The Use of Carboxyfluorescein Reveals the Transport Function of MCT6/SLC16A5 Associated with CD147 as a Chloride-Sensitive Organic Anion Transporter in Mammalian Cells

Oral drug absorption involves drug permeation across the apical and basolateral membranes of enterocytes. Although transporters mediating the influx of anionic drugs in the apical membranes have been identified, transporters responsible for efflux in the basolateral membranes remain unclear. Monocarboxylate transporter 6 (MCT6/SLC16A5) has been reported to localize to the apical and basolateral membranes of human enterocytes and to transport organic anions such as bumetanide and nateglinide in the Xenopus oocyte expression system; however, its transport functions have not been elucidated in detail. In this study, we characterized the function of MCT6 expressed in HEK293T cells and explored fluorescent probes to more easily evaluate MCT6 function. The results illustrated that MCT6 interacts with CD147 to localize at the plasma membrane. When the uptake of various fluorescein derivatives was examined in NaCl-free uptake buffer (pH 5.5), the uptake of 5-carboxyfluorescein (5-CF) was significantly greater in MCT6 and CD147-expressing cells. MCT6-mediated 5-CF uptake was saturable with a Km of 1.07 mM and inhibited by several substrates/inhibitors of organic anion transporters and extracellular Cl ion with an IC50 of 53.7 mM. These results suggest that MCT6 is a chloride-sensitive organic anion transporter that can be characterized using 5-CF as a fluorescent probe.

Design and fabrication of a coupled high-Q photonic nanocavity system with large coupling coefficients

In a previous work, we demonstrated a coupled cavity system where photons in one storage cavity can be transferred to another storage cavity at an arbitrary time by applying a voltage pulse to a third cavity placed in a p-i-n junction. In this work, we demonstrate methods to improve the transfer efficiency and photon lifetimes of such a coupled system. Firstly, we designed a photonic-crystal structure that achieves a large coupling coefficient without reducing the radiation quality factor compared to the previously proposed structure: The photonic-crystal design was changed to a more symmetric configuration to suppress radiation losses and then optimized using an automatic structure tuning method based on the Covariance Matrix Adaptive Evolutional Strategy (CMAES). Here we added two improvements to achieve an evolution toward the desired direction in the two-dimensional target parameter space (spanned by the coupling coefficient and the inverse radiation loss). Secondly, to improve the experimental cavity quality factors, we developed a fabrication process that reduces the surface contamination associated with the fabrication of the p-i-n junction: We covered the photonic structure with a SiO2 mask to avoid the contamination and the electrode material was changed from Al to Au/Cr to enable cleaning by a weak acid. Owing to these improvements of the cavity design and the fabrication process, the obtained system provides coupling strengths that are about three times stronger and photon lifetimes that are about two times longer, compared to the previously reported system.

Magnitude of Fruit Juice-Drug Interactions Due to Osmolality-Dependent Fluid Secretion: Differences among Apple, Orange, and Grapefruit Juices

We recently reported that the gastrointestinal (GI) fluid volume is influenced by the solution osmolality, and proposed that this effect may play a role in beverage-drug interactions. Here, we investigated whether osmolality-dependent fluid secretion can explain the difference in the magnitudes of fruit juice-drug interactions depending on the type of fruit juice (grapefruit juice (GFJ), orange juice (OJ), and apple juice (AJ)). The osmolality of GFJ, OJ, and AJ used in this study was found to be 552, 686, and 749 mOsm/kg, respectively. Measurements of intestinal fluid movement following beverage administration by the in situ closed-loop technique revealed the following rank order for fluid volume in rat ileum: AJ > OJ > GFJ > purified water, suggesting that water movement is dependent on the osmolality of these beverages. Such changes in GI fluid volume are expected to alter the luminal drug concentration, potentially contributing to the magnitude of beverage-drug interactions. Indeed, in vivo pharmacokinetic study in rats revealed that the plasma concentration of atenolol, a low-permeability drug, was the highest after oral administration in purified water, followed by GFJ and OJ, and was the lowest after administration in AJ. In contrast, antipyrine, a high-permeability drug, showed no significant difference in plasma concentration after administration in purified water and fruit juices, suggesting that the absorption of high-permeability drugs is less affected by solution osmolality. Our findings indicate that differences in the magnitude of beverage-drug interactions can be at least partly explained by differences in the osmolality of the beverages ingested.

Macrolide and Ketolide Antibiotics Inhibit the Cytotoxic Effect of Trastuzumab Emtansine in HER2-Positive Breast Cancer Cells: Implication of a Potential Drug-ADC Interaction in Cancer Chemotherapy

Macrolides are widely used for the long-term treatment of infections and chronic inflammatory diseases. The pharmacokinetic features of macrolides include extensive tissue distribution because of favorable membrane permeability and accumulation within lysosomes. Trastuzumab emtansine (T-DM1), a HER2-targeting antibody-drug conjugate (ADC), is catabolized in the lysosomes, where Lys-SMCC-DM1, a potent cytotoxic agent, is processed by proteinase degradation and subsequently released from the lysosomes to the cytoplasm through the lysosomal membrane transporter SLC46A3, resulting in an antitumor effect. We recently demonstrated that erythromycin and clarithromycin inhibit SLC46A3 and attenuate the cytotoxicity of T-DM1; however, the effect of other macrolides and ketolides has not been determined. In this study, we evaluated the effect of macrolide and ketolide antibiotics on T-DM1 cytotoxicity in a human breast cancer cell line, KPL-4. Macrolides used in the clinic, such as roxithromycin, azithromycin, and josamycin, as well as solithromycin, a ketolide under clinical development, significantly attenuated T-DM1 cytotoxicity in addition to erythromycin and clarithromycin. Of these, azithromycin was the most potent inhibitor of T-DM1 efficacy. These antibiotics significantly inhibited the transport function of SLC46A3 in a concentration-dependent manner. Moreover, these compounds extensively accumulated in the lysosomes at the levels estimated to be 0.41-13.6 mM when cells were incubated with them at a 2 μM concentration. The immunofluorescence staining of trastuzumab revealed that azithromycin and solithromycin inhibit the degradation of T-DM1 in the lysosomes. These results suggest that the attenuation of T-DM1 cytotoxicity by macrolide and ketolide antibiotics involves their lysosomal accumulation and results in their greater lysosomal concentrations to inhibit the SLC46A3 function and T-DM1 degradation. This suggests a potential drug-ADC interaction during cancer chemotherapy.

The effect of nano hydroxyapatite coating implant surfaces on gene expression and osseointegration

BACKGROUND

Hierarchical micro-nano structured topography along with surface chemistry modifications of dental implants have been suggested to positively contribute to the osseointegration process. However, the effect of such surface modifications on the molecular response as well as bone formation rate and quality are still unclear, especially in the early healing period. This study aimed to evaluate the effect of coating a double acid etched (DAE) implant surface with nano-sized (20 nm) hydroxyapatite (Nano) with respect to gene expression, histologic parameters, and nanomechanical properties when compared to DAE control at 1 and 2 weeks after implant placement in a rodent femur model.

MATERIAL AND METHODS

Expression of bone-related genes was determined by qRT-PCR (Col-I, Runx-2, Osx, Opn, Ocn, Alp). Histomorphometric evaluation of bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) within implant threads was performed using photomicrographs after histologic processing. Mechanical properties, reduced elastic modulus and hardness, were determined through nanoindentation.

RESULTS

At 1 week, the Nano group demonstrated significantly higher expression of Col-I and Ocn compared to the DAE group, indicating upregulation of osteoprogenitor and osteoblast differentiation genes. At 2 weeks, Nano surface further exhibited enhanced gene expression of Col-I and Osx in comparison to the DAE surface, suggesting an increased mineralization of the newly formed bone. Nanoindentation analysis revealed that the Nano group presented no significant difference on the ranks of reduced elastic modulus and hardness compared to DAE for both timepoints. Histomorphometric analysis yielded no significant difference in the percentage of BIC and BAFO between the Nano and DAE surfaces at 1 and 2 weeks. However, Nano implants did present a higher mean value, ~50%, of BIC compared to DAE, ~30%, after 2 weeks in vivo.

CONCLUSIONS

While no significant differences were observed in the amount and mechanical properties of newly formed bone, Nano surface positively and significantly increased the expression osteogenic genes compared to DAE surface at early healing periods.

Quantitative analysis of gastrointestinal fluid absorption and secretion to estimate luminal fluid dynamics in rats

The drug absorption profile is dependent on the luminal drug concentration, which in turn is influenced by the gastrointestinal (GI) fluid dynamics. In the present study, therefore, we aimed to examine the luminal fluid dynamics by kinetically analyzing fluid absorption and secretion along the GI tract in rats using the in situ closed-loop technique with non-absorbable fluorescein isothiocyanate-dextran 4000 (FD-4) and tritium water labeling ([3H]water) under different osmotic conditions. We found that the luminal fluid volume in the jejunum and ileum, but not the colon, gradually decreased and reached a steady state. In contrast, [3H]water almost completely disappeared in all intestinal regions. Kinetic analysis revealed the following rank order for the rate constant of fluid secretion: jejunum > ileum > colon, whereas a negligible regional difference was observed in the rate constant of fluid absorption. Fluid secretion under an isosmotic condition (300 mOsm/kg) was higher than that at 0 mOsm/kg in all intestinal regions, though no significant changes in fluid absorption were observed. Thus, the fluid secretion process appears to be the major determinant of the regional differences in GI fluid dynamics. Our findings indicate that the luminal fluid volume is altered as a result of water ingestion, absorption, and secretion, and finally reaches an apparent steady state, which is regulated mainly by the process of fluid secretion.

Monocarboxylate Transporter 13 (MCT13/SLC16A13) Functions as a Novel Plasma Membrane Oligopeptide Transporter

SLC16A13, which encodes the monocarboxylate transporter 13 (MCT13), is a susceptibility gene for type 2 diabetes and is expressed in the liver and duodenum. Some peptidase-resistant oligopeptides are absorbed in the gastrointestinal tract and affect glycemic control in the body. Their efficient absorption is mediated by oligopeptide transporter(s) at the apical and basolateral membranes of the intestinal epithelia; however, the molecules responsible for basolateral oligopeptide transport have not been identified. In this study, we examined whether MCT13 functions as a novel basolateral oligopeptide transporter. We evaluated the uptake of oligopeptides and peptidomimetics in MCT13-transfected cells. The uptake of cephradine, a probe for peptide transport system(s), significantly increased in MCT13-transfected cells, and this increase was sensitive to membrane potential. The cellular accumulation of bioactive peptides, such as anserine and carnosine, was decreased by MCT13, indicating MCT13-mediated efflux transport activity. In polarized Caco-2 cells, MCT13 was localized at the basolateral membrane. MCT13 induction enhanced cephradine transport in an apical-to-basal direction across Caco-2 cells. These results indicate that MCT13 functions as a novel efflux transporter of oligopeptides and peptidomimetics, driven by electrochemical gradients across the plasma membrane, and it may be involved in the transport of these compounds across the intestinal epithelia.

Distribution of natural radionuclides in NORM samples from North Abu Rusheid area, Egypt

The North Abu Rusheid area in Egypt is a well-known high background natural radiation area (HBNRA) due to the existence of naturally occurring radioactive materials (NORMs) in mylonitic rocks. In this study, 27 rock samples were selected for dose estimation studies. ²³⁸U and ²³²Th were measured using inductively coupled plasma mass spectrometry (ICP-MS) and ⁴⁰K was measured using sodium iodide (thallium) gamma-ray spectroscopy. The ranges of activity concentrations (Bq/kg) of ²³⁸U, ²³²Th and ⁴⁰K in the samples varied from 270 ± 2 to 2120 ± 29, 350 ± 2 to 1840 ± 27 and 20 ± 2 to 1390 ± 35 with mean values of 980 ± 349, 770 ± 351, and 640 ± 402 Bq/kg, respectively. The radiological hazard parameters were estimated from activity concentrations of ²³⁸U, ²³²Th and ⁴⁰K and compared to United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) values. The present study revealed that the hazard parameters were several times higher than the worldwide averages. The U/Th concentration ratio ranged from 0.7 to 3 and could be attributed to the presence of kasolite, uranothorite, zircon, and columbite in mylonitic rocks. From the radiological protection viewpoint, it is necessary to monitor natural radionuclides in these rocks prior to their use in residential and commercial construction materials.

Quantitative Analysis of Gastrointestinal Water Dynamics by Means of a Physiologically Based Fluid Kinetic Model

Since the processes of dissolution and membrane permeation are affected by the water content in the gastrointestinal (GI) tract, the water dynamics in the GI tract is expected to have a significant impact on the absorption of orally administered drugs. Here, we aimed to develop a physiologically based fluid kinetic (PBFK) model using GI water kinetic parameters obtained from in situ closed-loop studies in rats in order to quantitatively predict GI water dynamics. By incorporating the experimentally measured site-specific parameters of GI water absorption and secretion into a GI compartment model, we developed a bottom-up PBFK model that successfully simulates the reported GI fluid dynamics in rats and humans observed using positron emission tomography and magnetic resonance imaging, respectively. The simulations indicate that the water volume in both the stomach and duodenum is transiently increased by water ingestion, while that in the intestine below the jejunum is unchanged and remains in a steady state in both rats and humans. Furthermore, sensitivity analysis of the effect of ingested water volume on the volume-time profiles of water in the GI tract indicated that the impact of ingested water is limited to the proximal part of the GI tract. Simulations indicated that changes in water kinetic parameters may alter the impact of the ingested water on GI fluid dynamics, especially in the proximal part. Incorporating this PBFK model into a physiologically based pharmacokinetic (PBPK) absorption model has the potential to predict oral drug absorption in a variety of GI water environments.

The Glycosylated N-Terminal Domain of MUC1 Is Involved in Chemoresistance by Modulating Drug Permeation Across the Plasma Membrane

Mucin 1 (MUC1) is aberrantly expressed in various cancers and implicated in cancer progression and chemoresistance. Although the C-terminal cytoplasmic tail of MUC1 is involved in signal transduction, promoting chemoresistance, the role of the extracellular MUC1 domain [N-terminal glycosylated domain (NG)-MUC1] remains unclear. In this study, we generated stable MCF7 cell lines expressing MUC1 and cytoplasmic tail-deficient MUC1 (MUC1ΔCT) and show that NG-MUC1 is involved in drug resistance by modulating the transmembrane permeation of various compounds without cytoplasmic tail signaling. Heterologous expression of MUC1ΔCT increased cell survival in treating anticancer drugs (such as 5-fluorouracil, cisplatin, doxorubicin, and paclitaxel), in particular by causing an approximately 150-fold increase in the IC₅₀ of paclitaxel, a lipophilic drug, compared with the control [5-fluorouracil (7-fold), cisplatin (3-fold), and doxorubicin (18-fold)]. The uptake studies revealed that accumulations of paclitaxel and Hoechst 33342, a membrane-permeable nuclear staining dye, were reduced to 51% and 45%, respectively, in cells expressing MUC1ΔCT via ABCB1/P-gp-independent mechanisms. Such alterations in chemoresistance and cellular accumulation were not observed in MUC13-expressing cells. Furthermore, we found that MUC1 and MUC1ΔCT increased the cell-adhered water volume by 2.6- and 2.7-fold, respectively, suggesting the presence of a water layer on the cell surface created by NG-MUC1. Taken together, these results suggest that NG-MUC1 acts as a hydrophilic barrier element against anticancer drugs and contributes to chemoresistance by limiting the membrane permeation of lipophilic drugs. Our findings could help better the understanding of the molecular basis of drug resistance in cancer chemotherapy. SIGNIFICANCE STATEMENT: Membrane-bound mucin (MUC1), aberrantly expressed in various cancers, is implicated in cancer progression and chemoresistance. Although the MUC1 cytoplasmic tail is involved in proliferation-promoting signal transduction thereby leading to chemoresistance, the significance of the extracellular domain remains unclear. This study clarifies the role of the glycosylated extracellular domain as a hydrophilic barrier element to limit the cellular uptake of lipophilic anticancer drugs. These findings could help better the understanding of the molecular basis of MUC1 and drug resistance in cancer chemotherapy.

Formation and evolution of carbonaceous asteroid Ryugu: Direct evidence from returned samples

Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed through aqueous alteration reactions at low temperature, high pH, and water/rock ratios of <1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate that Ryugu's parent body formed ~2 million years after the beginning of Solar System formation.

Search for the Majorana Nature of Neutrinos in the Inverted Mass Ordering Region with KamLAND-Zen

The KamLAND-Zen experiment has provided stringent constraints on the neutrinoless double-beta (0νββ) decay half-life in ^{136}Xe using a xenon-loaded liquid scintillator. We report an improved search using an upgraded detector with almost double the amount of xenon and an ultralow radioactivity container, corresponding to an exposure of 970 kg yr of ^{136}Xe. These new data provide valuable insight into backgrounds, especially from cosmic muon spallation of xenon, and have required the use of novel background rejection techniques. We obtain a lower limit for the 0νββ decay half-life of T_{1/2}^{0ν}>2.3×10^{26}  yr at 90% C.L., corresponding to upper limits on the effective Majorana neutrino mass of 36-156 meV using commonly adopted nuclear matrix element calculations.

Identification of 5-Carboxyfluorescein as a Probe Substrate of SLC46A3 and Its Application in a Fluorescence-Based In Vitro Assay Evaluating the Interaction with SLC46A3

The therapeutic modalities that involve the endocytosis pathway, including antibody-drug conjugates (ADCs), have recently been developed. Since the drug escape from endosomes/lysosomes is a determinant of their efficacy, it is important to optimize the escape, and the cellular evaluation system is needed. SLC46A3, a lysosomal membrane protein, has been implicated in the pharmacological efficacy of trastuzumab emtansine (T-DM1), a noncleavable ADC used for the treatment of breast cancer, and the cellular uptake efficacy of lipid-based nanoparticles. Recently, we identified the SLC46A3 function as a proton-coupled steroid conjugate and bile acid transporter, which can directly transport active catabolites of T-DM1. Thus, the rapid and convenient assay systems for evaluating the SLC46A3 function may help to facilitate ADC development and to clarify the physiological roles in endocytosis. Here, we show that SLC46A3 dC, which localizes to the plasma membrane owing to lacking a lysosomal-sorting motif, has a great ability to transport 5-carboxyfluorescein (5-CF), a fluorescent probe, in a pH-dependent manner. 5-CF uptake mediated by SLC46A3 was significantly inhibited by compounds reported to be SLC46A3 substrates/inhibitors and competitively inhibited by estrone 3-sulfate, a typical SLC46A3 substrate. The inhibition assays followed by uptake studies revealed that SG3199, a pyrrolobenzodiazepine dimer, which has been used as an ADC payload, is a substrate of SLC46A3. Accordingly, the fluorescence-based assay system for the SLC46A3 function using 5-CF can provide a valuable tool to evaluate the interaction of drugs/drug candidates with SLC46A3.

Extensive ablation strategy for persistent atrial fibrillation impairs left atrial function but reduces recurrence rate

Background

In catheter ablation for persistent atrial fibrillation (AF), extensive ablation strategy, such as linear ablation and/or complex fractionated atrial electrogram (CFAE) ablation in addition to pulmonary vein isolation (PVI-plus), might impair left atrial function more severely than PVI-alone strategy.

Purpose

The aim of this study is to investigate the impact of extensive ablation strategy on LA function and assess the relationship between post-ablation LA function and recurrence.

Methods

This study is a post-hoc subanalysis of the EARNEST-PVI randomized controlled trial, which investigated the efficacy of the PVI-alone strategy in comparison with PVI-plus strategy for persistent AF. From the 497 participants of EARNEST-PVI trial, we enrolled 191 patients with full datasets of pre- and post-ablation cardiac computed tomography (CT) at our Hospital. Patients were divided into PVI-alone and PVI-plus groups. Within one month before and 3 months after ablation, LA volume index (LAVI) and LA emptying fraction (LAEF) were calculated by using the Comprehensive Cardiac Analysis software on the Extended Brilliance Workspace. We assessed i) post-ablation LA function, ii) AF/atrial tachycardia (AT) -free rate after single and final session, and iii) relationship between post-ablation LAEF and ablation success in each group.

Results

The indices of baseline LA remodeling were not different between PVI-alone (N=96) and PVI-plus groups (N=95) [LAVI: 71.4 (57.8, 82.0) vs. 68.7 (61.0, 78.1), P=0.92, LAEF: 13.7 (10.0, 17.4) vs. 13.0 (10.0, 16.9), PVI-alone vs. PVI-plus, P=0.78]. In overall patients, post-ablation LAEF did not differ among them [34.4 (26.1, 40.7) vs. 31.6 (26.0, 37.4), P=0.13]. In the analysis of patients showing sinus rhythm during the CT study, LAEF was significantly higher in PVI-alone (N=87) than in PVI-plus group (N=93) [35.7 (29.0, 41.0) vs. 31.7 (26.1, 37.5), P=0.011] (Figure 1A). AF/AT-free survival rate during median follow-up of 44 months was not different after first session (63.5% vs. 68.4%, P=0.33), while PVI-plus had a tendency towards higher success rate after final session (72.9% vs. 84.2%, P=0.053) (Figure 2). In receiver operating characteristics analysis for recurrence after first session, post-ablation decreased LAEF had significantly related to recurrence after PVI-alone (AUC: 0.733, P&lt;0.0001), but not after PVI-plus (AUC: 0.567, P=0.31) (Figure 1B, C).

Conclusion

Compared with PVI-alone strategy, PVI-plus strategy damaged LA function more severely, but tended to be related to higher success rate. Post-ablation LA function was related to recurrence in PVI-alone, but not in PVI-plus. Extensive ablation might have additional anti-arrhythmic effect regardless of iatrogenic myocardial damage. Myocardial injury by extensive ablation may less attribute to recurrence than intrinsic damage of LA.

Funding Acknowledgement

Type of funding sources: None.

Sex differences in terms of recurrent atrial fibrillation after catheter ablation according to the history of heart failure: insights from the Kansai Plus Atrial Fibrillation (KPAF) registry

Background

There are significant differences in the prevalence and prognosis of cardiovascular diseases between male and female. We previously reported that catheter ablation (CA) of atrial fibrillation (AF) was less effective in female than male, but whether their history of heart failure influence the recurrence after CA of AF remains still unknown.

Purpose

We sought to clarify sex differences in terms of AF recurrence after RFCA of AF according to the history of heart failure.

Methods

We conducted a large-scale, prospective, multicenter, observational study (Kansai Plus Atrial Fibrillation Registry). We enrolled 5010 consecutive patients who underwent an initial RFCA of AF at 26 centers (64±10 years; 1369 [27.3%] females; non-paroxysmal AF, 35.7%). The median follow-up duration was 2.9 years.

Results

Fourteen % of female had a history of heart failure prior to CA, while 12.8% of male had a history of heart failure at baseline (p=0.29). The 3-year cumulative incidence of AF recurrence after a single procedure was 43.3% in female and 39.0% in male (log rank P=0.0046). In patients with the history of heart failure, AF recurrence rates were 42.2% in female and 45.8% in male (log rank P=0.51). On the other hand, in patients without history of heart failure, more females experienced AF recurrence (female vs. male, 43.5% vs. 38.0%, log rank P=0.001).

The rate of AF recurrence after multiple procedures was higher in female (24.2% vs. 19.6%, log rank P&lt;0.0001). AF recurrence rates were similar between sexes in patients with history of heart failure (female vs. male, 26.0% vs. 26.7%, log rank P=0.86), while AF recurrence rates were higher in female without history of heart failure than those in male (females vs. males, 23.9% vs. 18.5%, log rank P&lt;0.0001).

Conclusion

The Kansai Plus Atrial Fibrillation Registry revealed a distinct sex difference in terms of the AF recurrence after CA of AF. Females had higher recurrence rates compared with males in patients without history of heart failure, while recurrence rates were similar between sexes in patients with history of heart failure.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Research Institute for Production Development in Kyoto, Japan.

Premature atrial contraction on Holter electrocardiogram predicts the recurrence of atrial fibrillation after catheter ablation

Introduction

It is important to detect the recurrence of atrial fibrillation (AF) after catheter ablation (CA) early, but the method of detection has not been established. The purpose of this study is to determine whether 24-h Holter electrocardiogram (ECG) can predict the recurrence of AF after CA.

Methods

We studied 336 patients of 497 patients enrolled in EARNEST-PVI trial to investigate whether the total number of premature atrial contraction (PAC) and the maximum number of PAC run by 24-h Holter ECG at 6 months after CA predicted AF recurrence after 6 months. We excluded 86 patients with recurrence by 6 months after CA and 75 patients without Holter ECG at 6 months after CA.

Results

Median age was 66 years, male were 77% and median follow-up period was 1138 days. Receiver operating characteristic curve analysis identified the total number of PAC ≥270 beats and the maximum number of PAC run ≥8 beats as the optimal cutoff for prediction of AF recurrence. Kaplan-Meier analysis showed patients with the total number of PAC ≥270 beats had more frequent AF recurrence than those without (Kaplan-Meier estimated 3-year AF recurrence rate 34% vs. 17%, Log-rank P=0.001) and patients with the maximum number of PAC run ≥8 beats had more frequent AF recurrence than those without (Kaplan-Meier estimated 3-year AF recurrence rate 33% vs. 20%, Log-rank P=0.006). Multivariate analysis revealed that the total number of PAC ≥270 beats and the maximum number of PAC run were significantly associated with AF recurrence (hazard ratio [95% confidence interval] 1.83 [1.16–2.91], P=0.01 and 1.01 [1.01–1.02], P=0.001, respectively)

Conclusion

The total number of PAC and the maximum number of PAC run on the Holter ECG may be useful in predicting AF recurrence after CA.

Funding Acknowledgement

Type of funding sources: None.

Influence of using history of immune checkpoint inhibitor therapy for neutropenia caused by combination therapy of ramucirumab and docetaxel

Recently, pretreatment with immune checkpoint inhibitors (ICIs) has been shown to enhance the therapeutic effects of the combination therapy of ramucirumab (RAM) and docetaxel (DTX); however, its influence on the drug's side effects remains unclear. This study investigated the influence of pretreatment with ICIs on the incidence of neutropenia caused by RAM + DTX therapy in patients with non-small cell lung cancer (NSCLC). Patients with NSCLC who received RAM + DTX therapy at Gifu Prefectural General Medical Center between April 2016 and December 2020 were enrolled. Retrospective data regarding age, sex, performance status and detailed treatment history, among others, at treatment initiation were collected from the patients' electronic medical records. Additionally, data on the course number of RAM + DTX therapy, supportive therapy and blood biochemical parameters, including leukocyte and neutrocyte counts, during the treatment period were collected. We identified 41 patients receiving RAM + DTX therapy. Among the more than grade 3 adverse events caused by this therapy, neutropenia was the most common (78.1%). Despite the fact that all previous risk factors influencing this incidence rate had corresponded, the only factor influencing the incidence rate of neutropenia more than grade 3 was ICI treatment history. A difference in the incidence of neutropenia more than grade 3 in the Kaplan-Meier curve was observed between patients with and without ICI pretreatment history (p = 0.037). The pretreatment history of ICI therapy affects the incidence of neutropenia caused by RAM + DTX therapy in patients with NSCLC.

AB0431 THE EFFICACY OF BELIMUMAB (BEL) AS A SPARING CORTICOSTEROID AGENCY IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS (SLE)

Background

Patients with SLE are recommended to continue the maintenance therapy with as less glucocorticoid as possible.1) However, tapering glucocorticoid often results in the recurrence of SLE. Current reports suggested that adding BEL to the standard therapy could lead to the reduction of glucocorticoid and the recurrence of SLE.2)

Objectives

The aim of this study is to evaluate the efficacy and the safety of BEL as co-treatment in the standard therapy of SLE.

Methods

Fourteen patients receiving the maintenance therapy of SLE were enrolled in this study. Dose of prednisolone (PSL), titer of anti-DNA antibody, WBC count, serum complement and SLE disease activity index (SLEDAI) were examined retrospectively at baseline and 24 months after administration of BEL.

Results

At the baseline, the mean age of patients was 48 years old, 11 patients were female, and the mean disease duration was 8.6 years. The mean dose of PSL was significantly reduced (meansease apre-administration of BEL:6.1±1.1 mg/day, 24 months after administration of BEL: 1.2 the baseline,p=0.001). Furthermore, six patients (43 %) could withdraw PSL without the flare of the disease. There were also statistical significance about SLEDAI between baseline and after treatment by BEL(2.1patients (43 %) cp=0.03) and the titer of anti-DNA antibody (6.8 withdraw PSL without tp=0.03). There were no statistical significant in WBC count (6177out the fla7e of the dp=0.24) and serum complement (C3 87significant in WBC count (61p=0.78, C4 20erum complement (C3 87signifp=0.54).

As for adverse event, bacterial pneumonia (n=1) and pulmonary cryptococcosis (n=1) was revealed.

Conclusion

Our study is suggested that co-treatment with BEL on standard SLE therapy was enable to prevent the flare of SLE and reduce the dose of PSL with statistical significance among the patients under the maintenance treatment of SLE. In almost half of the cases, patients could withdraw PSL without the flare.

References

[1]Ann Rheum Dis 2019; 78: 736-745.

[2]Ann Rheum Dis 2018; 77: 355-745.

Disclosure of Interests

None declared

SLC46A3 is a lysosomal proton-coupled steroid conjugate and bile acid transporter involved in transport of active catabolites of T-DM1

Antibody-drug conjugates (ADCs) represent a new class of cancer therapeutics that enable targeted delivery of cytotoxic drugs to cancer cells. Although clinical efficacy has been demonstrated for ADC therapies, resistance to these conjugates may occur. Recently, SLC46A3, a lysosomal membrane protein, was revealed to regulate the efficacy of trastuzumab emtansine (T-DM1), a noncleavable ADC that has been widely used for treating breast cancer. However, the role of SLC46A3 in mediating T-DM1 cytotoxicity remains unclear. In this study, we discovered the function of SLC46A3 as a novel proton-coupled steroid conjugate and bile acid transporter. SLC46A3 preferentially recognized lipophilic steroid conjugates and bile acids as endogenous substrates. In addition, we found that SLC46A3 directly transports Lys-SMCC-DM1, a major catabolite of T-DM1, and potent SLC46A3 inhibitors attenuate the cytotoxic effects of T-DM1, suggesting a role in the escape of Lys-SMCC-DM1 from the lysosome into the cytoplasm. Our findings reveal the molecular mechanism by which T-DM1 kills cancer cells and may contribute to the rational development of ADCs that target SLC46A3.

Angelica keiskei (Ashitaba) has potential as an antithrombotic health food

Angelica keiskei (Ashitaba) is a large perennial herb that is native to the Pacific coast of Japan. It has recently become popular as a healthy food in Asian countries because it might have various physiological benefits including antithrombotic properties. Most studies of the bioactive constituents from Ashitaba have focused on the activities of the major chalcones, xanthoangelol and 4-hydroxyderricin. However, other chalcones, flavanones and coumarins have also been isolated from Ashitaba, precisely characterized, and investigated in vivo. Platelets play a key role in haemostasis and wound healing processes. Dysregulated platelet activity is associated with the progression of platelet aggregation and decreased venous blood flow, which results in thrombotic diseases. A minor chalcone, xanthoangelol E, inhibits TXB2 synthesis in rabbit platelets, which seems to be the source of the belief that Ashitaba has antithrombotic properties. However, recent data showed that xanthoangelol and 4-hydroxyderricin inhibited the aggregation of rabbit platelets. Platelet aggregation stimulated by collagen was also inhibited in whole blood incubated with Xanthoangelol or 4-hydroxyderricin. Plasminogen activator inhibitor-1 is the primary physiological inhibitor of tissue type plasminogen activator, a key protease of the fibrinolytic system. An increase in plasma of this inhibitor is associated with thrombotic conditions. Ashitaba yellow exudate inhibited the elevation of plasma plasminogen activator inhibitor-1 in mice induced by obesity or chronic low-grade inflammation. These studies showed the yellow exudate from stem cuttings and chalcones isolated from Ashitaba roots and leaves might have antithrombotic activity. This article reviews the possible antithrombotic properties of Ashitaba.

Mammalian monocarboxylate transporter 7 (MCT7/Slc16a6) is a novel facilitative taurine transporter

Monocarboxylate transporter 7 (MCT7) is an orphan transporter expressed in the liver, brain, and in several types of cancer cells. It has also been reported to be a survival factor in melanoma and breast cancers. However, this survival mechanism is not yet fully understood due to MCT7’s unidentified substrate(s). Therefore, here we sought to identify MCT7 substrate(s) and characterize the transport mechanisms by analyzing amino acid transport in HEK293T cells and polarized Caco-2 cells. Analysis of amino acids revealed significant rapid reduction in taurine from cells transfected with enhanced green fluorescent protein-tagged MCT7. We found that taurine uptake and efflux by MCT7 was pH-independent and that the uptake was not saturated in the presence of taurine excess of 200 mM. Furthermore, we found that monocarboxylates and acidic amino acids inhibited MCT7-mediated taurine uptake. These results imply that MCT7 may be a low-affinity facilitative taurine transporter. We also found that MCT7 was localized at the basolateral membrane in polarized Caco-2 cells and that the induction of MCT7 expression in polarized Caco-2 cells enhanced taurine permeation. Finally, we demonstrated that interactions of MCT7 with ancillary proteins basigin/CD147 and embigin/GP70 enhanced MCT7-mediated taurine transport. In summary, these findings reveal that taurine is a novel substrate of MCT7 and that MCT7-mediated taurine transport might contribute to the efflux of taurine from cells.

Impact of heart rate reduction on recurrence after catheter ablation of persistent atrial fibrillation

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Johnson & Johnson KK

OnBehalf

OCVC Arrhythmia Investigators

Background

Predicting heart rate (HR) after restoration of sinus rhythm (SR) remains one of the challenges when performing catheter ablation (CA) of persistent atrial fibrillation (AF).

Purpose

To evaluate the association between pre-ablation HR during AF and post-ablation HR during SR, and whether the HR reduction is associated with AF recurrence.

Methods

The analysis was performed from the EARNEST-PVI trial, a randomized controlled trial designed to assess a CA strategy for persistent AF, which was conducted in the Osaka region of Japan. After excluding patients with beta-blocker prescription, a total of 216 patients (median age, 67 years; 20% female; 23% long-standing persistent AF) with AF rhythm at baseline and SR at discharge were enrolled in this study. Baseline HR during AF and post-ablation HR during SR was measured on admission and at discharge using the 12-lead electrocardiograms, respectively.

Results

There was a mild correlation between baseline HR (median 82 [interquartile range 72-95] bpm) and post-ablation HR (78 [48-117] bpm) (r = 0.27, p &lt;0.001). Reduction in HR was positively associated with baseline HR (r = 0.79, p &lt;0.001) and was negatively associated with post-ablation HR (r = - 0.37, p &lt;0.001). During the follow-up of 1 year, 56 patients (25.9%) experienced AF recurrence. HR reduction had the higher diagnostic accuracy in predicting AF recurrence than HR at baseline and HR after CA (area under the curve, 0.625; 95% confidence interval, 0.557–0.690; p = 0.003). AF recurrence rate was significantly higher in 141 patients with smaller HR reduction (cut-off, &lt;14bpm) than those with larger HR reduction (31.9% vs. 14.7%, p = 0.009). After adjustment of age, gender, long-standing persistent AF, and CA strategy, HR reduction of &lt;14 bpm was a significant predictor of AF recurrence (hazard ratio, 2.32; 95% confidence interval, 1.20–4.51; p = 0.013).

Conclusions

There was a mild correlation between HR during AF and HR after restoration of SR in patients underwent CA of persistent AF. HR reduction after restoration of SR predicted AF recurrence.

Effect of Ingested Fluid Volume and Solution Osmolality on Intestinal Drug Absorption: Impact on Drug Interaction with Beverages

It was recently shown that osmolality-dependent fluid movement is a significant factor causing the clinically observed apple juice (AJ)-atenolol interaction. Here we examined whether osmolality-dependent fluid movement may also explain the AJ volume dependence of the AJ-atenolol interaction. In Wistar rats, the luminal fluid volume after administration of different volumes of purified water (0.5 and 1.0 mL) gradually reduced to a similar steady-state level, while that after administration of different volumes of AJ (0.5 and 1.0 mL) increased and attained different apparent steady-state levels. It was hypothesized that osmolality-dependent fluid secretion would account for the volume dependence of the apparent steady-state. Indeed, the luminal concentration of FD-4, a non-permeable compound, after administration in AJ was attenuated depending upon the ingested volume, whereas that after administration in purified water was independent of the ingested fluid volume. An in vivo pharmacokinetic study in rats showed that co-administration of AJ and hyperosmotic solution (adjusted to the osmolality of AJ) with atenolol volume-dependently reduced the AUC and C_max of atenolol significantly. These results show that osmolality-dependent variations in luminal fluid volume may indirectly influence the absorption characteristics of drugs, and can account for the observed volume dependence of beverage-drug interactions.

A Simple and Rapid Bioluminescence-Based Functional Assay of Organic Anion Transporter 1 as a D-Luciferin Transporter

Organic anion transporter 1 (SLC22A6/OAT1) plays a key role in renal tubular excretion of endo- and exogenous anionic substances including drugs. Since the inhibition of OAT1 function by a concomitant drug may cause pharmacokinetic drug-drug interactions (DDIs) in clinical practice, an in vitro uptake study to evaluate the inhibition potency of OAT1 is useful for the prediction and avoidance of DDIs and recommended for drug candidates in drug development. In this chapter, we describe a rapid and highly sensitive functional assay of OAT1 based on bioluminescence (BL) detection using D-luciferin as a substrate in living cells. The principle of measurement simply relies on the biochemical feature of D-luciferin to be recognized as a substrate of OAT1, and the BL intensity depending on intracellular D-luciferin level and luciferase activity, thereby allowing the quantitative analysis of OAT1-mediated D-luciferin transport. The BL measurement can be completed within 1 min without experimental procedures for removing extracellular uptake solution and washing cells, both of which involve in the conventional uptake studies using isotope-labeled or fluorescent compounds. The present method is applicable to high-throughput screening to identify and avoid potential OAT1 inhibitors in drug development.

Assessment of the albumin-bilirubin grade as a prognostic factor in patients with non-small-cell lung cancer receiving anti-PD-1-based therapy

Introduction

The albumin-bilirubin (ALBI) grade is a novel indicator of the liver function. Some studies showed that the ALBI grade was a prognostic and predictive biomarker for the efficacy of chemotherapy in cancer patients. The association between the ALBI grade and outcomes in patients with non-small-cell lung cancer (NSCLC) treated with cancer immunotherapy, however, is poorly understood.

Methods

We retrospectively enrolled 452 patients with advanced or recurrent NSCLC who received anti-programmed cell death protein 1 (PD-1)-based therapy between 2016 and 2019 at three medical centers in Japan. The ALBI score was calculated from albumin and bilirubin measured at the time of treatment initiation and was stratified into three categories, ALBI grade 1-3, with reference to previous reports. We examined the clinical impact of the ALBI grade on the outcomes of NSCLC patients receiving anti-PD-1-based therapy using Kaplan–Meier survival curve analysis with log-rank test and Cox proportional hazards regression analysis.

Results

The classifications of the 452 patients were as follows: grade 1, n = 158 (35.0%); grade 2, n = 271 (60.0%); and grade 3, n = 23 (5.0%). Kaplan–Meier survival curve analysis showed that the ALBI grade was significantly associated with progression-free survival and overall survival. Moreover, Cox regression analysis revealed that the ALBI grade was an independent prognostic factor for progression-free survival and overall survival.

Conclusion

The ALBI grade was an independent prognostic factor for survival in patients with advanced or recurrent NSCLC who receive anti-PD-1-based therapy. These findings should be validated in a prospective study with a larger sample size.

•

ALBI grade is calculated from albumin and bilirubin.

•

We evaluated the impact of ALBI grade on survival in NSCLC patients receiving immune checkpoint inhibitors.

•

ALBI grade was an independent prognostic factor for progression-free survival (PFS) and overall survival (OS).

•

ALBI grade effectively stratified PFS and OS in patients with performance status 1-3.

•

ALBI grade was significantly associated with PFS and OS, regardless of programmed death ligand-1.

Utilization of Sodium Nitroprusside as an Intestinal Permeation Enhancer for Lipophilic Drug Absorption Improvement in the Rat Proximal Intestine

As advanced synthetic technology has enabled drug candidate development with complex structure, resulting in low solubility and membrane permeability, the strategies to improve poorly absorbed drug bioavailability have attracted the attention of pharmaceutical companies. It has been demonstrated that nitric oxide (NO), a vital signaling molecule that plays an important role in various physiological systems, affects intestinal drug absorption. However, NO and its oxidants are directly toxic to the gastrointestinal tract, thereby limiting their potential clinical application as absorption enhancers. In this study, we show that sodium nitroprusside (SNP), an FDA-approved vasodilator, enhances the intestinal absorption of lipophilic drugs in the proximal parts of the small intestine in rats. The SNP pretreatment of the rat gastrointestinal sacs significantly increased griseofulvin and flurbiprofen permeation in the duodenum and jejunum but not in the ileum and colon. These SNP-related enhancement effects were attenuated by the co-pretreatment with dithiothreitol or c-PTIO, an NO scavenger. The permeation-enhancing effects were not observed in the case of antipyrine, theophylline, and propranolol in the duodenum and jejunum. Furthermore, the SNP treatment significantly increased acidic glycoprotein release from the mucosal layers specifically in the duodenum and jejunum but not in the ileum and colon. These results suggest that SNP increases lipophilic drug membrane permeability specifically in the proximal region of the small intestine through disruption of the mucosal layer.

Determination of physiological cardiac myosin-binging protein levels (cMyc) in healthy populations

Background

Cardiac myosin–binding protein C (cMyC) is a cardiac-restricted protein that has more abundant, rapid release and clearance kinetics than cardiac troponin. The current ESC guideline suggests the cMyC may provide value as an alternative to cardiac troponin. The 99th percentile value is universally endorsed as the reference cut off to aid in the diagnosis of acute myocardial infarction (AMI), however, none of the report of healthy population of cMyC.

Purpose

The aim of this study was to evaluate the distribution of cMyC values in healthy subjects.

Methods

We used two cohorts in this retrospective study. 1) Healthy subjects; a total of 500 subjects (250 men and 250 women) who had annual health examinations in 2012 in the area of Kamigoto, a suburb of Nagasaki city in Southern Japan were enrolled. All participants showed none of abnormal findings including cell blood counts, chemical analysis, liver function tests, general urine tests, occult blood tests of stool, barium swallow, mammography for women, abdominal ultrasound sonography, and electrocardiogram. All blood samples were obtained in a fasting state in the morning. 2) Chest pain subjects; we collected samples from 250 subjects including 50 with non-ST elevation myocardial infarction visited admitted to a university hospital for measurement of high-sensitivity troponin T and coronary artery assessment by coronary angiography. We measured cMyC level in both cohorts by HISCL™-800 system (Sysmex corporation, Japan). The assay has a limit of detection of 0.5 ng/L and a lower limit of quantification of 1.3 ng/L.

Result

In healthy subjects, median age (IQR) was 44 (20, 82) in men and 50 (23, 91) in women. The 99th percentile of cMyC was 27.3 ng/L, which was around one-third lower than that in previous report (87 ng/L). In chest pain subjects, the concentrations of cMyC at presentation were significantly higher in those with versus without AMI (median, 66 ng/L versus 10 ng/L, P&lt;0.001). Discriminatory power for AMI, as quantified by the area under the receiver-operating characteristic curve (AUC), was comparable for cMyC (AUC, 0.85 (95% CI 0.79–0.91) and hs-cTnT (AUC, 0.81 (95% CI 0.76–0.88)).

Conclusion

We defined the normal range of cMyC in healthy Japanese subjects. The level of cMyC at presentation provides discriminatory power comparable to hs-cTnT in the diagnosis of AMI. To determine the physiological value of a biomarker may be necessary to evaluate enough information about their health status.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Grant-in-Aid for Scientific Research

Association between myocardial wall thickness and left ventricular functional recovery after catheter ablation of atrial fibrillation in patients with reduced ejection fraction

Background

Catheter ablation of atrial fibrillation (AFCA) is an effective treatment to develop left ventricular (LV) functional recovery. However, the degree of recovery differs between individuals due to the different extent of myocardial fibrosis and scarring.

Purpose

To examine whether pre-ablation LV wall thickness (WT) and its regional heterogeneity predict LV functional recovery after AFCA in patients with LV systolic dysfunction.

Methods

Of 3682 consecutive patients who underwent first-time AFCA between January 2012 and September 2020 in our institution, 174 (age, 63±10 years; male, 83%; ischemic cardiomyopathy, 14%) with a baseline LV ejection fraction (LVEF) of &lt;40% were retrospectively evaluated. They were subjected to 256-slice MDCT scanning at baseline and 3 months after AFCA. Baseline WT was evaluated by 16-segment model. Mean and standard deviation (SD) of 16 regional WT were calculated in both end-systolic and end-diastolic phase.

Results

LVEF significantly improved from 30±7% to 57±17% (p&lt;0.001) after AFCA. Increase in LVEF (delta-LVEF) was positively correlated with baseline end-diastolic WT (r=0.31, p&lt;0.001) and negatively correlated with SD of end-systolic WT (r=−0.21, p=0.007). Independent of WT measurements, delta-LVEF was negatively correlated with LV end-diastolic volume (r=−0.42, p&lt;0.001). We created a scoring system to predict the degree of wall motion recovery using the median value of the 3 variables; assigned 1 point each for end-diastolic WT &gt;7.4mm, SD of end-systolic WT &lt;1.61mm, and LV end-diastolic volume &lt;125ml. The model successfully predicted improvement in LVEF after AFCA (0 point (N=13) vs. 1 point (N=72) vs. 2–3 point (N=89), 11±16% vs. 20±17% vs. 33±12%, p&lt;0.001).

Conclusion

Myocardial WT and its regional heterogeneity as well as LV end-diastolic volume predicted functional recovery after AFCA in patients with reduced LVEF.

Funding Acknowledgement

Type of funding sources: None.

Exploration of electrocardiographic and echocardiographic findings to screen transthyretin amyloid cardiomyopathy in patients with mild left ventricular hypertrophy

Background

The transthyretin amyloid cardiomyopathy (ATTR-CM), a common condition in the elderly, is a life-threatening disease; however, it is treatable. The early accurate diagnosis is, therefore, an important key to improve the patient's outcomes. Electrocardiography and echocardiography are instant diagnostic tools with red flags for the screening of the ATTR-CM. In fact, ATTR-CM often mimics left ventricular hypertrophy (LVH), and the differential diagnosis is difficult to establish. Thus, the characteristics of cardiac amyloidosis may be obscured in ATTR-CM patients with mild LVH, possibly making the disease difficult to diagnose. Therefore, in this study, the effect of LVH on the occurrence of electrocardiographic and echocardiographic parameters for ATTR-CM was investigated, and their incremental value over the age for the screening of ATTR-CM in the patients with mild LVH was recorded.

Methods

This study retrospectively studied 319 consecutive nonischemic LVH patients with a sinus rhythm who underwent detailed diagnostic tests. The light chain-associated amyloidosis was an exclusion criterion. The mean left ventricular wall thickness (MWT) &lt;12 mm was defined as mild LVH, while MWT ≥12 mm was defined as moderate to severe LVH. The ATTR-CM was diagnosed with biopsy or 99 mTc-PYP scintigraphy. The elderly were defined as people aged ≥65 years in males and ≥70 years in females, according to the literature. Each electrocardiographic and echocardiographic parameter was binarized with an external cut-off point to increase the external validity, being the incremental benefit of each parameter over age for identifying ATTR-CM assessed using a receiver operating characteristic curve analysis and comparisons of the area under the curve (AUC).

Results

Fourteen patients (8%) among the 170 patients with mild LVH had ATTR-CM, while 27 patients (18%) among the 149 patients with moderate to severe LVH had ATTR-CM. The patients with mild LVH had fewer electrocardiographic and echocardiographic parameters, showing a significant difference between ATTR-CM and non-ATTR-CM patients than those with moderate to severe LVH (Table 1). Among several binarized parameters, the voltage-to-mass ratio, E/A ratio, the global longitudinal strain, and also the relative apical sparing pattern demonstrated additive value for identifying the ATTR-CM over aging (Table 2). In addition, the discriminative ability of the propensity score calculated from these four variables and age was considered excellent for the screening of ATTR-CM (AUC = 0.98).

Conclusion

The patients with mild LVH appear to have fewer electrocardiographic and echocardiographic specific findings of the ATTR-CM compared to patients with moderate to severe LVH. However, several red flags may be useful for screening ATTR-CM even in patients with a mild LVH.

Funding Acknowledgement

Type of funding sources: None. Table 1Table 2

Reappraising the role of baseline plasma C-reactive protein levels on recurrence after catheter ablation of persistent atrial fibrillation: insight from EARNEST-PVI trial

Background

Subclinical inflammation is an important pathogenesis of developing and sustaining atrial fibrillation (AF). Because AF itself contribute to the inflammatory response, the role of baseline subclinical inflammation on AF recurrence after catheter ablation (CA) remains controversial in patients with persistent AF.

Purpose

To evaluate whether baseline plasma C-reactive protein (CRP) levels, a sensitive marker of inflammation, are associated with AF recurrence following CA.

Methods

The analysis was performed from the EARNEST-PVI trial, a randomized controlled trial designed to assess a CA strategy for persistent AF, which was conducted in the Osaka region of Japan. A total of 441 patients (median age, 67 years; 26% female; 25% long-standing persistent AF) whose plasma CRP levels were measured at baseline were included in this study.

Results

At baseline, a median (interquartile range) of plasma CRP level was 0.10 [0.06–0.19] mg/dl. Plasma CRP levels significantly increased at discharge (0.83 [0.21–1.84] mg/dl, p&lt;0.001) and decreased 1 year after CA (0.10 [0.05–0.20] mg/dl, p=0.040) compared to the baseline value. During the follow-up of 1 year, 115 patients (26%) experienced AF recurrence, and the incidence was significantly higher in 124 patients with low CRP levels at baseline (cut-off ≤0.06 mg/dl) than the other 317 patients (33.9% vs. 23.0%, p=0.017). After adjustment of age, gender, body mass index, long-standing persistent AF, CA strategy, and plasma brain natriuretic peptide levels, low plasma CRP levels was a significant predictor of AF recurrence (hazard ratio, 1.51; 95% confidence interval, 1.02–2.24; p=0.042).

Conclusions

Low plasma CRP levels at baseline predicted AF recurrence in the EARNEST-PVI trial. Reappraising the role of CRP on AF recurrence may be needed in patients with persistent AF.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Johnson & Johnson KK

Left atrial dysfunction still exists in patients who obtain normal left atrial volume after successful ablation of atrial fibrillation

Introduction

Atrial fibrillation (AF) promotes left atrial (LA) remodeling and vice versa. LA volume index (LAVI) ≥34 mL/m2 is an established cut-off value for identifying an enlarged left atrium. Catheter ablation has become an established therapy for AF and provides a reduction of LA volume by maintaining sinus rhythm (reverse remodeling). However, the definition of LA reverse remodeling after AF ablation is undetermined.

Purpose

We hypothesized that patients with LA dilatation who obtain normal LA volume (LAVI &lt;34 mL/m2) after AF ablation would have better long-term outcomes than those who do not. Furthermore, we investigated whether patients with a normal LA volume could also obtain normal LA function with AF ablation.

Methods

We enrolled 140 AF patients with baseline LAVI ≥34 mL/m2, without AF recurrence for 1 year after the initial AF ablation. We acquired conventional and speckle-tracking echocardiographic parameters within 24 h and at 1 year after the procedure. Late recurrence was defined as AF recurrence &gt;1 year after the initial ablation. To define the normal range of LA function, age-and sex-matched 140 controls without a history of AF were also enrolled.

Results

After restoration of sinus rhythm, overall LA structural and functional parameters were significantly improved, and 75 patients (54%) had normal LA volume at the time of follow-up (Table). During a median follow-up of 44 (31–61) months, 32 patients (23%) experienced a late recurrence of AF. Patients who obtained normal LA volume after AF ablation had fewer late recurrences than those who did not (P&lt;0.01) (Figure). However, LA functional abnormalities still existed in AF patients, even if LA volume was normalized as in controls (Table).

Conclusion

Patients who obtain normal LA volume have better long-term outcomes of AF ablation than those who do not. Although AF ablation promotes beneficial effects on LA structure and function, LA function cannot be normalized even in patients who obtain normal LA volume after successful ablation. Thus, physicians should carefully consider long-term follow-up and residual AF risks, regardless of sinus rhythm restoration by catheter ablation.

Funding Acknowledgement

Type of funding sources: None.

Renal function and arrhythmia outcomes in persistent atrial fibrillation patients after catheter ablation: subanalysis of the EARNEST-PVI trial

Background

Atrial fibrillation (AF) reduces the renal function. Renal dysfunction and AF often coexist. Catheter ablation (CA) of persistent AF can maintain a sinus rhythm and may improve the renal function.

Purpose

We sought to elucidate whether the estimated glomerular filtration rate (eGFR) in patients with persistent AF was increased after CA, especially with the presence of an AF recurrence.

Methods

We enrolled 487 persistent AF patients whose eGFR data were available both before and 1-year after the CA out of 512 patients in the EARNEST-PVI trial.

Results

The mean age was 65±9 year and 113 patients (24.8%) had long-standing persistent AF. We compared the eGFR at baseline with that 1-year after the CA. AF recurrences were recognized in 118 patients (25.8%). The eGFR was similar between the group without recurrence and that with recurrence at baseline (without AF recurrence vs. with AF recurrence; 63.8±14.3 vs. 62.7±13.6 mL/min/1.73m2, p=0.46). In patients without AF recurrence, the G1, G2, G3a, G3b, G4, and G5 were 13 (3.8%), 198 (58.4%), 98 (28.9%), 26 (7.7%), 3 (0.9%), and 1 (0.3%), respectively at baseline. In the patients with AF recurrence, the G1, G2, G3a, G3b, G4, and G5 were 3 (2.5%), 68 (57.8%), 38 (32.2%), 6 (5.1%), 3 (2.5%), and 0 (0%), respectively at baseline. The ΔeGFR was significantly higher in the patients without AF recurrence than in those with AF recurrence (without AF recurrence vs. with AF recurrence; 5.1 [−0.3, 10.8] vs. 3.0 [−3.0, 7.6], p=0.0033). In the patients without AF recurrence, a better eGFR class at 1-year after the CA than in those before the CA was recognized in 75 patients (22.1%), while it was recognized in 19 patients (16.1%) with AF recurrences.

Conclusion

Successful catheter ablation in patients with persistent AF led to a better renal outcome.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): This study was funded by Medtronic, Johnson & Johnson, and Abbott.

Left ventricular longitudinal shortening at cardiac base as a determinant of left atrial reservoir function in cardiac amyloidosis

Objective

To investigate a mechanistic determinant of left atrial (LA) reservoir function in patients presenting left ventricular (LV) hypertrophy, and clarify diagnostic and prognostic values of LA reservoir strain in patients with cardiac amyloidosis (CA).

Methods

Three-hundred sixty patients (median age: 68 years, male gender: 65%) with left ventricular hypertrophy (LVH) assessed by echocardiography were retrospectively included. The LVH etiologies were diagnosed by any of biopsy, cardiac magnetic resonance imaging or 99mTc-PYP scintigraphy. LV segmental longitudinal strain was estimated from apical three views, and LA reservoir strain was measured from an apical 4-chamber view.

Results

The LVH etiologies were confirmed with CA in 81 patients, hypertensive heart disease in 87 patients, hypertrophic cardiomyopathy in 143 patients, and miscellaneous disorders in 49 patients. The median (25th, 75th percentile) value of LV ejection fraction was 59% (48–67). LV basal longitudinal strain and LA reservoir strain were significantly reduced in patients with CA compared with those with other etiologies; LV basal strain: 5.4% (3.9–8.7) vs. 11.9% (9.3–14.6), LA reservoir strain: 9.2% (6.3–12.3) vs. 17.5% (11.3–24.1), p&lt;0.01 respectively. LV basal strain was significantly correlated with LA reservoir strain in patients with CA (r=0.57, p&lt;0.01) and in those with other etiologies (r=0.45, p&lt;0.01). The area under the receiver-operating characteristic curves of LA reservoir strain and E/e' (0.78 and 0.74) to identify CA etiology were significantly larger than that of LA volume index (0.62) (p&lt;0.01). During the follow-up period (median 2.9 years), 53 patients experienced heart failure hospitalization. The Cox regression model including age, gender, LV ejection fraction, E/e' and LA reservoir strain showed that male gender (hazard ratio: 0.46, p=0.03), E/e' (hazard ratio: 1.04, p&lt;0.01) and LA reservoir strain (hazard ratio: 0.94, p&lt;0.01) independently predicted heart failure hospitalization.

Conclusions

The decrease of LV longitudinal shortening at cardiac base could worsen LA reservoir function especially in patients with CA. LA reservoir strain might be an alternative measure to identify CA etiology and have a predictive value of heart failure hospitalization in patients with LV hypertrophy.

Funding Acknowledgement

Type of funding sources: None.

Differences in quality of life improvement with pulmonary vein isolation alone vs. more extensive ablation of persistent atrial fibrillation: insights from the EARNEST-PVI trial

Background

Improving the quality of life (QoL) is one of the main purposes of catheter ablation (CA) of persistent atrial fibrillation (AF). QoL improvement in persistent AF patients has not been fully clarified. The EARNEST-PVI trial was a multi-center randomized trial comparing clinical outcomes of pulmonary vein isolation (PVI) alone and more intensive ablation in addition to PVI including complex fractionated atrial electrogram (CFAE) and linear ablation (PVI plus).

Purpose

To investigate the QoL change after persistent AF ablation and the differences between the PVI-alone strategy and the PVI plus strategy.

Methods

In the EARNEST-PVI trial, patients with persistent AF who underwent an initial catheter ablation (n=512) were randomly assigned in a 1:1 ratio to either PVI alone or PVI plus. Quality of life was assessed at baseline and at 12 months after ablation for AF using the 36-Item Short Form Health Survey. Scores were also converted to a physical health component summary (PCS), a mental health component summary (MCS) and a role/social component summary (RCS).

Results

In the EARNEST-PVI trial, the PVI alone strategy was associated with higher recurrence rate compared with the PVI plus additional ablation strategy. After excluding 68 patients for whom preoperative or postoperative QoL assessment was not available, 222 patients were evaluated respectively. Overall, significant improvements in PCS (46.2±11.4 to 48.7±11.4]), MCS (50.1±8.8 to 54.3±8.6) and RCS (44.6±13.3 to 48.6±11.3) occurred 12 months after ablation (P&lt;0.001, respectively). Although significant QoL improvement occurred in both PVI alone and PLI plus strategies, the changes in PCS was greater in the PVI-plus than that in PVI-alone (3.5±10.3 vs 1.5±10.6, P=0.04).

Conclusions

Ablation for persistent atrial fibrillation improved both physical and mental quality of life. The PVI-plus strategy showed greater improvement in physical QoL.

Funding Acknowledgement

Type of funding sources: None. QoL improvement

Influence of osmolality on gastrointestinal fluid volume and drug absorption: potential impact on oral salt supplementation

Background

The syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is the most frequent cause of hyponatremia in patients with cerebrovascular disease, and is often treated with oral salt tablets. However, we have shown that osmolality-dependent variations in gastrointestinal (GI) fluid volume can alter the concentration of a poorly permeable drug in the GI tract, potentially affecting its absorption. Here, we examined the effect of ingestion of hyperosmotic solution (10% NaCl) on drug concentration and absorption in the GI tract.

Methods

The effects of osmolality on luminal fluid volume and drug absorption in rat intestine (jejunum, ileum and colon) were examined by means of an in situ closed loop method using fluorescein isothiocyanate-dextran 4000 (FD-4) and atenolol. In vivo absorption in rats was determined by measuring the plasma concentration after oral administration of the test compounds dissolved in purified water or hyperosmotic solution (10% NaCl).

Results

Administration of hyperosmotic solution directly into the GI tract significantly increased the GI fluid volume, owing to secretion of water into the lumen. After administration in hyperosmotic solution, the luminal concentration of non-permeable FD-4 was significantly lower than the initial dosing concentration, whereas after administration in purified water, the luminal concentration exceeded the initial concentration. The fraction absorbed of atenolol was markedly lower after administration in hyperosmotic solution than after administration in purified water. An in vivo pharmacokinetic study in rats was consistent with these findings.

Conclusions

Administration of hyperosmotic NaCl solution increased GI fluid volume and reduced the plasma level of orally administered atenolol. This may imply that oral salt tablets used to treat hyponatremia in SIADH patients could decrease the intestinal absorption of concomitantly administered drugs, resulting in lower plasma exposure.

Model Analysis of the Apparent Saturation Kinetics of Purine Nucleobase Uptake in Cells co-Expressing Transporter and Metabolic Enzyme

PURPOSE

This study aims to understand the effect of salvage enzyme activity on the saturable kinetics of facilitated cellular uptake of purine nucleobase by developing a cellular kinetic model incorporating equilibrative nucleobase transporter 1 (ENBT1) and adenine phosphoribosyltransferase (APRT), with adenine as a model nucleobase.

METHODS

A cellular kinetic model incorporating the functions of ENBT1 and APRT was developed using Napp software and employed for model-based analysis of the cellular disposition of adenine.

RESULTS

Simulation analysis using the developed cellular kinetic model could account for the experimentally observed time-dependent changes in the K_m(app) value of adenine for ENBT1-mediated uptake. At a long experimental time, the model shows that uptake of adenine is rate-limited by APRT, enabling determination of the K_m value for APRT. At early time, the rate-limiting step for adenine uptake is ENBT1-mediated transport, enabling determination of the K_m value for ENBT1. Further simulations showed that the effect of experimental time on the K_m(app) value for ENBT1-mediated uptake is dependent on the APRT expression level.

CONCLUSION

Our findings indicate that both enzyme expression levels and experimental time should be considered when using cellular uptake studies to determine the K_m values of purine nucleobases for facilitated transporters.

Gender differences in self-perceived changes among Japanese workers with depression

BACKGROUND

The number of patients living with depression continues to increase in Japan. The economic effects of depression include loss of productivity due to both absenteeism and presenteeism. Gender differences have been reported in prevalence, onset pathways and subjective symptoms of depression.

AIMS

To understand how workers with major depressive disorder (MDD) perceive problems in the workplace and examine gender differences in their self-perceived levels of functioning at work, noticed during the initial stages of depression.

METHODS

This is a cross-sectional study of Japanese workers with MDD. Participants' self-perceived changes in the level of functioning at work were surveyed after the diagnosis during the first visit. The relationship between gender and changes in the level of functioning at work as initially perceived by the participants themselves was analysed using the chi-square test, supplemented by a residual analysis.

RESULTS

We administered the survey to 147 workers with MDD. In terms of gender differences in initial self-perceived changes in the level of functioning at work, the proportion of men reporting reduced work efficiency was significantly higher than that of women, while the proportion of women reporting deterioration in relationships with colleagues and superiors was significantly higher than that of men.

CONCLUSIONS

The findings suggest that greater attention to reduced work efficiency by men and to deterioration in work relationships by women with MDD should be essential components of self-care. Managers need to pay attention to the level of functioning and provide adequate social support for employees.

Gefitinib induction followed by chemoradiotherapy in EGFR-mutant, locally advanced non-small-cell lung cancer: LOGIK0902/OLCSG0905 phase II study

Background

The role of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) induction coupled with standard concurrent chemoradiotherapy (CRT) is unclear in unresectable, stage III, EGFR-mutant non-small-cell lung cancer (NSCLC). Therefore, a phase II trial was conducted to evaluate the efficacy and safety of gefitinib induction followed by CRT in this disease setting.

Patients and methods

Patients with unresectable, EGFR-mutant, stage III NSCLC were administered gefitinib monotherapy (250 mg/day) for 8 weeks. Subsequently, patients without disease progression during induction therapy were administered cisplatin and docetaxel (40 mg/m² each) on days 1, 8, 29, and 36 with concurrent radiotherapy at a total dose of 60 Gy. The primary endpoint was the 2-year overall survival (OS) rate, which was hypothesized to reach 85%, with a threshold of the lower limit of 60%.

Results

Twenty patients (median age: 66 years; male/female: 9/11; histology: 20 adenocarcinoma; stage IIIA/IIIB: 9/11; and exon 19/21: 10/10) were enrolled. The 2-year OS rate was 90% (90% confidence interval: 71.4% to 96.8%), indicating that this trial met the primary objective. The overall response rate and 1- and 2-year progression-free survival rates were 85.0%, 58.1%, and 36.9%, respectively. Grade ≥3 adverse events (>10%) included hepatic toxicity during the induction phase and neutropenia and febrile neutropenia in the CRT phase. Radiation pneumonitis grade ≥3 or treatment-related death did not occur.

Conclusions

This is the first prospective study to demonstrate the favorable efficacy and safety of EGFR-TKI induction followed by standard CRT in EGFR-mutant, stage III NSCLC. Further confirmatory studies are needed.

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This is the first prospective study evaluating gefitinib induction followed by CRT in EGFR-mutated, locally advanced NSCLC.

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The 2-year OS rate was 90% (90% confidence interval: 71.4% to 96.8%), indicating that this trial met the primary objective.

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The objective response rate throughout the treatment protocol was 85.0% (17 of 20).

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The safety findings were consistent with the known safety profiles of all agents administered.

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Our results might raise a critical point that needs to be evaluated in further studies to improve the cure rate.

Current Understanding of the Intestinal Absorption of Nucleobases and Analogs

It has long been suggested that a Na⁺-dependent carrier-mediated transport system is involved in the absorption of nucleobases and analogs, including some drugs currently in therapeutic use, for their uptake at the brush border membrane of epithelial cells in the small intestine, mainly based on studies in non-primate experimental animals. The presence of this transport system was indeed proved by the recent identification of sodium-dependent nucleobase transporter 1 (SNBT1/Slc23a4) as its molecular entity in rats. However, this transporter has been found to be genetically deficient in humans and higher primates. Aware of this deficiency, we need to revisit the issue of the absorption of these compounds in the human small intestine so that we can understand the mechanisms and gain information to assure the more rational use and development of drugs analogous to nucleobases. Here, we review the current understanding of the intestinal absorption of nucleobases and analogs. This includes recent knowledge about the efflux transport of those compounds across the basolateral membrane when exiting epithelial cells, following brush border uptake, in order to complete the overall absorption process; the facilitative transporters of equilibrative nucleoside transporter 1 (ENT1/SLC29A1) and equilibrative nucleobase transporter 1 (ENBT1/SLC43A3) may be involved in that in many animal species, including human and rat, without any major species differences.

Transport Characteristics of 6-Mercaptopurine in Brain Microvascular Endothelial Cells Derived From Human Induced Pluripotent Stem Cells

The likelihood of reoccurrence of acute lymphoblastic leukemia is influenced by the cerebral concentration of the therapeutic agent 6-mercaptopurine (6-MP) during treatment. Therefore, it is important to understand the blood-brain barrier (BBB) transport mechanism of 6-MP. The purpose of this study was to characterize this mechanism using human induced pluripotent stem cell-derived microvascular endothelial cells (hiPS-BMECs). The permeability coefficient of 6-MP across hiPS-BMECs monolayer in the basal-to-apical direction (B-to-A) was significantly greater than that in the opposite direction (A-to-B). The inhibition profiles of 6-MP transport in the A-to-B direction were different from those in the B-to-A direction. Transport in the A-to-B direction was mainly inhibited by adenine (an inhibitor of equilibrative nucleobase transporter 1; ENBT1), while transport in the B-to-A direction was significantly reduced by inhibitors of multidrug resistance-associated proteins (MRPs), especially zaprinast (an MRP5 inhibitor). Immunocytochemical analyses demonstrated the expression of ENBT1 and MRP5 proteins in hiPS-BMECs. We confirmed that the cellular uptake of 6-MP is decreased by ENBT1 inhibitors in hiPS-BMECs and by knockdown of ENBT1 in hCMEC/D3 cells. These results suggest that ENBT1 and MRP5 make substantial contributions to the transport of 6-MP in hiPS-BMECs and hCMEC/D3 cells.

Geochemical characterization of monazite sands based on rare earth elements, thorium and uranium from a natural high background radiation area in Tamil Nadu, India

The Kanyakumari coastal area in the southernmost part of Tamil Nadu, India is a well-known natural high background radiation area due to the abundance of monazite in beach placer deposits. In the present study, the concentrations of major oxides, rare earth elements (REEs), Th and U were measured to understand geochemical characteristics of these monazite sands. Based on the ambient dose rate, 23 locations covering an area of about 60 km along the coast were selected for sample collection. The concentrations of U and Th ranged from 1.1 to 737.8 μg g^-1 and 25.2-12250.6 μg g^-1, respectively. The Th/U ratio ranged from 2.2 to 61.6, which clearly indicated that Th was the dominant contributing radionuclide to the enhanced natural radioactivity in this coastal region. The chondrite-normalized REEs pattern of the placer deposits showed enrichment in light REEs and depletion in heavy REEs with a negative Eu anomaly that indicated the monazite sands were derived from granite, charnockite, and granitoid rocks from the Nagercoil and the Trivandrum Blocks of the Southern Granulite Terrain.

Evaluation of left ventricular filling pressure by echocardiography: incremental diagnostic information from left atrial strain

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): South-Eastern Norway Regional Health Authority

Background

Elevated left ventricular (LV) filling pressure is an important diagnostic feature of heart failure.

Objectives

To investigate determinants of left atrial (LA) reservoir and pump strain and if these parameters may serve as markers of LV filling pressure.

Methods

In a multicenter study of 322 patients with cardiovascular disease of different etiologies, LA strain by speckle tracking echocardiography was compared to conventional echocardiographic markers using invasive pressure as reference.

Results

Left ventricular filling pressure correlated well with LA reservoir and pump strain (r-values

‑0.52 and ‑0.57, respectively) (Figure). However, LV global longitudinal strain (GLS) was the strongest determinant of LA reservoir strain (r = 0.64), and correlated well with LA pump strain (r = 0.51).  For both LA strains, association with filling pressure was strongest in patients with reduced LV ejection fraction. In patients with normal GLS (≥18%), atrial strains provided no information regarding filling pressure (Figure). Reservoir strain &lt;18% and pump strain &lt;8% predicted elevated LV filling pressure better (p &lt; 0.05) than the conventional indices LA volume, ratio of mitral early filling velocity/annular velocity and tricuspid regurgitation velocity. Accuracy to classify filling pressure as normal or elevated was 75% for both LA strains . When any one of the conventional indices were missing, and were replaced by LA strains, the combination of indices had accuracy 82% to correctly classify filling pressure.

Conclusions

Left atrial reservoir and pump strain may serve as clinical markers of LV filling pressure, but will be useful predominantly in patients with reduced systolic function.  Due to limited diagnostic accuracy, LA strain should be used in combination with other indices.

Abstract Figure

The utility of a novel approach to quantify dyssynchrony by multidetector computed tomography

Funding Acknowledgements

Type of funding sources: None.

Background

Quantification of left ventricular (LV) dyssynchrony is of great interest for resynchronization therapy (CRT). Recently, cardiac computed tomography (CCT) is feasible for evaluation of dyssynchrony. Our aim was to assess a novel simplified approach using CCT to quantify LV dyssynchrony.

Methods

We studied 346 consecutive patients with a wide range of QRS width and ejection fractions (EF). Electrocardiogram-gated contrast-enhanced 256-slice multidetector CT (Brilliance 256 iCT, Philips Medical Systems) was performed before CRT. After CCT scan, the LV endocardial boundaries from short-axis images reconstructed at 5% increments of cardiac cycle were automatically detected, and a time from R-wave to maximal wall motion was calculated for each of the 16 standardized segments for all slices using software "Myocardial Contraction Map" (Argus, Inc Ehime, Japan). The standard deviation of all segments modified by mean heart rate (%SD) was respectively calculated as the global parameter of dyssynchrony. LVEF was also measured using MDCT.

Results

%SD was feasible in all patients, respectably. %SD was significantly different between the different QRS duration groups; narrow QRS (&lt;120ms): 9 ± 5%, relatively wide QRS (120-150 ms): 11 ± 6%, and significantly wide QRS (&gt;150 ms): 14 ± 7% (p &lt;0.001). Moreover, there was significantly difference in %SD between the different morphology groups; normal: 9 ± 7%, Non-left bundle branch block (Non-LBBB): 10 ± 6%, LBBB: 17 ± 7% (p &lt;0.001).

Conclusion

This novel simplified approach by CCT can quantify dyssynchrony in different QRS duration and morphology groups. This method has promise for clinical applications to the evaluation of patients for CRT.

Abstract Figure.

Validation of the HFA-PEFF- and H2FPEF score in Japanese patients with heart failure with preserved ejection fraction

Background

Diagnosing heart failure with preserved ejection fraction (HFpEF) still remains challenging, and simple and reliable diagnostic tools have been required. Recently, novel and evidence-based diagnostic algorithms for HFpEF were proposed, such as H2FPEF score (Circulation. 2018) and HFA-PEFF score (Eur Heart J 2019), and their accuracy was validated in the outside patient group. However, there are regional and ethnic variations in patient characteristics of HFpEF, particularly between Western and Asian countries, and it is not elucidated whether these diagnostic scores are useful in Asian population.

Purpose

To investigate the validity of the HFA-PEFF- and H2FPEF score in Japanese patients with HFpEF.

Methods

We calculated H2FPEF score and the second step of HFA-PEFF score among the registered patients in the PURSUIT-HFpEF (Prospective, Multicenter, Observational Study of Patients with Heart Failure with Preserved Ejection Fraction) study, which is a multicenter registration of patients hospitalized for HFpEF. The obtained scores were compared with the scores of the HFpEF cohort in the previous validation studies. We followed the study patients for median of 360 days (IQR 237–630 days) to observe the major adverse cardiovascular events (MACE; composite of death, heart failure hospitalization and stroke).

Results

We enrolled 757 patients hospitalized for HFpEF between June 2016 and August 2019 for the present study. H2FPEF score was obtained in 588 (77.7%) patients among them. Compared with the HFpEF cohorts in the previously reported sub-analysis of TOPCAT trial, the PURSUIT-HFpEF cohort had lower mean value of HFpEF score (4.0±1.8 points vs. 6.0±2.0 points in Americans or 5.3±1.9 points in Russians). It had significantly higher proportion (40.3%, p&lt;0.001) of patients in the low likelihood of HFpEF category (0–3 points) than the TOPCAT cohorts (8.0% in Americans and 19.6% in Russians).

HFA-PEFF score was obtained in 615 (81.2%) patients, though global longitudinal strain was not available. The mean value of HFA-PEFF score was 5.0±0.8, and all patients had ≥2 points. The proportion of patients in the high likelihood of HFpEF category (5–6 points) was 88.3%, which was significantly higher (p&lt;0.001) than those of the HFpEF cohort from Europe and USA in the previous validation study (Eur J Heart Fail 2019). There was no correlation between H2FPEF score and HFA-PEFF score (R=0.06, p=0.14). Cox proportional hazard model selected HFA-PEFF score as a significant predictor for MACE during follow-up period, whereas H2PEF score was not selected. Kaplan-Meier survival analysis demonstrated that patients with 6 points of HFA-PEFF score had higher incidence rate of MACE than those with ≤5 points (p=0.002).

Conclusion

The HFA-PEFF score could be more useful for the diagnosis and risk stratification for HFpEF than the H2PEF score in the Japanese cohort.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Roche Diagnostics K.K.; Fuji Film Toyama Chemical Co. Ltd.

Clinical significance of the relative apical sparing pattern of longitudinal strain in patients with cardiac amyloidosis

Background

The relative apical sparing pattern (RASP) of left ventricular (LV) longitudinal strain (LS) is frequently associated with cardiac amyloidosis (CA). However, some patients with CA do not show the RASP, and their clinical characteristics have not been fully clarified. We sought to investigate the clinical significance of RASP in patients with CA.

Methods

One hundred consecutive CA patients who were diagnosed by biopsy or myocardial pyrophosphate scintigraphy and evaluated for RASP (mean age: 76 years, male: 77%, LV mean wall thickness: 13.5 mm, light-chain [AL] type: 33 cases, transthyretin [TTR] type: 67 cases) were retrospectively enrolled. The RASP was semi-quantitatively and quantitatively assessed. Semi-quantitative RASP was defined as reduction of LS (≥−10%) in ≥5 (of 6) basal segments relative to preserved LS (&lt;−15%) in ≥1 apical segment. Quantitative RASP was calculated according to the following formula: Quantitative RASP = [Average apical LS] / [Average basal LS + Average mid LS]. We adapted three validated thresholds (&gt;1.00, &gt;0.90, and &gt;0.87) according to the literature.

Results

Semi-quantitative and binalized quantitative RASP (&gt;1.00, &gt;0.90, and &gt;0.87) were observed in 55, 55, 63, and 65 patients, respectively. RASP in each definition was more prevalent in the TTR group than in the AL group. Additionally, RASP was significantly associated with higher LV wall thickness even after adjustment for the CA subtypes (all, p&lt;0.05, Figure). After the RASP assessment, 35 all-cause deaths and 26 cardiac deaths were observed during the follow-up period (median, 1.1 years). Although these events were significantly associated with poor nutrition, lower blood pressure, higher New York Heart Association class, and the AL group, no association was found with RASP and LV wall thickness.

Conclusions

The incidence of RASP is low in the case of thin LV wall thickness in CA patients, which may indicate the difficulty of early diagnosis of CA using RASP in patients with mild LV hypertrophy. The prognostic prediction using RASP may be challenging in this cohort.

Figure 1

Funding Acknowledgement

Type of funding source: None

Alpelisib plus fulvestrant for PIK3CA-mutated, hormone receptor-positive, human epidermal growth factor receptor-2-negative advanced breast cancer: final overall survival results from SOLAR-1

BACKGROUND

Activation of the phosphatidylinositol-3-kinase (PI3K) pathway via PIK3CA mutations occurs in 28%-46% of hormone receptor-positive (HR+), human epidermal growth factor receptor-2-negative (HER2-) advanced breast cancers (ABCs) and is associated with poor prognosis. The SOLAR-1 trial showed that the addition of alpelisib to fulvestrant treatment provided statistically significant and clinically meaningful progression-free survival (PFS) benefit in PIK3CA-mutated, HR+, HER2- ABC.

PATIENTS AND METHODS

Men and postmenopausal women with HR+, HER2- ABC whose disease progressed on or after aromatase inhibitor (AI) were randomized 1 : 1 to receive alpelisib (300 mg/day) plus fulvestrant (500 mg every 28 days and once on day 15) or placebo plus fulvestrant. Overall survival (OS) in the PIK3CA-mutant cohort was evaluated by Kaplan-Meier methodology and a one-sided stratified log-rank test was carried out with an O'Brien-Fleming efficacy boundary of P ≤ 0.0161.

RESULTS

In the PIK3CA-mutated cohort (n = 341), median OS [95% confidence interval (CI)] was 39.3 months (34.1-44.9) for alpelisib-fulvestrant and 31.4 months (26.8-41.3) for placebo-fulvestrant [hazard ratio (HR) = 0.86 (95% CI, 0.64-1.15; P = 0.15)]. OS results did not cross the prespecified efficacy boundary. Median OS (95% CI) in patients with lung and/or liver metastases was 37.2 months (28.7-43.6) and 22.8 months (19.0-26.8) in the alpelisib-fulvestrant and placebo-fulvestrant arms, respectively [HR = 0.68 (0.46-1.00)]. Median times to chemotherapy (95% CI) for the alpelisib-fulvestrant and placebo-fulvestrant arms were 23.3 months (15.2-28.4) and 14.8 months (10.5-22.6), respectively [HR = 0.72 (0.54-0.95)]. No new safety signals were observed with longer follow-up.

CONCLUSIONS

Although the analysis did not cross the prespecified boundary for statistical significance, there was a 7.9-month numeric improvement in median OS when alpelisib was added to fulvestrant treatment of patients with PIK3CA-mutated, HR+, HER2- ABC. Overall, these results further support the statistically significant prolongation of PFS observed with alpelisib plus fulvestrant in this population, which has a poor prognosis due to a PIK3CA mutation. CLINICALTRIALS.

GOV ID

NCT02437318.