Inhibition of de novo ceramide synthesis by Sirtuin-1 improves beta-cell function and glucose metabolism in type 2 diabetes.

BACKGROUND: Obesity and type 2 diabetes (T2D) are major risk factors for cardiovascular diseases (CVD). Dysregulated pro-apoptotic ceramide synthesis reduces ß-cell insulin secretion, thereby promoting hyperglycemic states which may manifest as T2D. Pro-apoptotic ceramides modulate insulin sensitivity and glucose tolerance while being linked to poor cardiovascular outcomes. Sirtuin-1 (SIRT1) is a NAD + - dependent deacetylase that protects against pancreatic ß-cell dysfunction; however, systemic levels are decreased in obese T2D mice and may promote pro-apoptotic ceramide synthesis and hyperglycemia. Herein, we aimed to assess the effects of restoring circulating SIRT1 levels to prevent metabolic imbalance in obese and diabetic mice. METHODS AND RESULTS: Circulating SIRT1 levels were reduced in obese diabetic mice (db/db) as compared to age-matched non-diabetic db/+ controls. Restoration of SIRT1 plasma levels with recombinant murine SIRT1 for 4-weeks prevented body weight gain, improved glucose tolerance, insulin sensitivity and vascular function in mice models of obesity and T2D. Untargeted lipidomics revealed that SIRT1 restored insulin-secretory function of ß-cells by reducing synthesis and accumulation of pro-apoptotic ceramides. Molecular mechanisms involved direct binding to and deacetylation of Toll-like receptor 4 (TLR4) by SIRT1 in ß-cells thereby decreasing the rate limiting enzymes of sphingolipid synthesis SPTLC1/2 via AKT/NF-κB. Among T2D patients, those with high baseline plasma levels of SIRT1 prior to metabolic surgery displayed restored ß-cell function (HOMA2- ß) and were more likely to have T2D remission during follow-up. CONCLUSION: Acetylation of TLR4 promotes ß-cell dysfunction via ceramide synthesis in T2D, which is blunted by systemic SIRT1 replenishment. Hence, restoration of systemic SIRT1 may provide a novel therapeutic strategy to counteract toxic ceramide synthesis and mitigate cardiovascular complications of T2D.

Preferred monotherapy after short-term dual antiplatelet therapy: Systematic review and network meta-analysis of randomized trials.

BACKGROUND: Randomized controlled trials (RCTs) have demonstrated the efficacy and safety of P2Y12 inhibitor monotherapy following short-term dual antiplatelet therapy (DAPT) in patients undergoing percutaneous coronary intervention (PCI). However, no studies have compared P2Y12 inhibitor and aspirin monotherapy following short-term DAPT. We aimed to compare available strategies for DAPT duration and post-DAPT antiplatelet monotherapy following PCI. METHODS: Seven DAPT strategies [ticagrelor or clopidogrel following 1-month DAPT, ticagrelor following 3-month DAPT, aspirin following 3-6 months of DAPT (reference strategy), aspirin or P2Y12 inhibitor following 6-18-months of DAPT, and DAPT for ≥18 months] were compared using a network meta-analysis. The primary efficacy outcome was defined as a composite of all-cause death, myocardial infarction, and stroke. The primary bleeding outcome was trial-defined major or minor bleeding. RESULTS: Our analysis identified 25 eligible RCTs, including 89,371 patients who underwent PCI. Overall, none of the strategies negatively affected the primary efficacy outcomes. For primary bleeding outcomes, ticagrelor following 3-month DAPT was associated with a reduced risk of primary bleeding outcomes (HR 0.73; 95 % CI 0.57-0.95). Clopidogrel following 1-month DAPT was also associated with a reduced risk of primary bleeding outcomes (HR 0.54; 95 % CI 0.34-0.85), however, the strategy was associated with an increased risk of myocardial infarction or stent thrombosis. Similar trends were observed among patients with acute coronary syndrome and high bleeding risk. CONCLUSIONS: Compared with aspirin monotherapy following short-term DAPT, ticagrelor following 3-month DAPT was associated with a reduced risk of primary bleeding outcomes without increasing any ischemic outcomes.

Comparison of Antiplatelet Monotherapies After Percutaneous Coronary Intervention According to Clinical, Ischemic, and Bleeding Risks.

BACKGROUND: Clopidogrel was superior to aspirin monotherapy in secondary prevention after percutaneous coronary intervention (PCI). OBJECTIVES: The purpose of this study was to evaluate the benefits of clopidogrel across high-risk subgroups METHODS: This was a post hoc analysis of the HOST-EXAM (Harmonizing Optimal Strategy for Treatment of coronary artery diseases-EXtended Antiplatelet Monotherapy) trial that randomly assigned patients who were event free for 6 to 18 months post-PCI on dual antiplatelet therapy (DAPT) to clopidogrel or aspirin monotherapy. Two clinical risk scores were used for risk stratification: the DAPT score and the Thrombolysis In Myocardial Infarction Risk Score for Secondary Prevention (TRS 2°P) (the sum of age ≥75 years, diabetes, hypertension, current smoking, peripheral artery disease, stroke, coronary artery bypass grafting, heart failure, and renal dysfunction). The primary composite endpoint was a composite of all-cause death, nonfatal myocardial infarction, stroke, readmission because of acute coronary syndrome, and major bleeding (Bleeding Academic Research Consortium type ≥3) at 2 years after randomization. RESULTS: Among 5,403 patients, clopidogrel monotherapy showed a lower rate of the primary composite endpoint than aspirin monotherapy (HR: 0.73; 95% CI: 0.59-0.90). The benefit of clopidogrel over aspirin was consistent regardless of TRS 2°P (high TRS 2°P [≥3] group: HR: 0.65 [95% CI: 0.44-0.96]; and low TRS 2°P [<3] group: HR: 0.77 [95% CI: 0.60-0.99]) (P for interaction = 0.454) and regardless of DAPT score (high DAPT score [≥2] group: HR: 0.68 [95% CI: 0.46-1.00]; and low DAPT score [<2] group: HR: 0.75 [95% CI: 0.59-0.96]) (P for interaction = 0.662). The association was similar for the individual outcomes. CONCLUSIONS: The beneficial effect of clopidogrel over aspirin monotherapy was consistent regardless of clinical risk or relative ischemic and bleeding risks compared with aspirin monotherapy. (Harmonizing Optimal Strategy for Treatment of Coronary Artery Stenosis- EXtended Antiplatelet Monotherapy [HOST-EXAM]; NCT02044250).

Smoking and cardiovascular outcomes after percutaneous coronary intervention: a Korean study.

BACKGROUND AND AIMS: The authors investigated the impact of smoking and its cessation after percutaneous coronary intervention (PCI) on cardiovascular outcomes. METHODS: Using a nationwide database from the Korean National Health Insurance System, 74 471 patients undergoing PCI between 2009 and 2016 were classified as non-, ex-, or current smokers, depending on smoking status at the first health check-up within 1 year after PCI. The primary outcome was major adverse cardiovascular and cerebrovascular event (MACCE), a composite of all-cause death, myocardial infarction, coronary revascularization, and stroke. RESULTS: During 4.0 years of follow-up, current smokers had a 19.8% higher rate of MACCE than non-smokers [adjusted hazard ratio (aHR) 1.198; 95% confidence interval (CI) 1.137-1.263], and ex-smokers tended to have a comparable rate with that of non-smokers (aHR 1.036; 95% CI .992-1.081). For 31 887 patients with both pre- and post-PCI health check-up data, the effects of smoking cessation were analysed. Among quitters who stopped smoking after PCI, quitters with cumulative smoking exposure of <20 pack-years (PYs) tended to have a comparable rate of MACCE with that of persistent non-smokers. However, the rate in quitters with cumulative exposure of ≥20 PYs was comparable with that of persistent smokers [aHR (95% CI) for <10 PY, 1.182 (.971-1.438); 10-20 PYs 1.114 (.963-1.290); 20-30 PYs 1.206 (1.054-1.380); ≥ 30 PYs 1.227 (1.113-1.352); persistent smokers 1.223 (1.126-1.328), compared with persistent non-smokers, respectively, P for interaction <.001]. CONCLUSIONS: Smoking is associated with a higher risk of adverse outcomes in patients undergoing PCI. Quitters after PCI with <20 PYs were associated with a risk comparable with that of non-smokers.

Efficacy and safety of standard dose triple combination of telmisartan 80 mg/amlodipine 5 mg/chlorthalidone 25 mg in primary hypertension: A randomized, double-blind, active-controlled, multicenter phase 3 trial.

The authors evaluated the efficacy, safety, and characteristics of patients who respond well to standard dose triple combination therapy including chlorthalidone 25 mg with telmisartan 80 mg plus amlodipine 5 mg in hypertensive patients. This is a multicenter, double-blind, active-controlled, phase 3, randomized trial. Patients are randomized to triple combination (telmisartan 40 mg/amlodipine 5 mg/chlorthalidone 12.5 mg, TEL/AML/CHTD group) or dual combination (telmisartan 40 mg/amlodipine 5 mg, TEL/AML group) treatment and then dose up titration to TEL 80/AML5/CHTD25mg and TEL80/AML5, respectively. The primary endpoint is the change of mean sitting systolic blood pressure (MSSBP) at week 8. A Target BP achievement rate, a response rate, and the safety endpoints are also evaluated. Total 374 patients (mean age = 60.9 ± 10.7 years, male = 78.3%) were randomized to the study. The baseline MSSBPs/diastolic BPs were 149.9 ± 12.2/88.5 ± 10.4 mm Hg. After 8 weeks treatment, the change of MSSBPs at week 8 are -19.1 ± 14.9 mm Hg (TEL/AML/CHTD) and -11.4 ± 14.7 mm Hg (TEL/AML) (p < .0001). The achievement rates of target BP (53.8% vs. 37.8%, p = .0017) and responder rate (54.8% vs. 35.6%, p = .0001) at week 8 were significantly higher in TEL/AML/CHTD. There are no serious adverse event and no one discontinued medication due to adverse event. Among the TEL 80/AML5/CHTD25mg treatment group, patients of female or age ≥ 65 years old showed higher rate of target BP achievement than relatively young male. (61.4 vs. 46.8%, p = .042) Our study showed standard dose triple combination of telmisartan 80 mg/amlodipine 5 mg/chlorthalidone 25 mg is efficacious and safe in treatment of primary hypertension. Target BP achievement with triple therapy would be facilitated in female or old age.

The maintenance mechanism of hematopoietic stem cell dormancy: role for a subset of macrophages.

Hematopoiesis is regulated by crosstalk between long-term repopulating hematopoietic stem cells (LT-HSCs) and supporting niche cells in the bone marrow (BM). Here, we describe the role of KAI1, which is mainly expressed on LT-HSCs and rarely on other hematopoietic stem-progenitor cells (HSPCs), in nichemediated LT-HSC maintenance. KAI1 activates TGF-ß1/Smad3 signal in LT-HSCs, leading to the induction of CDK inhibitors and inhibition of the cell cycle. The KAI1-binding partner DARC is expressed on macrophages and stabilizes KAI1 on LT-HSCs, promoting their quiescence. Conversely, when DARC+ BM macrophages were absent, the level of surface KAI1 on LT-HSCs decreases, leading to cell-cycle entry, proliferation, and differentiation. Thus, KAI1 acts as a functional surface marker of LTHSCs that regulates dormancy through interaction with DARCexpressing macrophages in the BM stem cell niche. Recently, we showed very special and rare macrophages expressing α-SMA+ COX2+ & DARC+ induce not only dormancy of LTHSC through interaction of KAI1-DARC but also protect HSCs by down-regulating ROS through COX2 signaling. In the near future, the strategy to combine KAI1-positive LT-HSCs and α-SMA/Cox2/DARC triple-positive macrophages will improve the efficacy of stem cell transplantation after the ablative chemo-therapy for hematological disorders including leukemia. [BMB Reports 2023; 56(9): 482-487].

SOX17-mediated LPAR4 expression plays a pivotal role in cardiac development and regeneration after myocardial infarction.

Lysophosphatidic acid receptor 4 (LPAR4) exhibits transient expression at the cardiac progenitor stage during pluripotent stem cell (PSC)-derived cardiac differentiation. Using RNA sequencing, promoter analyses, and a loss-of-function study in human PSCs, we discovered that SRY-box transcription factor 17 (SOX17) is an essential upstream factor of LPAR4 during cardiac differentiation. We conducted mouse embryo analyses to further verify our human PSC in vitro findings and confirmed the transient and sequential expression of SOX17 and LPAR4 during in vivo cardiac development. In an adult bone marrow transplantation model using LPAR4 promoter-driven GFP cells, we observed two LPAR4+ cell types in the heart following myocardial infarction (MI). Cardiac differentiation potential was shown in heart-resident LPAR4+ cells, which are SOX17+, but not bone marrow-derived infiltrated LPAR4+ cells. Furthermore, we tested various strategies to enhance cardiac repair through the regulation of downstream signals of LPAR4. During the early stages following MI, the downstream inhibition of LPAR4 by a p38 mitogen-activated protein kinase (p38 MAPK) blocker improved cardiac function and reduced fibrotic scarring compared to that observed following LPAR4 stimulation. These findings improve our understanding of heart development and suggest novel therapeutic strategies that enhance repair and regeneration after injury by modulating LPAR4 signaling.

P2Y12 Inhibitor or Aspirin Monotherapy for Secondary Prevention of Coronary Events.

BACKGROUND: Aspirin is the only antiplatelet agent with a Class I recommendation for long-term prevention of cardiovascular events in patients with coronary artery disease (CAD). There is inconsistent evidence on how it compares with alternative antiplatelet agents. OBJECTIVES: This study compared P2Y12 inhibitor monotherapy vs aspirin in patients with CAD. METHODS: We conducted a patient-level meta-analysis of randomized trials comparing P2Y12 inhibitor monotherapy vs aspirin monotherapy for the prevention of cardiovascular events in patients with established CAD. The primary outcome was the composite of cardiovascular death, myocardial infarction, and stroke. Prespecified key secondary outcomes were major bleeding and net adverse clinical events (the composite of the primary outcome and major bleeding). Data were pooled in a 1-step meta-analysis. RESULTS: Patient-level data were obtained from 7 trials. Overall, 24,325 participants were available for analysis, including 12,178 patients assigned to receive P2Y12 inhibitor monotherapy (clopidogrel in 7,545 [62.0%], ticagrelor in 4,633 [38.0%]) and 12,147 assigned to receive aspirin. Risk of the primary outcome was lower with P2Y12 inhibitor monotherapy compared with aspirin over 2 years (HR: 0.88; 95% CI: 0.79-0.97; P = 0.012), mainly owing to less myocardial infarction (HR: 0.77; 95% CI: 0.66-0.90; P < 0.001). Major bleeding was similar (HR: 0.87; 95% CI: 0.70-1.09; P = 0.23) and net adverse clinical events were lower (HR: 0.89; 95% CI: 0.81-0.98; P = 0.020) with P2Y12 inhibitors. The treatment effect was consistent across prespecified subgroups and types of P2Y12 inhibitors. CONCLUSIONS: Given its superior efficacy and similar overall safety, P2Y12 inhibitor monotherapy might be preferred over aspirin monotherapy for long-term secondary prevention in patients with established CAD. (P2Y12 Inhibitor or Aspirin Monotherapy as Secondary Prevention in Patients With Coronary Artery Disease: An Individual Patient Data Meta-Analysis of Randomized Trials [PANTHER collaborative initiative]; CRD42021290774).

Prasugrel-Based De-Escalation in Patients With Acute Coronary Syndrome According to Renal Function.

Background: Patients with coronary artery disease and impaired renal function are at higher risk for both bleeding and ischemic adverse events after percutaneous coronary intervention (PCI). Objectives: This study assessed the efficacy and safety of a prasugrel-based de-escalation strategy in patients with impaired renal function. Methods: We conducted a post hoc analysis of the HOST-REDUCE-POLYTECH-ACS study. Patients with available estimated glomerular filtration rate (eGFR) (n = 2,311) were categorized into 3 groups. (high eGFR: >90 mL/min; intermediate eGFR: 60 to 90 mL/min; and low eGFR: <60 mL/min). The end points were bleeding outcomes (Bleeding Academic Research Consortium type 2 or higher), ischemic outcomes (cardiovascular death, myocardial infarction, stent thrombosis, repeated revascularization, and ischemic stroke), and net adverse clinical event (including any clinical event) at 1-year follow-up. Results: Prasugrel de-escalation was beneficial regardless of baseline renal function (P for interaction = 0.508). The relative reduction in bleeding risk from prasugrel de-escalation was higher in the low eGFR group than in both the intermediate and high eGFR groups (relative reductions, respectively: 64% (HR: 0.36; 95% CI: 0.15-0.83) vs 50% (HR: 0.50; 95% CI: 0.28-0.90) and 52% (HR: 0.48; 95% CI: 0.21-1.13) (P for interaction = 0.646). Ischemic risk from prasgurel de-escalation was not significant in all eGFR groups (HR: 1.18 [95% CI: 0.47-2.98], HR: 0.95 [95% CI: 0.53-1.69], and HR: 0.61 [95% CI: 0.26-1.39]) (P for interaction = 0.119). Conclusions: In patients with acute coronary syndrome receiving PCI, prasugrel dose de-escalation was beneficial regardless of the baseline renal function.

Identification of cell-biologic mechanisms of coronary artery spasm and its ex vivo diagnosis using peripheral blood-derived iPSCs.

BACKGROUND: Although vasospastic angina (VSA) is known to be caused by coronary artery spasm, no study has fully elucidated the exact underlying mechanism. Moreover, in order to confirm VSA, patients should undergo invasive coronary angiography with spasm provocation test. Herein, we investigated the pathophysiology of VSA using peripheral blood-derived induced pluripotent stem cells (iPSCs) and developed an ex vivo diagnostic method for VSA. METHODS AND RESULTS: With 10 mL of peripheral blood from patients with VSA, we generated iPSCs and differentiated these iPSCs into target cells. As compared with vascular smooth muscle cells (VSMCs) differentiated from iPSCs of normal subjects with negative provocation test, VSA patient-specific iPSCs-derived VSMCs showed very strong contraction in response to stimulants. Moreover, VSA patient-specific VSMCs exhibited a significant increase in stimulation-induced intracellular calcium efflux (Changes in the relative fluorescence unit [ΔF/F]; Control group vs. VSA group, 2.89 ± 0.34 vs. 10.32 ± 0.51, p < 0.01), and exclusively induced a secondary or tertiary peak of calcium efflux, suggesting that those findings could be diagnostic cut-off values for VSA. The observed hyperreactivity of VSA patient-specific VSMCs were caused by the upregulation of sarco/endoplasmic reticulum Ca2+-ATPase 2a (SERCA2a) due to its enhanced small ubiquitin-related modifier (SUMO)ylation. This increased activity of SERCA2a was reversed by treatment with ginkgolic acid, an inhibitor of SUMOylated E1 molecules (pi/µg protein; VSA group vs. VSA + ginkgolic acid, 52.36 ± 0.71 vs. 31.93 ± 1.13, p < 0.01). CONCLUSIONS: Our findings showed that abnormal calcium handling in sarco/endoplasmic reticulum could be induced by the enhanced SERCA2a activity in patients with VSA, leading to spasm. Such novel mechanisms of coronary artery spasm could be useful for drug development and diagnosis of VSA.

Real-world evidence of switching P2Y12 receptor-inhibiting therapies to prasugrel after PCI in patients with ACS: results from EFF-K registry.

BACKGROUND: Potent P2Y12 inhibitors are recommended for up to 12 months after percutaneous coronary intervention (PCI) in patients diagnosed with acute coronary syndrome (ACS). However, the prescription pattern is diverse in real world practice, which includes various switching between antiplatelet regimens. In this study, we analyzed the prescription patterns of prasugrel, and assessed the safety and effectiveness of P2Y12 inhibitors switching patterns in a real world registry of patients subjected to PCI after ACS. METHODS: The EFF-K study included 3077 ACS patients receiving prasugrel-based dual antiplatelet therapy. The cohort was divided into those who were administered with prasugrel as the primary antiplatelet treatment (naïve cohort) or as a substitute agent after clopidogrel or ticagrelor pre-treatment (switch cohort). The primary endpoint was a net adverse clinical event (NACE; a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, or TIMI major bleeding unrelated to coronary-artery bypass grafting). RESULTS: A total of 3077 patients diagnosed with ACS were included in the analysis. Among the total population, 726 patients (23.6%) were classed as the naïve cohort and 2351 patients (76.4%) as the switch cohort. Baseline characteristics showed that the switch cohort had more comorbidities, such as hypertension, diabetes mellitus, heart failure and previous PCI. The major cause of switching to prasugrel in the switch cohort was the necessity for a more potent antiplatelet agent (56.3%). During a 12-month follow-up period, 51 patients (1.7%) experienced at least one NACE. The incidence of NACE did not differ between the naïve and switch cohort (1.5% vs. 1.7%, Hazard ratio 1.17, 95% Confidence interval 0.56-2.43, P = 0.677). In subgroup analysis, no significant interaction was observed between the treatment strategy and the incidence of NACE across various subgroups. CONCLUSIONS: Dual antiplatelet therapy with prasugrel seems to be safe and effective both as a primary treatment and as a substitute for other P2Y12 inhibitors in a real world registry of Asian ACS patients receiving PCI. TRIAL REGISTRATION: KCT0002356, registered June 13, 2017.

Resistin impairs mitochondrial homeostasis via cyclase-associated protein 1-mediated fission, leading to obesity-induced metabolic diseases.

OBJECTIVE: One of the suggested mechanisms of obesity-induced insulin resistance is mitochondrial dysfunction in target tissues such as skeletal muscle. In our study, we examined whether resistin, an adipokine associated with obesity-mediated insulin resistance, induced metabolic disorders by impairing mitochondrial homeostasis. METHODS: The morphology and function of mitochondria of skeletal muscle were examined in resistin-knockout and humanized resistin mice that were subjected to high-fat diet for 3 months. Morphology was examined by transmission electron microscopy. Mitochondria bioenergetics of skeletal muscle were evaluated using a Seahorse XF96 analyzer. Human skeletal myoblasts were used for in vitro studies on signaling mechanisms in responses to resistin. RESULTS: A high-fat diet in humanized resistin mice increased fragmented and shorter mitochondria in the skeletal muscle, whereas resistin-knockout mice had healthy normal mitochondria. In vitro studies showed that human resistin treatment impaired mitochondrial homeostasis by inducing mitochondrial fission, leading to a decrease in ATP production and mitochondrial dysfunction. Induction of mitochondrial fission by resistin was accompanied by increased formation of mitochondria-associated ER membranes (MAM). At the same time, resistin induced up-regulation of the protein kinase A (PKA) pathway. This activation of PKA induced phosphorylation of Drp1 at serine 616, leading to Drp1 activation and subsequent induction of mitochondrial fission. The key molecule that mediated human resistin-induced mitochondrial fission was adenylyl cyclase-associated protein 1 (CAP1), which was reported as a bona fide receptor for human resistin. Moreover, our newly developed biomimetic selective blocking peptide could repress human resistin-mediated mitochondrial dysfunction. High-fat diet-fed mice showed lower exercise capacity and higher insulin resistance, which was prevented by a novel peptide to block the binding of resistin to CAP1 or in the CAP1-knockdown mice. CONCLUSIONS: Our study demonstrated that human resistin induces mitochondrial dysfunction by inducing abnormal mitochondrial fission. This result suggests that the resistin-CAP1 complex could be a potential therapeutic target for the treatment of obesity-related metabolic diseases such as diabetes and cardiometabolic diseases.

Impact of Clinical and Lesion Features on Outcomes After Percutaneous Coronary Intervention in Bifurcation Lesions.

Background: Bifurcation percutaneous coronary intervention (PCI) is associated with higher risk of clinical events. Objectives: This study aimed to determine clinical and lesion features that predict adverse outcomes, and to evaluate the differential prognostic impact of these features in patients undergoing PCI for bifurcation lesions. Methods: We analyzed 5,537 patients from the BIFURCAT (comBined Insights From the Unified RAIN and COBIS bifurcAtion regisTries) registry. The primary outcome was major adverse cardiac events (MACE) at 2-year follow-up; secondary outcomes included hard endpoints (all-cause death, myocardial infarction) and lesion-oriented clinical outcomes (LOCO) (target-vessel myocardial infarction, target lesion revascularization). The least absolute shrinkage and selection operator (LASSO) model was used for feature selection. Results: During the 2-year follow-up period, MACE occurred in 492 patients (8.9%). The LASSO model identified 5 clinical features (old age, chronic renal disease, diabetes mellitus, current smoking, and left ventricular dysfunction) and 4 lesion features (left main disease, proximal main branch disease, side branch disease, and a small main branch diameter) as significant features that predict MACE. A combination of all 9 features improved the predictive value for MACE compared with clinical and lesion features (area under the receiver-operating characteristics curve: 0.657 vs 0.636 vs 0.581; P < 0.001). For secondary endpoints, the clinical features had a higher impact than lesion features on hard endpoints, whereas lesion features had a higher impact than clinical features on LOCO. Conclusions: In bifurcation PCI, 9 features were associated with MACE. Clinical features were predominant predictors for hard endpoints, and lesion features were predominant for predicting LOCO. Clinical and lesion features have distinct values, and both should be considered in bifurcation PCI.

The Impact of Surgical versus Transcatheter Aortic Valve Replacement on Postprocedural Acute Kidney Injury in Patients with Chronic Kidney Disease.

Background: This study aimed to evaluate the impact of the treatment modality on post-procedural acute kidney injury (AKI) and other clinical outcomes in patients with advanced chronic kidney disease who underwent surgical or transcatheter aortic valve replacement (AVR). Methods: A total of 147 patients with advanced chronic kidney disease (stage 3 to 5) who underwent isolated surgical AVR (SAVR group; n=70) or transcatheter AVR (TAVR group; n=77) were retrospectively studied. Postprocedural AKI was defined according to the RIFLE definition (an acronym corresponding to the risk of renal dysfunction, injury to the kidney, failure of kidney function, loss of kidney function, and end-stage kidney disease). Factors associated with postoperative complications and mortality were analyzed using multivariable logistic regression models and Cox proportional hazard models. Results: Postprocedural AKI occurred in 17 (24.3%) and 6 (7.8%) patients in the SAVR and TAVR groups, respectively (p=0.006). Multivariable analyses demonstrated that the SAVR group had higher risks of AKI (odds ratio [OR], 5.63; 95% confidence interval [CI], 1.85-17.73; p=0.002) and atrial fibrillation (OR, 16.65; 95% CI, 4.44-62.50; p<0.001), whereas the TAVR group had a higher risk of permanent pacemaker insertion (OR, 5.67; 95% CI, 1.21-26.55; p=0.028). The Cox proportional hazard models showed that the occurrence of AKI, contrary to the treatment modality, was associated with overall survival. Conclusion: In patients with chronic kidney disease, the risk of postprocedural AKI might be higher after SAVR than after TAVR.

A subset of macrophages and monocytes in the mouse bone marrow express atypical chemokine receptor 1.

Duffy antigen receptor for chemokines (DARC)/CD234, also known as atypical chemokine receptor 1 (ACKR1), is a seven-transmembrane domain protein expressed on erythrocytes, vascular endothelium, and a subset of epithelial cells (Peiper et al., 1995). Previously, we reported that ACKR1 was expressed in bone marrow macrophages. ACKR1 interacts with CD82 on long-term repopulating hematopoietic stem cells (LT-HSCs) to maintain the dormancy of LT-HSCs during homeostasis (Hur et al., 2016). We also demonstrated that ACKR1 interacts with CD82 in HSCs from human umbilical cord blood (hUCB). These findings demonstrated that CD82 is a functional surface marker of LT-HSCs and this molecule maintains LT-HSC quiescence by interactions with ACKR1-expressing macrophages in mice and humans.

Cardiovascular Regeneration via Stem Cells and Direct Reprogramming: A Review.

Cardiovascular disease (CVD) is the leading causes of morbidity and death globally. In particular, a heart failure remains a major problem that contributes to global mortality. Considerable advancements have been made in conventional pharmacological therapies and coronary intervention surgery for cardiac disorder treatment. However, more than 15% of patients continuously progress to end-stage heart failure and eventually require heart transplantation. Over the past year, numerous numbers of protocols to generate cardiomyocytes (CMCs) from human pluripotent stem cells (hPSCs) have been developed and applied in clinical settings. Number of studies have described the therapeutic effects of hPSCs in animal models and revealed the underlying repair mechanisms of cardiac regeneration. In addition, biomedical engineering technologies have improved the therapeutic potential of hPSC-derived CMCs in vivo. Recently substantial progress has been made in driving the direct differentiation of somatic cells into mature CMCs, wherein an intermediate cellular reprogramming stage can be bypassed. This review provides information on the role of hPSCs in cardiac regeneration and discusses the practical applications of hPSC-derived CMCs; furthermore, it outlines the relevance of directly reprogrammed CMCs in regenerative medicine.

Angiographic complete revascularization versus incomplete revascularization in patients with diabetes mellitus.

BACKGROUND: Considering the nature of diabetes mellitus (DM) in coronary artery disease, it is unclear whether complete revascularization is beneficial or not in patients with DM. We investigated the clinical impact of angiographic complete revascularization in patients with DM. METHODS: A total of 5516 consecutive patients (2003 patients with DM) who underwent coronary stenting with 2nd generation drug-eluting stent were analyzed. Angiographic complete revascularization was defined as a residual SYNTAX (SYNergy between percutaneous coronary intervention with TAXus and cardiac surgery) score of 0. The patient-oriented composite outcome (POCO, including all-cause death, any myocardial infarction, and any revascularization) and target lesion failure (TLF) at three years were analyzed. RESULTS: Complete revascularization was associated with a reduced risk of POCO in DM population [adjusted hazard ratio (HR) 0.70, 95% confidence interval (CI) 0.52-0.93, p = 0.016], but not in non-DM population (adjusted HR 0.90, 95% CI 0.69-1.17, p = 0.423). The risk of TLF was comparable between the complete and incomplete revascularization groups in both DM (adjusted HR 0.75, 95% CI 0.49-1.16, p = 0.195) and non-DM populations (adjusted HR 1.11, 95% CI 0.75-1.63, p = 0.611). The independent predictors of POCO were incomplete revascularization, multivessel disease, left main disease and low ejection fraction in the DM population, and old age, peripheral vessel disease, and low ejection fraction in the non-DM population. CONCLUSIONS: The clinical benefit of angiographic complete revascularization is more prominent in patients with DM than those without DM after three years of follow-up. Relieving residual disease might be more critical in the DM population than the non-DM population. Trial registration The Grand Drug-Eluting Stent registry NCT03507205.

The current status and outcomes of in-hospital P2Y12 receptor inhibitor switching in Korean patients with acute myocardial infarction.

BACKGROUND/AIMS: While switching strategies of P2Y12 receptor inhibitors (RIs) have sometimes been used in acute myocardial infarction (AMI) patients, the current status of in-hospital P2Y12RI switching remains unknown. METHODS: Overall, 8,476 AMI patients who underwent successful revascularization from Korea Acute Myocardial Infarction Registry-National Institute of Health (KAMIR-NIH) were divided according to in-hospital P2Y12RI strategies, and net adverse cardiovascular events (NACEs), defined as a composite of cardiac death, non-fatal myocardial infarction (MI), stroke, or thrombolysis in myocardial infarction (TIMI) major bleeding during hospitalization were compared. RESULTS: Patients with in-hospital P2Y12RI switching accounted for 16.5%, of which 867 patients were switched from clopidogrel to potent P2Y12RI (C-P) and 532 patients from potent P2Y12RI to clopidogrel (P-C). There were no differences in NACEs among the unchanged clopidogrel, the unchanged potent P2Y12RIs, and the P2Y12RI switching groups. However, compared to the unchanged clopidogrel group, the C-P group had a higher incidence of non-fatal MI, and the P-C group had a higher incidence of TIMI major bleeding. In clinical events of in-hospital P2Y12RI switching, 90.9% of non-fatal MI occurred during pre-switching clopidogrel administration, 60.7% of TIMI major bleeding was related to pre-switching P2Y12RIs, and 71.4% of TIMI major bleeding was related to potent P2Y12RIs. Only 21.6% of the P2Y12RI switching group switched to P2Y12RIs after a loading dose (LD); however, there were no differences in clinical events between patients with and without LD. CONCLUSION: In-hospital P2Y12RI switching occurred occasionally, but had relatively similar clinical outcomes compared to unchanged P2Y12RIs in Korean AMI patients. Non-fatal MI and bleeding appeared to be mainly related to pre-switching P2Y12RIs.

Direct Conversion of Cell Fate and Induced Endothelial Cells.

Advances in nuclear reprogramming technology have enabled the dedifferentiation and transdifferentiation of mammalian cells. Forced induction of the key transcription factors constituting a transcriptional network can convert cells back to their pluripotent status or directly to another cell fate without inducing pluripotency. To date, direct conversion to several cell types, including cardiomyocytes, various types of neurons, and pancreatic ß-cells, has been reported. We previously demonstrated direct lineage reprogramming of adult fibroblasts into induced endothelial cells (iECs) in mice and humans. In contrast to induced pluripotent stem cells, for which there is consensus on the criteria defining pluripotency, such criteria have not yet been established in the field of direct conversion. We thus suggest that careful assessment of the status of converted cells using genetic and epigenetic profiling, various functional assays, and the use of multiple readouts is essential to determine successful conversion. As direct conversion does not go through pluripotent status, this technique can be utilized for therapeutic purposes without the risk of tumorigenesis. Further, direct conversion can be induced in vivo by gene delivery to the target tissue or organ in situ. Thus, direct conversion technology can be developed into cell therapy or gene therapy for regenerative purposes. Here, we review the potential and future directions of direct cell fate conversion and iECs.

Clinical Outcomes of Ticagrelor in Korean Patients with Acute Myocardial Infarction without High Bleeding Risk.

BACKGROUND: Although ticagrelor is known to increase the bleeding risk compared to clopidogrel in East Asian patients, its clinical benefits in patients with acute myocardial infarction (AMI) without high bleeding risk (HBR) remains unknown. METHODS: A total of 7,348 patients who underwent successful percutaneous coronary intervention (PCI) from the Korea Acute Myocardial Infarction Registry-National Institute of Health (KAMIR-NIH), between November 2011 and December 2015, were divided into two groups according to the Academic Research Consortium for HBR criteria (KAMIR-HBR, 2,469 patients; KAMIR-non HBR, 4,879 patients). We compared in-hospital major adverse cardiovascular events (MACEs, defined as a composite of cardiac death, non-fatal myocardial infarction, or stroke), and the thrombolysis in myocardial infarction (TIMI) major bleeding between ticagrelor and clopidogrel in the KAMIR-HBR and the KAMIR-non HBR groups, respectively. RESULTS: After propensity score matching, ticagrelor had a higher incidence of in-hospital TIMI major bleeding than clopidogrel in all patients (odds ratio [OR], 1.683; 95% confidence interval [CI], 1.010-2.805; P = 0.046) and the KAMIR-HBR group (OR, 3.460; 95% CI, 1.374-8.714; P = 0.008). However, there was no significant difference in in-hospital TIMI major bleeding between ticagrelor and clopidogrel in the KAMIR-non HBR group (OR, 1.436; 95% CI, 0.722-2.855; P = 0.303). No differences were observed in the cumulative incidences of in-hospital and 6-month MACEs between ticagrelor and clopidogrel in both groups. CONCLUSIONS: The bleeding risk of ticagrelor was attenuated in Korean patients with AMI without HBR. Appropriate patient selection could reduce in-hospital bleeding complications associated with ticagrelor in Korean patients with AMI who underwent successful PCI.