Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Simulation test for impartment of use-dependent plasticity by inactivation of axonal potassium channels on hippocampal mossy fibers

Modification of axonal excitability directly impacts information transfer through the neuronal networks in the brain. However, the functional significance of modulation of axonal excitability by the preceding neuronal activity largely remains elusive. One remarkable exception is the activity-dependent broadening of action potential (AP) propagating along the hippocampal mossy fibers. The duration of AP is progressively prolonged during repetitive stimuli and facilitated presynaptic Ca2+ entry and subsequent transmitter release. As an underlying mechanism, accumulated inactivation of axonal K+ channels during AP train has been postulated. As the inactivation of axonal K+ channels proceeds on a timescale of several tens of milliseconds slower than the millisecond scale of AP, the contribution of K+ channel inactivation in AP broadening needs to be tested and evaluated quantitatively. Using the computer simulation approach, this study aimed to explore the effects of the removal of the inactivation process of axonal K+ channels in the simple but sufficiently realistic model of hippocampal mossy fibers and found that the use-dependent AP broadening was completely abolished in the model replaced with non-inactivating K+ channels. The results demonstrated the critical roles of K+ channel inactivation in the activity-dependent regulation of axonal excitability during repetitive action potentials, which critically imparts additional mechanisms for robust use-dependent short-term plasticity characteristics for this particular synapse.

Modeling analysis of subthreshold voltage signaling along hippocampal mossy fiber axons

Axons are classically thought of as electrically well isolated from other parts of the neurons due to the shape of a long cable-like structure. In contrast to this classical view on axonal compartmentalization, recent studies revealed that subthreshold depolarization of soma and dendrite passively propagates to the axons for a substantial distance, as demonstrated in some experimentally accessible axons including hippocampal mossy fibers and cortical pyramidal cell axons. Passive propagation of subthreshold dendritic EPSPs to the axons, defined as EPreSPs (excitatory presynaptic potentials), has been demonstrated to affect transmitter release from the axon terminals. To further characterize and explore the functional significance of passive subthreshold voltage signaling along the axons, the model of EPreSPs along hippocampal mossy fibers, proposed by Alle and Geiger, was reconstructed on the NEURON simulator. To test the effect of EPreSPs on action potentials and transmitter release from the axon terminals, additional conductances were incorporated into the previous passive propagation model. These include the axonal sodium, potassium, and leak channels as well as presynaptic calcium channels composed of P/Q-, N-, and R-types, which are reconstructed from the properties of those recorded from mossy fiber boutons experimentally. In this revised model, the preceding subthreshold EPreSPs slightly reduced the action potential-evoked presynaptic calcium currents by a decrease in the amplitude of action potentials due to the slow depolarization. It should be mentioned that EPreSPs by themselves elicited small calcium currents during subthreshold depolarization through these high-voltage activated calcium channels. Since the previous experimental study by simultaneous pre and postsynaptic recordings demonstrated that EPreSPs enhanced action potential-evoked transmitter release from the mossy fiber terminals, it has been suggested that different mechanisms from the enhancement of action potential-evoked presynaptic calcium entry may involve enhanced transmitter release by EPreSP. Small calcium entry by subthreshold EPreSPs may enhance transmitter release from the mossy fiber terminals by acting as high-affinity calcium sensors for enhancing transmitter release. Another form of axonal subthreshold voltage signaling, GABA-EPreSPs elicited by a spillover of GABA from surrounding interneurons, was also explored. Functional consequences of the two modes of axonal subthreshold voltage signaling were discussed with the simulation results.

P-384 Efficacy of endometrial microbiome metagenomic analysis with recurrent implantation failure and recurrent pregnancy loss: multicenter study in Japan

Study question

Does the result of endometrial microbiome metagenomic analysis (EMMA), a next generation sequencing (NGS)-based test of the intrauterine microbiome, have an impact on pregnancy rate after the test?

Summary answer

After recommend treatment with antimicrobial and probiotic therapy, the group diagnosed as dysbiosis by EMMA achieved pregnancy significantly earlier than the group with Normal result.

What is known already

Using NGS technology, EMMA testing can determine the composition of the endometrial microbiome by analysing bacterial 16S ribosomal RNA with a focus on the lactobacillus population. Endometrial flora in patients undergoing in vitro fertilization (IVF) is often composed of pathogenic microorganisms which decrease implantation rates, such as the Enterobacteriaceae family, Staphylococcus spp., Escherichia coli and Gram-negative bacteria. Other studies also indicate that Lactobacillus spp. is a major microorganism in the endometrium. Especially, lactobacillus-dominated microbiota (LDM, defined as &gt; 90% Lactobacillus spp.) in the endometrium has been reported to lead to better pregnancy outcomes than non-LDM (&lt;90% Lactobacillus spp.).

Study design, size, duration

This study was a prospective, multicenter cohort study of 527 patients (under 42 years old) with recurrent implantation failure (RIF) and recurrent pregnancy loss (RPL) at 14 IVF treatment facilities in Japan from June 2019 to August 2021. Defining RIF as three or more failed implantation attempts and RPL as two or more miscarriages, we examined the prognosis of two additional embryo transfers (ETs) after the EMMA test in patients who underwent the test.

Participants/materials, setting, methods

Endometrial tissue was obtained by aspiration from patients in day 15-25 of their menstrual cycles, and sample tissues were analyzed by NGS for EMMA. Participant centers treated patients according to the therapies specified in the reports, including antibiotic treatments, probiotic treatments, re-analysis, and embryo transfer. Multivariate analysis was performed using a generalized linear model with the endpoint of ongoing pregnancy. For the time-to-event analyses, we used Kaplan-Meier survival analysis to compare time to ongoing pregnancy.

Main results and the role of chance

The results of the first EMMA were as follows: 229 patients (43.4%) were normal with Lactobacillus spp. &gt;90% (Normal group), 110 patients (20.9%) were abnormal with less than 90% Lactobacillus spp. and predominantly pathogenic bacteria (Abnormal group), and 188 patients (35.7%) were mild with low absolute amounts of bacteria and ultralow biomass indicating almost sterile (Mild + Ultralow group). There were no significant differences in background factors such as age, duration of infertility, number of previous ETs, or history of deliveries among the three groups. Gardnerella was the most pathogenic bacteria detected in patients with Abnormal EMMA results. All patients in the Abnormal group were treated with antimicrobials and probiotics, and those in Mild + Ultralow group were treated with probiotics. Odds ratio for ongoing pregnancy rate was 1.10(95%CI 0.67-1.82, p = 0.699) in Abnormal group and 1.23(95%CI 0.80-1.89, p = 0.342) in Mild + Ultralow group, respectively. After the intervention, ongoing pregnancies were comparable to those in Normal group.Analysis of time to pregnancy using Kaplan-Meier survival curves showed that Abnormal group had a significantly higher rate of ongoing pregnancies during the observation period than the other groups (p = 0.031).

Limitations, reasons for caution

Since this study was not necessarily limited to euploid embryos transferred after testing, an aging bias cannot be excluded. Since this study was conducted with all patients receiving EMMA, the effectiveness of the test needs to be further validated by comparison to patients without EMMA testing.

Wider implications of the findings

This study is the first multicenter study to demonstrate that the intervention based on EMMA reports improve pregnancy outcome in the patients with RIF and RPL. We suggest that the EMMA procedure, which aims at establishing an appropriate uterine microbiome, may be important for implantation and pregnancy continuation.

Trial registration number

UMIN000036917

P–763 Neonatal outcomes of the first 65 infants delivered after IVF treatment with progestin-primed ovarian stimulation using dienogest in patients with endometriosis

Study question

What is the perinatal outcome of pregnancies resulting from a controlled ovarian hyperstimulation (COH) regimen of progestin-primed ovarian stimulation (PPOS) protocol using dienogest (DNG) in patients with endometriosis?

Summary answer

No difference in mean birth weight, however preterm and low birth weight babies are significantly more in the group treated with PPOS using DNG.

What is known already

Dienogest is an oral progestin effective for the treatment of endometriosis, such as reduction of endometrial lesion and control of pain intensity with safety profile and good tolerability. We reported for the first time in the world that DNG was better than dydrogesterone (DYG) for PPOS in terms of the mature oocytes rate and the fertilization rate in patients with endometriosis. Although there have been several reports of infants born with PPOS using DYG, it is essential to report on the perinatal outcome of embryos transferred after treatment with PPOS using DNG from now on. Study design, size, duration: We prospectively investigated the perinatal outcomes of 65 newborns which were the result of using a new COH regimen; PPOS with DNG. The results were compared with perinatal outcome data of babies born between 2018 and 2020 to 815 patients who underwent assisted reproductive technology (ART) treatment at our fertility center. As for the congenital malformation rate, the data was also compared with the 2017 Japanese data bank of babies born after ART treatment.

Participants/materials, setting, methods

We studied the perinatal data of all babies born after transfer of frozen embryos acquired by COH using PPOS protocol with DNG. The rate of maternal complications during pregnancy, pregnancy duration, birth weight, congenital malformations and method of delivery were investigated. We compared the perinatal outcomes of infants born after in vitro fertilization (IVF) and frozen embryo transfer at our center during the same period.

Main results and the role of chance

Perinatal data of 65 babies (study group) were compared with the perinatal data of 840 babies born after IVF at our center, and 47807 babies born after ART in Japan, 2017. We found 3 twin and 59 singleton pregnancies in the study group, compared to 23 twins, 1 triplet and 791 singleton pregnancies during the same period at our center. Considering singletons, there was no difference in mean birthweight (study group; 2893.2±652g vs. total at our center; 3001.2±425g, respectively, p = 0.102). Preterm births (&lt;37 weeks) were significantly more frequent in the PPOS using DNG treatment group than in total at our center (19.2% vs. 9.7%, p = 0.016). The percentage of infants with a birth weight &lt; 2.5 kg was also significantly higher in the PPOS treatment group compared to the total at our center (22.6% vs.11.9%, p = 0.015). The Caesarean section rate was 53.2% in the study group vs. 47.1% control group of our center respectively (p = 0.353). One babies in the study group had malformations in the ocular region. There was no significant difference in congenital malformations between the study group and ART data bank in Japan, 2017 (OR 0.67, 95% CI 0.093: 4.836).

Limitations, reasons for caution

The number of babies is still low, further prospective studies including larger populations are needed to confirm the efficacy of PPOS protocol with DNG.

Wider implications of the findings: This is the first report on the perinatal outcome of babies born by a new COH method using PPOS with DNG, which is a combination of endometriosis treatment and COH for IVF. The association of endometriosis with preterm birth and low birth weight needs to be further investigated.

Trial registration number

UMIN000031111

A multi-centre, retrospective case series of oocyte cryopreservation in unmarried women diagnosed with haematological malignancies

STUDY QUESTION

Is oocyte cryopreservation an applicable option for fertility preservation in unmarried patients with haematological malignancies?

SUMMARY ANSWER

Oocyte cryopreservation via the vitrification method is accessible and may be considered an option for fertility preservation in unmarried patients with haematological malignancies.

WHAT IS KNOWN ALREADY

Haematological malignancies are most commonly observed amongst adolescent and young adult women. Although the survival rate and life expectancy of those with haematological malignancies have improved, chemotherapy and radiotherapy may impair their reproductive potential. Oocyte cryopreservation is thus an ideal option to preserve their fertility.

STUDY DESIGN SIZE DURATION

This study retrospectively evaluated 193 unmarried patients (age: 26.2 ± 0.4 years) with haematological malignancies, who consulted for oocyte cryopreservation across 20 different fertility centres in Japan between February 2007 and January 2015. The primary outcome measures were the oocyte retrievals and oocyte cryopreservation outcomes. The secondary outcome measures were the outcomes following oocyte warming for IVF.

PARTICIPANTS/MATERIALS SETTING METHODS

The patients had commenced ovarian stimulation cycles via antagonist, agonist, natural and minimal methods for oocyte retrievals, defined according to the treatment strategy of each respective fertility centre. A vitrification method using the Cryotop safety kit was used for oocyte cryopreservation. ICSIs were used for insemination of warmed oocytes. The endometrial preparation method for embryo transfer was hormonal replacement therapy, except in the case of a patient who underwent a spontaneous ovulatory cycle.

MAIN RESULTS AND THE ROLE OF CHANCE

Among 193 patients, acute myeloid leukaemia (n = 45, 23.3%) was most common, followed by acute lymphoid leukaemia (n = 38, 19.7%) and Hodgkin's lymphoma (n = 30, 15.5%). In total, 162 patients (83.9%) underwent oocyte retrieval, and oocytes were successfully cryopreserved for 155 patients (80.3%). The mean number of oocyte retrieval cycles and cryopreserved oocytes were 1.7 ± 0.2 and 6.3 ± 0.4, respectively. As of December 2019, 14 patients (9.2%) had requested oocyte warming for IVF. The survival rate of oocytes after vitrification-warming was 85.2% (75/88). The rates of fertilisation and embryo development were 80.0% (60/75) and 46.7% (28/60), respectively. Ten patients (71.4%) had successful embryo transfers, and seven live births (50.0%) were achieved.

LIMITATIONS REASONS FOR CAUTION

This study was limited by its retrospective nature. Additionally, there remains an insufficient number of cases regarding the warming of vitrified oocytes to reliably conclude whether oocyte cryopreservation is effective for patients with haematological malignancies. Further long-term follow-up study is required.

WIDER IMPLICATIONS OF THE FINDINGS

Oocyte retrieval and oocyte cryopreservation were accessible for patients with haematological malignancies; however, the number of oocyte retrievals may have been limited due to the initiation of cancer treatments. Acceptable embryonic and pregnancy outcomes could be achieved following oocyte warming; therefore, our results suggest that oocyte cryopreservation can be considered an option for fertility preservation in patients with haematological malignancies.

STUDY FUNDING/COMPETING INTERESTS

This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors. The authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Comparison between optical frequency domain imaging and intravascular ultrasound in PCI guidance for Biolimus A9 eluting stent implantation

Background

It has been reported that intravascular ultrasound (IVUS) guided PCI reduced a risk of major adverse cardiac event compared to conventional angiography guided PCI, while comparison between IVUS-guided and optical frequency domain imaging (OFDI)-guided PCI specifically in long-term clinical outcomes (&gt;1 year) has been unexplored.

Purpose

We sought to compare imaging surrogates at 8 months and clinical outcomes beyond 1 year after drug-eluting stent implantation between IVUS and OFDI guidance.

Methods

The MISTIC-1 is a prospective, multi-centre, single-blinded, randomised-controlled, non-inferiority trial comparing OFDI-guided and IVUS-guided PCI using Biolimus A9 eluting Nobori stent. We enrolled patients with stable coronary artery disease who have symptoms or clinically relevant myocardial ischemia. Stent landing zones were selected in the most normal looking sites with largest lumen and without percentage plaque area &gt;50% in IVUS group while without lipidic plaque of &gt;2 quadrants or suggestive thin-cap fibroatheroma in OFDI group. Stent sizing was based on external elastic lamina (EEL) in IVUS group, while by taking 10% or 0.25mm larger than mean lumen diameter at reference sites in OFDI group. Stent optimisation with in-stent minimum lumen area ≥80% of the average lumen area at proximal and distal reference sites was encouraged in both groups. Primary efficacy endpoint is in-segment minimum lumen area (MLA) assessed by OFDI at 8 months. Secondary safety endpoint is a composite of cardiovascular death, target vessel myocardial infarction, or target lesion revascularisation. Based on the assumption that mean in-segment MLA at follow-up was 4.5mm2 with a standard deviation of 2.0mm2 in the control (IVUS) group and a non-inferiority limit of 1.2mm2 for OFDI group, sample size was estimated as 48 cases in each group with 5% type I error and 90% statistical power.

Results

Since June-2014 and August-2016, we prospectively enrolled 109 patients (mean age 70 years, male 78%) with 126 lesions. Baseline patient and lesion characteristics were well balanced and average nominal size and length of stent used did not differ between OFDI-guided and IVUS-guided PCI (3.0 and 19.1mm vs. 3.1 and 19.3mm, respectively). Post-procedural minimum stent area was 6.24mm2 in OFDI group and 6.72mm2 in IVUS group (p=0.20). At 8-month follow-up, in-segment MLA was 4.56mm2 in OFDI group and 4.13mm2 in IVUS group (P for non-inferiority &lt;0.001). During the follow-up (median 4.5 years [1654 days]), incidence rates of major adverse cardiac event were comparable between the two groups (7.4% in OFDI group and 7.3% in IVUS group, hazard ratio 0.96, 95% CI 0.24–3.83, p=0.95). No definite or probable stent thrombosis were documented in both groups.

Conclusion

OFDI-guided PCI demonstrated comparable results in achieving satisfactory imaging surrogates as well as long-term clinical outcomes after newer generation DES implantation as compared to IVUS-guided PCI.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Suzuken Memorial Foundation

6108Efficacy of the PCSK9 inhibitor for lipid-rich coronary plaque reduction: a near-infrared spectroscopy analysis

Background

Recently, some studies have highlighted proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors produce incremental low-density lipoprotein cholesterol (LDL-C) lowering effect. However, it is unknown whether the lipid composition of plaque changes is associated with serum LDL-C reduction due to PCSK9 inhibitors administration.

Purpose

The purpose of this study was to determine the effects of PCSK9 inhibitor (PCSK9i) on coronary plaque component in patients with a history of coronary artery disease (CAD) assessed by near-infrared spectroscopy intravascular ultrasound (NIRS-IVUS).

Methods

A total of 67 non-culprit coronary segments were identified in 34 patients. These lesions were analyzed utilizing NIRS-IVUS at baseline and follow-up coronary angiography (CAG). The subjects were divided into two groups according to lipid-lowering treatment; administration of PCSK9i group (PCSK9i: 19 segments, 9 patients) and traditional statin treatment group (Control: 48 segments, 25 patients). The change of lipid-rich plaque distribution between baseline and follow-up NIRS-IVUS was defined as the change of maximal lipid core burden index (LCBI) score for each of the 4-mm longitudinal segments (maxLCBI4mm).

Results

Mean duration from baseline to follow-up CAG was 239.4±52.4 days in the PCSK9i group and 341.0±84.1 days in the Control group (p<0.001). Despite the higher total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in the PCSK9i group at baseline (206.6±40.9 mg/dl vs. 168.5±37.1 mg/dl, 131.5±35.4 mg/dl vs. 100.0±29.5 mg/dl; respectively, p<0.001 for both), the PCSK9i group was significantly lower TC and LDL-C at the follow-up (111.5±23.5 mg/dl vs. 157.4±27.8 mg/dl, 40.8±15.7 mg/dl vs. 86.2±19.6 mg/dl; respectively, p<0.001 for both). Furthermore, the PCSK9i group induced greater regression of maxLCBI4mm than that of Control group (99.6±156.6 vs. 27.9±118.0, p=0.046) (Figure).

Figure 1

Conclusion

Compared with traditional statin therapy, PCSK9i treatment resulted in a greater decrease in lipid component in non-culprit coronary plaques. Therefore, PCSK9i may be useful option in preventing from adverse coronary events for the patients with CAD.

Excitability Tuning of Axons by Afterdepolarization

The axon provides a sole output of the neuron which propagates action potentials reliably to the axon terminal and transmits neuronal information to the postsynaptic neuron across the synapse. A classical view of neuronal signaling is based on these two processes, namely binary (all or none) signaling along the axon and graded (tunable) signaling at the synapse. Recent studies, however, have revealed that the excitability of the axon is subject to dynamic tuning for a short period after axonal action potentials. This was first described as post-spike hyperexcitability, as measured by the changes in stimulus threshold for a short period after an action potential. Later on, direct recordings from central nervous system (CNS) axons or axon terminals using subcellular patch-clamp recording showed that axonal spikes are often followed by afterdepolarization (ADP) lasting for several tens of milliseconds and has been suggested to mediate post-spike hyperexcitability. In this review article, I focused on the mechanisms as well as the functional significance of ADP in fine-scale modulation of axonal spike signaling in the CNS, with special reference to hippocampal mossy fibers, one of the best-studied CNS axons. As a common basic mechanism underlying axonal ADP, passive propagation by the capacitive discharge of the axonal membrane as well as voltage-dependent K⁺ conductance underlies the generation of ADP. Small but prolonged axonal ADP lasting for several tens of milliseconds may influence the subsequent action potential and transmitter release from the axon terminals. Both duration and amplitude of axonal spike are subject to such modulation by preceding action potential-ADP sequence, deviating from the conventional assumption of digital nature of axonal spike signaling. Impact on the transmitter release is also discussed in the context of axonal spike plasticity. Axonal spike is subject to dynamic control on a fine-scale and thereby contributes to the short-term plasticity at the synapse.

Modeling Analysis of Axonal After Potential at Hippocampal Mossy Fibers

Action potentials reliably propagate along the axons, and after potential often follows the axonal action potentials. After potential lasts for several tens of millisecond and plays a crucial role in regulating excitability during repetitive firings of the axon. Several mechanisms underlying the generation of after potential have been suggested, including activation of ionotropic autoreceptors, accumulation of K⁺ ions in the surrounding extracellular space, the opening of slow voltage-dependent currents, and capacitive discharge of upstream action potentials passively propagated through axon cable. Among them, capacitive discharge is difficult to examine experimentally, since the quantitative evaluation of a capacitive component requires simultaneous recordings from at least two different sites on the connecting axon. In this study, a series of numerical simulation of the axonal action potential was performed using a proposed model of the hippocampal mossy fiber where morphological as well as electrophysiological data are accumulated. To evaluate the relative contribution of the capacitive discharge in axonal after potential, voltage-dependent Na⁺ current as well as voltage-dependent K⁺ current was omitted from a distal part of mossy fiber axons. Slow depolarization with a similar time course with the recorded after potential in the previous study was left after blockade of Na⁺ and K⁺ currents, suggesting that a capacitive component contributes substantially in axonal after potential following propagating action potentials. On the other hand, it has been shown that experimentally recorded after potential often showed clear voltage-dependency upon changes in the initial membrane potential, obviously deviating from voltage-independent nature of the capacitive component. The simulation revealed that activation of voltage-dependent K⁺ current also contributes to shape a characteristic waveform of axonal after potential and reconstitute similar voltage-dependency with that reported for the after potential recorded from mossy fiber terminals. These findings suggest that the capacitive component reflecting passive propagation of upstream action potential substantially contributes to the slow time course of axonal after potential, although voltage-dependent K⁺ current provided a characteristic voltage dependency of after potential waveform.

Post-occlusional hyperemia for fractional flow reserve assessment and pull-back curve analysis

Balloon occlusion is a potential method for inducing hyperemia to measure post-percutaneous coronary intervention (PCI) fractional flow reserve (FFR). The objective of this study was to determine the clinical usefulness of post-occlusional hyperemia. FFRs measured using post-occlusional hyperemia caused by 30 (FFR_occl30) and 60 s (FFR_occl60) of balloon occlusion after PCI were compared in 60 lesions from 60 patients. The duration of hyperemia was also measured. There was a strong correlation between FFR_occl30 and FFR_occl60 (r = 0.969, p < 0.01). The duration of hyperemia was significantly longer with FFR_occl60 than with FFR_occl30 (68 ± 23 vs. 37 ± 15 s, p < 0.01). The time required for pullback curve analysis was around 45 s. However, in 7 (12%) cases, the duration of hyperemia with FFR_occl60 was < 45 s, which was not enough for pull-back curve analysis. To predict the duration of hyperemia with FFR_occl60 ≥ 45 s, the receiver operating characteristic curve analysis revealed a cut-off value of 25 s of hyperemia with FFR_occl30. FFR_occl30 is sufficient for diagnostic purposes. FFR_occl60 is suitable for pull-back curve analysis in select cases based on predictions made using the duration of hyperemia with FFR_occl30.

Angiogram based fractional flow reserve in patients with dual/triple vessel coronary artery disease

OBJECTIVE

To assess the performance of angiography derived Fractional Flow Reserve (FFRangio) in multivessel disease (MVD) patients undergoing angiography.

BACKGROUND

FFR is the reference standard for physiologic assessment of coronary stenosis and guidance of revascularization, especially in patients with MVD, yet it remains grossly underutilized. The non-wire based FFRangio performs well in non-MVD patients, but its accuracy in MVD is unknown.

METHODS

A prospective clinical study was conducted at Gifu Heart Centre, Japan. Patients underwent physiologic assessment of all relevant coronary lesions using wire-based FFR (wbFFR) and FFRangio. Primary outcome was diagnostic performance (sensitivity, specificity, accuracy) for FFRangio with wbFFR as reference. Other outcomes were the correlation between wbFFR/FFRangio, time required for wbFFR/FFRangio measurements, and the effect of wbFFR/FFRangio on the reclassification of coronary disease severity.

RESULTS

Fifty patients (118 lesions in total) were included. Mean age was 72 ± 9 years, 72% were male, 36% had triple vessel disease and the average SYNTAX score was 13. The mean measurement of wbFFR and FFRangio were 0.83 ± 0.12 and 0.81 ± 0.11, respectively. Accuracy, sensitivity and specificity for FFRangio were 92.3% (95% CI 79.1-98.4%), 92.4% (95% CI 84.3-97.2%) and 92.4% (95% CI 87.4-97.3%), respectively. Pearson's r between wbFFR and FFRangio was 0.83. FFRangio measurement was faster than wbFFR (9.6 ± 3.4 vs. 15.0 ± 8.9 min, p < 0.001).

CONCLUSIONS

In patients with MVD, FFRangio shows good correlation and excellent diagnostic performance compared to wbFFR, and measuring FFRangio is faster than wbFFR. These results highlight the potential clinical benefits of utilizing FFRangio among patients with MVD.

Sevoflurane inhibits presynaptic calcium influx without affecting presynaptic action potentials in hippocampal CA1 region

Although diverse effects of volatile anesthetics have been investigated in various studies, the mechanisms of action of such anesthetics, especially sevoflurane, remain elusive. In contrast to their potent modulation of inhibitory synaptic transmission there is little information about their effects on excitatory transmission in the brain. In this study, we examined the effect of sevoflurane on the excitatory synaptic transmission at CA1 synapses in hippocampal slices of mice. Sevoflurane at 5% was mixed with 95% O₂ and 5% CO₂ and bubbled in artificial cerebral spinal fluid (0.69 mM). Extracellular recordings of the field excitatory postsynaptic potential (fEPSP) and presynaptic fiber volley (FV) were made at physiological temperature. In addition, fluorescent measurements of presynaptic Ca²⁺ transients were performed while simultaneously recording fEPSP. Application of sevoflurane reduced the amplitude of fEPSP (45 ± 8%, n = 5). This effect was accompanied by concurrent enhancement of the paired-pulse facilitation of fEPSP (127 ± 5%, n = 12), suggesting a possible presynaptic site of action of sevoflurane. The amplitude of FV was not significantly affected (102 ± 5%, n = 5). In contrast, fluorescent measurements revealed that presynaptic Ca²⁺ influx was suppressed by sevoflurane (69 ± 5%, n = 7), as was simultaneously recorded fEPSP (44 ± 5%, n = 7). Our results suggest that sevoflurane potently suppresses excitatory synaptic transmission via inhibition of presynaptic Ca²⁺ influx without affecting presynaptic action potentials.

A Precise Sampling Strip with Microstructures

This paper presents a precise sampling microstructure formed as a paper strip. We have been developing dialysis system that can be implanted into a human body as an artificial kidney. For the safe use of our artificial kidney, the patients' urine needs to be constantly monitored to detect the abnormal value of ion concentration essential for human life. We are conceiving the monitoring system based on sampling by a paper strip. In this study, we fabricated the strip consisting of slanted and interlocked micropillars for the sampling, known as synthetic microfluidic paper. The paper-like substrate can be fabricated with a well-controlled geometry and subsequently enables precise sampling. Through the conducted experiments, it was shown that synthetic microfluidic paper had better mechanical properties, showed more precision in sampling than paper filter as well as corresponding liquid holding capability to the paper filter. Our proposed paper-based sampling system is expected to lead to the development of minimally invasive ion monitoring system with quantitative sampling strip.

Synapse-specific effects of IL-1β on long-term potentiation in the mouse hippocampus

Interleukin-1β (IL-1β) is a key molecule in the inflammatory responses elicited during infection and injury. It exerts local effects on synaptic plasticity by binding to IL-1 receptors that are expressed at high levels in the hippocampus. We examined the effects of IL-1β on synaptic plasticity in different hippocampal regions in acute mouse brain slices by measuring long-term potentiation (LTP). IL-1β (1 ng/mL) was applied for 30 min before LTP was induced with high-frequency stimulation (HFS). LTP was significantly impaired by either IL-1β application to the Schaffer collateral-CA1 synapses or the associational/commissural (A/C) fiber-CA3 synapses, which are both dependent on N-methyl-D-aspartate (NMDA) receptor activation. However, mossy fiber-CA3 LTP, which is expressed presynaptically in an NMDA-independent manner, was not impaired by IL-1β. Our results demonstrate that IL-1β exerts variable effects on LTP at different kinds of synapses, indicating that IL-1β has synapse-specific effects on hippocampal synaptic plasticity.

Geosmin-producing Species of Coelosphaerium (Synechococcales, Cyanobacteria) in Lake Shinji, Japan

In Lake Shinji, Japan, periodic outbreaks of musty odour have occurred since mid-May 2007. Although the substance responsible for the odour was identified as geosmin, the odour-producing organism was unknown. We cultivated an axenic unialgal strain and determined that a species of Coelosphaerium (Synechococcales) was responsible for the production of geosmin in Lake Shinji. Our analysis was conducted using gas chromatography/mass spectrometry to determine the odorous compound. To determine the algae species, it was observed by optical microscopy to describe its morphological characteristics and the polymerase chain reaction was used to characterise the nucleotide sequence of the 16S rRNA gene and the 16S-23S rRNA internal transcribed spacer region. In addition, we explored the relationship between the number of cells of the Coelosphaerium sp. and the concentration of geosmin. In conclusion, geosmin, the cause of the musty odour in Lake Shinji in autumn 2009, was produced by Coelosphaerium sp., and to our knowledge, this is the first report of a geosmin-producing species in the family Coelosphaeriaceae.

Formation kinetics of particulate films in directional drying of a colloidal suspension

We observed the kinetics of formation of colloidal films through directional drying with a pinned drying interface. The volume fraction of particles accumulated at the pinned drying interface increased in two stages: it rapidly increased in the initial stage of drying and then slowly increased. The final filling factor of the dried films decreased with increasing drying flux. We found a threshold drying flux for the formation of colloidal films below which uneven films are formed at the drying interface. This threshold flux is well explained by the competition between transport of particles by flow and transport by diffusion. We also found a minimum thickness for the formation of a packed layer of particles. The formation kinetics of a packed layer of particles due to drying was discussed.

Excitability tuning of axons in the central nervous system

The axon is a long neuronal process that originates from the soma and extends towards the presynaptic terminals. The pioneering studies on the squid giant axon or the spinal cord motoneuron established that the axon conducts action potentials faithfully to the presynaptic terminals with self-regenerative processes of membrane excitation. Recent studies challenged the notion that the fundamental understandings obtained from the study of squid giant axons are readily applicable to the axons in the mammalian central nervous system (CNS). These studies revealed that the functional and structural properties of the CNS axons are much more variable than previously thought. In this review article, we summarize the recent understandings of axon physiology in the mammalian CNS due to progress in the subcellular recording techniques which allow direct recordings from the axonal membranes, with emphasis on the hippocampal mossy fibers as a representative en passant axons typical for cortical axons.

PSD-95 regulates synaptic kainate receptors at mouse hippocampal mossy fiber-CA3 synapses

Kainate-type glutamate receptors (KARs) are the third class of ionotropic glutamate receptors whose activation leads to the unique roles in regulating synaptic transmission and circuit functions. In contrast to AMPA receptors (AMPARs), little is known about the mechanism of synaptic localization of KARs. PSD-95, a major scaffold protein of the postsynaptic density, is a candidate molecule that regulates the synaptic KARs. Although PSD-95 was shown to bind directly to KARs subunits, it has not been tested whether PSD-95 regulates synaptic KARs in intact synapses. Using PSD-95 knockout mice, we directly investigated the role of PSD-95 in the KARs-mediated components of synaptic transmission at hippocampal mossy fiber-CA3 synapse, one of the synapses with the highest density of KARs. Mossy fiber EPSCs consist of AMPA receptor (AMPAR)-mediated fast component and KAR-mediated slower component, and the ratio was significantly reduced in PSD-95 knockout mice. The size of KARs-mediated field EPSP reduced in comparison with the size of the fiber volley. Analysis of KARs-mediated miniature EPSCs also suggested reduced synaptic KARs. All the evidence supports critical roles of PSD-95 in regulating synaptic KARs.

Voltage-gated calcium and sodium channels mediate Sema3A retrograde signaling that regulates dendritic development

Growing axons rely on local signaling at the growth cone for guidance cues. Semaphorin3A (Sema3A), a secreted repulsive axon guidance molecule, regulates synapse maturation and dendritic branching. We previously showed that local Sema3A signaling in the growth cones elicits retrograde retrograde signaling via PlexinA4 (PlexA4), one component of the Sema3A receptor, thereby regulating dendritic localization of AMPA receptor GluA2 and proper dendritic development. In present study, we found that nimodipine (voltage-gated L-type Ca(2+) channel blocker) and tetrodotoxin (TTX; voltage-gated Na(+) channel blocker) suppress Sema3A-induced dendritic localization of GluA2 and dendritic branch formation in cultured hippocampal neurons. The local application of nimodipine or TTX to distal axons suppresses retrograde transport of Venus-Sema3A that has been exogenously applied to the distal axons. Sema3A facilitates axonal transport of PlexA4, which is also suppressed in neurons treated with either TTX or nimodipine. These data suggest that voltage-gated calcium and sodium channels mediate Sema3A retrograde signaling that regulates dendritic GluA2 localization and branch formation.

[Mitral regurgitation in heart failure. Surgical therapy]

The optimal treatment of mitral regurgitation concomitant to heart failure remains controversial. A lack of consensus between cardiologists and cardiac surgeons, because of limited studies and heterogeneous data, has led to vaguely defined guidelines and different handling in the clinical routine in the past. However, progress in the operative management with excellent results of individual experienced centers suggests that a variety of patients might benefit from surgical therapy. Each patient should be evaluated individually regarding the benefits of surgical therapy which requires an interdisciplinary approach ("heart team") due to the complex pathophysiology and demanding diagnostics.