dysfunction of plaques, enhance aggrephagy of p62-enriched protein aggregates and blunt macrophage apoptosis and pro-inflammatory IL-1β levels, leading to reduced atherosclerosis. In order to harness this degradative response therapeutically, we also describe a natural sugar called trehalose as an inducer of macrophage autophagy–lysosomal biogenesis and show trehalose's ability to recapitulate the atheroprotective properties of macrophage TFEB overexpression. Our data support this practical method of enhancing the degradative capacity of macrophages as a therapy for atherosclerotic vascular disease., Dysfunction of autophagy in plaque macrophages aggravates atherosclerosis. Here the authors show that induction of macrophage autophagy–lysosomal biogenesis either genetically by overexpression of the master transcriptional regulator of this process, TFEB, or pharmacologically with trehalose is atheroprotective.

Purpose In October 2018, a new heart allocation policy was implemented. The new system was intended to decrease time on the wait list and prioritize allocation to the sickest patients. We examined the effects of this new policy on heart transplant recipients who underwent transplant one year prior to and one year after the policy change. Methods Adult patients who underwent heart transplant at our institution from October 2017 to September 2019 were identified and divided into two cohorts based on whether the date of transplant was before or after October 2018. Patient demographics, clinical data, and bridging strategy were recorded. Early outcomes studied included ischemic time, presence of severe PGD, need for renal replacement therapy or tracheostomy, duration of ICU stay, and total hospital stay. Results In total, 66 patients were identified. 38 patients were transplanted the year prior to the allocation change and 28 patients the year after. The most common listing status prior to the change was Status 1B (74%) and after was Status 2 (54%). After the allocation change, there was a decrease in average wait-time to transplant (313 days vs. 53 days, p=.04). In addition, patients were more likely to be inpatient prior to their transplant (11% vs. 68%, p Conclusion Implementation of the new allocation system resulted in dramatic changes in the bridging strategy utilized at our institution. The number of patients supported with durable LVADs prior to transplant was substantially decreased and the use of temporary mechanical support increased following the change. Early post-transplant outcomes appear similar. Further investigation is needed to assess the long-term impact of the allocation change.

Lysosomes are at the epicenter of cellular processes critical for inflammasome activation in macrophages. Inflammasome activation and IL-1β secretion are implicated in myocardial infarction (MI) and resultant heart failure; however, little is known about how macrophage lysosomes regulate these processes. In mice subjected to cardiac ischemia/reperfusion (IR) injury and humans with ischemic cardiomyopathy, we observed evidence of lysosomal impairment in macrophages. Inducible macrophage-specific overexpression of transcription factor EB (TFEB), a master regulator of lysosome biogenesis (Mϕ-TFEB), attenuated postinfarction remodeling, decreased abundance of proinflammatory macrophages, and reduced levels of myocardial IL-1β compared with controls. Surprisingly, neither inflammasome suppression nor Mϕ-TFEB-mediated attenuation of postinfarction myocardial dysfunction required intact ATG5-dependent macroautophagy (hereafter termed "autophagy"). RNA-seq of flow-sorted macrophages postinfarction revealed that Mϕ-TFEB upregulated key targets involved in lysosomal lipid metabolism. Specifically, inhibition of the TFEB target, lysosomal acid lipase, in vivo abrogated the beneficial effect of Mϕ-TFEB on postinfarction ventricular function. Thus, TFEB reprograms macrophage lysosomal lipid metabolism to attenuate remodeling after IR, suggesting an alternative paradigm whereby lysosome function affects inflammation.

SUMMARYMacrophage activation involves metabolic reprogramming to support antimicrobial cellular functions. How these metabolic shifts influence the outcome of infection by intracellular pathogens remains incompletely understood. M. tuberculosis (Mtb) modulates host metabolic pathways and utilizes host nutrients, including cholesterol and fatty acids, to survive within macrophages. We found that intracellular growth of Mtb depends on host fatty acid catabolism: when host fatty acid β-oxidation (FAO) was blocked chemically with trimetazidine, a compound in clinical use, or genetically by deletion of the mitochondrial fatty acid transporter carnitine palmitoyltransferase 2 (CPT2), Mtb failed to grow in macrophages and its growth was attenuated in mice. Global metabolic profiling and mechanistic studies support a model in which inhibition of FAO generates mitochondrial reactive oxygen species, which enhance macrophage NADPH oxidase and xenophagy activity to better control Mtb infection. Thus, FAO inhibition promotes key antimicrobial functions of macrophages and overcomes immune evasion mechanisms of Mtb.

Background: Autophagy, lipid metabolism, and inflammation are interrelated cellular processes that implicate lysosomes in human disease. After ischemia reperfusion (IR) injury, inflammasome activation and interleukin 1-beta (IL1-beta) secretion promote heart failure progression. Whether macrophage autophagy and lysosomal biogenesis can attenuate post-IR remodeling and inflammation is unknown. We hypothesized that macrophages exhibit lysosome dysfunction and autophagic impairment after IR injury, and that augmentation of macrophage lysosomal biogenesis via macrophage-specific overexpression of transcription factor EB (Mf-TFEB), a master regulator of autophagy and lysosomal biogenesis, would attenuate myocardial remodeling and inflammation in ischemic cardiomyopathy. Methods and Results: In mice subject to IR injury and humans with ischemic cardiomyopathy, we observed evidence of lysosomal and autophagic impairment. To ameliorate post-IR macrophage lysosomal injury, we expressed Mf-TFEB in a closed-chest IR murine model using a tamoxifen-inducible CX3CR1erCre and TFEB overexpression cassette bearing a Cre-excisable STOP codon. Compared to Cre-only controls, Mf-TFEB mice had significantly increased left ventricular (LV) ejection fraction 28-days post-IR (40% relative increase, p=0.002, n=15-17 per group), decreased abundance of pro-inflammatory macrophages, and reduced levels of IL1-beta in myocardial tissue. Surprisingly, neither inflammasome suppression nor TFEB-mediated attenuation of post-IR remodeling required intact macro-autophagy as evidenced by Mf-TFEB-mediated rescue of post-IR LV dysfunction in mice with concomitant inducible ATG5 ablation. RNA sequencing of flow-sorted macrophages from post-IR mice identified lysosomal acid lipase amongst other lipases regulated by TFEB. Mechanistically, pharmacologic inhibition of lysosomal acid lipase specifically abrogated the in vivo effects of TFEB on post-IR remodeling. Conclusions: Our findings suggest that macrophage TFEB regulates lysosomal lipolysis to attenuate inflammasome activity and protect against post-IR LV dysfunction, suggesting an alternative paradigm for how lysosome function may impact acute inflammation in vivo.

Whereas prior studies have demonstrated an important immunomodulatory role for the neuronal cholinergic system in the heart, the role of the nonneuronal cholinergic system is not well understood. To address the immunomodulatory role of the nonneuronal cholinergic system in the heart, we used a previously validated diphtheria toxin–induced (DT-induced) cardiomyocyte ablation model (Rosa26-DT(Mlc2v-Cre) mice). DT-injected Rosa26-DT(Mlc2v-Cre) mice were treated with diluent or pyridostigmine bromide (PYR), a reversible cholinesterase inhibitor. PYR treatment resulted in increased survival and decreased numbers of MHC-II(lo)CCR2(+) macrophages in DT-injected Rosa26-DT(Mlc2v-Cre) mice compared with diluent-treated Rosa26-DT(Mlc2v-Cre) mice. Importantly, the expression of CCL2/7 mRNA and protein was reduced in the hearts of PYR-treated mice. Backcrossing Rosa26-DT(Mlc2v-Cre) mice with a transgenic mouse line (Chat-ChR2) that constitutively overexpresses the vesicular acetylcholine transporter (VAChT) resulted in decreased expression of Ccl2/7 mRNA and decreased numbers of CD68(+) cells in DT-injured Rosa26-DT(Mlc2v-Cre)/Chat-ChR2 mouse hearts, consistent with the pharmacologic studies with PYR. In vitro studies with cultures of LPS-stimulated peritoneal macrophages revealed a concentration-dependent reduction in CCL2 secretion following stimulation with acetylcholine, nicotine, and muscarine. To our knowledge, these findings reveal a previously unappreciated immunomodulatory role for the nonneuronal cholinergic system in regulating homeostatic responses in the heart following tissue injury.

Obesity and diabetes are associated with macrophage dysfunction and increased NLRP3 inflammasome activation. Saturated fatty acids (FAs) are abundant in these metabolic disorders and have been associated with lysosome dysfunction and inflammasome activation in macrophages. However, the interplay between cellular metabolic pathways and lipid-induced toxicity in macrophages remains poorly understood. In this study, we investigated the role of the lipid metabolic enzyme long chain acyl-CoA synthetase (ACSL1) in primary macrophages. ACSL1 is upregulated in TLR4-activated macrophages via a TIR (toll/IL-1R) domain-containing adapter inducing IFN-β (TRIF)-dependent pathway, and knockout of this enzyme decreased NLRP3 inflammasome activation. The mechanism of this response was not related to inflammasome priming, lipid uptake, or endoplasmic reticulum (ER) stress generation. Rather, ACSL1 was associated with mitochondria where it modulated fatty acid metabolism. The development of lysosome damage with palmitate exposure likely occurs via the formation of intracellular crystals. Herein, we provide evidence that loss of ACSL1 in macrophages decreases FA crystal formation thereby reducing lysosome damage and IL-1β release. These findings suggest that targeting lipid metabolic pathways in macrophages may be a strategy to reduce lipotoxity and to decrease pathologic inflammation in metabolic disease.

Immune-checkpoint blockade (ICB) has demonstrated efficacy in many tumor types, but predictors of responsiveness to anti-PD1 ICB are incompletely characterized. In this study, we analyzed a clinically annotated cohort of patients with melanoma (n = 144) treated with anti-PD1 ICB, with whole-exome and whole-transcriptome sequencing of pre-treatment tumors. We found that tumor mutational burden as a predictor of response was confounded by melanoma subtype, whereas multiple novel genomic and transcriptomic features predicted selective response, including features associated with MHC-I and MHC-II antigen presentation. Furthermore, previous anti-CTLA4 ICB exposure was associated with different predictors of response compared to tumors that were naive to ICB, suggesting selective immune effects of previous exposure to anti-CTLA4 ICB. Finally, we developed parsimonious models integrating clinical, genomic and transcriptomic features to predict intrinsic resistance to anti-PD1 ICB in individual tumors, with validation in smaller independent cohorts limited by the availability of comprehensive data. Broadly, we present a framework to discover predictive features and build models of ICB therapeutic response. © 2019, The Author(s).

Summary: Macrophage-mediated inflammation is critical in the pathogenesis of non-alcoholic steatohepatitis (NASH). Here, we describe that, with high-fat, high-sucrose-diet feeding, mature TIM4pos Kupffer cells (KCs) decrease in number, while monocyte-derived Tim4neg macrophages accumulate. In concert, monocyte-derived infiltrating macrophages enter the liver and consist of a transitional subset that expresses Cx3cr1/Ccr2 and a second subset characterized by expression of Trem2, Cd63, Cd9, and Gpmnb; markers ascribed to lipid-associated macrophages (LAMs). The Cx3cr1/Ccr2-expressing macrophages, referred to as C-LAMs, localize to macrophage aggregates and hepatic crown-like structures (hCLSs) in the steatotic liver. In C-motif chemokine receptor 2 (Ccr2)-deficient mice, C-LAMs fail to appear in the liver, and this prevents hCLS formation, reduces LAM numbers, and increases liver fibrosis. Taken together, our data reveal dynamic changes in liver macrophage subsets during the pathogenesis of NASH and link these shifts to pathologic tissue remodeling.

Background In October 2018, a new heart allocation policy was implemented with intent of prioritizing the sickest patients and decreasing waitlist time. We examined the effects of the new policy on transplant practices and outcomes 1 year before and 1 year after the change. Methods Transplant recipients from October 2017 to September 2019 at our institution were identified and divided into 2 cohorts, a preallocation and postallocation criteria change. Patient demographics, clinical data, and bridging strategy were assessed. Early outcomes including ischemic time, severe primary graft dysfunction, need for renal replacement therapy, and duration of hospital stay were investigated. Results In the 12 months before the change, 38 patients were transplanted as compared to 33 patients in the 12 months after the change. The average wait-time to transplant decreased after the allocation change (49 versus 313 d, P = 0.02). Patients were more likely to be bridged with an intra-aortic balloon pump (45% versus 3%) and less likely to be supported with a durable left ventricular assist device (LVAD) after the change (24% versus 82%). There was an increase in total ischemic time after the change (177 versus 117 min, P ≤ 0.01). There were no significant differences in other early posttransplant outcomes. Conclusions Implementation of the new allocation system for heart transplantation resulted in dramatic changes in the bridging strategy utilized at our institution. Temporary mechanical support usage increased following the change and the number of recipients supported with durable LVADs decreased. Early posttransplant outcomes appear similar.

Macrophage dysfunction in obesity and diabetes is associated with persistent inflammation and poor wound healing responses. Relevant to these phenotypes, we have previously shown that macrophage activation in a high-fat environment results in cell death via a mechanism that involves lysosome damage. While searching for signaling pathways that were required for this response, we discovered that mTOR inhibitors, torin and rapamycin, were protective against lipotoxic cell death in primary peritoneal macrophages. The protective effect of mTOR inhibition was also confirmed by using genetic loss-of-function approaches. Given the importance of mTOR in regulation of autophagy we hypothesized that this pathway would be important in protection from cell death. We first demonstrated that autophagy was disrupted in response to palmitate and LPS as a consequence of impaired lysosome function. Conversely, the mTOR inhibitor, torin, increased macrophage autophagy and protected against lysosome damage; however, the beneficial effects of torin persisted in autophagy-deficient cells. Inhibition of mTOR also triggered nuclear localization of TFEB, a transcription factor that regulates lysosome biogenesis and function, but the rescue phenotype did not require the presence of TFEB. Instead, we demonstrated that mTOR inhibition reduces mitochondrial oxidative metabolism and attenuates the negative effects of palmitate on LPS-induced mitochondrial respiration. These results suggest that inhibition of mTOR is protective against lipotoxicity via an autophagy-independent mechanism that involves relieving mitochondrial substrate overload. On the basis of these findings, we suggest that therapies to reduce macrophage mTOR activation may protect against dysfunctional inflammation in states of overnutrition, such as diabetes.

Objectives This study sought to determine whether severe right ventricular (RV) dysfunction in the pre-operative setting is associated with an increased risk of gastrointestinal bleeding (GIB) post-left ventricular assist device (LVAD). Background GIB is a significant complication in patients supported with continuous-flow LVADs. The impact of RV dysfunction on the risk of GIB has not been investigated. Methods We retrospectively identified 212 patients who survived index hospitalization after implantation of HeartMate II (Thoratec Corp., Pleasanton, California) or Heartware HVAD (HeartWare Corp., Framingham, Massachusetts) from June 2009 to April 2013. Patients with severe RV dysfunction on pre-LVAD echocardiogram (n = 37) were compared to patients without severe RV dysfunction (n = 175). The primary outcome was freedom from GIB. Results The majority of patients were male (79%) with a median INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support) profile of 2 at LVAD implantation. There were no significant differences between cohorts with respect to demographics, comorbidities, device type, international normalization ratio, or aspirin strategy. During follow-up, 81 patients had GIB events: 23 of 37 (62%) in the severe RV dysfunction group versus 58 of 175 (33%) in the control group (p = 0.001). After adjustment for age and ischemic cardiomyopathy, severe RV dysfunction was associated with increased risk of GIB (hazard ratio: 1.799, 95% confidence interval: 1.089 to 2.973, p = 0.022). Conclusions In this single-center sample of patients supported with continuous-flow LVADs, severe RV dysfunction on pre-LVAD echocardiogram was associated with an increased risk of GIB. Further studies are needed to investigate possible mechanisms by which RV dysfunction increases the risk of GIB and to identify patient populations who may benefit from alterations in antithrombotic strategies.

Purpose Acute kidney injury (AKI) is a common complication following heart transplant and has been found to be associated with increased morbidity and mortality. The goal of this study is to examine pre- and peri-operative risk factors for AKI post-heart transplant and to identify potentially modifiable risk factors. Methods We conducted a retrospective cohort study evaluating patients who underwent heart transplant between 2009 and 2016 at a single institution. Data were obtained from the Society of Thoracic Surgeons (STS) national database and retrospective chart review. Exclusion criteria were age Results A total of 189 heart transplant patients were included in the study for analysis. In total, 113 (60%) developed AKI, where 37 (33%) were classified as stage I, 23 (20%) as stage II, 53 (47%) as stage III, and 45 patients (24%) required dialysis. Risk factors found to be associated with the presence of AKI included elevated pre-op central venous pressure (CVP) (16 mmHg non-AKI group vs 19 mmHg AKI group, p = 0.020), increased use of vasopressors and inotropes post-transplant, number of blood products transfused (9 vs 11 units, p = 0.009), cardiopulmonary bypass time (163 vs 180 min, p = 0.002), and complications such as delayed sternal closure (19 (29%) vs 48 (45%), p = 0.030). Dialysis after discharge was needed for 7 (8%, p = 0.090) AKI patients. No significant association was found between presence of AKI and hospital readmission, 30-day mortality, and 1-year mortality. Conclusion Risk factors such as elevated pre-op CVP, high use of vasopressors and inotropes, number of blood products transfused, and delayed sternal closure were closely associated with the development of AKI. Delayed sternal closure and number of blood products transfused highlight the impact of bleeding, and the elevated pre-operative CVP is of particular interest due to its potentially modifiable nature.

Purpose There is a significant unmet patient need for heart transplantation, driven partly by low donor heart utilization. Donor left ventricular dysfunction (LVD) is the most common reason for non-allocation. A significant proportion of brain-dead donors will have transient LVD with subsequent recovery, and these donor hearts are considered an underutilized subset. However, their association with post-transplant outcomes, specifically primary graft dysfunction (PGD), remains unclear. This study investigates the relationship between donor clinical characteristics and post-transplant PGD. Methods Donor and post-transplant data was obtained for all donor hearts originating from a centralized diagnostic and recovery OPO that were transplanted at a single institution between 2010-2017. Transient LVD was defined as initial LV ejection fraction (LVEF) at OPO Results 152 heart transplant patients were identified with corresponding donor hearts originating from the OPO, of which 32 (21%) had post-transplant PGD. PGD was not associated with donor baseline characteristics, pressor requirements, or lab values (Table 1). PGD was associated with lower donor final LVEF (57.5% vs. 60%, p Conclusion This study indicates that patients receiving donor hearts with transient LV dysfunction have a two-fold increased risk of PGD. Given these findings, vigilance for PGD, careful consideration regarding donor-recipient matching, and early hemodynamic support should be considered in these patients.

Purpose Antibody mediated rejection (AMR) following heart transplant (OTHx) causes significant morbidity and mortality. In particular, diagnosis and management of non-HLA AMR remains challenging. Antibodies to the angiotensin II type 1 receptor (AT1R) causing rejection after kidney transplant have been described, but there is limited data on AT1R-Ab mediated rejection following OHTx. Here, we present our single center experience. Methods We retrospectively reviewed all OHTx cases from the past 2 years with clinically suspected AMR without evidence of canonical donor-specific AMR who had a positive AT1R-Ab titer. Clinical and pathological features were documented. Results We identified 7 patients, the majority were female (71%), African American (71%), and had prior LVAD support (71%). All patients had NICM pretransplant. Patients presented both early (∼2 weeks) and late (∼7 years) with heart failure; 3 patients presented within 1 year post OHTx. Echocardiography showed progressive graft dysfunction, primarily decreased EF, ventricular wall thickening, and diastolic dysfunction. The average AT1R-Ab titer was 22U/mL at 1:100 dilution (range: 3 to >40 U/mL). Biopsies showed reactive endothelium and increased interstitial macrophages, without pathologic AMR features (negative C4d and Conclusion AT1R-Ab mediated rejection is an underdiagnosed and emerging entity following OHTx that remains ill-defined; it requires a high index of suspicion and should be considered for all OHTx recipients with evidence of graft dysfunction or decompensation. Empiric AMR treatment followed by oral ARB therapy anecdotally improves patient outcomes; however, future studies are needed to better define the pathophysiology, long-term clinical sequelae, and optimal treatment modalities of this disease.

Alaska Native and American Indian (AN/AI) people have unique pharmacogene variation that may affect warfarin disposition and therapeutic response. We performed targeted genotyping for cytochrome P450 (CYP)2C9, vitamin K epoxide oxidase reductase complex subunit 1 (VKORC1), CYP4F2,CYP4F11, and gamma‐glutamyl carboxylase (GGCX) variants in AN/AI people receiving warfarin. The primary outcome was stable warfarin dose, defined as one dose, and associated international normalized ratio within the target range, at least 6 months after starting therapy, with two matching doses at least 2 weeks apart. Genotype–phenotype relationships were assessed by multivariate regression analysis, adjusted for self‐reported heritage, age, gender, and concurrent statin use. VKORC1 genotype explained 34% of dose variability, with VKORC1 −1639G>A and 1173C>T associated with a 1.7 mg/day (P = 1.4e‐05) dose reduction. Additionally, CYP2C9 N218I was suggestively significant (P = 0.077), with heterozygotes requiring 1.1 mg/day less than reference individuals. Self‐reported heritage was significantly associated with dose, largely driven by differences in the diagnostic VKORC1 allele frequencies among AN/AI people.

BACKGROUND: In preclinical studies we have defined IDH1R132H as a clonal neoantigen presented on MHC class II. A peptide vaccine encompassing IDH1R132H induces tumor-specific T helper cell responses effective in controlling syngeneic IDH1R132H-mutant tumors in humanized mouse models. MATERIAL AND METHODS: NOA-16 (NCT02454634) is a first-in-man, multicenter, phase I trial testing the safety and immunogenicity of an IDH1R132H peptide in incomplete Freund’s adjuvant in patients with newly diagnosed, IDH1R132H mutant WHO °III and °IV astrocytomas. Between September 2015 and October 2016, 32 patients were enrolled in seven German sites. 23 patients (71.9%) received radiochemotherapy with temozolomide, six patients (18.8%) received radiotherapy alone and three patients (9.4%) received temozolomide alone. RESULTS: 249 vaccines were administered, 29 (90.6%) of the patients of the safety set (N=32) and 27 (90.0%) patients of the immunogenicity set (N=30) received all eight vaccines. No regime-limiting toxicity was observed. The majority of the patients (N=29, 90.6%) experienced treatment related adverse events (trAE), 1 (3.1%) of them had treatment related SAE. None of the reported AEs were severe. 28/30 (93.3%) patients, who were evaluable for immunogenicity, displayed mutation-specific T cellular (24/30 (80%)) or humoral (26/30 patients (87%)) immune responses not detectable before vaccination. Until end of study no deaths were observed. 4/32 (12.5 %) patients had PD according to RANO criteria, all other patients (N=28, 87.5%) had SD. 12/32 (37.5%) patients displayed pseudoprogressions after the initiation of the vaccine. Single-cell T cell receptor (TCR) sequencing allowed for the identification of IDH1R132H-specific TCRs. CONCLUSION: NOA-16 met its primary endpoints by demonstrating safety and immunogenicity of a mutation-specific IDH1R132H peptide vaccine given with standard of care in patients with newly diagnosed IDH1R132H mutant malignant astrocytoma.

Despite the long-standing recognition that the immune response to acute myocardial injury contributes to adverse left ventricular (LV) remodeling, it has not been possible to effectively target this clinically. Using 2 different in vivo models of acute myocardial injury, we show that pirfenidone confers beneficial effects in the murine heart through an unexpected mechanism that depends on cardiac B lymphocytes. Naive hearts contained a large population of CD19+CD11b-CD23-CD21-IgD+IgMlo lymphocytes, and 2 smaller populations of CD19+CD11b+ B1a and B1b cells. In response to tissue injury, there was an increase in neutrophils, monocytes, macrophages, as well as an increase in CD19+ CD11b- B lymphocytes. Treatment with pirfenidone had no effect on the number of neutrophils, monocytes, or macrophages, but decreased CD19+CD11b- lymphocytes. B cell depletion abrogated the beneficial effects of pirfenidone. In vitro studies demonstrated that stimulation with lipopolysaccharide and extracts from necrotic cells activated CD19+ lymphocytes through a TIRAP-dependent pathway. Treatment with pirfenidone attenuated this activation of B cells. These findings reveal a previously unappreciated complexity of myocardial B lymphocytes within the inflammatory infiltrate triggered by cardiac injury and suggest that pirfenidone exerts beneficial effects in the heart through a unique mechanism that involves modulation of cardiac B lymphocytes.

Left ventricular assist devices (LVADs) improve survival and quality of life in patients with advanced heart failure. Despite these benefits, combined post- and precapillary pulmonary hypertension can be particularly problematic in patients on LVAD support, often exacerbating right ventricular (RV) dysfunction. Both persistently elevated pulmonary vascular resistance and RV dysfunction are associated with adverse outcomes, including death after LVAD. These observations have led to significant interest in the use of pulmonary vasodilators to treat pulmonary hypertension and preserve RV function among LVAD-supported patients. Although pulmonary vasodilators are commonly used for the treatment of pulmonary hypertension and RV dysfunction in LVADs, the benefits of this practice remain unclear. The purpose of this review is to highlight the current challenges in managing pulmonary vascular disease and RV dysfunction in patients with heart failure on LVAD support.

Urinary tract infections (UTIs) are frequent, commonly recurrent, and costly. Deficiency in a key autophagy protein, ATG16L1, protects mice from infection with the predominant bacterial cause of UTIs, Uropathogenic E. coli (UPEC). Here, we report that loss of ATG16L1 in macrophages accounts for this protective phenotype. Compared with wild-type macrophages, macrophages deficient in ATG16L1 exhibit increased uptake of UPEC and enhanced secretion of interleukin-1β (IL-1β). The increased IL-1β production is dependent upon activation of the NLRP3 inflammasome and caspase-1. IL-1β secretion was also enhanced during UPEC infection of ATG16L1-deficient mice in vivo, and inhibition of IL-1β signaling abrogates the ATG16L1-dependent protection from UTIs. Our results argue that ATG16L1 normally suppresses a host-protective IL-1β response to UPEC by macrophages.

The number of patients supported with left ventricular assist devices (LVADs) is rising rapidly, and noncardiac surgery (NCS) in these patients presents unique challenges. Given the controversy regarding the safety and timing of elective NCS, we performed a systematic review examining the perioperative morbidity and mortality of NCS in stable patients with LVADs. The published literature was searched using strategies created by a medical librarian. All reports involving five or more patients with implanted LVAD undergoing NCS were eligible for inclusion. One hundred and sixty one patients who underwent 252 surgeries were included from seven studies. Cohort size ranged from 8 to 47 patients undergoing 12 to 67 NCS. Median age ranged from 50.1 to 68 years and 75 to 100% were male. Thirty day postoperative mortality ranged from 6.4 to 16.7%, although four studies reported no deaths. Due to the small number of included studies with relative few patients and widely heterogeneous reporting of outcomes a formal quantitative meta-analysis was not performed. Noncardiac surgery in patients with LVADs appears to be safe and feasible in select patients. Future studies should use standard study design and reporting parameters to facilitate the systematic examination of safety and outcomes for elective NCS in LVAD patients.

Summary Introduction Secondary pulmonary hypertension (PH) and right ventricular dysfunction are common and associated with poor prognosis in HF patients with left ventricular assist devices (LVADs). The role of pulmonary vasodilator therapy for these patients is currently unclear. Aims We sought to evaluate the safety and clinical course of patients treated with bosentan, an endothelin receptor antagonist, after the implementation of a LVAD. Results Between 10/2008 and 5/2011, 50 consecutive patients with mean PAP >25 mmHg were treated with bosentan after LVAD implantation for a mean duration of 15.7 (±12.4) months. Ten patients discontinued the drug for possible side effects, including three for LFT abnormalities. Comparison of baseline to 6-month follow-up data revealed laboratory evidence for decongestion with a decrease in bilirubin (2.3–0.6, P

Despite evidence that pharmacogenetics can improve tamoxifen pharmacotherapy, there are few studies with American Indian and Alaska Native (AIAN) people. We examined variation in cytochrome P450 (CYP) genes (CYP2D6, CYP3A4, CYP3A5, and CYP2C9) and tamoxifen biotransformation in AIAN patients with breast cancer (n = 42) from the Southcentral Foundation in Alaska and the Confederated Salish and Kootenai Tribes in Montana. We tested for associations between CYP diplotypes and plasma concentrations of tamoxifen and metabolites. Only the CYP2D6 variation was significantly associated with concentrations of endoxifen (P = 0.0008) and 4‐hydroxytamoxifen (P = 0.0074), tamoxifen's principal active metabolites, as well as key metabolic ratios. The CYP2D6 was also the most significant predictor of active metabolites and metabolic ratios in a multivariate regression model, including all four genes as predictors, with minor roles for other CYP genes. In AIAN populations, CYP2D6 is the largest contributor to tamoxifen bioactivation, illustrating the importance of validating pharmacogenetic testing for therapy optimization in an understudied population.

Right heart failure is a potentially devastating complication of mechanical circulatory support, occurring at a rate of 0.49 events per 100 patient-months. Pulmonary vasodilators such as phosphodiesterase-5 inhibitors (PDE5i) have been frequently used to unload the right ventricle in left ventricular assist device (LVAD) patients, but there is scant evidence to support this practice., The purpose of this analysis is to provide additional data regarding the safety and efficacy of the PDE5i sildenafil in a real world population of patients supported with LVADs at Washington University in St. Louis. Sildenafil use was not associated with differences in gastrointestinal (GI) bleeding, stroke, mortality, heart failure (HF) admission, or orthotopic heart transplantation (OHT).

Background Published data from UNOS demonstrated that donor hearts with transient LV dysfunction can be used without increasing the risk of poor transplant outcomes, but account for less than 3% of allocated donors. Our organ procurement organization (OPO) utilizes a centralized treatment and recovery facility allowing for aggressive protocol driven management and frequent assessment of organ function early after brain death declaration. Methods We retrospectively reviewed our OPO experience with cardiac allograft donors from 2013-2017. Clinical data (patient demographics, cause of death, medical management, biomarkers, and serial echocardiographic imaging) were extracted from the OPO EMR for all 168 allocated cardiac donors during this time period. Improved LV systolic function was defined as an initial LVEF ≤40% which later improved to ≥50% consistent with the definition used in the prior UNOS analysis. Results We found that 23% (38/168) of allocated cardiac allografts from our OPO had transient LV dysfunction with an EF ≤40% on the initial echocardiogram. This rate was consistent over the years examined. Moreover 55% of donors had an initial echocardiogram with an EF of less than 50%. Comparison of donors with an initial EF ≤40% to donors with normal LV function on initial examination revealed minimal differences. There was no difference in the average age or sex between the two groups. No differences were found in the dose of vasopressors used either at the time of arrival to the facility or at organ harvest. The average amount of blood transfused was not different between the two groups. Although peak ALT was significantly higher in donors with transient LV dysfunction (402 vs 175 Units/L), there was no differences found in peak AST, troponin, lactate, or creatinine. Conclusion We found a markedly higher percentage of cardiac donors with transient LV dysfunction in allografts coming from our OPO facility compared to the UNOS database. The extent to which this reflects increased recognition versus increased organ yield is unknown at this time. These donors did not differ significantly from donors with normal LV function on initial examination. Coupled with prior data that showed equivalent outcomes in donors with recovered LV function, these data suggest that additional efforts to recover cardiac allografts initially found to have LV dysfunction could be an important means of increasing the donor pool and further work is ongoing to understand the most important factors in the recovery process.

Purpose Pulmonary arterial catheters (PAC) are valuable tools for guiding heart failure management and evaluating patients for advanced therapies. Although several hemodynamically-derived indices have prognostic value in patients with advanced heart failure, the short-term variance that can be seen in these measurements has not been well described. This study aimed to determine short-term variations in hemodynamic measurements and associated indices among heart failure patients. Methods Patients undergoing clinically-indicated PAC placement at our institution from April 2018 with serial hemodynamic measurements were prospectively recruited. Hemodynamics and clinical variables were collected at the time 0 and again at 24 hours. Hemodynamic indices frequently used to assess the right ventricle, including pulmonary artery pulsatility index (PAPi), right atrial pressure (RAP) to pulmonary capillary wedge pressure (PCWP) ratio, and transpulmonary gradient were also calculated for both time points. Results Data was available for 57 patients with an average of age 58.3 years. Compared to baseline measurements, 24-hour data revealed a significant reduction in RAP (-1.6 mmHg; p= Conclusion Our single-center experience with short-term hemodynamic measurements revealed improvement in filling pressures over 24 hours. Notably, in patients with initially elevated RAP, PAPi significantly improved. Such findings demonstrate that PAPi's utility as a risk prediction index must be considered in the context of its variability based on loading conditions, rather than as a static value.

Purpose Invasive hemodynamic monitoring with Swan-Ganz catheters (SGC) provides clinical information that can help guide heart failure management and inform decisions regarding advanced heart failure therapies. However, measurements in the cardiac catheterization laboratory (CCL) can potentially be affected by anxiety, stress, and colder temperatures. To address the magnitude of this effect, we investigated the magnitude of variation in hemodynamics between the CCL and the cardiac care unit (CCU). Methods We prospectively enrolled patients who underwent SGC placement in the CCL and then were moved to the cardiac care unit (CCU) for continuous hemodynamic monitoring. Hemodynamic measurements obtained in CCL were compared to on arrival to the CCU before the initiation of additional medical interventions. Results Data was obtained from 53 patients with heart failure [58.8 ± 13 years; 17% female; LVEF 20% ± 12%] who had leave-in SGCs placed since April 2018. Compared to the CCU, patients in the CCL were found to have higher biventricular filling pressures, systemic vascular resistance (p pulmonary vascular resistance (p Conclusion Invasive hemodynamic measurements obtained from patients with heart failure in the CCL are significantly worse than those obtained hours later in the CCU environment. In patients that have unfavorable hemodynamics in the CCL, there may be utility in reassessing parameters in an inpatient setting to optimize patient management.

Antibody-mediated rejection (AMR) after cardiac transplantation is associated with significant mortality, and the optimal treatment of this condition is poorly defined. Rituximab has been used successfully for the treatment for antibody-mediated diseases; however, its role in AMR is unclear. We review our experience with rituximab in patients with cardiac allograft AMR. We conducted a retrospective analysis of cardiac transplant patients with a diagnosis of AMR from 2001 to 2011. Inclusion criteria were clinical suspicion of rejection with the presence of C4d complement staining on endomyocardial biopsy and the absence of cellular rejection of grade 2R or greater. Patients were divided into Rituximab and NoRituximab groups. The primary endpoint was all-cause mortality. Secondary endpoints were infection, change in ejection fraction (EF), and rehospitalization. Thirty-three patients met inclusion criteria, of whom 13 received rituximab and 20 did not. Baseline characteristics were similar between groups. Kaplan-Meier curves for a three-yr follow-up period demonstrate improved survival in the Rituximab group (p = 0.0089). There were no differences in secondary endpoints. We found that rituximab therapy was associated with improved survival in cardiac allograft AMR. Further prospective, randomized studies in larger patient populations are needed to confirm this finding and to define ideal timing for rituximab administration.