Sodium-glucose cotransporter 2 inhibitors for transthyretin amyloid cardiomyopathy: Analyses of short-term efficacy and safety.

AIMS: Despite their potential, sodium-glucose cotransporter 2 inhibitors (SGLT2i) have not been well-studied in transthyretin amyloid cardiomyopathy (ATTR-CM) as randomized trials have excluded patients with this morbid disease. We performed a retrospective study assessing the short-term efficacy and safety of SGLT2i in ATTR-CM. METHODS AND RESULTS: We screened consecutive patients seen at a tertiary care centre and identified 87 ATTR-CM patients treated with SGLT2i and 95 untreated control patients. Endpoints included changes in weight, loop diuretic dose, and cardiac/renal biomarkers. The median age of the overall population was 79 (interquartile range [IQR] 11) years. Nearly 90% of patients were male, and 93% were on a transthyretin stabilizer. Control patients demonstrated generally less severe disease at baseline compared to SGLT2i-treated patients, with lower median Columbia risk score (p < 0.001). Median follow-up time was 5.6 (IQR 5.2) and 8.4 (IQR 2.1) months in the SGLT2i and control cohorts, respectively. Compared with controls, SGLT2i treatment was associated with significantly greater reductions from baseline in weight, loop diuretic dose, and uric acid during follow-up (p < 0.001). While no significant between-group differences were observed on cardiac biomarkers, estimated glomerular filtration rate was significantly reduced versus controls 1 month after SGLT2i initiation (p = 0.002), but no significant differences were observed at later timepoints. Results were similar in a propensity score-matched analysis (n = 42 per cohort). A total of 10 (11.5%) patients discontinued SGLT2i, most commonly due to genitourinary symptoms. CONCLUSION: Sodium-glucose cotransporter 2 inhibitors were well tolerated by most patients with ATTR-CM and appeared to improve volume status and combat diuretic resistance. Randomized studies are needed to confirm these findings.

Post-COVID-19 Condition.

An estimated 10-15% of those infected with SARS-CoV-2 may have post-COVID-19 condition. Common lingering signs and symptoms include shortness of breath, fatigue, high heart rate, and memory and cognitive dysfunction even several months after infection, often impacting survivors' quality of life. The prevalence and duration of individual symptoms remain difficult to ascertain due to the lack of standardized research methods across various studies and limited patient follow-up in clinical studies. Nonetheless, data indicate post-COVID-19 condition may occur independent of acuity of initial infection, hospitalization status, age, or pre-existing comorbidities. Risk factors may include female sex and underlying respiratory or psychiatric disease. Supportive therapies to mitigate symptoms remain the mainstay of treatment. Reassuringly, most patients experience a reduction in symptoms by 1 year. The use of a universal case definition and shared research methods will allow for further clarity regarding the pervasiveness of this entity and its long-term health consequences.

Post-acute COVID-19 syndrome.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the pathogen responsible for the coronavirus disease 2019 (COVID-19) pandemic, which has resulted in global healthcare crises and strained health resources. As the population of patients recovering from COVID-19 grows, it is paramount to establish an understanding of the healthcare issues surrounding them. COVID-19 is now recognized as a multi-organ disease with a broad spectrum of manifestations. Similarly to post-acute viral syndromes described in survivors of other virulent coronavirus epidemics, there are increasing reports of persistent and prolonged effects after acute COVID-19. Patient advocacy groups, many members of which identify themselves as long haulers, have helped contribute to the recognition of post-acute COVID-19, a syndrome characterized by persistent symptoms and/or delayed or long-term complications beyond 4 weeks from the onset of symptoms. Here, we provide a comprehensive review of the current literature on post-acute COVID-19, its pathophysiology and its organ-specific sequelae. Finally, we discuss relevant considerations for the multidisciplinary care of COVID-19 survivors and propose a framework for the identification of those at high risk for post-acute COVID-19 and their coordinated management through dedicated COVID-19 clinics.

Association between antecedent statin use and decreased mortality in hospitalized patients with COVID-19.

The coronavirus disease 2019 (COVID-19) can result in a hyperinflammatory state, leading to acute respiratory distress syndrome (ARDS), myocardial injury, and thrombotic complications, among other sequelae. Statins, which are known to have anti-inflammatory and antithrombotic properties, have been studied in the setting of other viral infections, but their benefit has not been assessed in COVID-19. This is a retrospective analysis of patients admitted with COVID-19 from February 1st through May 12th, 2020 with study period ending on June 11th, 2020. Antecedent statin use was assessed using medication information available in the electronic medical record. We constructed a multivariable logistic regression model to predict the propensity of receiving statins, adjusting for baseline sociodemographic and clinical characteristics, and outpatient medications. The primary endpoint includes in-hospital mortality within 30 days. A total of 2626 patients were admitted during the study period, of whom 951 (36.2%) were antecedent statin users. Among 1296 patients (648 statin users, 648 non-statin users) identified with 1:1 propensity-score matching, statin use is significantly associated with lower odds of the primary endpoint in the propensity-matched cohort (OR 0.47, 95% CI 0.36-0.62, p < 0.001). We conclude that antecedent statin use in patients hospitalized with COVID-19 is associated with lower inpatient mortality.

Association Between Antecedent Statin Use and Decreased Mortality in Hospitalized Patients with COVID-19.

The coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), can result in a hyperinflammatory state, leading to acute respiratory distress syndrome (ARDS), myocardial injury, and thrombotic complications, among other sequelae. Statins, which are known to have anti-inflammatory and antithrombotic properties, have been studied in the setting of other viral infections and ARDS, but their benefit has not been assessed in COVID-19. Thus, we sought to determine whether antecedent statin use is associated with lower in-hospital mortality in patients hospitalized for COVID-19. This is a retrospective analysis of patients admitted with COVID-19 from February 1 st through May 12 th , 2020 with study period ending on June 11 th , 2020. Antecedent statin use was assessed using medication information available in the electronic medical record. We constructed a multivariable logistic regression model to predict the propensity of receiving statins, adjusting for baseline socio-demographic and clinical characteristics, and outpatient medications. The primary endpoint included in-hospital mortality within 30 days. A total of 2626 patients were admitted during the study period, of whom 951 (36.2%) were antecedent statin users. Among 1296 patients (648 statin users, 648 non-statin users) identified with 1:1 propensity-score matching, demographic, baseline, and outpatient medication information were well balanced. Statin use was significantly associated with lower odds of the primary endpoint in the propensity-matched cohort (OR 0.48, 95% CI 0.36 â€" 0.64, p<0.001). We conclude that antecedent statin use in patients hospitalized with COVID-19 was associated with lower inpatient mortality. Randomized clinical trials evaluating the utility of statin therapy in patients with COVID-19 are needed.

Tissue Myeloid Progenitors Differentiate into Pericytes through TGF-ß Signaling in Developing Skin Vasculature.

Mural cells (pericytes and vascular smooth muscle cells) are essential for the regulation of vascular networks and maintenance of vascular integrity, but their origins are diverse in different tissues and not known in the organs that arise from the ectoderm, such as skin. Here, we show that tissue-localized myeloid progenitors contribute to pericyte development in embryonic skin vasculature. A series of in vivo fate-mapping experiments indicates that tissue myeloid progenitors differentiate into pericytes. Furthermore, depletion of tissue myeloid cells and their progenitors in PU.1 (also known as Spi1) mutants results in defective pericyte development. Fluorescence-activated cell sorting (FACS)-isolated myeloid cells and their progenitors from embryonic skin differentiate into pericytes in culture. At the molecular level, transforming growth factor-ß (TGF-ß) induces pericyte differentiation in culture. Furthermore, type 2 TGF-ß receptor (Tgfbr2) mutants exhibit deficient pericyte development in skin vasculature. Combined, these data suggest that pericytes differentiate from tissue myeloid progenitors in the skin vasculature through TGF-ß signaling.

TGFß signaling is required for sprouting lymphangiogenesis during lymphatic network development in the skin.

Dermal lymphatic endothelial cells (LECs) emerge from the dorsolateral region of the cardinal veins within the anterior trunk to form an intricate, branched network of lymphatic vessels during embryogenesis. Multiple growth factors and receptors are required for specification and maintenance of LECs, but the mechanisms coordinating LEC movements and morphogenesis to develop three-dimensional lymphatic network architecture are not well understood. Here, we demonstrate in mice that precise LEC sprouting is a key process leading to stereotypical lymphatic network coverage throughout the developing skin, and that transforming growth factor ß (TGFß) signaling is required for LEC sprouting and proper lymphatic network patterning in vivo. We utilized a series of conditional mutants to ablate the TGFß receptors Tgfbr1 (Alk5) and Tgfbr2 in LECs. To analyze lymphatic defects, we developed a novel, whole-mount embryonic skin imaging technique to visualize sprouting lymphangiogenesis and patterning at the lymphatic network level. Loss of TGFß signaling in LECs leads to a severe reduction in local lymphangiogenic sprouting, resulting in a significant decrease in global lymphatic network branching complexity within the skin. Our results also demonstrate that TGFß signaling negatively regulates LEC proliferation during lymphatic network formation. These data suggest a dual role for TGFß signaling during lymphatic network morphogenesis in the skin, such that it enhances LEC sprouting and branching complexity while attenuating LEC proliferation.

Evaluation of the use of an induced puripotent stem cell sheet for the construction of tissue-engineered vascular grafts.

OBJECTIVE: The development of a living, tissue-engineered vascular graft (TEVG) holds great promise for advancing the field of cardiovascular surgery. However, the ultimate source and time needed to procure these cells remain problematic. Induced puripotent stem (iPS) cells have recently been developed and have the potential for creating a pluripotent cell line from a patient's own somatic cells. In the present study, we evaluated the use of a sheet created from iPS cell-derived vascular cells as a potential source for the construction of TEVG. METHODS: Male mouse iPS cells were differentiated into embryoid bodies using the hanging-drop method. Cell differentiation was confirmed by a decrease in the proportion of SSEA-1-positive cells over time using fluorescence-activated cell sorting. The expression of endothelial cell and smooth muscle cell markers was detected using real-time polymerase chain reaction (PCR). The differentiated iPS cell sheet was made using temperature-responsive dishes and then seeded onto a biodegradable scaffold composed of polyglycolic acid-poly-l-lactide and poly(l-lactide-co-ε-caprolactone) with a diameter of 0.8 mm. These scaffolds were implanted as interposition grafts in the inferior vena cava of female severe combined immunodeficiency/beige mice (n = 15). Graft function was serially monitored using ultrasonography. The grafts were analyzed at 1, 4, and 10 weeks with histologic examination and immunohistochemistry. The behavior of seeded differentiated iPS cells was tracked using Y-chromosome fluorescent in situ hybridization and SRY real-time PCR. RESULTS: All mice survived without thrombosis, aneurysm formation, graft rupture, or calcification. PCR evaluation of iPS cell sheets in vitro demonstrated increased expression of endothelial cell markers. Histologic evaluation of the grafts demonstrated endothelialization with von Willebrand factor and an inner layer with smooth muscle actin- and calponin-positive cells at 10 weeks. The number of seeded differentiated iPS cells was found to decrease over time using real-time PCR (42.2% at 1 week, 10.4% at 4 weeks, 9.8% at 10 weeks). A fraction of the iPS cells were found to be Y-chromosome fluorescent positive at 1 week. No iPS cells were found to co-localize with von Willebrand factor or smooth muscle actin-positive cells at 10 weeks. CONCLUSIONS: Differentiated iPS cells offer an alternative cell source for constructing TEVG. Seeded iPS cells exerted a paracrine effect to induce neotissue formation in the acute phase and were reduced in number by apoptosis at later time points. Sheet seeding of our TEVG represents a viable mode of iPS cell delivery over time.

Comparison of human bone marrow mononuclear cell isolation methods for creating tissue-engineered vascular grafts: novel filter system versus traditional density centrifugation method.

INTRODUCTION: We created the first tissue-engineered vascular graft (TEVG) to be successfully used in humans. The TEVG is made by seeding autologous bone marrow-derived mononuclear cells (BM-MNCs) onto a biodegradable tubular scaffold fabricated from polyglycolic-acid mesh coated with a 50:50 copolymer of poly-L-lactide and-ɛ-caprolactone. In the initial clinical study, the BM-MNCs were isolated using a Ficoll density centrifugation method. Use of this cell isolation technique is problematic in that it is performed using an open system and therefore is susceptible to contamination. As a first step toward creating a closed system for assembling a TEVG, we evaluated the use of a filter-based method for isolating BM-MNCs and compared it to density centrifugation in Ficoll. METHODS: BM-MNCs were isolated from human BM using density centrifugation in Ficoll or a filter-based method. BM-MNCs were seeded onto biodegradable tubular scaffold and incubated for 24 h before implantation. The TEVG were implanted as inferior vena cava interposition grafts in SCID/bg mice (n=24) using microsurgical technique. Grafts were followed with ultrasonography and computed tomography-angiography. Ten weeks after implantation the TEVG were explanted and examined using histology and immunohistochemistry. RESULTS: Both methods isolated similar number of cells (Ficoll: 8.5±6.6×10(6)/mL, Filter: 6.6±3.5×10(6)/mL; p=0.686) with similar viability as assayed using fluorescence-activated cell sorting (FACS) (Ficoll: 97.0%±1.5%, Filter: 95.9%±3.0%; p=0.339). FACS analysis demonstrated that the fraction of lymphocytes and monocytes to total cells was lower in the filter group (CD4 in Ficoll: 8.9%±1.1%, CD4 in Filter: 3.5%±0.8%; p=0.002, CD8 in Ficoll: 9.4%±2.1%, CD8 in Filter: 3.9%±1.4%; p=0.021, Monocyte in Ficoll: 6.9%±1.0%, Monocyte in Filter: 2.7%±1.0%; p=0.008), consistent with granulocyte contamination (Ficoll: 46.6±2.7×10(6)/mL, Filter: 58.1±5.2×10(6)/mL; p<0.001). The ratio of stem cells to BM-MNCs was comparable between groups. There were no statistically significant differences with regard to TEVG patency and morphology between groups. Both methods of cell isolation produced neovessels with similar histology. CONCLUSION: Filter-based BM-MNC isolation is comparable to BM-MNC isolation using density centrifugation in Ficoll for TEVG assembly. The filter-based cell isolation technique has the added advantage of the potential to create a closed disposable system.

Tissue-engineered vascular grafts transform into mature blood vessels via an inflammation-mediated process of vascular remodeling.

Biodegradable scaffolds seeded with bone marrow mononuclear cells (BMCs) are the earliest tissue-engineered vascular grafts (TEVGs) to be used clinically. These TEVGs transform into living blood vessels in vivo, with an endothelial cell (EC) lining invested by smooth muscle cells (SMCs); however, the process by which this occurs is unclear. To test if the seeded BMCs differentiate into the mature vascular cells of the neovessel, we implanted an immunodeficient mouse recipient with human BMC (hBMC)-seeded scaffolds. As in humans, TEVGs implanted in a mouse host as venous interposition grafts gradually transformed into living blood vessels over a 6-month time course. Seeded hBMCs, however, were no longer detectable within a few days of implantation. Instead, scaffolds were initially repopulated by mouse monocytes and subsequently repopulated by mouse SMCs and ECs. Seeded BMCs secreted significant amounts of monocyte chemoattractant protein-1 and increased early monocyte recruitment. These findings suggest TEVGs transform into functional neovessels via an inflammatory process of vascular remodeling.