Exosome Therapy for a Nonhealing Scalp Wound Following Chemoradiation and Surgical Therapy.

This case report describes the safety and utility of a noninvasive therapy, Purified Exosome Product (PEP), for poorly healing scalp wounds in the setting of prior chemoradiation and surgery. A man in his 60s with a history of high-grade angiosarcoma of the right temporoparietal scalp reconstruction had a 1-year history of 2 nonhealing scalp wounds after neoadjuvant chemotherapy followed by concurrent chemoradiation therapy, wide local excision, and latissimus dorsi free flap and split-thickness skin graft. The patient underwent débridement followed by 4 collagen (Bellafill)-PEP and 4 fibrin (Tisseel)-PEP applications during 7 months in 2022. Photographs of the area of exposed bone of the temporoparietal wound were measured and standardized by ImageJ open-source software. The frontal wound was not routinely measured and therefore was qualitatively assessed by reviewing photographs over time. The frontal wound completely healed, and the temporoparietal wound showed a 96% decrease in overall size. The patient had no adverse effects of treatment and continues to demonstrate ongoing healing. This case exhibits the safety and utility of topical PEP therapy for noninvasive treatment of poorly healing scalp wounds and offers the potential for an alternative treatment of patients who are poor candidates for additional surgical intervention.

Infliximab Limits Injury in Myocardial Infarction.

BACKGROUND: The purpose of this study was to investigate a therapeutic approach targeting the inflammatory response and consequent remodeling from ischemic myocardial injury. METHODS AND RESULTS: Coronary thrombus aspirates were collected from patients at the time of ST-segment-elevation myocardial infarction and subjected to array-based proteome analysis. Clinically indistinguishable at myocardial infarction (MI), patients were stratified into vulnerable and resilient on the basis of 1-year left ventricular ejection fraction and death. Network analysis from coronary aspirates revealed prioritization of tumor necrosis factor-α signaling in patients with worse clinical outcomes. Infliximab, a tumor necrosis factor-α inhibitor, was infused intravenously at reperfusion in a porcine MI model to assess whether infliximab-mediated immune modulation impacts post-MI injury. At 3 days after MI (n=7), infliximab infusion increased proregenerative M2 macrophages in the myocardial border zone as quantified by immunofluorescence (24.1%±23.3% in infliximab versus 9.29%±8.7% in sham; P<0.01). Concomitantly, immunoassays of coronary sinus samples quantified lower troponin I levels (41.72±7.34 pg/mL versus 58.11±10.75 pg/mL; P<0.05) and secreted protein analysis revealed upregulation of injury-modifying interleukin-2, -4, -10, -12, and -18 cytokines in the infliximab-treated cohort. At 4 weeks (n=12), infliximab treatment resulted in significant protective influence, improving left ventricular ejection fraction (53.9%±5.4% versus 36.2%±5.3%; P<0.001) and reducing scar size (8.31%±10.9% versus 17.41%±12.5%; P<0.05). CONCLUSIONS: Profiling of coronary thrombus aspirates in patients with ST-segment-elevation MI revealed highest association for tumor necrosis factor-α in injury risk. Infliximab-mediated immune modulation offers an actionable pathway to alter MI-induced inflammatory response, preserving contractility and limiting adverse structural remodeling.

Biventricular catheterization combined with pressure-volume loop monitoring provides insight into the dynamic effects of left ventricular assist devices ramp on right ventricular function.

Ramp studies are utilized for speed optimization of continuous flow left ventricular assist devices (CF-LVADs). We here report the utility of combined left and right heart catheterization during a ramp study to ensure a comprehensive understanding of the hemodynamic implications on both ventricles. Pressure-volume loop (PV loop) monitoring uncovered compromised systolic and mildly compromised right ventricular function with increasing LVAD speeds, despite improvement in left ventricular unloading. These findings informed patient management and highlight the potential utility of PV loop monitoring as an adjunct to left and right heart catheterization during ramp studies of next-generation LVADs.

Pulmonary Biodistribution of Platelet-Derived Regenerative Exosomes in a Porcine Model.

The purpose of this study was to evaluate the biodistribution of a platelet-derived exosome product (PEP), previously shown to promote regeneration in the setting of wound healing, in a porcine model delivered through various approaches. Exosomes were labeled with DiR far-red lipophilic dye to track and quantify exosomes in tissue, following delivery via intravenous, pulmonary artery balloon catheter, or nebulization in sus scrofa domestic pigs. Following euthanasia, far-red dye was detected by Xenogen IVUS imaging, while exosomal protein CD63 was detected by Western blot and immunohistochemistry. Nebulization and intravenous delivery both resulted in global uptake of exosomes within the lung parenchyma. However, nebulization resulted in the greatest degree of exosome uptake. Pulmonary artery balloon catheter-guided delivery provided the further ability to localize pulmonary delivery. No off-target absorption was noted in the heart, spleen, or kidney. However, the liver demonstrated uptake primarily in nebulization-treated animals. Nebulization also resulted in uptake in the trachea, without significant absorption in the esophagus. Overall, this study demonstrated the feasibility of pulmonary delivery of exosomes using nebulization or intravenous infusion to accomplish global delivery or pulmonary artery balloon catheter-guided delivery for localized delivery.

Nebulized platelet-derived extracellular vesicles attenuate chronic cigarette smoke-induced murine emphysema.

Chronic obstructive pulmonary disease (COPD) is a prevalent lung disease usually resulting from cigarette smoking (CS). Cigarette smoking induces oxidative stress, which causes inflammation and alveolar epithelial cell apoptosis and represents a compelling therapeutic target for COPD. Purified human platelet-derived exosome product (PEP) is endowed with antioxidant enzymes and immunomodulatory molecules that mediate tissue repair. In this study, a murine model of CS-induced emphysema was used to determine whether nebulized PEP can influence the development of CS-induced emphysema through the mitigation of oxidative stress and inflammation in the lung. Nebulization of PEP effectively delivered the PEP vesicles into the alveolar region, with evidence of their uptake by type I and type II alveolar epithelial cells and macrophages. Lung function testing and morphometric assessment showed a significant attenuation of CS-induced emphysema in mice treated with nebulized PEP thrice weekly for 4 weeks. Whole lung immuno-oncology RNA sequencing analysis revealed that PEP suppressed several CS-induced cell injuries and inflammatory pathways. Validation of inflammatory cytokines and apoptotic protein expression on the lung tissue revealed that mice treated with PEP had significantly lower levels of S100A8/A9 expressing macrophages, higher levels of CD4+/FOXP3+ Treg cells, and reduced NF-κB activation, inflammatory cytokine production, and apoptotic proteins expression. Further validation using in vitro cell culture showed that pretreatment of alveolar epithelial cells with PEP significantly attenuated CS extract-induced apoptotic cell death. These data show that nebulization of exosomes like PEP can effectively deliver exosome cargo into the lung, mitigate CS-induced emphysema in mice, and suppress oxidative lung injury, inflammation, and apoptotic alveolar epithelial cell death.

Novel Left Ventricular Unloading Strategies in Patients on Peripheral Venoarterial Extracorporeal Membrane Oxygenation Support.

The purpose of this study was to evaluate left ventricular (LV) unloading strategies in patients supported with peripheral venoarterial extracorporeal membrane oxygenation (VA-ECMO). A retrospective review was conducted of all consecutive patients requiring VA-ECMO support for any indication, who underwent novel LV unloading strategies with either direct left atrial venoarterial (LAVA) cannulation or pulmonary artery venoarterial (PAVA) venting, in comparison to Impella and intra-aortic balloon pump (IABP). The primary outcome was successful bridge to transplant, LV assist device, or myocardial recovery. Forty-six patients (63% male, mean age 52.8 ± 17.6 years) were included. Fourteen patients (30%) underwent novel unloading with either LAVA or PAVA, 11 patients (24%) underwent IABP placement, and 21 patients (46%) underwent Impella insertion. In the novel LV unloading cohort, 10 patients (71%) survived to hospital discharge. Four patients (29%) were weaned from ECMO and eight patients (57%) underwent cardiac transplantation. Although a trend favoring cannula-based unloading for the primary outcome was noted, the cohort was too small for statistical significance (79% LAVA/PAVA, 57% Impella, 45% IABP; p = 0.21). However, probability of survival was greater in the LAVA/PAVA cohort compared to Impella and IABP ( p < 0.05). Thus, we demonstrate the efficacy of LA and PA cannulation as an alternative LV unloading strategy for patients supported with peripheral VA-ECMO.

Cell Therapy Improves Quality-of-Life in Heart Failure: Outcomes From a Phase III Clinical Trial.

Patients with heart failure experience limitations in daily activity and poor quality-of-life. Prospective surveillance of health-related quality-of-life supplemented traditional death and hospitalization outcomes in the multinational, randomized, double-blinded CHART-1 clinical trial that assessed cardiopoiesis-guided cell therapy in ischemic heart failure patients with reduced left ventricular ejection fraction. The Minnesota Living with Heart Failure Questionnaire (MLHFQ), a Food and Drug Administration qualified instrument for evaluating therapeutic effectiveness, was applied through the 1-year follow-up. Cell treated (n = 109) and sham procedure (n = 140) cohorts reported improved MLHFQ scores comparable between the 2 study arms (mean treatment difference with baseline adjustment -3.2 points, P = .107). Superiority of cell treatment over sham in betterment of the MLHFQ score was demonstrated in patients with pre-existing advanced left ventricular enlargement (baseline-adjusted mean treatment difference -6.4 points, P = .009). In this highly responsive subpopulation, benefit on the MLHFQ score paralleled reduction in death and hospitalization post-cell therapy (adjusted Mann-Whitney odds 1.43, 95% CI, 1.01-2.01; P = .039). The potential of cell therapy in addressing the quality-of-life dimension of heart failure requires further evaluation for disease relief.

Inhibition of angiogenesis in the management of refractory gastrointestinal bleeding in patients with LVAD support.

BACKGROUND: Gastrointestinal bleeding (GIB) in patients with continuous flow left ventricular assist devices (CF-LVADs) is often related to GI angiodysplasia (GIAD). We previously reported data on VEGF inhibition with IV bevacizumab in the treatment of LVAD-associated GIAD bleeding, and now present follow-up data on patients treated with IV bevacizumab and/or low-dose oral pazopanib. METHODS: All consecutive adult patients with LVAD-associated GIB from GIAD treated with bevacizumab or pazopanib, from July 20, 2017 to June 22, 2022, were included in the analysis. Data on hospitalizations, GI endoscopic procedures, and blood transfusions were obtained from first admission for GIB up to a median of 35.7 months following treatment initiation (range 1.3-59.8 months). RESULTS: Eleven patients (91% male, mean 69.5 ± 8.9 years) were included. Eight patients (73%) received IV bevacizumab, two patients (18%) received oral pazopanib, and one patient (9%) received bevacizumab followed by pazopanib therapy. We observed a significantly decreased number of annualized hospitalizations for GIB (median difference - 2.87, p = 0.002), blood transfusions (median difference - 20.9, p = 0.01), and endoscopies (median difference - 6.95, p = 0.007) in patients pre- and post-anti-angiogenic therapy (bevacizumab and/or pazopanib). Similarly, a significant improvement in these clinical outcomes was noted in the bevacizumab group with decreased annualized hospitalizations (median difference - 2.75, p = 0.014), blood transfusions (median difference - 24.5, p = 0.047), and number of endoscopies (median differences -6.88, p = 0.006). CONCLUSION: Anti-angiogenic therapy with IV bevacizumab and/or low-dose oral pazopanib appears to provide benefits in patients with LVAD-associated GIB with reduced hospitalizations, blood transfusions, and need for GI endoscopic procedures.

A Comparative Study of Two Topical Treatments for Photoaging of the Hands.

BACKGROUND: Multiple effective treatments exist for correction of skin photoaging. Topical L-ascorbic acid (Vitamin C) is a well-known anti-oxidant and topical human platelet extract (HPE), a novel off-the-shelf cosmetic ingredient has shown positive results in recent clinical studies. HPE is a leukocyte-depleted allogeneic product derived from U.S.-sourced, pooled, apheresed platelets produced with consistent batch quality, purity, and effect. AIMS: The authors sought to characterize the effect of topical HPE (plated ) Intense Serum (Rion Aesthetics, Rochester, MN) compared to vitamin C (C E Ferulic® with 15% L-Ascorbic Acid, SkinCeuticals, L'Oréal, Paris) in skin rejuvenation of dorsal hands after 12 to 26-weeks twice daily use. METHODS: This prospective, longitudinal study sought to compare the effectiveness of two known treatments for skin rejuvenation. Evaluations at baseline, 6, 12, and 26 weeks included photo documentation to assess common skin concerns related to aging. RESULTS: For age-related skin appearance on the dorsal hands, topical HPE was non-inferior to topical vitamin C for improvement in brown spot fractional area, wrinkle fractional area, and improvement in luminosity at 12 weeks after twice-daily topical use. CONCLUSIONS: HPE performed as well as vitamin C to rejuvenate the skin on the dorsal hands after 12 to 26 weeks of twice daily topical use. Both topical serums may yield similar or superior results than invasive procedures, such as intense pulsed light (IPL), in reducing brown spots on the dorsal hands. These topical products work equally well in both sexes. Skin improvements lasted through 6 months.

Effect of Topical Platelet Extract Daily Serum as a Cosmetic Product to Reduce Facial Redness.

Objective: The primary objective of this pilot study was to demonstrate the benefits of topical human platelet extract (plated)™ serum for the improvement of persistent facial redness. Methods: This single-center, open-label pilot study evaluated six subjects using (plated)™ serum containing human platelet extract (HPE) with Renewosome™ technology twice daily for six weeks. The primary efficacy endpoint was a reduction in the Clinical Erythema Assessment (CEA) grade, and a reduction in Patient Subjective Assessment grade at six weeks. Secondary endpoints included an improvement in quality of life related to facial redness, and a reduction in redness by Mexameter™ spectrometry measurement. Safety data included monitoring for adverse events. Results: Topical HPE serum demonstrated a statistically significant improvement in facial redness at Week 9 when averaging the Mexameter™ spectrometry results across nine regions of the face (p=0.0052). The primary and secondary endpoints were achieved. CEA grade at Week 6 demonstrated that all subjects improved by at least one grade, while one subject improved by two grades. One patient reported dryness. No other adverse effects were observed. Limitations: Study limitations included a small sample size and lack of darker skin types (Fitzpatrick IV-VI). Conclusion: This study demonstrates that topical HPE with Renewosome™ technology provides statistically significant reduction in facial redness and is safe and well-tolerated.

A Ready-to-Use Purified Exosome Product for Volumetric Muscle Loss and Functional Recovery.

Large skeletal muscle defects owing to trauma or following tumor extirpation can result in substantial functional impairment. Purified exosomes are now available clinically and have been used for wound healing. The objective of this study was to evaluate the regenerative capacity of commercially available exosomes on an animal model of volumetric muscle loss (VML) and its potential translation to human muscle injury. An established VML rat model was used. In the in vitro experiment, rat myoblasts were isolated and cocultured with 5% purified exosome product (PEP) to validate uptake. Myoblast proliferation and migration was evaluated with increasing concentrations of PEP (2.5%, 5%, and 10%) in comparison with control media (F10) and myoblast growth medium (MGM). In the in vivo experiment, a lateral gastrocnemius-VML defect was made in the rat hindlimb. Animals were randomized into four experimental groups; defects were treated with surgery alone, fibrin sealant, fibrin sealant and PEP, or platelet-rich plasma (PRP). The groups were further randomized into four recovery time points (14, 28, 45, or 90 days). The isometric tetanic force (ITF), which was measured as a percentage of force compared with normal limb, was used for functional evaluation. Florescence microscopy confirmed that 5% PEP demonstrated cellular uptake ∼8-12 h. Compared with the control, myoblasts showed faster proliferation with PEP irrespective of concentration. PEP concentrations of 2.5% and 5% promoted myoblast migration faster compared with the control (<0.05). At 90 days postop, both the PEP and fibrin sealant and PRP groups showed greater ITF compared with control and fibrin sealant alone (<0.05). At 45 days postop, PEP with fibrin sealant had greater cellularity compared with control (<0.05). At 90 days postop, both PEP with fibrin sealant and the PRP-treated groups had greater cellularity compared with fibrin sealant and control (<0.05). PEP promoted myoblast proliferation and migration. When delivered to a wound with a fibrin sealant, PEP allowed for muscle regeneration producing greater functional recovery and more cellularity in vivo compared with untreated animals. PEP may promote muscle regeneration in cases of VML; further research is warranted to evaluate PEP for the treatment of clinical muscle defects.

Reconstituted Extracellular Vesicles from Human Platelets Decrease Viral Myocarditis in Mice.

Patients with viral myocarditis are at risk of sudden death and may progress to dilated cardiomyopathy (DCM). Currently, no disease-specific therapies exist to treat viral myocarditis. Here it is examined whether reconstituted, lyophilized extracellular vesicles (EVs) from platelets from healthy men and women reduce acute or chronic myocarditis in male mice. Human-platelet-derived EVs (PEV) do not cause toxicity, damage, or inflammation in naïve mice. PEV administered during the innate immune response significantly reduces myocarditis with fewer epidermal growth factor (EGF)-like module-containing mucin-like hormone receptor-like 1 (F4/80) macrophages, T cells (cluster of differentiation molecules 4 and 8, CD4 and CD8), and mast cells, and improved cardiac function. Innate immune mediators known to increase myocarditis are decreased by innate PEV treatment including Toll-like receptor (TLR)4 and complement. PEV also significantly reduces perivascular fibrosis and remodeling including interleukin 1 beta (IL-1ß), transforming growth factor-beta 1, matrix metalloproteinase, collagen genes, and mast cell degranulation. PEV given at days 7-9 after infection reduces myocarditis and improves cardiac function. MicroRNA (miR) sequencing reveals that PEV contains miRs that decrease viral replication, TLR4 signaling, and T-cell activation. These data show that EVs from the platelets of healthy individuals can significantly reduce myocarditis and improve cardiac function.

Clinical Significance of Biological Age in Patients Undergoing Percutaneous Coronary Intervention.

OBJECTIVE: To test whether biological age calculated using deficits, functional impairments, or their combination will provide improved estimation of long-term mortality among older adults undergoing percutaneous coronary intervention. PATIENTS AND METHODS: Cardiovascular deficits, noncardiovascular deficits, and functional impairments were prospectively studied in 535 patients aged 55 years or older from August 1, 2014, to March 31, 2018. Models for biological age included deficits (acquired, increase with age, associated with worse prognosis, did not saturate early), functional impairments (subjective-help with daily activities, difficulty with sensory input, continence, weight, balance, mobility; or objective-timed up and go, functional reach), or their combination. RESULTS: The mean ± SD age of the study patients was 72.1±9.5 years. For every 5-year increase in chronological age, the mean number of cardiovascular deficits increased from 2.36 among patients younger than 70 years to 3.44 in nonagenarians. The mean number of functional impairments increased from 2.15 for those younger than 70 years to 6.74 for nonagenarians. During a median follow-up of 2.05 years, 99 patients died. Significant improvement in the Harrell concordance index (C index) for prediction of long-term all-cause mortality was noted with biological age calculated from deficits and impairments compared with chronological age (0.77 vs 0.65; P<.001) and when estimating biological age via functional impairments alone vs chronological age (0.75 vs 0.65; P<.001) but not via deficits alone (0.71 vs 0.65; P=.08). Biological age estimates from subjective functional impairments captured most of the prognostic information related to all-cause and noncardiac mortality, whereas deficit-based estimation favored cardiovascular mortality. CONCLUSION: The derivation of biological age from deficits and functional impairments provides a major improvement in the estimation of survival as estimated by chronological age.

Safety and efficacy of human platelet extract in skin recovery after fractional CO2 laser resurfacing of the face: A randomized, controlled, evaluator-blinded pilot study.

BACKGROUND: Fractional carbon dioxide (CO2 ) laser resurfacing is used successfully for facial rejuvenation. Post procedure skincare is a variable that influences downtime caused by pain/tenderness, erythema, crusting, and bruising. AIMS: The primary objective of this pilot study was to demonstrate the benefits of human platelet extract (HPE) (plated)™ CALM Serum, a new topical cosmetic product, following fractionated CO2 ablative laser resurfacing treatment to the entire face versus standard of care. METHODS: In a single-center, randomized, evaluator-blinded pilot study, a total of 18 subjects were randomized into two groups, CO2 facial resurfacing followed by post-procedural standard of care (Stratacel silicone gel) or CO2 facial resurfacing with the addition of HPE renewosomes in the CALM Serum. RESULTS: CALM Serum demonstrated statistically significant less crusting at Day 10 compared to the control group (p = 0.0193) with less downtime in the first 14 days (p = 0.03). Subjects treated with CALM Serum had statistically significant brighter appearing skin at 14 days (p = 0.007) and more youthful looking skin on Days 14 and 30 (p = 0.003 and 0.04, respectively). CONCLUSIONS: This study demonstrates that Renewosome™ technology provides statistically significant post-laser clinical recovery over silicone gel for reducing crusting, and downtime. Subjects reported less diary days of symptoms of pain/tenderness, redness, crusting/flaking, bruising, and itching in the first 14 days compared to the control group. CALM also demonstrated statistically significant improvements in brighter and more youthful appearing skin. CALM is safe and well tolerated.

Percutaneous Mechanical Circulatory Support as a Bridge to Transplantation in Ebstein Anomaly.

Ebstein anomaly is a rare congenital heart defect occurring in 0.0005% of the population because of mispositioning and malformation of the tricuspid valve. Here, we present the first description and associated imaging of percutaneous mechanical circulatory support in the setting of cardiogenic shock secondary to Ebstein anomaly.

Artificial Intelligence-Derived Electrocardiogram Assessment of Cardiac Age and Molecular Markers of Senescence in Heart Failure.

OBJECTIVE: To ascertain whether heart failure (HF) itself is a senescent phenomenon independent of age, and how this is reflected at a molecular level in the circulating progenitor cell niche, and at a substrate level using a novel electrocardiogram (ECG)-based artificial intelligence platform. PATIENTS AND METHODS: Between October 14, 2016, and October 29, 2020, CD34+ progenitor cells were analyzed by flow cytometry and isolated by magnetic-activated cell sorting from patients of similar age with New York Heart Association functional classes IV (n = 17) and I-II (n = 10) heart failure with reduced ejection fraction and healthy controls (n = 10). CD34+ cellular senescence was quantitated by human telomerase reverse transcriptase expression and telomerase expression by quantitative polymerase chain reaction, and senescence-associated secretory phenotype (SASP) protein expression assayed in plasma. An ECG-based artificial intelligence (AI) algorithm was used to determine cardiac age and difference from chronological age (AI ECG age gap). RESULTS: CD34+ counts and telomerase expression were significantly reduced and AI ECG age gap and SASP expression increased in all HF groups compared with healthy controls. Expression of SASP protein was closely associated with telomerase activity and severity of HF phenotype and inflammation. Telomerase activity was more closely associated with CD34+ cell counts and AI ECG age gap. CONCLUSION: We conclude from this pilot study that HF may promote a senescent phenotype independent of chronological age. We show for the first time that the AI ECG in HF shows a phenotype of cardiac aging beyond chronological age, and appears to be associated with cellular and molecular evidence of senescence.

Risks of Right Heart Catheterization and Right Ventricular Biopsy: A 12-year, Single-Center Experience.

OBJECTIVE: To study the incidence of complications when undergoing right heart catheterization (RHC) and right ventricular biopsy (RVB). METHODS: Complications following RHC and RVB are not well reported. We studied the incidence of death, myocardial infarction, stroke, unplanned bypass, pneumothorax, hemorrhage, hemoptysis, heart valve repair/replacement, pulmonary artery perforation, ventricular arrhythmias, pericardiocentesis, complete heart block, and deep vein thrombosis (primary endpoint) following these procedures. We also adjudicated the severity of tricuspid regurgitation and causes of in-hospital death following RHC. Diagnostic RHC procedures, RVB, multiple right heart procedures alone or combined with left heart catheterization, and complications from January 1, 2002, through December 31, 2013, were identified using the clinical scheduling system and electronic records at Mayo Clinic, Rochester, Minnesota. International Classification of Diseases, Ninth Revision billing codes were used. Registration was queried to identify all-cause mortality. All clinical events and echocardiograms for worsening tricuspid regurgitation were reviewed and adjudicated. RESULTS: A total of 17,696 procedures were identified. Procedures were categorized into those undergoing RHC (n=5556), RVB (n=3846), multiple right heart catheterization (n=776), and combined right and left heart catheterization procedures (n=7518). Primary endpoint was seen in 21.6 and 20.8 of 10,000 procedures for RHC and RVB, respectively. There were 190 (1.1%) deaths during hospital admission and none was related to the procedure. CONCLUSION: Complications following diagnostic RHC and RVB are seen in 21.6 and 20.8 procedures, respectively, of 10,000 procedures and all deaths were secondary to acute illness.

Enhancing Functional Recovery after Segmental Nerve Defect Using Nerve Allograft Treated with Plasma-Derived Exosome.

BACKGROUND: Nerve injuries can result in detrimental functional outcomes. Currently, autologous nerve graft offers the best outcome for segmental peripheral nerve injury. Allografts are alternatives, but do not have comparable results. This study evaluated whether plasma-derived exosome can improve nerve regeneration and functional recovery when combined with decellularized nerve allografts. METHODS: The effect of exosomes on Schwann cell proliferation and migration were evaluated. A rat model of sciatic nerve repair was used to evaluate the effect on nerve regeneration and functional recovery. A fibrin sealant was used as the scaffold for exosome. Eighty-four Lewis rats were divided into autograft, allograft, and allograft with exosome groups. Gene expression of nerve regeneration factors was analyzed on postoperative day 7. At 12 and 16 weeks, rats were subjected to maximum isometric tetanic force and compound muscle action potential. Nerve specimens were then analyzed by means of histology and immunohistochemistry. RESULTS: Exosomes were readily taken up by Schwann cells that resulted in improved Schwann cell viability and migration. The treated allograft group had functional recovery (compound muscle action potential, isometric tetanic force) comparable to that of the autograft group. Similar results were observed in gene expression analysis of nerve regenerating factors. Histologic analysis showed no statistically significant differences between treated allograft and autograft groups in terms of axonal density, fascicular area, and myelin sheath thickness. CONCLUSIONS: Plasma-derived exosome treatment of decellularized nerve allograft may provide comparable clinical outcomes to that of an autograft. This can be a promising strategy in the future as an alternative for segmental peripheral nerve repair. CLINICAL RELEVANCE STATEMENT: Off-the-shelf exosomes may improve recovery in nerve allografts.

Non-invasive detection of cardiac allograft rejection among heart transplant recipients using an electrocardiogram based deep learning model.

Aims: Current non-invasive screening methods for cardiac allograft rejection have shown limited discrimination and are yet to be broadly integrated into heart transplant care. Given electrocardiogram (ECG) changes have been reported with severe cardiac allograft rejection, this study aimed to develop a deep-learning model, a form of artificial intelligence, to detect allograft rejection using the 12-lead ECG (AI-ECG). Methods and results: Heart transplant recipients were identified across three Mayo Clinic sites between 1998 and 2021. Twelve-lead digital ECG data and endomyocardial biopsy results were extracted from medical records. Allograft rejection was defined as moderate or severe acute cellular rejection (ACR) based on International Society for Heart and Lung Transplantation guidelines. The extracted data (7590 unique ECG-biopsy pairs, belonging to 1427 patients) was partitioned into training (80%), validation (10%), and test sets (10%) such that each patient was included in only one partition. Model performance metrics were based on the test set (n = 140 patients; 758 ECG-biopsy pairs). The AI-ECG detected ACR with an area under the receiver operating curve (AUC) of 0.84 [95% confidence interval (CI): 0.78-0.90] and 95% (19/20; 95% CI: 75-100%) sensitivity. A prospective proof-of-concept screening study (n = 56; 97 ECG-biopsy pairs) showed the AI-ECG detected ACR with AUC = 0.78 (95% CI: 0.61-0.96) and 100% (2/2; 95% CI: 16-100%) sensitivity. Conclusion: An AI-ECG model is effective for detection of moderate-to-severe ACR in heart transplant recipients. Our findings could improve transplant care by providing a rapid, non-invasive, and potentially remote screening option for cardiac allograft function.

Interventricular-Septal Output While Supported on Left Ventricular Assist Device Therapy.

The effects of left ventricular unloading on septal function in patients with left ventricular assist devices (LVADs) have not been well characterized in vivo. The purpose of this study was to evaluate the relationship between markers of septal function with echocardiography in relationship to RV dysfunction and late RV failure after LVAD implantation. A retrospective study was conducted of patients supported on centrifugal-flow LVADs implanted over a 10-year period. Echocardiographic data were collected pre-operatively and up to 2 years after implantation. Interventricular septum (IVS) measurements were taken at end-systole and end-diastole. Interventricular-septal output (ISO) was calculated using the formula: (IVSs-IVSd)×heart rate. A total of 110 patients were included. An immediate and sustained reduction in both lateral annulus systolic velocity (RVS') and TAPSE were observed after implant ( p < 0.0001). However, ISO gradually decreased over time ( p < 0.0001). While ISO was not predictive of late RV failure, a decrease in ISO by 25% or greater from pre-implant to hospital discharge was associated with late RV failure (OR 4.8; 95% CI, 1.4-16.5; p = 0.012) even after adjusting for relevant clinical variables ( p ≤ 0.01 for each model). RV function is known to be influenced by mechanical ventricular interdependence and we demonstrate that measurement of ISO may be a useful marker in assessing RV dysfunction and predicting RV failure in patients following LVAD implantation.