Pathological evaluation of a fluoropolymer-based drug-eluting stent in an arteriovenous graft outflow venous stenosis

A fluoropolymer-based drug-eluting stent was implanted in an arteriovenous graft outflow venous stenosis. Two and a half years later, due to a local infection, the stent was removed surgically, and a pathological evaluation was conducted. The stent struts exhibited partial endothelial cell coverage, with the remaining surface predominantly covered by fibrin. Notably, there was no evidence of restenosis or aneurysmal change.

Rapid progression of a coronary artery aneurysm caused by IgG4-related disease

BACKGROUND

IgG4-related disease (IgG4-RD) is a recently recognized fibro-inflammatory disorder that can affect almost any organ. IgG4-RD has also been reported in coronary arteries as periarteritis. IgG4-related coronary periarteritis may cause coronary artery aneurysms, and IgG4-related coronary artery aneurysms (IGCAs) are life-threatening. We describe a case of a patient with IGCA that highlights the usefulness and limitations of various IGCA evaluation modalities and provides insight into disease pathophysiology.

CASE SUMMARY

A 60-year-old man with IgG4-RD diagnosed 2 years before and with IGCA at the proximal right coronary artery (RCA) on coronary angiography (CAG) 9 months prior to admission to the hospital presented with acute coronary syndrome. Emergent CAG revealed the rapid progression of IGCA at the RCA, an obstruction of the diagonal branch, and stenosis of the left anterior descending artery (LAD) and the high lateral branch (HL). The patient underwent percutaneous coronary intervention for the diagonal branch. The RCA aneurysm was resected and bypassed with a saphenous vein graft (SVG); coronary bypass grafting (left internal mammary artery to LAD and SVG to HL) was performed. Pathological findings showed inflammatory cell infiltration and disruption of the elastic plate.

CONCLUSION

IGCAs require careful follow-up with computed tomography scans for early detection of aneurysmal enlargement.

Biological differences of three paclitaxel- and sirolimus-coated balloons on coronary lesions in a rabbit model

BACKGROUND

Drug-coated balloons (DCBs) are important treatment options for coronary artery disease; however, randomised controlled trials comparing various DCB technologies are sparse, and further investigations are needed.

AIMS

This preclinical study aimed to histologically and biologically compare the drug effects and safety of a low-dose paclitaxel-coated DCB (PCB; AGENT), a regular-dose PCB (SeQuent Please NEO) and a sirolimus-coated DCB (SCB; MagicTouch).

METHODS

The DCBs were inflated in the healthy iliac arteries of 18 rabbits, which were euthanised after 28 days. The treated iliac arteries and distal skeletal muscles were histopathologically evaluated, and drug concentrations were measured.

RESULTS

In the histopathological evaluation, the medial smooth muscle cell loss score regarding depth, an indicator of drug efficacy, was significantly higher with AGENT and SeQuent Please NEO than with MagicTouch (4.0 [3.6-4.0] vs 3.7 [3.7-4.0] vs 2.2 [2.0-2.4]), with significant differences in comparisons between AGENT and MagicTouch (p<0.01) and between SeQuent Please NEO and MagicTouch (p<0.01). AGENT and SeQuent Please NEO showed comparable drug concentrations in the treated artery (p=0.61). In contrast, the drug concentrations in distal skeletal muscles were the highest for MagicTouch, followed by SeQuent Please NEO and AGENT (28.07 [13.19-52.46] ng/mg vs 0.66 [0.22-3.76] ng/mg vs 0.25 [0.04-3.23] ng/mg, respectively).

CONCLUSIONS

This study demonstrated that PCBs might have higher efficacy and lower drug concentrations in distal skeletal muscles than the MagicTouch SCB. The efficacy of the AGENT low-dose PCB and the SeQuent Please NEO regular-dose PCB was comparable.

Cultural adaptation, content, and protocol of a feasibility study of school-based "Let's learn about emotions" intervention for Finnish primary school children

Introduction

Emotional awareness and emotion regulation are crucial for cognitive and socio-emotional development in children. School-based interventions on socio-emotional skills have the potential to prevent these problems and promote well-being of children. The Japanese school-based program, Universal Unified Prevention Program for Diverse Disorders (Up2-D2), has shown preventive effects on mental health of children in Japan. The aims of this protocol paper are to describe the unique process of adapting the Up2-D2 from Eastern to Western context, and to present a feasibility study of the intervention, conducted in Finland.

Methods

The cultural adaptation process started with the linguistic translation of materials, followed by the modification of language to fit the Finnish context. While the Japanese ideology was saved, some content was adapted to fit Finnish school children. Further modifications were made based on feedback from pupils and teachers. The Finnish version of the program was named "Let's learn about emotions" and consisted of 12 sessions and targeted 8- to 12-year-old pupils. A teacher education plan was established to assist Finnish teachers with the intervention, including a workshop, teachers' manual, brief introductory videos, and online support sessions. A feasibility study involving 512 4th graders in the City of Hyvinkää, South of Finland, was conducted. It assessed emotional and behavioral problems, classroom climate, bullying, loneliness, perception of school environment, knowledge of emotional awareness, and program acceptability.

Discussion

The originality of this study underlies in the East-West adaptation of a cognitive behavioral therapy-based program. If promising feasibility findings are replicated in Finland, it could pave the way for further research on implementing such programs in diverse contexts and cultures, promoting coping skills, awareness, social skills and early prevention of child mental health problems.

Ethics

The ethical board of the University of Turku gave ethics approval for this research. The educational board of the City of Hyvinkää accepted this study.

Review of Bleeding and Thrombotic Risks Associated With Antithrombotic Therapy After Transcatheter Structural Heart Interventions

Transcatheter structural heart interventions have drastically evolved over the past 2 decades. However, most catheterization procedures require the deployment of devices in the body; therefore, the adhesion of thrombi to those devices is a major problem, resulting in the requirement of a period of postprocedural antithrombotic regimen. However, in recent years, bleeding associated with these antithrombotic therapies has also become a major concern, attracting the attention of investigators. This is complicated by the fact that patients at high thrombotic risk are also at high bleeding risk, making the issue of administrating antithrombotic therapy challenging. The objective of this review was to identify the important issues and summarize the current status of postoperative antithrombotic therapy and assessment of the bleeding risk following transcatheter structural heart interventions such as transcatheter aortic valve replacement, transcatheter edge-to-edge repair, and transcatheter left atrial appendage occlusion.

Replacement of pulmonary venous stent during Fontan operation

Post-operative pulmonary venous stenosis is a poor prognostic factor in single-ventricle haemodynamics. Implantation of a drug-eluting stent is a therapeutic option. However, due to their small size, they inevitably become inadequate as the patient grows. We present the first case, to the best of our knowledge, of the replacement of a small-diameter stent with a large-diameter stent during Fontan surgery.

Feasibility and Outcome of Transjugular Intracardiac Echocardiography-Guided Transcatheter Aortic Valve Replacement

Background

There are limited data on the impact of intracardiac echocardiography (ICE)-guided transcatheter aortic valve replacement (TAVR) on the new permanent pacemaker implantation (PPMI) rate.

Objectives

This study investigated the feasibility and outcome of transjugular ICE (TJ-ICE) -guided TAVR, by visualizing the relationship between the membranous septum (MS) and the transcatheter aortic valve (TAV).

Methods

Among patients with severe aortic stenosis who underwent TAVR between February 2017 and June 2020, this study enrolled a total of 163 patients with TJ-ICE-guided TAVR. MS length was measured by ICE. The primary endpoint of this study was the incidence of new PPMI at 30 days.

Results

The mean age of the patients in this study was 84.9 ± 4.6 years, and 71.2% of the patients were female. Device success was 96.3% with TJ-ICE guidance. A TJ-ICE-related complication occurred in 1 case (0.6%). The median length of the MS was 5.8 mm (IQR: 5.0-6.9 mm). Excellent intraobserver (intraclass correlation coefficient [ICC]: 0.94; 95% CI:0.79-0.98; P < 0.001) and interobserver (ICC: 0.93; 95% CI: -0.05 to 0.98; P < 0.001) agreements were shown. The new PPMI rate was 6.7% at 30 days without a significant difference between balloon-expandable valves and self-expandable valves (3.4% vs 8.7%; P = 0.226). Patients with a TAV implantation depth less than MS length had a significantly lower incidence of new PPMI compared with patients with a TAV implantation depth greater than MS length (2.1% vs 13.4%; P = 0.005), regardless of baseline right bundle branch block presence (6.7% vs 66.7%; P = 0.004) or absence (1.2% vs 8.2%; P = 0.041).

Conclusions

TJ-ICE-guided TAVR demonstrated remarkable feasibility and safety. The TJ-ICE-guided final TAV position had a significant impact on the new PPMI rate. (Tokai Valve Registry; UMIN000036671).

Direct Measurement of the Spectral Structure of Cosmic-Ray Electrons+Positrons in the TeV Region with CALET on the International Space Station

Detailed measurements of the spectral structure of cosmic-ray electrons and positrons from 10.6 GeV to 7.5 TeV are presented from over 7 years of observations with the CALorimetric Electron Telescope (CALET) on the International Space Station. The instrument, consisting of a charge detector, an imaging calorimeter, and a total absorption calorimeter with a total depth of 30 radiation lengths at normal incidence and a fine shower imaging capability, is optimized to measure the all-electron spectrum well into the TeV region. Because of the excellent energy resolution (a few percent above 10 GeV) and the outstanding e/p separation (10^{5}), CALET provides optimal performance for a detailed search of structures in the energy spectrum. The analysis uses data up to the end of 2022, and the statistics of observed electron candidates has increased more than 3 times since the last publication in 2018. By adopting an updated boosted decision tree analysis, a sufficient proton rejection power up to 7.5 TeV is achieved, with a residual proton contamination less than 10%. The observed energy spectrum becomes gradually harder in the lower energy region from around 30 GeV, consistently with AMS-02, but from 300 to 600 GeV it is considerably softer than the spectra measured by DAMPE and Fermi-LAT. At high energies, the spectrum presents a sharp break around 1 TeV, with a spectral index change from -3.15 to -3.91, and a broken power law fitting the data in the energy range from 30 GeV to 4.8 TeV better than a single power law with 6.9 sigma significance, which is compatible with the DAMPE results. The break is consistent with the expected effects of radiation loss during the propagation from distant sources (except the highest energy bin). We have fitted the spectrum with a model consistent with the positron flux measured by AMS-02 below 1 TeV and interpreted the electron+positron spectrum with possible contributions from pulsars and nearby sources. Above 4.8 TeV, a possible contribution from known nearby supernova remnants, including Vela, is addressed by an event-by-event analysis providing a higher proton-rejection power than a purely statistical analysis.

Poor Below Knee Runoff Impacts Femoropopliteal Stent Failure and Fluoropolymer Antithrombotic Effect in Healthy Swine Model

OBJECTIVE

Poor below knee (BTK) runoff is a predictor of stent failure after endovascular femoropopliteal artery treatment; however, lack of pathological evaluation has prevented characterisation of stent failure. The study aimed to investigate the impact of poor BTK runoff and the antithrombotic effect of the polymer of fluoropolymer coated paclitaxel eluting stents (FP-PESs) in a healthy swine femoropopliteal artery model.

METHODS

FP-PESs and bare metal stents (BMSs) and FP-PES and polymer free paclitaxel coated stents (PF-PCSs) were implanted in the bilateral femoral arteries of healthy swine (n = 6, respectively) following coil embolisation in both tibial arteries to induce poor BTK runoff. Histological assessment and intravascular imaging device evaluation were performed at one month. The Japanese Association for Laboratory Animal Science approved the study protocol (reference number: IVT22-90).

RESULTS

Optical coherence tomography showed significantly lower percent area stenosis in FP-PES compared with BMS (37.3%, [interquartile range (IQR), 25.6 - 54.3] % vs. 92.5% [IQR, 75.5 - 96.1] %, respectively, p = .031), and PF-PCS (8.3% [IQR, 4.5 - 27.0] % vs. 31.2% [IQR, 23.3 - 52.2] %, respectively, p = .031). Histopathological evaluation demonstrated that thin fibrin attachment without re-stenosis was the most dominant neointimal tissue characteristic in FP-PES. On the other hand, neointimal tissue characteristics with significant restenosis of BMS and PF-PCS were mainly organising or organised thrombus.

CONCLUSION

Organising and or organised thrombus attachment due to poor BTK runoff was the main cause of in stent restenosis of the swine femoral artery. FP-PES demonstrated the least percent area stenosis, suggesting the importance of the antithrombotic effect of polymer.

Erratum: Charge-Sign Dependent Cosmic-Ray Modulation Observed with the Calorimetric Electron Telescope on the International Space Station [Phys. Rev. Lett. 130, 211001 (2023)]

This corrects the article DOI: 10.1103/PhysRevLett.130.211001.

Acute pulmonary hypertension due to microthrombus formation following COVID-19 vaccination: a case report

BACKGROUND

Several side effects have been reported after mRNA COVID-19 vaccinations. Nonetheless, the risk of pulmonary hypertension (PH) is rarely reported. Most cases with acute PH following vaccination were due to macropulmonary embolism secondary to deep vein thrombosis. However, acute PH due to microthrombus formation after COVID-19 vaccination has not been reported before, although a microthrombus has been considered to lead to the dysfunction of multiple organs, particularly in patients infected with COVID-19.

CASE SUMMARY

A 63-year-old woman without any past medical history presented to our hospital with facial and bilateral pedal oedema and progressive dyspnoea on exertion. Her symptoms began the day after her second COVID-19 vaccination and developed gradually, which prompted her to seek consultation in our hospital 6 weeks later. An echocardiogram revealed substantially elevated right heart pressure, and cardiac catheterization revealed high pulmonary artery pressure (mean PAP, 30 mmHg). Contrast-enhanced computed tomography and venous echography revealed no apparent thrombus, and ventilation/perfusion (V/Q) scintigraphy revealed no V/Q mismatch. However, elevated D-dimer indicated the presence of a coagulation-fibrinolysis system in her body; thus, heparin therapy was initiated intravenously on Day 3 for 4 days, followed by direct oral anticoagulants ended on Day 16. Her symptoms substantially improved as her D-dimer level decreased, and a follow-up cardiac catheterization on Day 14 revealed a decline in mean PAP (15 mmHg).

DISCUSSION

Our case suggests that the presence of acute PH is likely due to microangiopathy. Further studies are required to reveal the relationship between immune responses and microthrombus formation after COVID-19 vaccination.

Charge-Sign Dependent Cosmic-Ray Modulation Observed with the Calorimetric Electron Telescope on the International Space Station

We present the observation of a charge-sign dependent solar modulation of galactic cosmic rays (GCRs) with the Calorimetric Electron Telescope onboard the International Space Station over 6 yr, corresponding to the positive polarity of the solar magnetic field. The observed variation of proton count rate is consistent with the neutron monitor count rate, validating our methods for determining the proton count rate. It is observed by the Calorimetric Electron Telescope that both GCR electron and proton count rates at the same average rigidity vary in anticorrelation with the tilt angle of the heliospheric current sheet, while the amplitude of the variation is significantly larger in the electron count rate than in the proton count rate. We show that this observed charge-sign dependence is reproduced by a numerical "drift model" of the GCR transport in the heliosphere. This is a clear signature of the drift effect on the long-term solar modulation observed with a single detector.

Direct Measurement of the Cosmic-Ray Helium Spectrum from 40 GeV to 250 TeV with the Calorimetric Electron Telescope on the International Space Station

We present the results of a direct measurement of the cosmic-ray helium spectrum with the CALET instrument in operation on the International Space Station since 2015. The observation period covered by this analysis spans from October 13, 2015, to April 30, 2022 (2392 days). The very wide dynamic range of CALET allowed for the collection of helium data over a large energy interval, from ∼40  GeV to ∼250  TeV, for the first time with a single instrument in low Earth orbit. The measured spectrum shows evidence of a deviation of the flux from a single power law by more than 8σ with a progressive spectral hardening from a few hundred GeV to a few tens of TeV. This result is consistent with the data reported by space instruments including PAMELA, AMS-02, and DAMPE and balloon instruments including CREAM. At higher energy we report the onset of a softening of the helium spectrum around 30 TeV (total kinetic energy). Though affected by large uncertainties in the highest energy bins, the observation of a flux reduction turns out to be consistent with the most recent results of DAMPE. A double broken power law is found to fit simultaneously both spectral features: the hardening (at lower energy) and the softening (at higher energy). A measurement of the proton to helium flux ratio in the energy range from 60  GeV/n to about 60  TeV/n is also presented, using the CALET proton flux recently updated with higher statistics.

Histological evaluation of vascular changes after excimer laser angioplasty for neointimal formation after bare-metal stent implantation in rabbit iliac arteries

BACKGROUND

Excimer laser is used to treat coronary artery disease, especially in case of lesions with thrombus and in-stent restenosis (ISR). However, there are no in vivo preclinical studies that have evaluated the pathological reactions of the vessel wall after excimer laser ablation.

METHODS

Bare-metal stents were placed in the external iliac arteries of six healthy rabbits. Twenty-eight days later, excimer laser ablation was performed with low-power (45 (fluency)/25 (rate)) in one side, and high-power (60/40) in the opposite side, followed by optical coherence tomography (OCT) evaluation. Rabbits were sacrificed 15 min after the procedure, and histological assessment was performed.

RESULTS

Morphometry analysis of OCT showed similar stent and lumen size between low-power and high-power group. Histological evaluation suggested endothelial cell loss, fibrin deposition, and tissue loss. The low-power group showed significantly less pathological changes compared with the high-power group: angle of endothelial cell loss, 32.4° vs. 191.7° (interquartile range, 8.8°-131.7° vs. 125.7°-279.5°; p < 0.01); fibrin deposition, 1.1° vs. 59.6° (0.0°-70.4° vs. 31.4°-178.4°; p = 0.03); and tissue loss 0.0° vs. 18.2° (0.0°-8.7° vs. 0.0°-42.7°; p = 0.03).

CONCLUSIONS

The pathological changes in neointima were more prominent after high-power excimer laser ablation than after low-power excimer laser. To improve safety in clinical practice, understanding the pathological changes of tissues after excimer laser in lesions with ISR is essential.

Differences in Biologic Drug Effects and Distal Particulate Embolization in Three Paclitaxel-Coated Balloons for Femoropopliteal Lesions in a Rabbit Model

BACKGROUND

A recent meta-analysis of randomized control trials demonstrated a significantly higher risk of major amputation in patients treated with drug-coated balloons (DCBs) compared with standard treatment, especially in high-dose paclitaxel-coated DCBs. Distal particulate embolization after DCB use was considered a potential cause of the higher incidence of major amputation. The current study aimed to histologically and biologically compare biologic drug effect and distal particulate embolization in 3 DCBs (a high-dose paclitaxel-coated DCB [IN.PACT Admiral] and 2 low-dose paclitaxel-coated DCBs [Ranger and Lutonix]).

METHODS AND RESULTS

The DCBs were inflated in the healthy descending aortas of 18 rabbits, followed by euthanasia 28 days after the procedure. The treated descending aorta and distal skeletal muscles were histopathologically evaluated, and paclitaxel concentrations were measured. The paclitaxel concentration of the treated lesion was highest for Ranger, followed by IN.PACT and Lutonix (Ranger vs IN.PACT vs Lutonix: 1089 [745-2170] pmol/mg vs 638 [160-2075] pmol/mg vs 25 [10-304] pmol/mg, respectively; p<0.0001). In the histopathological evaluation, the angle of severe medial smooth muscle cell loss was largest for Ranger followed by IN.PACT and Lutonix (12.8 [8.0-20.4] degree vs 1.4 [1.2-5.2] degree vs 0.8 [0.5-2.5] degree, respectively), with significant differences for Ranger vs IN.PACT (p=0.007) and Ranger vs Lutonix (p=0.002). However, paclitaxel concentrations of distal skeletal muscles were lowest for Lutonix, followed by Ranger and IN.PACT (12 [1-58] pmol/mg vs 15 [13-21] pmol/mg vs 42 [19-108] pmol/mg, respectively, p<0.0001). The numbers of arteries with downstream DCB effects were highest for IN.PACT, followed by Ranger and Lutonix (Ranger vs IN.PACT vs Lutonix, 3 [3-4] vs 4 [3-7] vs 2 [1-2], respectively), which was consistent with the measured tissue paclitaxel concentrations.

CONCLUSION

These findings suggest that Ranger demonstrates the strongest paclitaxel effect, as well as the second-best effect regarding distal particulate embolization, making it a good treatment option for patients with peripheral artery disease among the 3 DCBs evaluated in the current study. Further clinical head-to-head comparisons with larger numbers of patients are needed to explore which DCB is the most effective and safe treatment option.Clinical Impact:The findings of the current preclinical study suggests that Ranger demonstrates the strongest paclitaxel effect, as well as the second-best effect regarding distal particulate embolization making it a good treatment for patients with intermittent claudication and chronic limb-threatening ischemia.

CD163+ macrophages restrain vascular calcification, promoting the development of high-risk plaque

Vascular calcification (VC) is concomitant with atherosclerosis, yet it remains uncertain why rupture-prone high-risk plaques do not typically show extensive calcification. Intraplaque hemorrhage (IPH) deposits erythrocyte-derived cholesterol, enlarging the necrotic core and promoting high-risk plaque development. Pro-atherogenic CD163+ alternative macrophages engulf hemoglobin:haptoglobin (HH) complexes at IPH sites. However, their role in VC has never been examined to our knowledge. Here we show, in human arteries, the distribution of CD163+ macrophages correlated inversely with VC. In vitro experiments using vascular smooth muscle cells (VSMCs) cultured with HH-exposed human macrophage - M(Hb) - supernatant reduced calcification, while arteries from ApoE-/- CD163-/- mice showed greater VC. M(Hb) supernatant-exposed VSMCs showed activated NF-κB, while blocking NF-κB attenuated the anticalcific effect of M(Hb) on VSMCs. CD163+ macrophages altered VC through NF-κB-induced transcription of hyaluronan synthase (HAS), an enzyme that catalyzes the formation of the extracellular matrix glycosaminoglycan, hyaluronan, within VSMCs. M(Hb) supernatants enhanced HAS production in VSMCs, while knocking down HAS attenuated its anticalcific effect. NF-κB blockade in ApoE-/- mice reduced hyaluronan and increased VC. In human arteries, hyaluronan and HAS were increased in areas of CD163+ macrophage presence. Our findings highlight an important mechanism by which CD163+ macrophages inhibit VC through NF-κB-induced HAS augmentation and thus promote the high-risk plaque development.

Cosmic-Ray Boron Flux Measured from 8.4 GeV/n to 3.8 TeV/n with the Calorimetric Electron Telescope on the International Space Station

We present the measurement of the energy dependence of the boron flux in cosmic rays and its ratio to the carbon flux in an energy interval from 8.4  GeV/n to 3.8  TeV/n based on the data collected by the Calorimetric Electron Telescope (CALET) during ∼6.4  yr of operation on the International Space Station. An update of the energy spectrum of carbon is also presented with an increase in statistics over our previous measurement. The observed boron flux shows a spectral hardening at the same transition energy E_{0}∼200  GeV/n of the C spectrum, though B and C fluxes have different energy dependences. The spectral index of the B spectrum is found to be γ=-3.047±0.024 in the interval 25<E<200  GeV/n. The B spectrum hardens by Δγ_{B}=0.25±0.12, while the best fit value for the spectral variation of C is Δγ_{C}=0.19±0.03. The B/C flux ratio is compatible with a hardening of 0.09±0.05, though a single power-law energy dependence cannot be ruled out given the current statistical uncertainties. A break in the B/C ratio energy dependence would support the recent AMS-02 observations that secondary cosmic rays exhibit a stronger hardening than primary ones. We also perform a fit to the B/C ratio with a leaky-box model of the cosmic-ray propagation in the Galaxy in order to probe a possible residual value λ_{0} of the mean escape path length λ at high energy. We find that our B/C data are compatible with a nonzero value of λ_{0}, which can be interpreted as the column density of matter that cosmic rays cross within the acceleration region.

Pathological analysis of struts coverage after second- and third-generation drug-eluting stents implantation for duration of dual anti-platelets therapy; an autopsy study

Background

Strut coverage of drug-eluting stents (DES) is one of the important factors for the duration of dual anti-platelets therapy (DAPT) after percutaneous coronary intervention. Several studies have reported percent coverage of struts assessed by optical coherence tomography (OCT), however, the timing of endothelial coverage of the latest second- and third-generation DES has not been revealed histologically.

Methods and results

From CVHills stent autopsy registry of 171 stented lesions, a total of 56 lesions from 39 autopsy cases with less than 370 days after second- and/or third-generation DES implantation was evaluated histologically. The lesions were stratified by duration: 1–30 days (n=39), 31–60 days (n=4), 61–90 days (n=5), 91–180 days (n=2), and 181–370 days (n=6), and percent coverage of struts, which was defined as neointimal coverage overlying with endothelial cells, was evaluated for each lesion. In addition, difference of coverage within 90 days after implantation between second-generation DES with circumferentially coated polymer and third-generation DES with abluminally coated polymer was also evaluated.

Percent strut coverage increased with time [1–30 days vs. 31–60 days vs. 61–90 days vs. 91–180 days vs. 181–370 days: median (interquartile range) 0.0% (0.0–0.3), 6.3% (1.0–11.7), 16.7% (8.0–32.6), 64.2% (55.6–72.9), and 86.5% (63.5–92.5), respectively, p&lt;0.0001]. When the coverage at the earlier time point was compared between second- and third-generation DES, prevalence of coverage with &gt;25% per section was higher in third-generation DES and the difference was more obvious in 61–90 days after stent implantation (0.0 vs. 1.0%, p=0.15 in 1–30 days, 7.7 vs. 14.3%, p=0.65 in 31–60 days, and 10.0 vs. 36.3%, p=0.04 in 61–90 days).

Conclusions

The current pathological analysis has demonstrated that the process of endothelial strut coverage in second- and third-generation DES proceeds over time, however, the speed was slower than reported in the previous studies evaluated with OCT. Furthermore, endothelial strut coverage of third-generation DES was faster than that of second-generation DES, suggesting a positive roll of abluminal coating on healthy endothelial coverage and safety de-escalation of DAPT at earlier timepoint.

Funding Acknowledgement

Type of funding sources: None.

Impact of poor below-the-knee run-off on stent failure of femoro-popliteal arteries in healthy swine model

Background

Poor below-the-knee (BTK) run-off is reported to be one of the predictors of stent failure after endovascular treatment to femoro-popliteal arteries (1), however, the mechanism of stent failure has never been characterized before. The aim of the current study was to evaluate impact of poor BTK run-off on stent failure in healthy swine femoro-popliteal (FP) lesions, and to compare the outcome of a bare-metal stent (BMS) and two drug-eluting stents (DES) in the arteries with poor BTK run-off.

Method

Fluoropolymer-coated paclitaxel-eluting stents (FP-PES, Eluvia) and BMS were implanted in bilateral femoral arteries of 6 healthy swine following coil embolization in both tibial arteries to induce poor BTK run-off. FP-PES and polymer-free paclitaxel-coated stents (PF-PCS, Zilver-PTX) were also implanted in 6 swine with the same fashion. Angiography with an optical coherence tomography (OCT) at one month followed by histological analysis was performed for each lesion.

Result

Angiography demonstrated that in-stent restenosis was observed exclusively in BMS, and percent stenosis was significantly less in FP-PES compared with BMS (FP-PES vs. BMS, median [interquartile range (IQR)], 17.8% [16.6–28.7] vs. 79.3% [64.2–87.2], respectively, p=0.03). FP-PES also demonstrated significantly less percent stenosis compared with PF-PCS (FP-PES vs. PF-PCS, 8.9% [4.7–44.7] vs. 31.2% [23.3–51.2], respectively, p=0.03). Histopathological evaluation demonstrated that organizing and/or organized fibrin thrombus was the main feature of the restenotic lesions, suggesting a risk of thrombus attachment in the FP lesions with poor BTK run-off. Biologic drug effect such as medial smooth muscle cell (SMC) loss score was significantly greater in FP-PES compared with BMS (4.0 [3.3–4.0] vs. 2.0 [1.0–3.0], respectively, p&lt;0.01), whereas, similar between FP-PES and PF-PCS (4.0 [3.0–4.0] vs. 4.0 [3.0–4.0], respectively, p=0.88).

Conclusion

Thrombus attachment would be the main causes of restenosis in FP lesions with poor BTK runoff. The results of the current study suggest that not only paclitaxel drug effect, but also anti-thrombotic effect of fluoropolymer might be needed to prevent stent failure.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): This study is supported by Boston Scientific.

Observation of Spectral Structures in the Flux of Cosmic-Ray Protons from 50 GeV to 60 TeV with the Calorimetric Electron Telescope on the International Space Station

A precise measurement of the cosmic-ray proton spectrum with the Calorimetric Electron Telescope (CALET) is presented in the energy interval from 50 GeV to 60 TeV, and the observation of a softening of the spectrum above 10 TeV is reported. The analysis is based on the data collected during ∼6.2  years of smooth operations aboard the International Space Station and covers a broader energy range with respect to the previous proton flux measurement by CALET, with an increase of the available statistics by a factor of ∼2.2. Above a few hundred GeV we confirm our previous observation of a progressive spectral hardening with a higher significance (more than 20 sigma). In the multi-TeV region we observe a second spectral feature with a softening around 10 TeV and a spectral index change from -2.6 to -2.9 consistently, within the errors, with the shape of the spectrum reported by DAMPE. We apply a simultaneous fit of the proton differential spectrum which well reproduces the gradual change of the spectral index encompassing the lower energy power-law regime and the two spectral features observed at higher energies.

Predictive value of neutrophil-to-lymphocyte ratio for the fatality of COVID-19 patients complicated with cardiovascular diseases and/or risk factors

Previous studies have reported that a high neutrophil-to-lymphocyte ratio (NLR) is associated with disease severity and poor prognosis in COVID-19 patients. We aimed to investigate the clinical implications of NLR in patients with COVID-19 complicated with cardiovascular diseases and/or its risk factors (CVDRF). In total, 601 patients with known NLR values were selected from the CLAVIS-COVID registry for analysis. Patients were categorized into quartiles (Q1, Q2, Q3, and Q4) according to baseline NLR values, and demographic and clinical parameters were compared between the groups. Survival analysis was conducted using the Kaplan-Meier method. The diagnostic performance of the baseline and follow-up NLR values was tested using receiver operating characteristic (ROC) curve analysis. Finally, two-dimensional mapping of patient characteristics was conducted using t-stochastic neighborhood embedding (t-SNE). In-hospital mortality significantly increased with an increase in the baseline NLR quartile (Q1 6.3%, Q2 11.0%, Q3 20.5%; and Q4, 26.6%; p < 0.001). The cumulative mortality increased as the quartile of the baseline NLR increased. The paired log-rank test revealed significant differences in survival for Q1 vs. Q3 (p = 0.017), Q1 vs. Q4 (p < 0.001), Q2 vs. Q3 (p = 0.034), and Q2 vs. Q4 (p < 0.001). However, baseline NLR was not identified as an independent prognostic factor using a multivariate Cox proportional hazards regression model. The area under the curve for predicting in-hospital death based on baseline NLR was only 0.682, whereas that of follow-up NLR was 0.893. The two-dimensional patient map with t-SNE showed a cluster characterized by high mortality with high NLR at follow-up, but these did not necessarily overlap with the population with high NLR at baseline. NLR may have prognostic implications in hospitalized COVID-19 patients with CVDRF, but its significance depends on the timing of data collection.

Assessment of thromboembolism risk in COVID-19 patients with cardiovascular disease risk factors: Analysis of a Japanese Nationwide Registry

Introduction

Patients with COVID-19 and cardiovascular disease risk factors (CVDRF) have been reported to develop coagulation abnormalities frequently. However, there are limitations in conventional predictive models for the occurrence of thromboembolism in patients with COVID-19 and CVDRF.

Methods

Among data on 1518 hospitalized patients with COVID-19 registered with CLAVIS-COVID, a Japanese nationwide cohort study, 693 patients with CVDRF were subjected to least absolute shrinkage and selection operator (LASSO) analysis; a method of shrinking coefficients for reducing variance and minimizing bias to increase predictive accuracy. LASSO analysis was performed to identify risk factors for systemic thromboembolic events; occurrence of arterial and venous thromboembolism during the index hospitalization as the primary endpoint.

Results

LASSO analysis identified a prior systemic thromboembolism, male sex, hypoxygenemia requiring invasive mechanical ventilation support, C-reactive protein levels and D-dimer levels at admission, and congestion on chest X-ray at admission as potential risk factors for the primary endpoint. The developed risk model consisting of these risk factors showed good discriminative performance (AUC-ROC: 0.83, 95 % confidence interval [CI]: 0.77–0.90), which was significantly better than that shown by D-dimer (AUC-ROC: 0.70, 95 % CI: 0.60–0.80) (p < 0.001). Furthermore, systemic embolic events were independently associated with in-hospital mortality (adjusted odds ratio: 3.29; 95 % CI: 1.31–8.00).

Conclusions

Six parameters readily available at the time of admission were identified as risk factors for thromboembolic events, and these may be capable of stratifying the risk of in-hospital thromboembolic events, which are associated with in-hospital mortality, in patients with COVID-19 and CVDRF.

Sex Differences in Clinical Outcomes Among Patients With COVID-19 and Cardiovascular Disease ― Insights From the CLAVIS-COVID Registry ―

Background: Male sex is associated with a worse clinical course and outcomes of COVID-19, particularly in older patients. However, studies on COVID-19 patients with cardiovascular disease and/or risk factors (CVDRF), which are representative risk factors of COVID-19, are limited. In this study, we investigated the effect of sex on the outcomes of hospitalized COVID-19 patients with CVDRF.

Methods and Results: We analyzed 693 COVID-19 patients with CVDRF. Patients were divided into 2 groups based on sex, and baseline characteristics and in-hospital outcomes were compared between the 2 groups. The mean age of the 693 patients was 68 years; 64.8% were men and 96.1% were Japanese. In a univariate analysis model, sex was not significantly associated with in-hospital mortality (odds ratio [OR] 1.22; 95% confidence interval [CI] 0.74–2.02; P=0.43). However, men had higher in-hospital mortality than women, especially among older (age ≥80 years) patients (OR 2.21; 95% CI 1.11–4.41; P=0.024). After adjusting for age and pivotal risk factors (hypertension, diabetes, heart failure, coronary artery disease, chronic lung disease, and chronic kidney disease), multivariate analysis suggested that male sex was an independent predictor of in-hospital mortality (OR 2.20; 95% CI 1.23–3.92; P=0.008).

Conclusions: In this post hoc analysis of a nationwide registry focusing on patients with COVID-19 and CVDRF, men had higher in-hospital mortality than women, especially among older patients.

Direct Measurement of the Nickel Spectrum in Cosmic Rays in the Energy Range from 8.8 GeV/n to 240 GeV/n with CALET on the International Space Station

The relative abundance of cosmic ray nickel nuclei with respect to iron is by far larger than for all other transiron elements; therefore it provides a favorable opportunity for a low background measurement of its spectrum. Since nickel, as well as iron, is one of the most stable nuclei, the nickel energy spectrum and its relative abundance with respect to iron provide important information to estimate the abundances at the cosmic ray source and to model the Galactic propagation of heavy nuclei. However, only a few direct measurements of cosmic-ray nickel at energy larger than ∼3  GeV/n are available at present in the literature, and they are affected by strong limitations in both energy reach and statistics. In this Letter, we present a measurement of the differential energy spectrum of nickel in the energy range from 8.8  to 240  GeV/n, carried out with unprecedented precision by the Calorimetric Electron Telescope (CALET) in operation on the International Space Station since 2015. The CALET instrument can identify individual nuclear species via a measurement of their electric charge with a dynamic range extending far beyond iron (up to atomic number Z=40). The particle's energy is measured by a homogeneous calorimeter (1.2 proton interaction lengths, 27 radiation lengths) preceded by a thin imaging section (3 radiation lengths) providing tracking and energy sampling. This Letter follows our previous measurement of the iron spectrum [1O. Adriani et al. (CALET Collaboration), Phys. Rev. Lett. 126, 241101 (2021).PRLTAO0031-900710.1103/PhysRevLett.126.241101], and it extends our investigation on the energy dependence of the spectral index of heavy elements. It reports the analysis of nickel data collected from November 2015 to May 2021 and a detailed assessment of the systematic uncertainties. In the region from 20 to 240  GeV/n our present data are compatible within the errors with a single power law with spectral index -2.51±0.07.

New-Onset Atrial Fibrillation in Patients With Coronavirus Disease 2019 (COVID-19) and Cardiovascular Disease - Insights From the CLAVIS-COVID Registry

BACKGROUND

Both pre-existing atrial fibrillation (AF) and new-onset AF (NOAF) are observed in patients with coronavirus disease 2019 (COVID-19); however, the effect of AF on clinical outcomes is unclear. This study aimed to investigate the effect of AF, especially NOAF, on the outcomes of hospitalized patients with COVID-19.Methods and Results:This study analyzed 673 COVID-19 patients with cardiovascular diseases and risk factors (CVDRF). Patients were divided into 3 groups; pre-existing AF (n=55), NOAF (n=28), and sinus rhythm (SR) (n=590). The baseline characteristics and in-hospital outcomes were evaluated. The mean age of the patients was 68 years, 65.4% were male, and the in-hospital mortality rate was 15.6%. The NOAF group demonstrated a higher in-hospital mortality rate (42.9%) than the pre-existing AF (30.9%) and SR (11.2%) groups (P<0.001). Patients with NOAF had a higher incidence of acute respiratory syndrome, multiple organ disease, hemorrhage, and stroke than those with pre-existing AF and NOAF. NOAF was independently associated with in-hospital mortality after adjusting for pre-existing AF and 4C mortality score (odds ratio [95% confidence interval]: 4.71 [1.63-13.6], P<0.001).

CONCLUSIONS

Patients with NOAF had significantly worse outcomes as compared to patients with pre-existing AF and SR. The incidence of NOAF would be a useful predictor of clinical outcomes during hospitalization.

Impact of serum lactate dehydrogenase on the short-term prognosis of COVID-19 with pre-existing cardiovascular diseases

Background

Patients with coronavirus disease 2019 (COVID-19) and underlying cardiovascular comorbidities have poor prognoses. Our aim was to identify the impact of serum lactate dehydrogenase (LDH), which is associated with mortality in acute respiratory distress syndrome, on the prognoses of patients with COVID-19 and underlying cardiovascular comorbidities.

Methods

Among 1518 patients hospitalized with COVID-19 enrolled in the CLAVIS-COVID (Clinical Outcomes of COVID-19 Infection in Hospitalized Patients with Cardiovascular Diseases and/or Risk Factors study), 515 patients with cardiovascular comorbidities were analyzed. Patients were divided into tertiles based on LDH levels at admission [tertile 1 (T1), <235 U/L; tertile 2 (T2), 235–355 U/L; and tertile 3 (T3); ≥356 U/L]. We investigated the impact of LDH levels on the in-hospital mortality.

Results

The mean age was 70.4 ± 30.0 years, and 65.3% were male. There were significantly more in-hospital deaths in T3 than in T1 and T2 [n = 50 (29.2%) vs. n = 15 (8.7%), and n = 24 (14.0%), respectively; p < 0.001]. Multivariable analysis adjusted for age, comorbidities, vital signs, and laboratory data including D-dimer and high-sensitivity troponin showed T3 was associated with an increased risk of in-hospital mortality (adjusted hazard ratio, 3.04; 95% confidence interval, 1.50–6.13; p = 0.002).

Conclusions

High serum LDH levels at the time of admission are associated with an increased risk of in-hospital death in patients with COVID-19 and known cardiovascular disease and may aid in triage of these patients.

Multiple Cardiovascular Diseases or Risk Factors Increase the Severity of Coronavirus Disease 2019

BACKGROUND

This study aimed to determine whether disease severity varied according to whether coronavirus disease 2019 (COVID-19) patients had multiple or single cardiovascular diseases and risk factors (CVDRFs).Methods and Results:COVID-19 patients with single (n=281) or multiple (n=412) CVDRFs were included retrospectively. Multivariable logistic regression showed no significant difference in the risk of in-hospital death between groups, but patients with multiple CVDRFs had a significantly higher risk of acute respiratory distress syndrome (odds ratio: 1.75, 95% confidence interval: 1.09-2.81).

CONCLUSIONS

COVID-19 patients with multiple CVDRFs have a higher risk of complications than those with a single CDVRF.

Intravascular imaging and histological correlates of medial and intimal calcification in peripheral artery disease

BACKGROUND

In peripheral artery disease, two different types of calcification are frequently observed, i.e., medial and intimal calcification.

AIMS

The aim of this study was to determine the ability of intravascular ultrasound (IVUS) imaging and optical frequency domain imaging (OFDI) to detect medial and intimal calcification in human peripheral arteries.

METHODS

We performed ex vivo intravascular imaging of cadaveric human peripheral arteries with calcifications. IVUS and OFDI images were co-registered with histology. A total of 12 legs from nine patients were examined, and 438 cross-sectional images were co-registered with histology.

RESULTS

OFDI could detect 183 of 231 intimal calcifications by histology, whereas IVUS could detect 194 (OFDI: sensitivity 79%, specificity 86%, area under the curve [AUC] 0.83; IVUS: sensitivity 84%, specificity 85%, AUC 0.85). Of 245 medial calcifications by histology, 160 and 164 were detected by OFDI and IVUS, respectively (OFDI: sensitivity 65%, specificity 85%, AUC 0.75; IVUS: sensitivity 67%, specificity 80%, AUC 0.74). Medial calcification with overlying intimal calcification (overlapped calcification) and an unclear border between intima and media were the main reasons for misdiagnosis. Without those 89 overlapped calcifications, sensitivity in both OFDI and IVUS was improved (OFDI: sensitivity 81%, specificity 85%, AUC 0.83; IVUS: sensitivity 88%, specificity 80%, AUC 0.84).

CONCLUSIONS

There are limitations in detecting medial calcification in overlapped intimal calcification and with an unclear border between intima and media by both IVUS and OFDI. It is important to distinguish medial calcification from intimal calcification before proceeding with endovascular therapy since different approaches will be required.

Impact of body mass index on the outcome of Japanese patients with cardiovascular diseases and/or risk factors hospitalized with COVID-19 infection

BACKGROUND

Obesity is reported to be a predictor of adverse clinical events in coronavirus disease 2019 (COVID-19) in Western countries. However, there are limited data reported regarding the prognostic impact of obesity in Asian patients. We investigated the relationship between body mass index (BMI) and in-hospital outcomes in 580 Japanese patients with cardiovascular disease and/or risk factors and who were admitted for COVID-19 infection using data from 49 hospitals in Japan.

METHODS

We analyzed data from the Clinical Outcomes of COVID-19 Infection in Hospitalized Patients with Cardiovascular Disease and/or Risk Factors (CLAVIS-COVID) registry. BMI was classified into four groups accordance with the definition of the Japan Society for the Study of Obesity, as follows: underweight, <18.5 kg/m²; normal range, 18.5 to <25 kg/m²; pre-obese, 25 to 30 kg/m²; and obese, ≥30 kg/m².

RESULTS

In-hospital death occurred in 15.0% (n=87) of the patients and intubation was performed for 139 (24.0%) patients. In a multivariate analysis, we found a significant association between higher BMI and in-hospital mortality [underweight: hazard ratio (HR) 0.47, 95% confidence interval (CI) 0.23-0.97; p=0.041; pre-obese: HR 1.46, 95%CI 0.84-2.55; p=0.18; and obese: HR 3.28, 95%CI 1.34-8.02; p=0.009 vs. normal range]. In contrast, the association between BMI and the intubation rate was not statistically significant.

CONCLUSIONS

Obesity was associated with a stepwise increase in the risk of in-hospital mortality in Japanese patients with COVID-19 infection. The threshold BMI for the increased risk of a worse outcome was 30, which was much lower in comparison to Western countries.

Antiplatelet Effect of Single Antiplatelet Therapy With Prasugrel and Oral Anticoagulation After Stent Implantation in a Rabbit Arteriovenous Shunt Model

Background: Antiplatelet therapy following stent implantation in patients requiring oral anticoagulation (OAC) is controversial because triple therapy (i.e., dual antiplatelet therapy [DAPT] with OAC) is associated with a high risk of bleeding. Methods and Results: In this study, 21 rabbits were divided into 5 groups: prasugrel and warfarin (Prasugrel+OAC group); aspirin and warfarin (Aspirin+OAC group); prasugrel, aspirin, and warfarin group (Triple group); prasugrel and aspirin (Conventional DAPT group); and no medication (Control group). The treated groups were administered medication for 1 week. An arteriovenous shunt loop was established from the rabbit carotid artery to the jugular vein and 2 bare metal stents were deployed in a silicone tube. After 1 h of circulation, the volume of thrombi was evaluated quantitatively by measuring the amount of protein. Bleeding time was measured at the same time. The volume of the thrombus (amount of protein) around stent struts was lowest in the Triple group, followed by the Prasugrel+OAC and Conventional DAPT groups, and was highest in the Control group. Bleeding time was the longest in the Triple group, followed by the Aspirin+OAC, Prasugrel+OAC, Conventional DAPT, and Control groups. Conclusions: This study suggests that prasugrel with OAC may be a feasible antithrombotic regimen following stent implantation in patients who require OAC therapy.

External validation of the 4C Mortality Score for patients with COVID-19 and pre-existing cardiovascular diseases/risk factors

OBJECTIVES

Predictive algorithms to inform risk management decisions are needed for patients with COVID-19, although the traditional risk scores have not been adequately assessed in Asian patients. We aimed to evaluate the performance of a COVID-19-specific prediction model, the 4C (Coronavirus Clinical Characterisation Consortium) Mortality Score, along with other conventional critical care risk models in Japanese nationwide registry data.

DESIGN

Retrospective cohort study.

SETTING AND PARTICIPANTS

Hospitalised patients with COVID-19 and cardiovascular disease or coronary risk factors from January to May 2020 in 49 hospitals in Japan.

MAIN OUTCOME MEASURES

Two different types of outcomes, in-hospital mortality and a composite outcome, defined as the need for invasive mechanical ventilation and mortality.

RESULTS

The risk scores for 693 patients were tested by predicting in-hospital mortality for all patients and composite endpoint among those not intubated at baseline (n=659). The number of events was 108 (15.6%) for mortality and 178 (27.0%) for composite endpoints. After missing values were multiply imputed, the performance of the 4C Mortality Score was assessed and compared with three prediction models that have shown good discriminatory ability (RISE UP score, A-DROP score and the Rapid Emergency Medicine Score (REMS)). The area under the receiver operating characteristic curve (AUC) for the 4C Mortality Score was 0.84 (95% CI 0.80 to 0.88) for in-hospital mortality and 0.78 (95% CI 0.74 to 0.81) for the composite endpoint. It showed greater discriminatory ability compared with other scores, except for the RISE UP score, for predicting in-hospital mortality (AUC: 0.82, 95% CI 0.78 to 0.86). Similarly, the 4C Mortality Score showed a positive net reclassification improvement index over the A-DROP and REMS for mortality and over all three scores for the composite endpoint. The 4C Mortality Score model showed good calibration, regardless of outcome.

CONCLUSIONS

The 4C Mortality Score performed well in an independent external COVID-19 cohort and may enable appropriate disposition of patients and allocation of medical resources.Trial registration number UMIN000040598.

Gamma-Ray Observation of the Cygnus Region in the 100-TeV Energy Region

We report observations of gamma-ray emissions with energies in the 100-TeV energy region from the Cygnus region in our Galaxy. Two sources are significantly detected in the directions of the Cygnus OB1 and OB2 associations. Based on their positional coincidences, we associate one with a pulsar PSR J2032+4127 and the other mainly with a pulsar wind nebula PWN G75.2+0.1, with the pulsar moving away from its original birthplace situated around the centroid of the observed gamma-ray emission. This work would stimulate further studies of particle acceleration mechanisms at these gamma-ray sources.

Inflammatory and Hypercoagulable Biomarkers and Clinical Outcomes in COVID-19 Patients

Systemic inflammation and hypercoagulopathy are known pathophysiological processes of coronavirus disease 2019 (COVID-19), particularly in patients with known cardiovascular disease or its risk factors (CVD). However, whether a cumulative assessment of these biomarkers at admission could contribute to the prediction of in-hospital outcomes remains unknown. The CLAVIS-COVID registry was a Japanese nationwide retrospective multicenter observational study, supported by the Japanese Circulation Society. Consecutive hospitalized patients with pre-existing CVD and COVID-19 were enrolled. Patients were stratified by the tertiles of CRP and D-dimer values at the time of admission. Multivariable Cox proportional hazard models were constructed. In 461 patients (65.5% male; median age, 70.0), the median baseline CRP and D-dimer was 58.3 (interquartile range, 18.2-116.0) mg/L and 1.5 (interquartile range, 0.8-3.0) mg/L, respectively. Overall, the in-hospital mortality rate was 16.5%, and the rates steadily increased in concordance with both CRP (5.0%, 15.0%, and 28.2%, respectively p < 0.001) and D-dimer values (6.8%, 19.6%, and 22.5%, respectively p = 0.001). Patients with the lowest tertiles of both biomarkers (CRP, 29.0 mg/L; D-dimer, 1.00 mg/L) were at extremely low risk of in-hospital mortality (0% until day 50, and 1.4% overall). Conversely, the elevation of both CRP and D-dimer levels was a significant predictor of in-hospital mortality (Hazard ratio, 2.97; 95% confidence interval, 1.57-5.60). A similar trend was observed when the biomarker threshold was set at a clinically relevant threshold. In conclusion, the combination of these abnormalities may provide a framework for rapid risk estimation for in-hospital COVID-19 patients with CVD.

Intensive Care Unit Admission for Moderate-to-Severe COVID-19 Patients With Known Cardiovascular Diseases or Their Risk Factors - Insights From a Nationwide Japanese Cohort Study

Background: The COVID-19 pandemic has challenged healthcare systems, at times overwhelming intensive care units (ICUs). We aimed to describe the length and rate of ICU admission, and explore the clinical variables influencing ICU use, for COVID-19 patients with known cardiovascular diseases or their risk factors (CVDRF).

Methods and Results: A post hoc analysis was performed of 693 Japanese COVID-19 patients with CVDRF enrolled in the nationwide CLAVIS-COVID registration system between January and May 2020 (mean [±SD] age 68.3±14.9 years; 35% female); 199 patients (28.7%) required ICU management. The mean (±SD) ICU length of stay (LOS) was 19.3±18.5 days, and the rate of in-hospital death and hospital LOS were significantly higher (P<0.001) and longer (P<0.001), respectively, in the ICU than non-ICU group. Logistic regression analysis revealed that clinical variables reflecting impaired general condition (e.g., high C-reactive protein, low Glasgow Coma Scale score, SpO₂, albumin level), male sex, and previous use of β-blockers) were associated with ICU admission (all P<0.001). Notably, age was inversely associated with ICU admission, and this was particularly prominent among elderly patients (OR 0.97, 95% confidence interval 0.95–0.99; P=0.0018).

Conclusions: One-third of COVID patients with CVDRF required ICU care during the first phase of the pandemic in Japan. Other than anticipated clinical variables, such as hypoxia and altered mental status, age was inversely associated with the use of the ICU, warranting further investigation.

Comparison of acute thrombogenicity and albumin adsorption in three different durable polymer coronary drug-eluting stents

BACKGROUND

The relative thrombogenicity and albumin adsorption and retention of different durable polymers used in coronary stents has not been tested.

AIMS

This study sought to compare the thromboresistance and albumin binding capacity of different durable polymer drug-eluting stents (DES) using dedicated preclinical and in vitro models.

METHODS

In an ex vivo swine arteriovenous shunt model, a fluoropolymer everolimus-eluting stent (FP-EES) (n=14) was compared with two durable polymer DES, the BioLinx polymer-coated zotarolimus-eluting stent (BL-ZES) (n=9) and a CarboSil elastomer polymer-coated ridaforolimus-eluting stent (EP-RES) (n=6), and bare metal stents (BMS) (n=10). Stents underwent immunostaining using a cocktail of antiplatelet antibodies and a marker for inflammation and were then evaluated by confocal microscopy (CM). Albumin retention was assessed using a flow loop model with labelled human serum albumin (FP-EES [n=8], BL-ZES [n=4], EP-RES [n=4], and BMS [n=7]), and scanned by CM.

RESULTS

The area of platelet adherence (normalised to total stent surface area) was lower in the order FP-EES (9.8%), BL-ZES (32.7%), EP-RES (87.6%) and BMS (202.0%), and inflammatory cell density was least for FP-EES <BL-ZES <EP-RES <BMS. Although nearly full coverage by albumin binding was shown for all durable polymer DES, FP-EES showed significantly greater intensity of albumin as compared to BL-ZES, EP-RES and BMS (FP-EES 79.0%; BL-ZES 13.2%; EP-RES 6.1%; BMS 1.5%).

CONCLUSIONS

These results suggest that thromboresistance and albumin retention vary by polymer type and that these differences might result in different suitability for short-term dual antiplatelet therapy.

Measurement of the Iron Spectrum in Cosmic Rays from 10 GeV/n to 2.0 TeV/n with the Calorimetric Electron Telescope on the International Space Station

The Calorimetric Electron Telescope (CALET), in operation on the International Space Station since 2015, collected a large sample of cosmic-ray iron over a wide energy interval. In this Letter a measurement of the iron spectrum is presented in the range of kinetic energy per nucleon from 10  GeV/n to 2.0  TeV/n allowing the inclusion of iron in the list of elements studied with unprecedented precision by space-borne instruments. The measurement is based on observations carried out from January 2016 to May 2020. The CALET instrument can identify individual nuclear species via a measurement of their electric charge with a dynamic range extending far beyond iron (up to atomic number Z=40). The energy is measured by a homogeneous calorimeter with a total equivalent thickness of 1.2 proton interaction lengths preceded by a thin (3 radiation lengths) imaging section providing tracking and energy sampling. The analysis of the data and the detailed assessment of systematic uncertainties are described and results are compared with the findings of previous experiments. The observed differential spectrum is consistent within the errors with previous experiments. In the region from 50  GeV/n to 2  TeV/n our present data are compatible with a single power law with spectral index -2.60±0.03.

Genetic Variants Associated With Unexplained Sudden Cardiac Death in Adult White and African American Individuals

Importance

Unexplained sudden cardiac death (SCD) describes SCD with no cause identified. Genetic testing helps to diagnose inherited cardiac diseases in unexplained SCD; however, the associations between pathogenic or likely pathogenic (P/LP) variants of inherited cardiomyopathies (CMs) and arrhythmia syndromes and the risk of unexplained SCD in both White and African American adults living the United States has never been systematically examined.

Objective

To investigate cases of unexplained SCD to determine the frequency of P/LP genetic variants of inherited CMs and arrhythmia syndromes.

Design, Setting, and Participants

This genetic association study included 683 African American and White adults who died of unexplained SCD and were included in an autopsy registry. Overall, 413 individuals had DNA of acceptable quality for genetic sequencing. Data were collected from January 1995 to December 2015. A total of 30 CM genes and 38 arrhythmia genes were sequenced, and variants in these genes, curated as P/LP, were examined to study their frequency. Data analysis was performed from June 2018 to March 2021.

Main Outcomes and Measures

The frequency of P/LP variants for CM or arrhythmia in individuals with unexplained SCD.

Results

The median (interquartile range) age at death of the 413 included individuals was 41 (29-48) years, 259 (62.7%) were men, and 208 (50.4%) were African American adults. A total of 76 patients (18.4%) with unexplained SCD carried variants considered P/LP for CM and arrhythmia genes. In total, 52 patients (12.6%) had 49 P/LP variants for CM, 22 (5.3%) carried 23 P/LP variants for arrhythmia, and 2 (0.5%) had P/LP variants for both CM and arrhythmia. Overall, 41 P/LP variants for hypertrophic CM were found in 45 patients (10.9%), 9 P/LP variants for dilated CM were found in 11 patients (2.7%), and 10 P/LP variants for long QT syndrome were found in 11 patients (2.7%). No significant difference was found in clinical and heart characteristics between individuals with or without P/LP variants. African American and White patients were equally likely to harbor P/LP variants.

Conclusions and Relevance

In this large genetic association study of community cases of unexplained SCD, nearly 20% of patients carried P/LP variants, suggesting that genetics may contribute to a significant number of cases of unexplained SCD. Our findings regarding both the association of unexplained SCD with CM genes and race-specific genetic variants suggest new avenues of study for this poorly understood entity.

Late neointimal volume reduction is observed following biodegradable polymer-based drug eluting stent in porcine model

BACKGROUND

The BP-SES has an abluminally applied biodegradable polymer that is fully resorbed after 3-4 months but may have longer-lasting effects. The aim of this study was to determine the long-term vascular response to the novel Ultimaster™ sirolimus-eluting stent (BP-SES).

METHODS

BP-SESs, everolimus-eluting stents (DP-EESs), and bare metal stents were implanted in 22 coronary arteries of 15 mini-swine. All animals underwent optical frequent domain imaging (OFDI) to assess neointimal volume and quality at either 1 (n = 7) or 3 (n = 8) months and at 9 (n = 15) months and were euthanized at 9 months. Stents were subsequently histologically investigated to analyze the vascular response and maturity of neointimal tissue according to cell density.

RESULTS

OFDI revealed greater regression in neointimal volume from 3 to 9 months with BP-SESs than with DP-EESs (-0.6 ± 0.5 mm2 vs. 0.00 ± 0.4 mm2, p = 0.07). Although there was no significant difference between BP-SESs and DP-EESs in the inflammation score (BMS, BP-SES, and DP-EES: 0.1 ± 0.1, 0.3 ± 0.4, and 0.4 ± 0.4, respectively; p < 0.0001) in histological analysis, BP-SESs showed slightly greater maturity than DP-EESs (1.8 ± 0.3, 1.7 ± 0.3, and 1.6 ± 0.3, p = 0.09).

CONCLUSIONS

While both BP-SESs and DP-EESs showed minimal inflammatory responses at 9 months, BP-SESs showed a trend for greater neointimal maturity and regression, which may be related to earlier completion of the vascular response.

Reduction of door-to-balloon time in patients with ST-elevation myocardial infarction by single-catheter primary percutaneous coronary intervention method

Objectives

The objectives of this study is to confirm reduction of door‐to‐balloon (D2B) time with single‐catheter percutaneous coronary intervention (SC‐PCI) method.

Background

Reduction of total ischemic time is important in the emergency treatment of ST‐elevation myocardial infarction (STEMI). There have been no established methods in primary percutaneous coronary intervention (PCI) to shorten ischemic time via radial access. Ikari left curve was reported as a universal guiding catheter for left and right coronary arteries. Several procedure steps can be skipped by SC‐PCI method as the advantage of a universal catheter.

Methods

This study is a retrospective analysis of a total of 1,275 consecutive STEMI cases treated with primary PCI in 14 hospitals. Patients were divided into two groups, SC‐PCI method (n = 298) and conventional PCI method (n = 977). Primary endpoints were door‐to‐balloon (D2B) time and radiation exposure dose.

Results

The mean age was 68 ± 13 years old. Radial access was used in 85% of participants. PCI success was achieved in 99.5% of participants and the SC‐PCI method was successfully performed in 92.6%. The D2B time was shorter (68 ± 46 vs. 74 ± 50 min, respectively; p = .02), and the radiation exposure dose was lower (1,664 ± 970 vs. 2008 ± 1,605 mGy, respectively; p < .0001) in the SC‐PCI group than in the conventional group.

Conclusion

Primary PCI with SC‐PCI method for patients with STEMI demonstrated shorter D2B time and lower radiation exposure dose.