Alterations in Sarcopenia Index are Associated with Inflammation, Gut and Oral Microbiota among Heart Failure, Left Ventricular Assist Device and Heart Transplant Patients.

BACKGROUND: Sarcopenia, characterized by loss of muscle mass and function, is prevalent in heart failure (HF) and predicts poor outcomes. We investigated alterations in sarcopenia index (SI), a surrogate for skeletal muscle mass, in HF, left ventricular assist device (LVAD) and heart transplant (HT), and assessed its relationship with inflammation and digestive tract (gut and oral) microbiota. METHODS: We enrolled 460 HF, LVAD and HT patients. Repeated measures pre/post procedures were obtained prospectively in a subset of LVAD and HT patients. SI (serum Creatinine/Cystatin C) and inflammatory biomarkers (C-reactive protein, interleukin-6, tumor necrosis factor-alpha) were measured in 271 and 622 blood samples, respectively. Gut and saliva microbiota were assessed via 16S rRNA sequencing among 335 stool and 341 saliva samples. Multivariable regression assessed the relationship between SI and i) New York Heart Association class; ii) pre- vs. post-LVAD or HT; iii) biomarkers of inflammation and microbial diversity. RESULTS: Median (interquartile range) natural logarithm (ln)-SI was -0.13 (-0.32,0.05). Ln-SI decreased across worsening HF class, further declined at 1-month after LVAD and HT and rebounded over time. Ln-SI was correlated with inflammation (r=-0.28, p<0.01), and gut (r=0.28, p<0.01) and oral microbial diversity (r=0.24, p<0.01), these associations remained significant after multivariable adjustment in the combined cohort but not for all individual cohorts. Presence of the gut taxa Roseburia inulinivorans was associated with increased SI. CONCLUSIONS: SI levels decreased in symptomatic HF and remained decreased long-term after LVAD and HT. In the combined cohort, SI levels covaried with inflammation in a similar fashion and significantly related to overall microbial (gut and oral) diversity, including specific taxa compositional changes.

Extracellular Vesicles and Immunity: At the Crossroads of Cell Communication.

Extracellular vesicles (EVs), comprising exosomes and microvesicles, are small membranous structures secreted by nearly all cell types. They have emerged as crucial mediators in intercellular communication, playing pivotal roles in diverse physiological and pathological processes, notably within the realm of immunity. These roles go beyond mere cellular interactions, as extracellular vesicles stand as versatile and dynamic components of immune regulation, impacting both innate and adaptive immunity. Their multifaceted involvement includes immune cell activation, antigen presentation, and immunomodulation, emphasising their significance in maintaining immune homeostasis and contributing to the pathogenesis of immune-related disorders. Extracellular vesicles participate in immunomodulation by delivering a wide array of bioactive molecules, including proteins, lipids, and nucleic acids, thereby influencing gene expression in target cells. This manuscript presents a comprehensive review that encompasses in vitro and in vivo studies aimed at elucidating the mechanisms through which EVs modulate human immunity. Understanding the intricate interplay between extracellular vesicles and immunity is imperative for unveiling novel therapeutic targets and diagnostic tools applicable to various immunological disorders, including autoimmune diseases, infectious diseases, and cancer. Furthermore, recognising the potential of EVs as versatile drug delivery vehicles holds significant promise for the future of immunotherapies.

Lung-to-Heart Nano-in-Micro Peptide Promotes Cardiac Recovery in a Pig Model of Chronic Heart Failure.

BACKGROUND: The lack of disease-modifying drugs is one of the major unmet needs in patients with heart failure (HF). Peptides are highly selective molecules with the potential to act directly on cardiomyocytes. However, a strategy for effective delivery of therapeutics to the heart is lacking. OBJECTIVES: In this study, the authors sought to assess tolerability and efficacy of an inhalable lung-to-heart nano-in-micro technology (LungToHeartNIM) for cardiac-specific targeting of a mimetic peptide (MP), a first-in-class for modulating impaired L-type calcium channel (LTCC) trafficking, in a clinically relevant porcine model of HF. METHODS: Heart failure with reduced ejection fraction (HFrEF) was induced in Göttingen minipigs by means of tachypacing over 6 weeks. In a setting of overt HFrEF (left ventricular ejection fraction [LVEF] 30% ± 8%), animals were randomized and treatment was started after 4 weeks of tachypacing. HFrEF animals inhaled either a dry powder composed of mannitol-based microparticles embedding biocompatible MP-loaded calcium phosphate nanoparticles (dpCaP-MP) or the LungToHeartNIM only (dpCaP without MP). Efficacy was evaluated with the use of echocardiography, invasive hemodynamics, and biomarker assessment. RESULTS: DpCaP-MP inhalation restored systolic function, as shown by an absolute LVEF increase over the treatment period of 17% ± 6%, while reversing cardiac remodeling and reducing pulmonary congestion. The effect was recapitulated ex vivo in cardiac myofibrils from treated HF animals. The treatment was well tolerated, and no adverse events occurred. CONCLUSIONS: The overall tolerability of LungToHeartNIM along with the beneficial effects of the LTCC modulator point toward a game-changing treatment for HFrEF patients, also demonstrating the effective delivery of a therapeutic peptide to the diseased heart.

Experimentally Induced Peripheral Venous Congestion Exacerbates Inflammation, Oxidative Stress, and Neurohormonal and Endothelial Cell Activation in Patients With Systolic Heart Failure.

BACKGROUND: Venous congestion (VC) is a hallmark of symptomatic heart failure (HF) requiring hospitalization; however, its role in the pathogenesis of HF progression remains unclear. We investigated whether peripheral VC exacerbates inflammation, oxidative stress and neurohormonal and endothelial cell (EC) activation in patients with HF with reduced ejection fraction (HFrEF). METHODS AND RESULTS: Two matched groups of patients with HFrEF and with no peripheral VC vs without recent HF hospitalization were studied. We modeled peripheral VC by inflating a cuff around the dominant arm, targeting ∼ 30 mmHg increase in venous pressure (venous stress test [VST]). Blood and ECs were sampled before and after 90 minutes of VST. We studied 44 patients (age 53 ± 12 years, 32% female). Circulating endothelin-1, tumor necrosis factor-α, interleukin-6, isoprostane, angiotensin II (ang-2), angiopoietin-2, vascular cell adhesion molecule-1, and CD146 significantly increased after the VST. Enhanced endothelin-1 and angiopoietin-2 responses to the VST were present in patients with vs without recent hospitalization and were prospectively associated with incident HF-related events; 6698 messenger ribonucleic acid (mRNA probe sets were differentially expressed in ECs after VST. CONCLUSIONS: Experimental VC exacerbates inflammation, oxidative stress, neurohormonal and EC activation and promotes unfavorable transcriptome remodeling in ECs of patients with HFrEF. A distinct biological sensitivity to VC appears to be associated with high risk for HF progression.

The environmental pollutant BDE-47 modulates immune responses in invitro and in vivo murine models.

2,2',4,4'-tetra-bromodiphenyl ether (BDE-47) is widespread in the environment and biological samples. Its association with health risks is an increasing concern, yet information on BDE-47 immunotoxicity remains limited. This study investigated the impact of BDE-47 on innate and adaptive immune responses through in vitro and in vivo approaches. BDE-47's capacity to directly induce cell responses and modulate responses induced by known stimuli was studied in vitro using the RAW 264.7 murine macrophage cell line and spleen-derived lymphocytes, and in vivo using keyhole limpet hemocyanin (KLH)-immunized BALB/c mice orally administered (28 d) at dose levels (7.5, 15.0 and 30 mg/kg/bw/d) derived from relevant toxicokinetic data from rodent models. RAW 264.7 cells stimulated with lipopolysaccharide (LPS) and exposed to BDE-47 exhibited unchanged cell viability but decreased release of interleukin (IL)-6. Primary splenocytes from naïve mice stimulated with anti-CD3/anti-CD28 antibodies and exposed to BDE-47 showed a significant decrease of IL-17 A and IFNγ production. In vivo data showed that BDE-47 significantly reduced the KLH-specific antibody response. A generally decreasing trend of IFNγ, IL-10 and IL-5 production was observed after in vitro antigen-specific restimulation of spleen cells. Histopathological effects on liver, spleen, small intestine and thyroid were detected at the highest dose in the absence of general toxicity. In addition, the expression of Mm_mir155 and Mm_let7a was induced in livers of exposed mice. The data obtained in this study suggest that exposure to BDE-47 may perturb innate and adaptive immune responses, thus possibly decreasing resistance to bacterial and viral infections.

Comparing 3-year survival and readmissions between HeartMate 3 and heart transplant as primary treatment for advanced heart failure.

OBJECTIVE: To compare 3-year survival and readmissions of patients who received the HeartMate 3 (HM3) left ventricular assist device (LVAD) or underwent orthotopic heart transplantation (OHT) as primary treatment for advanced heart failure. METHODS: We retrospectively analyzed 381 adult patients who received an HM3 LVAD or were listed for OHT between January 2014 and March 2021 at our center. To minimize crossover bias, OHT recipients with a prior LVAD were excluded, and HM3 patients were censored at the time of transplant. Cohorts were propensity score-matched to reduce confounding variables. The primary outcome was 3-year survival, and the secondary outcome was mean cumulative all-cause unplanned readmission. RESULTS: The study population comprised 185 HM3 patients (49%) and 196 OHT patients (51%), with 104 propensity score-matched patients in each group. After propensity score matching, there was no statistical difference in 3-year survival (83.7% for HM3 vs 87.0% for OHT; P = .91; relative risk [RR], 1.00; 95% confidence interval [CI], 0.45-2.20). In the unmatched cohorts, patients age 18 to 49 years had comparable survival with HM3 and OHT (96.9% vs 95.9%; N = 91; P = 1.00; RR, 0.92; 95% CI, 0.09-9.78). Patients age 50+ years had slightly inferior survival with HM3 (75.0% vs 83.9%; N = 290; P = .60; RR, 1.51; 95% CI, 0.85-2.68). The mean number of readmissions at 3 years was higher in the HM3 group (3.89 vs 2.05; P < .001). CONCLUSIONS: This exploratory analysis suggests that for similar patients, HM3 may provide comparable 3-year survival to OHT as a primary treatment for heart failure but may result in more readmissions.

In Vitro Assessment of Cisplatin/Hyaluronan Complex for Loco-Regional Chemotherapy.

Loco-regional chemotherapy is a strategy used to achieve more precise anticancer drug effect directly on tumor mass, while decreasing whole body exposure, which can lead to undesirable side effects. Thus, the loco-regional chemotherapy is conceptually similar to the targeted drug delivery systems for delivering chemotherapeutics to cancer cells in a certain location of the body. Recently, it has been demonstrated that a novel polymeric film containing the complex between cisplatin (cisPt) and hyaluronan (sodium salt of hyaluronic acid; NaHA) enhanced in vivo efficacy and safety of cisplatin (cisPt) by loco-regional delivery in pleural mesothelioma. Biologically, hyaluronic acid (HA) binds with the CD44 receptor, which is a transmembrane glycoprotein overexpressed by other cancer cells. Thus, administering both cisPt and hyaluronan together as a complex loco-regionally to the tumor site could target cancer cells locally and enhance treatment safety. A slight excess of hyaluronan was required to have more than 85% cisPt complexation. In cell monolayers (2D model) the cisPt/NaHA complex in solution demonstrated dose- and time-dependent cytotoxic effect by decreasing the viability of pancreatic, melanoma, and lung cell lines (they all express CD44). At the same concentration in solution, the complex was as effective as cisPt alone. However, when applied as film to melanoma spheroids (3D model), the complex was superior because it prevented the tumor spheroid growth and, more importantly, the formation of new cell colonies. Hence, cisPt/NaHA complex could work in preventing metastases loco-regionally and potentially avoiding systemic relapses.

The utilization of molecular microscope in management of heart transplant recipients in the era of noninvasive monitoring.

INTRODUCTION: Monitoring for graft rejection is a fundamental tenet of post-transplant follow-up. In heart transplantation (HT) in particular, rejection has been traditionally assessed with endomyocardial biopsy (EMB). EMB has potential complications and noted limitations, including interobserver variability in interpretation. Additional tests, such as basic cardiac biomarkers, cardiac imaging, gene expression profiling (GEP) scores, donor-derived cell-free DNA (dd-cfDNA) and the novel molecular microscope diagnostic system (MMDx) have become critical tools in rejection surveillance beyond standard EMB. METHODS: This paper describes an illustrative case followed by a review of MMDx within the context of other noninvasive screening modalities for rejection. CONCLUSIONS: We suggest MMDx be used to assist with early detection of rejection in cases of discordance between EMB and other noninvasive studies.

Does lateral approach preserve the right ventricular function after HeartMate 3 insertion?

OBJECTIVES: Lateral thoracotomy (LT) approach may preserve the right ventricular (RV) function after left ventricular assist device (LVAD) implantation. This study evaluated the short- and long-term RV function using echocardiography after LVAD implantation via LT or median sternotomy (sternotomy). METHODS: The patients who underwent HeartMate 3 implantation were retrospectively reviewed. The RV function was assessed before and 1 month and 1 year after LVAD implantation. The primary and secondary outcomes were all-cause mortality and a composite of death or readmission due to RV failure, respectively. RESULTS: Of the 195 patients, 55 (28%) underwent LT and 140 (72%) underwent sternotomy. There were no significant differences in the preoperative RV geometry or function. One month after the LVAD implantation, the LT group had a smaller RV end-diastolic dimension [42 (29-48) vs 47 (42-52) mm; P = 0.003] and RV end-diastolic area [25 (21-28) vs 29 (24-36) cm2; P < 0.001] and a greater RV fractional area change [30 (25-34)% vs 28 (23-31)%; P = 0.04] and peak systolic tissue velocity [8 (7-9) vs 7 (6-8) cm/s; P = 0.01]. Twenty-four patients died and 46 met the composite end point. Kaplan-Meier curve analysis did not reveal significant differences between LT and sternotomy in the 2-year survival (93% vs 83%; log-rank test, P = 0.28) and adverse event rate (76% vs 71%; log-rank test, P = 0.65). CONCLUSIONS: LT approach yielded a better-preserved RV function at 1 month; however, there were no significant differences in the 2-year survival and adverse event rates.

Preoperative left ventricular diastolic dimension index is associated with outcomes after HeartMate 3 implantation.

OBJECTIVES: We investigated the association between indexed left ventricular diastolic dimension and clinical outcomes after HeartMate 3 implantation. METHODS: We retrospectively reviewed patients implanted with the HeartMate 3 at our centre between November 2014 and September 2021. Left ventricular diastolic dimension was assessed via preoperative transthoracic echocardiography and left ventricular diastolic dimension index was calculated as left ventricular diastolic dimension/body surface area. The primary outcome was a composite of death or readmission due to right heart failure or stroke. The cut-off left ventricular diastolic dimension index value most closely associated with outcomes was determined by receiver-operating characteristic curve and restricted cubic spline analyses. RESULTS: Left ventricular diastolic dimension index measurements were available for 252 of 253 (99.6%) patients. Using a left ventricular diastolic dimension index cut-off value of 33.5 mm/m2, the cohort was divided: left ventricular diastolic dimension index ≤ (n = 131) or > (n = 121) 33.5 mm/m2. While there were no significant differences in age, INTERMACS level and preoperative haemodynamics between groups, patients with smaller left ventricular diastolic dimension index were more likely to have a larger body surface area (2.1 vs 1.9 m2, P < 0.001), ischaemic cardiomyopathy [64 (49%) vs 40 (33%), P = 0.01] and smaller left atrium volume index [40.5 (32.3-54.0) ml/m2 vs 54.0 (43.0-66.8) ml/m2, P < 0.001]. Smaller left ventricular diastolic dimension index patients had significantly worse survival (74% vs 88%, log-rank P = 0.009) and freedom from adverse events (55% vs 73%, log-rank P = 0.005) at 3-year follow-up. Smaller left ventricular diastolic dimension index was independently associated with the composite outcome (Hazard ratio 2.24, P = 0.002). CONCLUSIONS: Smaller preoperative left ventricular diastolic dimension index is associated with worse outcomes in patients undergoing HeartMate 3 implantation.

Inhalable Microparticles Embedding Biocompatible Magnetic Iron-Doped Hydroxyapatite Nanoparticles.

Recently, there has been increasing interest in developing biocompatible inhalable nanoparticle formulations, as they have enormous potential for treating and diagnosing lung disease. In this respect, here, we have studied superparamagnetic iron-doped calcium phosphate (in the form of hydroxyapatite) nanoparticles (FeCaP NPs) which were previously proved to be excellent materials for magnetic resonance imaging, drug delivery and hyperthermia-related applications. We have established that FeCaP NPs are not cytotoxic towards human lung alveolar epithelial type 1 (AT1) cells even at high doses, thus proving their safety for inhalation administration. Then, D-mannitol spray-dried microparticles embedding FeCaP NPs have been formulated, obtaining respirable dry powders. These microparticles were designed to achieve the best aerodynamic particle size distribution which is a critical condition for successful inhalation and deposition. The nanoparticle-in-microparticle approach resulted in the protection of FeCaP NPs, allowing their release upon microparticle dissolution, with dimensions and surface charge close to the original values. This work demonstrates the use of spray drying to provide an inhalable dry powder platform for the lung delivery of safe FeCaP NPs for magnetically driven applications.

The Difference Between Cystatin C- and Creatinine-Based Estimated GFR in Heart Failure With Reduced Ejection Fraction: Insights From PARADIGM-HF.

RATIONALE & OBJECTIVE: The clinical implications of the discrepancy between cystatin C (cysC)- and serum creatinine (Scr)-estimated glomerular filtration rate (eGFR) in patients with heart failure (HF) and reduced ejection fraction (HFrEF) are unknown. STUDY DESIGN: Post-hoc analysis of randomized trial data. SETTING & PARTICIPANTS: 1,970 patients with HFrEF enrolled in PARADIGM-HF with available baseline cysC and Scr measurements. EXPOSURE: Intraindividual differences between eGFR based on cysC (eGFRcysC) and Scr (eGFRScr; eGFRdiffcysC-Scr). OUTCOMES: Clinical outcomes included the PARADIGM-HF primary end point (composite of cardiovascular [CV] mortality or HF hospitalization), CV mortality, all-cause mortality, and worsening kidney function. We also examined poor health-related quality of life (HRQoL), frailty, and worsening HF (WHF), defined as HF hospitalization, emergency department visit, or outpatient intensification of therapy between baseline and 8-month follow-up. ANALYTICAL APPROACH: Fine-Gray subdistribution hazard models and Cox proportional hazards models were used to regress clinical outcomes on baseline eGFRdiffcysC-Scr. Logistic regression was used to investigate the association of baseline eGFRdiffcysC-Scr with poor HRQoL and frailty. Linear regression models were used to assess the association of WHF with eGFRcysC, eGFRScr, and eGFRdiffcysC-Scr at 8-month follow-up. RESULTS: Baseline eGFRdiffcysC-Scr was higher than +10 and lower than-10mL/min/1.73m2 in 13.0% and 35.7% of patients, respectively. More negative values of eGFRdiffcysC-Scr were associated with worse outcomes ([sub]hazard ratio per standard deviation: PARADIGM-HF primary end point, 1.18; P=0.008; CV mortality, 1.34; P=0.001; all-cause mortality, 1.39; P<0.001; worsening kidney function, 1.31; P=0.05). For a 1-standard-deviation decrease in eGFRdiffcysC-Scr, the prevalences of poor HRQoL and frailty increased by 29% and 17%, respectively (P≤0.008). WHF was associated with a more pronounced decrease in eGFRcysC than in eGFRScr, resulting in a change in 8-month eGFRdiffcysC-Scr of-4.67mL/min/1.73m2 (P<0.001). LIMITATIONS: Lack of gold-standard assessment of kidney function. CONCLUSIONS: In patients with HFrEF, discrepancies between eGFRcysC and eGFRScr are common and are associated with clinical outcomes, HRQoL, and frailty. The decline in kidney function associated with WHF is more marked when assessed with eGFRcysC than with eGFRScr. PLAIN-LANGUAGE SUMMARY: Kidney function assessment traditionally relies on serum creatinine (Scr) to establish an estimated glomerular filtration rate (eGFR). However, this has been challenged with the introduction of an alternative marker, cystatin C (cysC). Muscle mass and nutritional status have differential effects on eGFR based on cysC (eGFRcysC) and Scr (eGFRScr). Among ambulatory patients with heart failure enrolled in PARADIGM-HF, we investigated the clinical significance of the difference between eGFRcysC and eGFRScr. More negative values (ie, eGFRScr>eGFRcysC) were associated with worse clinical outcomes (including mortality), poor quality of life, and frailty. In patients with progressive heart failure, which is characterized by muscle loss and poor nutritional status, the decline in kidney function was more pronounced when eGFR was estimated using cysC rather than Scr.

Extracellular vesicles from PBDE-47 treated M(LPS) THP-1 macrophages modulate the expression of markers of epithelial integrity, EMT, inflammation and muco-secretion in ALI culture of airway epithelium.

AIMS: The lung epithelial cells form a physical barrier to the external environment acting as the first line of defence against potentially harmful environmental stimuli. These cells interact with several other cellular components, of which macrophages are some of the most relevant. We analysed the effects of the PBDE-47 on the microRNA cargo of THP-1 macrophage like derived small Extracellular Vesicles (sEVs) and the effects on A549 lung epithelial cells. MAIN METHODS: sEVs from M(LPS) THP-1 macrophage-like cells after PBDE-47 treatment (sEVsPBDE+LPS) were characterized by nanoparticle tracking analysis and their microRNA cargo studied by qPCR. Confocal microscopy was applied to study sEVs cellular uptake by A549 cells. The expression of tight junctions (TJs), adhesion molecules, inflammation markers and mucus production in A549 cultured in air liquid interface (ALI) conditions were studied by Real Time PCR and confocal microscopy. KEY FINDINGS: sEVsPBDE+LPS microRNA cargo analysis showed that the PBDE-47 modulated the expression of the miR-15a-5p, miR29a-3p, miR-143-3p and miR-122-5p. Furthermore, ALI cultured A549 cells incubated with sEVsPBDE+LPS showed that zonula occludens-1 (p ≤ 0.04), claudin (p ≤ 0.02), E-cadherin (p ≤ 0.006) and Vimentin (p ≤ 0.0008) mRNAs were increased in A549 cells after sEVsPBDE+LPS treatment. Indeed, Interleukin (IL)-8 (p ≤ 0.008) and mucin (MUC5AC and MUC5B) (p ≤ 0.03 and p ≤ 0.0001) mRNA expression were up- and down-regulated, respectively. SIGNIFICANCE: PBDE-47 treated macrophages secrete sEVs with altered microRNA cargo that affect the mRNA expression of TJs, adhesion molecules, cytokines and EMT markers damaging the normal function of the lung epithelium, potentially contributing to the development of lung diseases.

Impact of preheart transplant spirometry and DCLO measurement on post-transplant pulmonary outcomes.

BACKGROUND: Pulmonary function tests (PFT) are a frequent component of heart transplant evaluation. In cardiac surgery abnormal PFTs, especially reduced DLCO, have been associated with poor outcomes. We sought to evaluate the impact of pretransplant PFTs on post-transplant pulmonary outcomes and patient survival. METHODS: Among the 652 adult heart transplant recipients between January 1, 2010 and July 31, 2021, 462 had PFTs and constituted the patient cohort. Obstructive ventilatory defects (OVD), restrictive ventilatory defects (RVD), and reduced DLCO were defined according to established criteria. The primary outcome was the combined endpoint of a post-transplant pulmonary complication defined as reintubation, postoperative pneumonia, prolonged intubation, or tracheostomy. Secondary outcomes included 90-day all-cause mortality, length of stay, and the odds of individual pulmonary complications. Kaplan-Meier survival analysis, multivariable Cox proportional-hazards regression, and multivariable logistic regression were performed to compare outcomes between the groups. RESULTS: Patients with severe OVD (OR 1.48, 95% CI 1.18-5.23, p = 0.02) or severely reduced DLCO (OR 1.95, 95% CI 1.19-3.20, p = 0.008) had increased odds of post-transplant pulmonary complications. Following multivariable adjustment, severe OVD (aOR 2.67, 95% CI 1.15-6.19, p = 0.02) and severely reduced DLCO (aOR 1.79, 95% CI 1.05-3.04) remained strongly associated with post-transplant pulmonary complications. Patients with any degree of extrinsic RVD, moderate or less OVD, or moderately reduced DLCO or less did not have increased odds of post-transplant pulmonary complications. Ninety-day post-transplant survival was significantly reduced for both severe OVD (97.2% vs 86.5%, p = 0.04) and severely reduced DLCO (97.3% vs 90.4%, p = 0.004). Post-transplant ICU and hospital length of stay were nominally longer for both groups as well. CONCLUSIONS: Severe OVD or severely reduced DLCO on preheart transplant PFTs were associated with increased odds of post-transplant pulmonary complications and early mortality.

Outflow Graft Narrowing of the HeartMate 3 Left Ventricular Assist Device.

BACKGROUND: In patients with the HeartMate 3 (HM3, Abbott) left ventricular (LV) assist device (LVAD), outflow graft narrowing has been reported as a result of accumulation of biodebris either internal or external to the graft. This study describes the prevalence, imaging findings, and clinical outcomes associated with HM3 LVAD outflow graft narrowing. METHODS: A single-center retrospective cohort study was performed in patients who received an HM3 LVAD between November 2014 and July 2019. All patients with a computed tomographic (CT) angiogram or a CT scan with intravenous contrast sufficient to evaluate the outflow graft lumen were included. Narrowing was defined as a hypodensity of ≥3 mm. RESULTS: Of 165 HM3 LVAD recipients, 46 (28%) had qualifying imaging. Outflow graft narrowing was present in 33% (15/46). One patient had complete obstruction requiring emergency surgery, whereas 14 patients had a median hypodensity of 4.5 mm (interquartile range, 3.3-5.8 mm). The presence of outflow graft narrowing was significantly associated with a longer duration of LVAD support (588.2 ± 277.5 days vs 131.5 ± 170.9 days; P < .0001). One-year survival after identification of narrowing was 93%, with death occurring in 1 patient with complete obstruction. LV unloading (mean percent decrease in LV end-diastolic diameter at time of CT imaging vs pre-LVAD) was 16.7% vs 17.7% in patients with and without narrowing, respectively (P = .86). CONCLUSIONS: Among patients with adequate imaging, one-third have evidence of narrowing. Outflow graft narrowing secondary to biodebris was more likely to be found in HM3 LVAD recipients with longer duration of LVAD support. There was no significant difference in LV unloading between patients with and without narrowing.

Dominantly acting KIF5B variants with pleiotropic cellular consequences cause variable clinical phenotypes.

Kinesins are motor proteins involved in microtubule (MT)-mediated intracellular transport. They contribute to key cellular processes, including intracellular trafficking, organelle dynamics and cell division. Pathogenic variants in kinesin-encoding genes underlie several human diseases characterized by an extremely variable clinical phenotype, ranging from isolated neurodevelopmental/neurodegenerative disorders to syndromic phenotypes belonging to a family of conditions collectively termed as 'ciliopathies.' Among kinesins, kinesin-1 is the most abundant MT motor for transport of cargoes towards the plus end of MTs. Three kinesin-1 heavy chain isoforms exist in mammals. Different from KIF5A and KIF5C, which are specifically expressed in neurons and established to cause neurological diseases when mutated, KIF5B is an ubiquitous protein. Three de novo missense KIF5B variants were recently described in four subjects with a syndromic skeletal disorder characterized by kyphomelic dysplasia, hypotonia and DD/ID. Here, we report three dominantly acting KIF5B variants (p.Asn255del, p.Leu498Pro and p.Leu537Pro) resulting in a clinically wide phenotypic spectrum, ranging from dilated cardiomyopathy with adult-onset ophthalmoplegia and progressive skeletal myopathy to a neurodevelopmental condition characterized by severe hypotonia with or without seizures. In vitro and in vivo analyses provide evidence that the identified disease-associated KIF5B variants disrupt lysosomal, autophagosome and mitochondrial organization, and impact cilium biogenesis. All variants, and one of the previously reported missense changes, were shown to affect multiple developmental processes in zebrafish. These findings document pleiotropic consequences of aberrant KIF5B function on development and cell homeostasis, and expand the phenotypic spectrum resulting from altered kinesin-mediated processes.

Outcomes of treatment for deep left ventricular assist device infection.

OBJECTIVE: Among left ventricular assist device patients, the most commonly infected component is the drive line, which can be managed with antibiotics and local debridement. Infection of intrathoracic device components is less common but more difficult to manage. Herein we describe the incidence of deep device infection (DDI) at our center as well as management and outcomes. METHODS: We retrospectively reviewed 658 patients who underwent implantable left ventricular assist device insertion with HeartMate 2 (Abbott) or HeartMate 3 (Abbott) devices between January 2004 and June 2021. DDI was defined according to radiographic and clinical criteria. Cumulative incidence was calculated using a Fine-Gray subdistribution model; survival analysis was performed using the method of Kaplan and Meier. RESULTS: There were 32 (4.8%) DDIs during this study period. Drive line infection and re-exploration for bleeding were associated with development of DDI. Cumulative incidence of DDI increased over time, affecting 11% (7%-18%) at 5 years. The dominant microbes involved in DDI were Pseudomonas aeruginosa (19%) and methicillin-resistant Staphylococcus aureus (13%). Nineteen patients (59%) with device infection underwent device exchange, 6 (19%) underwent initial transplant, and 7 (22%) were treated solely with debridement and antibiotics. Of those who underwent device exchange, 12 (63%) developed reinfection of their new device and 6 underwent subsequent heart transplant. Patients who underwent transplantation for management of device infection had improved 5-year survival (80% vs 11%; P = .01) but 3 patients (25%) developed deep sternal wound infection after transplant. CONCLUSIONS: DDI is a rare but challenging complication in this destination era. Heart transplantation is the preferred management strategy for eligible patients but infectious complication is common.

Letermovir for cytomegalovirus prophylaxis in high-risk heart transplant recipients.

Letermovir is a novel agent for the prevention of cytomegalovirus (CMV) infection and disease that, unlike traditional CMV DNA polymerase inhibitors, does not carry the risk of myelosuppression. The purpose of this study was to evaluate the safety, efficacy, and clinical application of letermovir for CMV prophylaxis in heart transplant (HT) recipients. Between November 1, 2019, and October 1, 2021, at a single, tertiary care hospital, 17 HT recipients were initiated on letermovir due to leukopenia while on valganciclovir. Fifteen (88%) had high-risk mismatch (CMV D+/R-). Median time on letermovir was 5 months (interquartile range, 2-8 months.) At the end of the study period, nine of 17 patients (52.9%) were still on letermovir and four of the 17 (23.5%) had successfully completed the prophylaxis window on letermovir and been switched to the pre-emptive strategy. One patient developed clinically significant CMV viremia in the setting of being unable to obtain medication due to insurance barriers but was later successfully restarted on letermovir. One patient was unable to tolerate letermovir due to symptoms of headache and myalgias. Two patients developed low-level non-clinically significant CMV viremia and were switched back to valacyclovir. All patients had tacrolimus dosages reduced at time of letermovir initiation to minimize the risk of supratherapeutic tacrolimus concentration. One patient required hospitalization due to symptomatic tacrolimus toxicity. For HT recipients who cannot tolerate valganciclovir, letermovir presents an alternative for CMV prophylaxis. Close monitoring for breakthrough CMV and calcineurin inhibitor levels is necessary. Larger studies are required to further delineate its use and help provide further evidence of its safety and efficacy.

Less is better? Comparing effects of median sternotomy and thoracotomy surgical approaches for left ventricular assist device implantation on postoperative outcomes and valvulopathy.

OBJECTIVE: Our objective was to compare outcomes after left ventricular assist device implantation performed via median sternotomy or lateral thoracotomy. METHODS: We retrospectively analyzed 222 adult patients with the HeartMate3 (Abbott Lab) left ventricular assist device implanted between November 2014 and November 2021. Outcomes stratified by surgical approach were evaluated in propensity score-matched groups. The primary outcome was 1-year survival. Secondary outcomes included in-hospital morbidity and mortality, readmissions, and significant valvular regurgitation. RESULTS: Our cohort consisted of 60 patients (27%) who underwent lateral thoracotomy and 162 patients (73%) who underwent median sternotomy. Propensity score matching compared 45 patients who underwent lateral thoracotomy with 68 patients who underwent median sternotomy. There were no differences in intensive care unit or hospital stay duration (median, 10 vs 11 days, P = .58; 46 vs 40 days, P = .279), time to extubation (median, 2 days, P = .627), vasoactive-inotropic scores at intensive care unit arrival (18.20 vs 16.60, P = .654), or in-hospital mortality (2 [5%] vs 4 [6.1%] patients, P = 1). One-year survival (95.56% vs 90.61%, P = .48) and all-cause hospital readmission rate (Gray's test: P = .532) were also comparable. Patients who underwent lateral thoracotomy had significantly less early right ventricular failure (24.4% vs 53.7%, P = .004), although they had more follow-up tricuspid regurgitation (17.6% vs 0%, P = .030) and volume overload readmissions (Gray's test: P = .0005). CONCLUSIONS: Our data suggest that lateral thoracotomy is a safe although not necessarily superior alternative to median sternotomy for HeartMate 3 implantation in the perioperative and postoperative periods, because it precludes concomitant tricuspid valve repairs and may be associated with increased risk of late tricuspid regurgitation and volume overload readmissions.

Alterations in the kallikrein-kinin system predict death after heart transplant.

Heart transplantation remains the definitive treatment for end stage heart failure. Because availability is limited, risk stratification of candidates is crucial for optimizing both organ allocations and transplant outcomes. Here we utilize proteomics prior to transplant to identify new biomarkers that predict post-transplant survival in a multi-institutional cohort. Microvesicles were isolated from serum samples and underwent proteomic analysis using mass spectrometry. Monte Carlo cross-validation (MCCV) was used to predict survival after transplant incorporating select recipient pre-transplant clinical characteristics and serum microvesicle proteomic data. We identified six protein markers with prediction performance above AUROC of 0.6, including Prothrombin (F2), anti-plasmin (SERPINF2), Factor IX, carboxypeptidase 2 (CPB2), HGF activator (HGFAC) and low molecular weight kininogen (LK). No clinical characteristics demonstrated an AUROC > 0.6. Putative biological functions and pathways were assessed using gene set enrichment analysis (GSEA). Differential expression analysis identified enriched pathways prior to transplant that were associated with post-transplant survival including activation of platelets and the coagulation pathway prior to transplant. Specifically, upregulation of coagulation cascade components of the kallikrein-kinin system (KKS) and downregulation of kininogen prior to transplant were associated with survival after transplant. Further prospective studies are warranted to determine if alterations in the KKS contributes to overall post-transplant survival.