Induced Pluripotent Stem Cells and Their Use in Human Models of Disease and Development.

The discovery of somatic cell nuclear transfer proved that somatic cells can carry the same genetic code as the zygote, and that activating parts of this code are sufficient to reprogram the cell to an early developmental state. The discovery of induced pluripotent stem cells (iPSCs) nearly half a century later provided a molecular mechanism for the reprogramming. The initial creation of iPSCs was accomplished by the ectopic expression of four specific genes (OCT4, KLF4, SOX2, and c-Myc; OSKM). iPSCs have since been acquired from a wide range of cell types and a wide range of species, suggesting a universal molecular mechanism. Furthermore, cells have been reprogrammed to iPSCs using a myriad of methods, although OSKM remains the gold standard. The sources for iPSCs are abundant compared with those for other pluripotent stem cells; thus the use of iPSCs to model the development of tissues, organs, and other systems of the body is increasing. iPSCs also, through the reprogramming of patient samples, are being used to model diseases. Moreover, in the 10 years since the first report, human iPSCs are already the basis for new cell therapies and drug discovery that have reached clinical application. In this review, we examine the generation of iPSCs and their application to disease and development.

Predictors of Optical Coherence Tomography-Defined Calcified Nodules in Patients With Acute Coronary Syndrome　- A Substudy From the TACTICS Registry.

BACKGROUND: Recent studies suggest that the presence of calcified nodules (CN) is associated with worse prognosis in patients with acute coronary syndrome (ACS). We investigated clinical predictors of optical coherence tomography (OCT)-defined CN in ACS patients in a prospective multicenter registry. METHODS AND RESULTS: We investigated 695 patients enrolled in the TACTICS registry who underwent OCT assessment of the culprit lesion during primary percutaneous coronary intervention. OCT-CN was defined as calcific nodules erupting into the lumen with disruption of the fibrous cap and an underlying calcified plate. Compared with patients without OCT-CN, patients with OCT-CN (n=28) were older (mean [±SD] age 75.0±11.3 vs. 65.7±12.7 years; P<0.001), had a higher prevalence of diabetes (50.0% vs. 29.4%; P=0.034), hemodialysis (21.4% vs. 1.6%; P<0.001), and Killip Class III/IV heart failure (21.4% vs. 5.7%; P=0.003), and a higher preprocedural SYNTAX score (median [interquartile range] score 15 [11-25] vs. 11 [7-19]; P=0.003). On multivariable analysis, age (odds ratio [OR] 1.072; P<0.001), hemodialysis (OR 16.571; P<0.001), and Killip Class III/IV (OR 4.466; P=0.004) were significantly associated with the presence of OCT-CN. In non-dialysis patients (n=678), age (OR 1.081; P<0.001), diabetes (OR 3.046; P=0.014), and Killip Class III/IV (OR 4.414; P=0.009) were significantly associated with the presence of OCT-CN. CONCLUSIONS: The TACTICS registry shows that OCT-CN is associated with lesion severity and poor clinical background, which may worsen prognosis.

eSPRESSO: topological clustering of single-cell transcriptomics data to reveal informative genes for spatio-temporal architectures of cells.

BACKGROUND: Bioinformatics capability to analyze spatio-temporal dynamics of gene expression is essential in understanding animal development. Animal cells are spatially organized as functional tissues where cellular gene expression data contain information that governs morphogenesis during the developmental process. Although several computational tissue reconstruction methods using transcriptomics data have been proposed, those methods have been ineffective in arranging cells in their correct positions in tissues or organs unless spatial information is explicitly provided. RESULTS: This study demonstrates stochastic self-organizing map clustering with Markov chain Monte Carlo calculations for optimizing informative genes effectively reconstruct any spatio-temporal topology of cells from their transcriptome profiles with only a coarse topological guideline. The method, eSPRESSO (enhanced SPatial REconstruction by Stochastic Self-Organizing Map), provides a powerful in silico spatio-temporal tissue reconstruction capability, as confirmed by using human embryonic heart and mouse embryo, brain, embryonic heart, and liver lobule with generally high reproducibility (average max. accuracy = 92.0%), while revealing topologically informative genes, or spatial discriminator genes. Furthermore, eSPRESSO was used for temporal analysis of human pancreatic organoids to infer rational developmental trajectories with several candidate 'temporal' discriminator genes responsible for various cell type differentiations. CONCLUSIONS: eSPRESSO provides a novel strategy for analyzing mechanisms underlying the spatio-temporal formation of cellular organizations.

Adult-onset idiopathic peripheral pulmonary artery stenosis.

BACKGROUND: Peripheral pulmonary artery stenosis (PPS) refers to stenosis of the pulmonary artery from the trunk to the peripheral arteries. Although paediatric PPS is well described, the clinical characteristics of adult-onset idiopathic PPS have not been established. Our objectives in this study were to characterise the disease profile of adult-onset PPS. METHODS: We collected data in Japanese centres. This cohort included patients who underwent pulmonary angiography (PAG) and excluded patients with chronic thromboembolic pulmonary hypertension or Takayasu arteritis. Patient backgrounds, right heart catheterisation (RHC) findings, imaging findings and treatment profiles were collected. RESULTS: 44 patients (median (interquartile range) age 39 (29-57) years; 29 females (65.9%)) with PPS were enrolled from 20 centres. In PAG, stenosis of segmental and peripheral pulmonary arteries was observed in 41 (93.2%) and 36 patients (81.8%), respectively. 35 patients (79.5%) received medications approved for pulmonary arterial hypertension (PAH) and 22 patients (50.0%) received combination therapy. 25 patients (56.8%) underwent transcatheter pulmonary angioplasty. RHC data showed improvements in both mean pulmonary arterial pressure (44 versus 40 mmHg; p<0.001) and pulmonary vascular resistance (760 versus 514 dyn·s·cm-5; p<0.001) from baseline to final follow-up. The 3-, 5- and 10-year survival rates of patients with PPS were 97.5% (95% CI 83.5-99.6%), 89.0% (95% CI 68.9-96.4%) and 67.0% (95% CI 41.4-83.3%), respectively. CONCLUSIONS: In this study, patients with adult-onset idiopathic PPS presented with segmental and peripheral pulmonary artery stenosis. Although patients had severe pulmonary hypertension at baseline, they showed a favourable treatment response to PAH drugs combined with transcatheter pulmonary angioplasty.

Extracellular vesicles and microRNAs in the regulation of cardiomyocyte differentiation and proliferation.

Cardiomyocyte differentiation and proliferation are essential processes for the regeneration of an injured heart. In recent years, there have been several reports highlighting the involvement of extracellular vesicles (EVs) in cardiomyocyte differentiation and proliferation. These EVs originate from mesenchymal stem cells, pluripotent stem cells, and heart constituting cells (cardiomyocytes, cardiac fibroblasts, cardiac progenitor cells, epicardium). Numerous reports also indicate the involvement of microRNAs (miRNAs) in cardiomyocyte differentiation and proliferation. Among them, miRNA-1, miRNA-133, and miRNA-499, recently demonstrated to promote cardiomyocyte differentiation, and miRNA-199, shown to promote cardiomyocyte proliferation, were found effective in various studies. MiRNA-132 and miRNA-133 have been identified as cargo in EVs and are reported to induce cardiomyocyte differentiation. Similarly, miRNA-30a, miRNA-100, miRNA-27a, miRNA-30e, miRNA-294 and miRNA-590 have also been identified as cargo in EVs and are shown to have a role in the promotion of cardiomyocyte proliferation. Regeneration of the heart by EVs or artificial nanoparticles containing functional miRNAs is expected in the future. In this review, we outline recent advancements in understanding the roles of EVs and miRNAs in cardiomyocyte differentiation and proliferation. Additionally, we explore the related challenges when utilizing EVs and miRNAs as a less risky approach to cardiac regeneration compared to cell transplantation.

Prevalence and Impact of Polyvascular Disease in Patients With Acute Myocardial Infarction in the Contemporary Era of Percutaneous Coronary Intervention　- Insights From the Japan Acute Myocardial Infarction Registry (JAMIR).

BACKGROUND: This post hoc subanalysis aimed to investigate the impact of polyvascular disease (PolyVD) in patients with acute myocardial infarction (AMI) in the contemporary era of percutaneous coronary intervention (PCI).Methods and Results: The Japan Acute Myocardial Infarction Registry (JAMIR), a multicenter prospective registry, enrolled 3,411 patients with AMI between December 2015 and May 2017. Patients were classified according to complications of a prior stroke and/or peripheral artery disease into an AMI-only group (involvement of 1 vascular bed [1-bed group]; n=2,980), PolyVD with one of the complications (2-bed group; n=383), and PolyVD with both complications (3-bed group; n=48). The primary endpoint was all-cause death. Secondary endpoints were major adverse cardiovascular events (MACE), including cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, and major bleeding. In the 1-, 2-, and 3-bed groups, the cumulative incidence of all-cause death was 6.8%, 17.5%, and 23.7%, respectively (P<0.001); that of MACE was 7.4%, 16.4%, and 33.8% (P<0.001), respectively; and that of major bleeding was 4.8%, 10.0%, and 13.9% (P<0.001), respectively. PolyVD was independently associated with all-cause death (hazard ratio [HR] 2.21; 95% confidence interval [CI], 1.48-3.29), MACE (HR 2.07; 95% CI 1.40-3.07), and major bleeding (HR 1.68; 95% CI 1.04-2.71). CONCLUSIONS: PolyVD was significantly associated with worse outcomes, including thrombotic and bleeding events, in the contemporary era of PCI in AMI patients.

The moral status of human embryo-like structures: potentiality matters?: The moral status of human synthetic embryos.

New techniques to generate and culture embryo-like structures from stem cells require a more fine-grained distinction of potential to define the moral status of these structures.

Effect of Infarction-Related Artery Location on Clinical Outcome of Patients With Acute Myocardial Infarction in the Contemporary Era of Percutaneous Coronary Intervention　- Subanalysis From the Prospective Japan Acute Myocardial Infarction Registry (JAMIR).

BACKGROUND: Previous studies have reported that acute myocardial infarction (AMI) related to left anterior descending (LAD) lesion is associated with worse outcomes than left circumflex artery (LCX) or right coronary artery (RCA) lesions. However, it is unknown whether those relationships are still present in the contemporary era of primary percutaneous coronary intervention (PCI), using newer generation drug-eluting stents and potent antiplatelet agents.Methods and Results:This study is a sub-analysis of the Japan AMI Registry (JAMIR), a multicenter, prospective registry enrolling 3,411 AMI patients between December 2015 and May 2017. Among them, 2,780 patients undergoing primary PCI for only a culprit vessel were included and stratified based on infarction-related artery type (LAD, LCX, and RCA). The primary outcome was 1-year cardiovascular death. The overall incidence of cardiovascular death was 3.4%. Patients with LAD infarction had highest incidence of cardiovascular death compared to patients with LCX and RCA infarction (4.8%, 1.3%, and 2.4%, respectively); however, landmark analysis showed that culprit vessel had no significant effect on cardiovascular death if a patient survived 30 days after primary PCI. LAD lesion infarction was an independent risk factor for cardiovascular death in adjusted Cox regression analysis. CONCLUSIONS: The present sub-analysis of the JAMIR demonstrated that LAD infarction is still associated with worse outcomes, especially during the first 30 days, even in the contemporary era of PCI.

Effect of Low Body Mass Index on the Clinical Outcomes of Japanese Patients With Acute Myocardial Infarction　- Results From the Prospective Japan Acute Myocardial Infarction Registry (JAMIR).

BACKGROUND: Acute myocardial infarction (AMI) patients with low body mass index (BMI) exhibit worse clinical outcomes than obese patients; however, to our knowledge, no prospective, nationwide study has assessed the effect of BMI on the clinical outcomes of AMI patients.Methods and Results:In this multi-center, prospective, nationwide Japanese trial, 2,373 AMI patients who underwent emergent percutaneous coronary intervention within 12 h of onset from the Japanese AMI Registry (JAMIR) were identified. Patients were divided into the following 4 groups based on their BMI at admission: Q1 group (BMI <18.5 kg/m2, n=133), Q2 group (18.5≤BMI<25.0 kg/m2, n=1,424), Q3 group (25.0≤BMI<30.0 kg/m2, n=672), and Q4 group (30.0 kg/m2≤BMI, n=144). The primary endpoint was all-cause death, and the secondary endpoint was a composite of cardiovascular death, non-fatal myocardial infarction (MI), and non-fatal stroke. The median follow-up period was 358 days. Q1 patients were older and had lower prevalence of coronary risk factors. Q1 patients also had higher all-cause mortality and higher incidence of secondary endpoints than normal-weight or obese AMI patients. Multivariate analysis showed that low BMI (Q1 group) was an independent predictor for primary endpoint. CONCLUSIONS: AMI patients with low BMI had fewer coronary risk factors but worse clinical outcomes than normal-weight or obese patients.

Protein kinase A accelerates the rate of early stage differentiation of pluripotent stem cells.

In normal development, the rate of cell differentiation is tightly controlled and critical for normal development and stem cell differentiation. However, the underlying mechanisms regulating the rate of the differentiation are unknown, and manipulation of the rate of the stem cell differentiation is currently difficult. Here we show that activation of protein kinase A (PKA) accelerates the rate of mouse embryonic stem cell (ESC) differentiation through an early loss of ESC pluripotency markers and early appearance of mesodermal and other germ layer cells. The activation of PKA hastened differentiation by increasing the expression of a histone H3 lysine 9 (H3K9) dimethyltransferase, G9a protein, and the level of a negative epigenetic histone mark, H3K9 dimethylation (H3K9me2), in the promoter regions of the pluripotency markers Nanog and Oct4. These results elucidate a novel role of PKA on ESC differentiation and offer an experimental model for controlling the rate of ESC differentiation.

Clinical Differences of Recent Myocardial Infarction Compared With Acute Myocardial Infarction　- Insights From the Tokyo CCU Network Multicenter Registry.

BACKGROUND: Characteristics and treatment outcomes of acute myocardial infarction (AMI) patients have been studied; however, those of recent myocardial infarction (RMI) patients remain unclear. This study aimed to clarify characteristics, treatment strategy, and in-hospital outcomes of RMI patients in the Tokyo CCU network database.Methods and Results:In total, 1,853 RMI and 12,494 AMI patients from the Tokyo CCU network database during 2013-2016 were compared. Both RMI and AMI were redefined by onset times of 2-28 days and ≤24 h, respectively. The RMI group had a higher average age (70.4±12.9 vs. 68.0±13.4 years, P<0.001), more women (27.6% vs. 23.6%, P<0.001), lower proportion of patients with chest pain as the chief complaint (75.2% vs. 83.6%, P<0.001), higher prevalence of diabetes mellitus (35.9% vs. 31.0%, P<0.001), and higher mechanical complication incidence (3.0% vs. 1.5%, P<0.001) than did the AMI group. Thirty-day mortality was comparable (5.3% vs. 5.8%, P=0.360); major causes of death were cardiogenic shock and mechanical complications in the AMI and RMI groups, respectively. Death from mechanical complications (not onset time) in the AMI group plateaued almost 1 week after hospitalization, whereas it continued to increase in the RMI group. CONCLUSIONS: Both RMI and AMI patients have distinctive clinical features, sequelae, and causes of death. Although treatment of RMI patients adhered to guidelines, it was insufficient, and death from mechanical complications continues to increase.

Monotherapy With Prasugrel After Dual-Antiplatelet Therapy for Japanese Percutaneous Coronary Intervention Patients With High Bleeding Risk　- A Prospective Cohort Study (PENDULUM mono Study).

BACKGROUND: The risks of bleeding and cardiovascular events in high bleeding risk (HBR) Japanese patients undergoing percutaneous coronary intervention (PCI) while receiving single-antiplatelet therapy (SAPT) remains unknown. We aimed to evaluate the frequency of bleeding and cardiovascular events associated with prasugrel monotherapy after short-term dual-antiplatelet therapy (DAPT) in Japanese HBR patients after PCI.Methods and Results:The PENDULUM mono study was a multicenter, non-interventional, prospective registry (n=1,173). The primary endpoint was the cumulative incidence of clinically relevant bleeding (CRB; Bleeding Academic Research Consortium types 2, 3, and 5) from 1 to 12 months after PCI. Secondary endpoints included major adverse cardiac and cerebrovascular events (MACCE). The proportion of patients who received prasugrel monotherapy at 12 months after PCI was 79.7%, and no cases of stent thrombosis were observed among these patients. The cumulative incidence of CRB was 3.2% from 1 to 12 months after PCI; that of MACCE was 3.8%. Severe anemia, chronic kidney disease, oral anticoagulant use at discharge, and heart failure were significantly associated with CRB. CONCLUSIONS: Among HBR patients undergoing PCI who were not suitable for concomitant aspirin and were scheduled for prasugrel monotherapy, most patients were on prasugrel monotherapy after DAPT. Cumulative incidences of CRB and MACCE after periprocedural period were 3.2% and 3.8%, respectively, and no cases of stent thrombosis were reported. SAPT might be a suitable alternative to DAPT.

AMPK activators contribute to maintain naïve pluripotency in mouse embryonic stem cells.

Pluripotent stem cells retain the property to self-renew and differentiate into all cell types under defined conditions. Among mouse embryonic stem cells (ESCs), which are pluripotent but heterogenous in gene expression and morphology, an ESC population cultured in small molecule inhibitors of two kinases, MAPK/ERK kinase (Mek) and Glycogen synthase kinase 3 (Gsk3), and leukemia inhibitory factor (Lif) (2i/L) is considered to be naïve pluripotent with uniform pluripotent machinery operation. Though the gene regulatory mechanism for the naïve pluripotency has been investigated in recent years, it is still not fully elucidated. Here we show a novel signaling involved in the maintenance of naïve pluripotency. An AMP-activated protein kinase (AMPK) activator, AICAR (5-Aminoimidazole-4-carboxamied-1-ß-riboside) blocked the differentiation of mouse naïve ESCs in the absence of 2i/L and maintained the naïve state. AICAR with Lif condition induced an almost comparable level of naïve pluripotent gene expression in mouse ESCs. Another AMPK activator, A769662, also showed similar effects. A p38 inhibitor, SB203580, blocked the AMPK activation-elicited naïve state maintenance. On the other hand, p38 activation partially mimicked the maintenance effects of AMPK activators, suggesting that p38 is one of the functional downstream molecules to conduct the AMPK effects. Thus, AMPK pathway should be involved in the molecular circuitry of naïve pluripotency in mouse ESCs. These findings would be a valuable clue to further elucidate the molecular machinery of naïve pluripotency.

Elevated serum levels of sialyl Lewis X (sLeX) and inflammatory mediators in patients with breast cancer.

PURPOSE: The carbohydrate sialyl LewisX (sLeX) mediates cell adhesion, is critical in the normal function of immune cells, and is frequently over-expressed on cancer cells. We assessed the association, differential levels, and prognostic value of sLeX and inflammatory cytokines/chemokines in breast cancer sera. METHODS: We retrospectively measured sLeX and a panel of cytokines/chemokines in the sera of 26 non-invasive ductal carcinoma in situ (DCIS), 154 invasive non-metastatic breast cancer (non-MBC), 63 metastatic breast cancer (MBC) patients, and 43 healthy controls. Differences in sLeX and inflammatory cytokines among and between patient groups and healthy controls were assessed with nonparametric tests and we performed survival analysis for the prognostic potential of sLeX using a cut-off of 8 U/mL as previously defined. RESULTS: Median serum sLeX was significantly higher than controls for invasive breast cancer patients (MBC and non-MBC) but not DCIS. In univariate analysis, we confirmed patients with serum sLeX > 8 U/mL have a significantly shorter progression-free survival (PFS) (P = 0.0074) and overall survival (OS (P = 0.0003). Similarly, patients with high serum MCP-1 and IP-10 had shorter OS (P = 0.001 and P < 0.001, respectively) and PFS (P = 0.010 and P < 0.001, respectively). sLeX, MCP-1 and IP-10 remained significant in multivariate survival analysis. CONCLUSION: Elevated serum sLeX was associated with invasive cancer but not DCIS. High serum sLeX levels were associated with inflammatory mediators and may play a role in facilitating local invasion of breast tumor. Furthermore, serum MCP-1, IP-10 and sLeX may have prognostic value in breast cancer.

Dynamically and epigenetically coordinated GATA/ETS/SOX transcription factor expression is indispensable for endothelial cell differentiation.

Although studies of the differentiation from mouse embryonic stem (ES) cells to vascular endothelial cells (ECs) provide an excellent model for investigating the molecular mechanisms underlying vascular development, temporal dynamics of gene expression and chromatin modifications have not been well studied. Herein, using transcriptomic and epigenomic analyses based on H3K4me3 and H3K27me3 modifications at a genome-wide scale, we analysed the EC differentiation steps from ES cells and crucial epigenetic modifications unique to ECs. We determined that Gata2, Fli1, Sox7 and Sox18 are master regulators of EC that are induced following expression of the haemangioblast commitment pioneer factor, Etv2. These master regulator gene loci were repressed by H3K27me3 throughout the mesoderm period but rapidly transitioned to histone modification switching from H3K27me3 to H3K4me3 after treatment with vascular endothelial growth factor. SiRNA knockdown experiments indicated that these regulators are indispensable not only for proper EC differentiation but also for blocking the commitment to other closely aligned lineages. Collectively, our detailed epigenetic analysis may provide an advanced model for understanding temporal regulation of chromatin signatures and resulting gene expression profiles during EC commitment. These studies may inform the future development of methods to stimulate the vascular endothelium for regenerative medicine.

Sarcomere gene variants act as a genetic trigger underlying the development of left ventricular noncompaction.

BACKGROUND: Left ventricular noncompaction (LVNC) is a primary cardiomyopathy with heterogeneous genetic origins. The aim of this study was to elucidate the role of sarcomere gene variants in the pathogenesis and prognosis of LVNC. METHODS AND RESULTS: We screened 82 Japanese patients (0-35 years old), with a diagnosis of LVNC, for mutations in seven genes encoding sarcomere proteins, by direct DNA sequencing. We identified variants in a significant proportion of cases (27%), which were associated with poor prognosis (p = 0.012), particularly variants in TPM1, TNNC1, and ACTC1 (p = 0.012). To elucidate the pathological role, we developed and studied human-induced pluripotent stem cells (hiPSCs) from a patient carrying a TPM1 p.Arg178His mutation, who underwent heart transplantation. These cells displayed pathological changes, with mislocalization of tropomyosin 1, causing disruption of the sarcomere structure in cardiomyocytes, and impaired calcium handling. Microarray analysis indicated that the TPM1 mutation resulted in the down-regulation of the expression of numerous genes involved in heart development, and positive regulation of cellular process, especially the calcium signaling pathway. CONCLUSIONS: Sarcomere genes are implicated as genetic triggers in the development of LVNC, regulating the expression of numerous genes involved in heart development, or modifying the severity of disease.

Sameuramide A, a new cyclic depsipeptide isolated from an ascidian of the family Didemnidae.

Sameuramide A (1), a new cyclic depsipeptide encompassing one each of alanine, N-methyl alanine, N-methyl dehydroalanine, N,O-dimethyl threonine, phenyllactic acid, three ß-hydroxy leucines, and two propionates, was isolated from a didemnid ascidian collected at the northern part of Japan. The planar structure was established based on the interpretation of MS and NMR data. The absolute configuration of the subunits was determined by the advanced Marfey's method and the chiral LC-MS analysis. Compound 1 exhibited the activity of maintaining colony formation of murine embryonic stem (mES) cells without leukemia inhibitory factor (LIF). Down regulation of the gene expression of Krüppel-like transcription factor 4 (Klf4) indicated that 1 itself was not able to maintain the undifferentiated state of the mES cells. However, the expression levels of the marker genes (Nestin, T, Sox17) for three germ layers were upregulated in embryoid bodies (EBs) after treatment of 1 together with LIF, suggesting that 1 plays a supportive role for LIF in maintaining the multipotency of mES cells.

Association of moderate chronic kidney disease with insufficient improvement of fractional flow reserve after stent implantation.

OBJECTIVES: This study aims to investigate the association of moderate chronic kidney disease (CKD) with fractional flow reserve (FFR) after stent implantation. BACKGROUND: Patients with moderate CKD have a higher prevalence of severe and diffuse coronary artery disease, and have increased risk of cardiovascular events even after stent implantation. On the other hand, in some patients, FFR could not be sufficiently improved even after stent implantation. However, the association between these pathophysiological processes is unclear. METHODS AND RESULTS: A total of 102 patients with stable angina, in whom a stent was implanted for the left anterior descending coronary artery (LAD) lesion, were included. Patients with a severely decreased glomerular filtration rate (GFR; > CKD stage 4) were excluded. Patients were stratified into 3 groups: those with an estimated GFR (eGFR) ≥ 60 mL per min per 1.73 m(2) (stage 0-2), 45 to 59 mL per min per 1.73 m(2) (stage 3a), and 30 to 44 mL per min per 1.73 m(2) (stage 3b). FFR after stent implantation (post-stent FFR) was significantly lower in the stage 3b group than in both the stage 0-2 group and the stage 3a group (P < 0.01). Post-stent FFR had a significant positive correlation with eGFR (r = 0.223, P = 0.024). Multivariate analysis demonstrated that eGFR was an independent predictor of post-stent FFR. CONCLUSIONS: Moderate CKD was independently associated with insufficient improvement of FFR after stent implantation. This can partly explain the poor prognosis of patients with CKD. © 2015 Wiley Periodicals, Inc.