Programmable Thermostats for MPLM Shell Heater Control ULF1

The Multi-Purpose Logistics Module (MPLM) is the primary carrier for "pressurized" logistics to and from the International Space Station (ISS). The MPLM is transported in the payload bay of the Space Shuttle and is docked to the ISS for unloading, and reloading, of contents within the ISS shirt sleeve environment. Foil heaters, controlled originally with bi-metallic thermostats, are distributed across the outside of the MPLM structure and are utilized to provide energy to the structure to avoid exposure to cold temperatures and prevent condensation. The existing bi-metallic, fixed temperature set point thermostats have been replaced with Programmable Thermostats Modules (PTMs) in the Passive Thermal Control Subsystem (PTCS) 28Vdc shell heater circuits. The goal of using the PTM thermostat is to improve operational efficiency of the MPLM on-orbit shell heaters by providing better shell temperature control via feedback control capability. Each heater circuit contains a programmable thermostat connected to an external temperature sensor, a Resistive Temperature Device (RTD), which is used to provide continuous temperature monitoring capability. Each thermostat has programmable temperature set points and control spans. The data acquisition system uses a standard RS-485 serial interface communications cable to provide digital control capability. The PTM system was designed by MSFC, relying upon ALTEC support for their integration within the MPLM system design, while KSC performed the installation and ground checkout testing of the thermostat and RS-485 communication cable on the MPLM FM1 flight module. The PTMs were used for the first time during the STS-121/ULF1.1 mission. This paper will describe the design, development and verification of the PTM system, as well as the PTM flight performance and comparisons with SINDA thermal model predictions

Impact of trans-stent gradient on outcome after PCI: results from a HAWKEYE substudy

To test whether quantitative flow ratio (QFR)-based trans-stent gradient (TSG) is associated with adverse clinical events at follow-up. A post-hoc analysis of the multi-center HAWKEYE study was performed. Vessels post-PCI were divided into four groups (G) as follows: G1: QFR >= 0.90 TSG = 0 (n = 412, 54.8%); G2: QFR >= 0.90, TSG > 0 (n = 216, 28.7%); G3: QFR < 0.90, TSG = 0 (n = 37, 4.9%); G4: QFR < 0.90, TSG > 0 (n = 86, 11.4%). Cox proportional hazards regression model was used to analyze the effect of baseline and prognostic variables. The final reduced model was obtained by backward stepwise variable selection. Receiver operating characteristic (ROC) was plotted and area under the curve (AUC) was calculated and reported. Overall, 449 (59.8%) vessels had a TSG = 0 whereas (40.2%) had TSG > 0. Ten (2.2%) vessel-oriented composite endpoint (VOCE) occurred in vessels with TSG = 0, compared with 43 (14%) in vessels with TSG > 0 (p < 0.01). ROC analysis showed an AUC of 0.74 (95% CI: 0.67 to 0.80; p < 0.001). TSG > 0 was an independent predictor of the VOCE (HR 2.95 [95% CI 1.77-4.91]). The combination of higher TSG and lower final QFR (G4) showed the worst long-term outcome while low TSG and high QFR showed the best outcome (G1) while either high TSG or low QFR (G2, G3) showed intermediate and comparable outcomes. Higher trans-stent gradient was an independent predictor of adverse events and identified a subgroup of patients at higher risk for poor outcomes even when vessel QFR was optimal (> 0.90)

Relationship between PCSK9 and endothelial function in patients with acute myocardial infarction

Background and aims: While the role of PCSK9 in lipid metabolism is well established, its link with endothelial function is less clear. The aim of the present study is to evaluate the relationship between PCSK9 and endothelial dysfunction in the setting of acute myocardial infarction. Methods and results: To this purpose, we analyzed the serum of 74 patients with ST-elevation myocardial infarction (STEMI) at the time of admission and after 5 days. Endothelial dysfunction was evaluated as rate of apoptosis (AR) of human umbilical vein endothelial cells incubated with patients' serum. There was a good correlation between PCSK9 and the apoptosis rate values, both at baseline (r = 0.649) and 5-day (r = 0.648). In the 5 days after STEMI, PCSK9 increased significantly (242-327 ng/ml, p < 0.001), while AR did not (p = 0.491). Overall, 21(28%) patients showed a reduction of PCSK9, and they had a significantly higher decrease of AR as compared to others (-13.87 vs 5.8%, p = 0.002). At the univariable analysis, the 5-day change of PCSK9 resulted to be the only variable associated with the 5-day change of the apoptosis rate (beta 0.217, 95% CI 0.091-0.344, p = 0.001). Conclusion: The variation of endothelial function and PCKS9 in the first days after an acute myocardial infarction are related. Further validation and research are necessary to confirm our findings.(c) 2022 The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved

Functional (Re)Development of SYNTAX Score II 2020: Predictive Performance and Risk Assessment

The present study investigates the prognostic value of the Syntax Score II 2020 corrected for flow-limiting lesions and its ability to better address treatment by benefit prediction among patients with left main or multivessel disease. We analyzed 1274 patients from the HALE-BOPP cohort and integrated the Syntax Score II 2020 with the result of the fractional flow reserve (FFR) evaluation. Absolute risk difference (ARD) between surgical and percutaneous revascularization was calculated for anatomic and functional Syntax Score II 2020 predicted mortality. The ARD allowed to stratify the population into two large categories: “coronary artery bypass graft (CABG) better” with ARD ≥ 4.5% and “CABG–percutaneous coronary intervention (PCI) equipoise” with ARD p p p < 0.01). The integration between Syntax Score II 2020 and physiology is feasible, and merging clinical, anatomic and functional data allows for better risk prediction and therapeutic guidance

Circulating Biomarkers of Endothelial Dysfunction and Inflammation in Predicting Clinical Outcomes in Diabetic Patients with Critical Limb Ischemia

Critical limb ischemia (CLI) is a severe manifestation of peripheral artery disease characterized by ischemic pain, which is frequently associated with diabetes and non-healing lesions to inferior limbs. The clinical management of diabetic patients with CLI typically includes percutaneous transluminal angioplasty (PTA) to restore limb circulation and surgical treatment of diabetic foot ulcers (DFU). However, even after successful treatment, CLI patients are prone to post-procedure complications, which may lead to unplanned revascularization or foot surgery. Unfortunately, the factors predicting adverse events in treated CLI patients are only partially known. This study aimed to identify potential biomarkers that predict the disease course in diabetic patients with CLI. For this purpose, we measured the circulating levels of a panel of 23 molecules related to inflammation, endothelial dysfunction, platelet activation, and thrombophilia in 92 patients with CLI and DFU requiring PTA and foot surgery. We investigated whether these putative biomarkers were associated with the following clinical endpoints: (1) healing of the treated DFUs; (2) need for new revascularization of the limb; (3) appearance of new lesions or relapses after successful healing. We found that sICAM-1 and endothelin-1 are inversely associated with DFU healing and that PAI-1 and endothelin-1 are associated with the need for new revascularization. Moreover, we found that the levels of thrombomodulin and sCD40L are associated with new lesions or recurrence, and we show that the levels of these biomarkers could be used in a decision tree to assign patients to clusters with different risks of developing new lesions or recurrences

Echocardiographic and clinical features of patients developing prosthesis‐patient mismatch after transcatheter aortic valve replacement: Insights from the Recovery-TAVR registry

Background: The impact of prosthesis-patient mismatch (PPM) on major endpoints after transcatheter aortic valve replacement (TAVR) is controversial and the effects on progression of heart damage are poorly investigated. Therefore, our study aims to evaluate the prevalence and predictors of PPM in a "real world" cohort of patients at intermediate and low surgical risk, its impact on mortality and the clinical-echocardiographic progression of heart damage. Methods: 963 patients who underwent TAVR procedure between 2017 and 2021, from the RECOVERY-TAVR international multicenter observational registry, were included in this analysis. Multiparametric echocardiographic data of these patients were analyzed at 1-year follow-up (FU). Clinical and echocardiographic features were stratified by presence of PPM and PPM severity, as per the most current international recommendations, using VARC-3 criteria. Results: 18% of patients developed post-TAVR. PPM, and 7.7% of the whole cohort had severe PPM. At baseline, 50.3% of patients with PPM were male (vs 46.2% in the cohort without PPM, P = .33), aged 82 (IQR 79-85y) years vs 82 (IQR 78-86 P = .46), and 55.6% had Balloon-Expandable valves implanted (vs 46.8% of patients without PPM, P = .04); they had smaller left ventricular outflow tract (LVOT) diameter (20 mm, IQR 19-21 vs 20 mm, IQR 20-22, P = .02), reduced SVi (34.2 vs 38 mL/m2, P &lt; .01) and transaortic flow rate (190.6 vs 211 mL/s, P &lt; .01). At predischarge FU patients with PPM had more paravalvular aortic regurgitation (moderate-severe AR 15.8% vs 9.2%, P &lt; .01). At 1-year FU, maladaptive alterations of left ventricular parameters were found in patients with PPM, with a significant increase in end-systolic diameter (33 mm vs 28 mm, P = .03) and a significant increase in left ventricle end systolic indexed volume in those with moderate and severe PPM (52 IQR 42-64 and 52, IQR 41-64 vs 44 IQR 35-59 in those without, P = .02)). No evidence of a significant impact of PPM on overall (P = .71) and CV (P = .70) mortality was observed. Patients with moderate/severe PPM had worse NYHA functional class at 1 year (NYHA III-IV 13% vs 7.8%, P = .03). Prosthesis size≤23 mm (OR 11.6, 1.68-80.1) was an independent predictor of PPM, while SVi (OR 0.87, 0.83-0.91, P &lt; .001) and LVOT diameter (OR 0.79, 0.65-0.95, P = .01) had protective effect. Conclusions: PPM was observed in 18% of patients undergoing TAVR. Echocardiographic evaluations demonstrated a PPM-related pattern of early ventricular maladaptive alterations, possibly precursor to a reduction in cardiac function, associated with a significant deterioration in NYHA class at 1 year. These findings emphasize the importance of prevention of PPM of any grade in patients undergoing TAVR procedure, especially in populations at risk

Stroke volume index and transvalvular flow rate trajectories in severe aortic stenosis treated with TAVR

Aims The prognostic impact of flow trajectories according to stroke volume index (SVi) and transvalvular flow rate (FR) in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR) remains poorly assessed. We evaluated and compared SVi and FR prior and after TAVR for severe AS. Methods and results Patients were categorized according to SVi (<35 mL/m(2)) and FR (<200 mL/s). The association of pre- and post-TAVR SVi and FR with all-cause mortality up to 3 years was assessed with multivariable Cox regression models. Among 980 patients with pre-TAVR flow assessment, SVi was reduced in 41.3% and FR in 48.1%. Baseline flow status was not an independent mortality predictor [SVi: hazard ratio (HR) 1.22, 95% confidence interval (CI) 0.85-1.82, FR: HR 0.78, 95% CI 0.48-1.27]. Among 731 patients undergoing early (5 days, interquartile range 2-29) post-TAVR flow assessment, SVi recovered in 40.1% and FR in 49.0% patients with baseline low flow. Reduced FR following TAVR was an independent predictor of mortality (HR 1.67, 95% CI 1.02-2.74), whereas SVi was not (HR 0.97, 95% CI 0.53-1.78). Three-year estimated mortality in patients with recovered FR was lower than that in patients with reduced FR (13.3 vs. 37.7% vs, P = 0.003) and similar to that in patients with normal baseline FR (P = 0.317). Conclusion Baseline flow status was not an independent predictor of mid-term mortality among all-comers with severe AS undergoing TAVR. Flow recovery early after TAVR was frequent. Post-TAVR FR, but not SVi, was independently associated with mid-term all-cause mortality. By impacting flow status, AV replacement modifies the association of flow status with outcomes