Exosomal miRNA Changes Associated with Restoration to Sinus Rhythm in Atrial Fibrillation Patients.

We aimed to identify serum exosomal microRNAs (miRNAs) associated with the transition from atrial fibrillation (AF) to sinus rhythm (SR) and investigate their potential as biomarkers for the early recurrence of AF within three months post-treatment. We collected blood samples from eight AF patients at Chang Gung Memorial Hospital in Taiwan both immediately before and within 14 days following rhythm control treatment. Exosomes were isolated from these samples, and small RNA sequencing was performed. Using DESeq2 analysis, we identified nine miRNAs (16-2-3p, 22-3p, 23a-3p, 23b-3p, 125a-5p, 328-3p, 423-5p, 504-5p, and 582-3p) associated with restoration to SR. Further analysis using the DIABLO model revealed a correlation between the decreased expression of miR-125a-5p and miR-328-3p and the early recurrence of AF. Furthermore, early recurrence is associated with a longer duration of AF, presumably indicating a more extensive state of underlying cardiac remodeling. In addition, the reads were mapped to mRNA sequences, leading to the identification of 14 mRNAs (AC005041.1, ARHGEF12, AMT, ANO8, BCL11A, DIO3OS, EIF4ENIF1, G2E3-AS1, HERC3, LARS, NT5E, PITX1, SLC16A12, and ZBTB21) associated with restoration to SR. Monitoring these serum exosomal miRNA and mRNA expression patterns may be beneficial for optimizing treatment outcomes in AF patients.

Naringin activates semaphorin 3A to ameliorate TGF-ß-induced endothelial-to-mesenchymal transition related to atrial fibrillation.

The loss of semaphorin 3A (Sema3A), which is related to endothelial-to-mesenchymal transition (EndMT) in atrial fibrosis, is implicated in the pathogenesis of atrial fibrillation (AF). To explore the mechanisms by which EndMT affects atrial fibrosis and assess the potential of a Sema3A activator (naringin) to prevent atrial fibrosis by targeting transforming growth factor-beta (TGF-ß)-induced EndMT, we used human atria, isolated human atrial endocardial endothelial cells (AEECs), and used transgenic mice expressing TGF-ß specifically in cardiac tissues (TGF-ß transgenic mice). We evaluated an EndMT marker (Twist), a proliferation marker (proliferating cell nuclear antigen; PCNA), and an endothelial cell (EC) marker (CD31) through triple immunohistochemistry and confirmed that both EndMT and EC proliferation contribute to atrial endocardial fibrosis during AF in TGF-ß transgenic mice and AF patient tissue sections. Additionally, we investigated the impact of naringin on EndMT and EC proliferation in AEECs and atrial fibroblasts. Naringin exhibited an antiproliferative effect, to which AEECs were more responsive. Subsequently, we downregulated Sema3A in AEECs using small interfering RNA to clarify a correlation between the reduction in Sema3A and the elevation of EndMT markers. Naringin treatment induced the expression of Sema3A and a concurrent decrease in EndMT markers. Furthermore, naringin administration ameliorated AF and endocardial fibrosis in TGF-ß transgenic mice by stimulating Sema3A expression, inhibiting EndMT markers, reducing atrial fibrosis, and lowering AF vulnerability. This suggests therapeutic potential for naringin in AF treatment.

Clinical significance of regional constructive and wasted work in patients receiving cardiac resynchronization therapy.

Background: Previous studies have shown that global constructive work (CW) and wasted work (WW) predict response to cardiac resynchronization therapy (CRT). This study evaluated the predictive value of regional CW and WW for reverse remodeling and clinical outcomes after CRT. Methods: We performed a prospective study involving 134 CRT candidates with left bundle branch block and left ventricular ejection fraction ≤35%. Global and regional CW and WW were calculated using pressure-strain loop analysis. CRT response was defined by reverse remodeling as a reduction of ≥15% in left ventricular end-systolic volume after six months. Results: At six-month follow-up, 92 (69%) patients responded to CRT. Of the regional CW and WW measures, lateral wall (LW) CW and septal WW were most strongly and significantly correlated with reverse remodeling. At multivariate analysis, LW CW and septal WW were both independent determinants of reverse remodeling. When LW CW and septal WW were included in the model, global CW and WW were not independently associated with reverse remodeling. LW CW and septal WW predicted reverse remodeling with an area under the curve (AUC) of 0.783 (95% CI: 0.700-0.866) and 0.737 (95% CI: 0.644-0.831), respectively. Using both variables increased the AUC to 0.832 (95% CI: 0.755-0.908). Both LW CW ≤878 mmHg% (HR 2.01; 95% CI: 1.07-3.79) and septal WW ≤181 mmHg% (HR 2.60; 95% CI: 1.38-4.90) were significant predictors of combined death and HF hospitalization at two-year follow-up. Conclusion: LW CW and septal WW before CRT are important determinants of reverse remodeling and clinical outcomes.

SGLT2 inhibitors vs. GLP-1 receptor agonists and clinical outcomes in patients with diabetes with/without atrial fibrillation.

CONTEXT: The coexistence of diabetes mellitus and atrial fibrillation (AF) is associated with substantial risks of adverse cardiovascular events. OBJECTIVE: The relevant outcomes associated with the use of sodium-glucose cotransporter-2 inhibitor (SGLT2i) versus glucagon-like peptide-1 receptor agonists (GLP-1RA) among patients with type 2 diabetes (T2D) with/without concomitant AF remained unknown. METHODS: In this nationwide retrospective cohort study from Taiwan National Health Insurance Research Database, there were 344,392 and 31,351 patients with T2D without AF, and 11,462 and 816 T2D patients with AF treated with SGLT2i and GLP-1RA from May 1, 2016, to December 31, 2019. Patients were followed from the drug-index date until the occurrence of study events, discontinuation of the index drug, or the end of the study period (December 31, 2020), whichever occurred first. We used propensity score stabilized weight to balance covariates across two medication groups. RESULTS: The incidence rate of all study outcomes in patients with concomitant AF was much higher than in those without concomitant AF. For the AF cohort, SGLT2i vs. GLP-1RA was associated with a lower risk of hospitalization for heart failure (2.32 vs. 4.74 events per 100 person-years; hazard ratio (HR):0.48 [95% confidential interval (CI):0.36-0.66]), with no benefit seen for the non-AF cohort (P for homogeneity < 0.01). SGLT2i vs. GLP-1RA was associated with a lower risk of composite kidney outcomes both in the AF (0.38 vs. 0.79 events per 100 person-years; HR:0.47; [95%CI:0.23-0.96]) and non-AF cohorts (0.09 vs. 0.18 events per 100 person-years; HR:0.53; [95%CI:0.43-0.64]). There were no significant differences in the risk of major adverse cardiovascular events and all-cause mortality in those who received SGLT2i compared to GLP-1RA for the AF or non-AF cohorts. CONCLUSION: Considering the high risk of developing HF and/or high prevalence of concomitant HF in patients with diabetes, whether SGLT2i should be the preferred treatment to GLP-1RA for such a high-risk population requires further investigation.

Aldehyde Dehydrogenase 2 (ALDH2) Deficiency, Obesity, and Atrial Fibrillation Susceptibility: Unraveling the Connection.

Atrial fibrillation (AF), characterized by structural remodeling involving atrial myocardial degradation and fibrosis, is linked with obesity and transforming growth factor beta 1 (TGF-ß1). Aldehyde dehydrogenase 2 (ALDH2) deficiency, highly prevalent in East Asian people, is paradoxically associated with a lower AF risk. This study investigated the impact of ALDH2 deficiency on diet-induced obesity and AF vulnerability in mice, exploring potential compensatory upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme-oxygenase 1 (HO-1). Wild-type (WT) and ALDH2*2 knock-in (KI) mice were administered a high-fat diet (HFD) for 16 weeks. Despite heightened levels of reactive oxygen species (ROS) post HFD, the ALDH2*2 KI mice did not exhibit a greater propensity for AF compared to the WT controls. The ALDH2*2 KI mice showed equivalent myofibril degradation in cardiomyocytes compared to WT after chronic HFD consumption, indicating suppressed ALDH2 production in the WT mice. Atrial fibrosis did not proportionally increase with TGF-ß1 expression in ALDH2*2 KI mice, suggesting compensatory upregulation of the Nrf2 and HO-1 pathway, attenuating fibrosis. In summary, ALDH2 deficiency did not heighten AF susceptibility in obesity, highlighting Nrf2/HO-1 pathway activation as an adaptive mechanism. Despite limitations, these findings reveal a complex molecular interplay, providing insights into the paradoxical AF-ALDH2 relationship in the setting of obesity.

Lithium downregulates phosphorylated acetyl­CoA carboxylase 2 and attenuates mitochondrial fatty acid utilization and oxidative stress in cardiomyocytes.

Acetyl-CoA carboxylase 2 plays a crucial role in regulating mitochondrial fatty acid oxidation in cardiomyocytes. Lithium, a monovalent cation known for its cardioprotective potential, has been investigated for its influence on mitochondrial bioenergetics. The present study explored whether lithium modulated acetyl-CoA carboxylase 2 and mitochondrial fatty acid metabolism in cardiomyocytes and the potential therapeutic applications of lithium in alleviating metabolic stress. Mitochondrial bioenergetic function, fatty acid oxidation, reactive oxygen species production, membrane potential and the expression of proteins involved in fatty acid metabolism in H9c2 cardiomyocytes treated with LiCl for 48 h was measured by using a Seahorse extracellular flux analyzer, fluorescence microscopy and western blotting. Small interfering RNA against glucose transporter type 4 was transfected into H9c2 cardiomyocytes for 48 h to induce metabolic stress mimicking insulin resistance. The results revealed that LiCl at a concentration of 0.3 mM (but not at a concentration of 0.1 or 1.0 mM) upregulated the expression of phosphorylated (p-)glycogen synthase kinase-3 beta and downregulated the expression of p-acetyl-CoA carboxylase 2 but did not affect the expression of adenosine monophosphate-activated protein kinase or calcineurin. Cotreatment with TWS119 (8 µM) and LiCl (0.3 mM) downregulated p-acetyl-CoA carboxylase 2 expression to a similar extent as did treatment with TWS119 (8 µM) alone. Moreover, LiCl (0.3 mM) inhibited mitochondrial fatty acid oxidation, improved coupling efficiency and the cellular respiratory control ratio, hindered reactive oxygen species production and proton leakage and restored mitochondrial membrane potential in glucose transporter type 4 knockdown-H9c2 cardiomyocytes. These findings suggested that low therapeutic levels of lithium can downregulate p-acetyl-CoA carboxylase 2, thus reducing mitochondrial fatty acid oxidation and oxidative stress in cardiomyocytes.

The Report of Community-Based and Government-Endorsed Screening Program of Atrial Fibrillation in Taiwan.

BACKGROUND: Although international guidelines recommended opportunistic screening for atrial fibrillation (AF), the community-based AF screening program incorporated into the government-endorsed health care system is rarely reported in Asian countries. OBJECTIVES: We aimed to test the feasibility of adding AF screening into the preexistent adult health check program and report the AF detection rate and percentages of OAC prescriptions before and after AF screening with the involvement of public health care systems. METHODS: We performed this program in three counties (Chiayi county, Keelung City, and Yilan county) in Taiwan which have their own official preexistent adult health check programs conducted by public health bureaus for years. However, electrocardiography (ECG) was not included in these programs before. We cooperated with the public health bureaus of the three counties and performed single-lead 30-second ECG recording for every participant. RESULTS: From January to December 2020, AF screening was performed in 199 sessions with 23,572 participants. AF was detected in 278 subjects with a detection rate of 1.19% (age ≥65 years: 2.39%; ≥75 years: 3.73%). The mean CHA2DS2-VASc score of these 278 subjects was 2.36, with 91% of them had a score ≥1 (males) or ≥2 (females). The number needed to screen was 42 and 27 for subjects aged ≥65 and ≥75 years, respectively. The prescription rate of OACs significantly increased from 11.4 to 60.6% in Chiayi county and from 15.8 to 50.0% in Keelung City after screening (both p-values <0.001). CONCLUSION: This community-based and government-endorsed AF screening project in Taiwan demonstrated that incorporation of AF screening into the preexistent adult health check programs through co-operations with the government was feasible. Actions to detect AF, good education, and well-organized transferring plan after AF being detected with the involvement of public health care systems could result in a substantial increase in the prescription rate of OACs.

Clinical outcomes in elderly atrial fibrillation patients at increased bleeding risk treated with very low dose vs. regular-dose non-vitamin K antagonist oral anticoagulants: a nationwide cohort study.

AIMS: The Edoxaban Low-Dose for Elder Care Atrial Fibrillation Patients (ELDERCARE-AF) trial showed that edoxaban at a very low dosage (VLD) of 15 mg/day was more effective than a placebo at preventing stroke/systemic embolism without significantly increasing the risk of serious bleeding. We aimed to compare the effectiveness and safety for VLD non-vitamin K antagonist oral anticoagulants (NOACs) [edoxaban 15 mg o.d., dabigatran 110 or 150 o.d., apixaban 2.5 mg o.d., or rivaroxaban 10 mg (without the diagnosis of chronic kidney disease) or <10 mg o.d.] vs. regular-dosage (RD) NOACs (edoxaban 60/30 mg o.d. or other labeling-dosage NOACs) among a real-world cohort of elderly atrial fibrillation (AF) population similar to the ELDERCARE-AF cohort. METHODS AND RESULTS: In this nationwide retrospective cohort study from Taiwan National Health Insurance Research Database (NHIRD), we identified a total of 7294 and 4151 consecutive AF patients aged 80 years or older with a CHADS2 (congestive heart failure, hypertension, age 75 years or older, diabetes mellitus, previous stroke/transient ischemic attack (2 points) score ≥2 who met the enrollment criteria (generally similar to ELDERCARE-AF) taking VLD and RD NOACs from 1 June 2012 to 31 December 2019, respectively. Propensity-score stabilized weighting (PSSW) was used to balance covariates across study groups. Patients were followed up from the first date of prescription for NOACs until the first occurrence of any study outcome, death, or until the end date of the study period (31 December 2020). After PSSW, VLD NOAC was associated with a comparable risk of ischemic stroke/systemic embolism and major bleeding but a higher risk of major adverse limb events (MALEs) requiring lower limb revascularization or amputation [hazard ratio (HR): 1.54, 95% confidential interval (CI): 1.09-2.18; P = 0.014), venous thrombosis (HR: 3.75, 95% CI: 1.56-8.97; P = 0.003), and all-cause mortality (HR: 1.21, 95% CI: 1.15-1.29; P <0.001) compared with RD NOACs. VLD NOACs showed worse outcomes in most net clinical outcome (NCO) benefits. The main result was consistent based on on-treatment analysis or accounting for death as a competing risk. In general, the advantage of NCOs for the RD NOACs over VLD NOACs persisted in most high-risk subgroups, consistent with the main analysis (P for interaction > 0.05). CONCLUSION: Use of VLD NOACs was associated with a greater risk of arterial and venous thrombosis, death as well as the composite outcomes, when compared with that of RD NOAC in high-risk elderly AF patients at increased bleeding risk. Thromboprophylaxis with RD NOAC is still preferable over VLD NOAC for the majority of elderly AF patients at increased bleeding risk.

A Novel KCNH2 S981fs Mutation Identified by Whole-Exome Sequencing Is Associated with Type 2 Long QT Syndrome.

KCNH2 loss-of-function mutations cause long QT syndrome type 2 (LQT2), an inherited cardiac disorder associated with life-threatening ventricular arrhythmia. Through whole-exome sequencing, we discovered a novel AGCGACAC deletion (S981fs) in the hERG gene of an LQT2 patient. Using a heterologous expression system and patch clamping, we found that the mutant K channel had reduced cell surface expression and lower current amplitude compared to the wild type. However, functional expression was restored by lowering temperature and using potassium channel inhibitors or openers (E4031, cisapride, nicorandil). Co-immunoprecipitation experiments confirmed the assembly of mutant proteins with wild-type hERG. Confocal imaging showed decreased hERG distribution on the cell membrane in cells expressing S981fs. Notably, treatment with G418 significantly increased hERG current in wild-type/S981fs heterozygotes. In conclusion, our study identifies a novel hERG mutation leading to impaired Kv11.1 function due to trafficking and nonsense-mediated RNA decay defects. These findings shed light on the mechanisms underlying LQT2 and offer potential therapeutic avenues.

CD44 regulates Epac1-mediated ß-adrenergic-receptor-induced Ca2+-handling abnormalities: implication in cardiac arrhythmias.

BACKGROUND: Sustained, chronic activation of ß-adrenergic receptor (ß-AR) signaling leads to cardiac arrhythmias, with exchange proteins directly activated by cAMP (Epac1 and Epac2) as key mediators. This study aimed to evaluate whether CD44, a transmembrane receptor mediating various cellular responses, participates in Epac-dependent arrhythmias. METHODS: The heart tissue from CD44 knockout (CD44-/-) mice, cultured HL-1 myocytes and the tissue of human ventricle were used for western blot, co-immunoprecipitaiton and confocal studies. Line-scanning confocal imaging was used for the study of cellular Ca2+ sparks on myocytes. Optical mapping and intra-cardiac pacing were applied for arrhythmia studies on mice's hearts. RESULTS: In mice, isoproterenol, a ß-AR agonist, upregulated CD44 and Epac1 and increased the association between CD44 and Epac1. Isoproterenol upregulated the expression of phospho-CaMKII (p-CaMKII), phospho-ryanodine receptor (p-RyR), and phospho-phospholamban (p-PLN) in mice and cultured myocytes; these effects were attenuated in CD44-/- mice compared with wild-type controls. In vitro, isoproterenol, 8-CPT-cAMP (an Epac agonist), and osteopontin (a ligand of CD44) significantly upregulated the expression of p-CaMKII, p-RyR, and p-PLN; this effect was attenuated by CD44 small interfering RNA (siRNA). In myocytes, resting Ca2+ sparks were induced by isoproterenol and overexpressed CD44, which were prevented by inhibiting CD44. Ex vivo optical mapping and in vivo intra-cardiac pacing studies showed isoproterenol-induced triggered events and arrhythmias in ventricles were prevented in CD44-/- mice. The inducibility of ventricular arrhythmias (VAs) was attenuated in CD44-/- HF mice compared with wild-type HF controls. In patients, CD44 were upregulated, and the association between CD44 and Epac1 were increased in ventricles with reduced contractility. CONCLUSION: CD44 regulates ß-AR- and Epac1-mediated Ca2+-handling abnormalities and VAs. Inhibition of CD44 is effective in reducing VAs in HF, which is potentially a novel therapeutic target for preventing the arrhythmias and sudden cardiac death in patients with diseased hearts.

High-phosphate diet causes atrial remodeling and increases atrial fibrillation vulnerability via STAT3/NF-κB signaling and oxidative stress.

AIM: Hyperphosphatemia is associated with adverse cardiovascular outcomes in both the general population and patients with end-stage renal disease. We evaluated whether high inorganic phosphate (Pi) intake causes atrial remodeling and increased atrial fibrillation (AF) risk. METHODS: The 5/6 nephrectomized chronic kidney disease (CKD) mice were fed a high-Pi (2%) diet for 10 weeks. AF vulnerability was evaluated through transesophageal burst atrial pacing. Phosphoproteomic, Western blotting, and immunohistochemistry were used to evaluate the effects of high Pi in atrial fibroblasts, atrial myocytes, and HL-1 myocytes. RESULTS: CKD and sham mice fed a high-Pi diet exhibited increased AF vulnerability, atrial fibrosis, and oxidative stress compared with mice fed a normal diet. Compared with normal (1 mM) Pi, high (2 mM) Pi significantly increased the activity of atrial fibroblasts and mitochondrial oxidative stress. Phosphoproteomic analysis revealed that compared with normal Pi, high Pi considerably increased the phosphorylation of intracellular proteins in atrial fibroblasts, including proteins related to NF-κB signaling and STAT3. Inhibition of NF-κB, STAT3, and Nox4 by small interfering RNA reduced the high-Pi-induced expression of collagen. In HL-1 myocytes, the high Pi induced the degradation of myofibril proteins and hyperphosphorylation of RyR2, which was abolished by Nox4 and CaMKII inhibition. Switching back to a normal-Pi diet improved the atrial abnormalities induced by high-Pi diet. CONCLUSIONS: High-Pi intake causes atrial structural and electrical remodeling and increases AF vulnerability, which is mediated through STAT3/NF-κB signaling and oxidative stress. High dietary Pi intake can exert detrimental effects on atria and may increase AF risk.

Neutral effects of SGLT2 inhibitors in acute coronary syndromes, peripheral arterial occlusive disease, or ischemic stroke: a meta-analysis of randomized controlled trials.

BACKGROUND: Patients with type 2 diabetes are at increased risk for cardiovascular diseases. Sodium-glucose transport 2 inhibitors (SGLT2i) have been shown to enhance cardiovascular health since their debut as a second-line therapy for diabetes. Acute coronary syndrome (ACS), peripheral arterial occlusive disease (PAOD), and ischemic stroke (IS) are types of atherosclerotic cardiovascular disease (ASCVD), although the benefits of treating these disorders have not been shown consistently. METHODS: We searched four databases (PubMed, Embase, the Cochrane library, and clinicaltrial.gov) for randomized clinical trials (RCTs) until November of 2022. Comparisons were made between SGLT2i-treated and control individuals with type 2 diabetes. Primary outcomes were ACS, PAOD, and IS; secondary outcomes included cardiovascular mortality and all-cause mortality. Risk ratio (RR) and 95% confidence intervals (CI) were determined using a fixed effects model. Cochrane's risk-of-bias (RoB2) instrument was used to assess the validity of each study that met the inclusion criteria. RESULTS: We enrolled 79,504 patients with type 2 diabetes from 43 RCTs. There was no difference in the risk of ACS (RR = 0.97, 95% CI 0.89-1.05), PAOD (RR = 0.98, 95% CI 0.78-1.24), or IS (RR = 0.95, 95% CI 0.79-1.14) among patients who took an SGLT2i compared to those who took a placebo or oral hypoglycemic drugs. Subgroup analysis revealed that none of the SGLT2i treatments (canagliflozin, dapagliflozin, empagliflozin, and ertugliflozin) significantly altered outcomes when analyzed separately. Consistent with prior findings, SGLT2i reduced the risk of cardiovascular mortality (RR = 0.85, 95% CI 0.77-0.93) and all-cause mortality (RR = 0.88, 95% CI 0.82-0.94). CONCLUSION: Our results appear to contradict the mainstream concepts regarding the cardiovascular effects of SGLT2i since we found no significant therapeutic benefits in SGLT2i to reduce the incidence of ACS, PAOD, or IS when compared to placebo or oral hypoglycemic drugs.

Empagliflozin suppressed cardiac fibrogenesis through sodium-hydrogen exchanger inhibition and modulation of the calcium homeostasis.

BACKGROUND: The novel sodium-glucose co-transporter 2 inhibitor (SGLT2i) potentially ameliorates heart failure and reduces cardiac arrhythmia. Cardiac fibrosis plays a pivotal role in the pathophysiology of HF and atrial myopathy, but the effect of SGLT2i on fibrogenesis remains to be elucidated. This study investigated whether SGLT2i directly modulates fibroblast activities and its underlying mechanisms. METHODS AND RESULTS: Migration, proliferation analyses, intracellular pH assay, intracellular inositol triphosphate (IP3) assay, Ca2+ fluorescence imaging, and Western blotting were applied to human atrial fibroblasts. Empagliflozin (an SGLT2i, 1, or 5 µmol/L) reduced migration capability and collagen type I, and III production. Compared with control cells, empagliflozin (1 µmol/L)- treated atrial fibroblasts exhibited lower endoplasmic reticulum (ER) Ca2+ leakage, Ca2+ entry, inositol trisphosphate (IP3), lower expression of phosphorylated phospholipase C (PLC), and lower intracellular pH. In the presence of cariporide (an Na+-H+ exchanger (NHE) inhibitor, 10 µmol/L), control and empagliflozin (1 µmol/L)-treated atrial fibroblasts revealed similar intracellular pH, ER Ca2+ leakage, Ca2+ entry, phosphorylated PLC, pro-collagen type I, type III protein expression, and migration capability. Moreover, empagliflozin (10 mg/kg/day orally for 28 consecutive days) significantly increased left ventricle systolic function, ß-hydroxybutyrate and decreased atrial fibrosis, in isoproterenol (100 mg/kg, subcutaneous injection)-induced HF rats. CONCLUSIONS: By inhibiting NHE, empagliflozin decreases the expression of phosphorylated PLC and IP3 production, thereby reducing ER Ca2+ release, extracellular Ca2+ entry and the profibrotic activities of atrial fibroblasts.

Osteopontin mediation of disturbed flow-induced endothelial mesenchymal transition through CD44 is a novel mechanism of neointimal hyperplasia in arteriovenous fistulae for hemodialysis access.

In dysfunctional arteriovenous fistulae (AVF) for hemodialysis access, neointimal hyperplasia (NH) is prone to occur in the region exposed to disturbed flow. We hypothesized that disturbed flow contributes to NH in AVF by inducing endothelial mesenchymal transition (EndMT) through activation of the osteopontin/CD44 axis. In rats with aortocaval fistula, a rodent model of AVF, we demonstrated development of EndMT and expression of osteopontin and CD44 specifically in the vicinity of the arteriovenous junction using immunostaining. Duplex scan confirmed this region was exposed to a disturbed flow. A mixed ultrastructural phenotype of endothelium and smooth muscle cells was found in luminal endothelial cells of the arteriovenous junction by electron microscopy ascertaining the presence of EndMT. Endothelial lineage tracing using Cdh5-Cre/ERT2;ROSA26-tdTomato transgenic mice showed that EndMT was involved in NH of AVF since the early stage and that the endothelial-derived cells contributed to 24% of neointimal cells. In human umbilical vein endothelial cells (HUVECs) in culture, osteopontin treatment induced EndMT, which was suppressed by CD44 knockdown. Exposure to low oscillatory wall shear stress using a parallel-plate system induced EndMT in HUVECs, also suppressed by osteopontin or CD44 knockdown. In AVF of CD44 knockout mice, EndMT was mitigated and NH decreased by 35% compared to that in wild-type mice. In dysfunctional AVF of patients with uremia, expressions of osteopontin, CD44, and mesenchymal markers in endothelial cells overlying the neointima was also found by immunostaining. Thus, the osteopontin/CD44 axis regulates disturbed flow-induced EndMT, plays an important role in neointimal hyperplasia of AVF, and may act as a potential therapeutic target to prevent AVF dysfunction.

Adverse cardiovascular, limb, and renal outcomes in patients with diabetes after peripheral artery disease revascularization treated with sodium glucose cotransporter 2 inhibitors versus dipeptidyl peptidase-4 inhibitors.

AIMS: The effectiveness and limb safety of sodium glucose co-transporter 2 inhibitors (SGLT2i) for patients with type-2 diabetes (T2D) who have received peripheral artery disease (PAD) revascularization are unknown. METHODS AND RESULTS: In this nationwide retrospective cohort study, we identified a total of 2,455 and 8,695 patients with T2D who had undergone PAD revascularization and received first prescriptions for SGLT2i and dipeptidyl peptidase-4 inhibitors (DPP4i), respectively, between May 1, 2016, and December 31, 2019. We used 1:1 propensity score matching (PSM) to balance covariates between the two study groups. Patients were followed up from the drug index date until the occurrence of specified outcomes, death, discontinuation of the index drug, or the end of the study period, whichever occurred first. After PSM, we observed that compared with DPP4i, SGLT2i were associated with comparable risks of ischemic stroke, acute myocardial infarction, and heart failure hospitalization but were associated with a lower risk of cardiac death (hazard ratio [HR]: 0.60; 95% confidence interval [CI]: 0.40-0.90]; p = 0.0126). Regarding major limb outcomes, SGLT2i were associated with comparable risks of repeated revascularization and lower limb amputation compared with DPP4i. SGLT2i were associated with a lower risk of composite renal outcomes (HR: 0.40; 95% CI: 0.27-0.59; p < 0.0001) compared with DPP4i. CONCLUSION: In a real-world study of patients with T2D who had undergone PAD revascularization, SGLT2i were associated with lower risks of cardiac death and composite renal outcomes but not associated with increased risks of adverse limb events compared with DPP4i.

Cardiovascular, renal, and lower limb outcomes in patients with type 2 diabetes after percutaneous coronary intervention and treated with sodium-glucose cotransporter 2 inhibitors vs. dipeptidyl peptidase-4 inhibitors.

AIMS: Patients with type 2 diabetes (T2D) who undergo percutaneous coronary intervention (PCI) are at higher risk of adverse cardiovascular and renal events than non-diabetic patients. However, limited evidence is available regarding the cardiovascular, renal, and limb outcomes of patients with T2D after PCI and who were treated with sodium-glucose cotransporter-2 inhibitors (SGLT2i). We compare the specified outcomes in patients with T2D after PCI who were treated with SGLT2i vs. dipeptidyl peptidase-4 inhibitors (DPP4i). METHODS AND RESULTS: In this nationwide retrospective cohort study, we identified 4248 and 37 037 consecutive patients with T2D who underwent PCI with SGLT2i and DPP4i, respectively, for 1 May 2016-31 December 2019. We used propensity score matching (PSM) to balance the covariates between study groups. After PSM, SGLT2i, and DPP4i were associated with comparable risks of ischaemic stroke, acute myocardial infarction, and lower limb amputation. However, SGLT2i was associated with significantly lower risks of heart failure hospitalization [HFH; 1.35% per year vs. 2.28% per year; hazard ratio (HR): 0.60; P = 0.0001], coronary revascularization (2.33% per year vs. 3.36% per year; HR: 0.69; P = 0.0003), composite renal outcomes (0.10% per year vs. 1.05% per year; HR: 0.17; P < 0.0001), and all-cause mortality (2.27% per year vs. 3.80% per year, HR: 0.60; P < 0.0001) than were DPP4i. CONCLUSION: Our data indicated that SGLT2i, compared with DPP4i, were associated with lower risks of HFH, coronary revascularization, composite renal outcomes, and all-cause mortality for patients with T2D after PCI. Further randomized or prospective studies can investigate the effects of SGLT2i in patients with T2D after PCI.

Prothrombin Time-International Normalized Ratio Predicts the Outcome of Atrial Fibrillation Patients Taking Rivaroxaban.

Background: Although direct oral anticoagulants (DOACs) for patients with atrial fibrillation (AF) are considered to be safe, over or under anticoagulation and increased bleeding or thromboembolic risk are still considered individually. We aimed to investigate whether there is an association between prothrombin time and international normalized ratio (PT-INR) or activated partial thromboplastin time (aPTT) ratio, and the risks of ischemic stroke/systemic embolism (IS/SE) and major bleeding among AF patients taking rivaroxaban or dabigatran. Methods: This multi-center cohort study in Taiwan included 3192 AF patients taking rivaroxaban and 958 patients taking dabigatran for stroke prevention where data about PT-INR and aPTT were available. Results: For patients treated with rivaroxaban, a higher INR level was not associated with a higher risk of major bleeding compared to an INR level < 1.1. The risk of IS/SE was lower for patients having an INR ≥ 1.5 compared to those with an INR < 1.1 (aHR:0.57; [95%CI: 0.37−0.87]; p = 0.01). On-label dosing of rivaroxaban and use of digoxin were independent factors associated with an INR ≥ 1.5 after taking rivaroxaban. For patients taking dabigatran, a higher aPTT ratio was not associated with a higher risk of major bleeding. The risk of IS/SE was lower for patients having an aPTT ratio of 1.1−1.2 and 1.3−1.4 than those with an aPTT ratio < 1.1. Conclusions: In AF patients, rivaroxaban with an INR ≥ 1.5 was associated with a lower risk of IS/SE. PT-INR or aPTT ratios were not associated with bleeding events for rivaroxaban or dabigatran. INR may help predict the outcome of AF patients who take rivaroxaban.

Upregulation of Myocardial Neutrophil Gelatinase-Associated Lipocalin during Development of Heart Failure Caused by Volume-Overload and the Effect in Regulating Activity of Matrix Metalloproteinase-9.

Background: In patients with heart failure (HF), circulating neutrophil gelatinase-associated lipocalin (NGAL) level is increased, which is considered to be a predictor of mortality or renal outcomes. The expression of NGAL in the heart and kidney and its role in HF remain unclear. Methods: Aortocaval fistula was created in rats as a model of volume overload (VO)-induced HF. Results: During the development of HF, NGAL expression was upregulated in the heart but not in the kidney at both transcriptional and translational levels in the compensatory and HF phases, with a similar level in both phases. Cardiomyocytes were identified as the cell type responsible for NGAL expression. Consistent with the myocardial NGAL expression pattern, the plasma NGAL level was increased in both phases, and the level was not significantly different between both phases. We demonstrated the presence of a matrix metalloproteinase (MMP)-9/NGAL complex in cultured medium of cardiomyocytes isolated from volume-overloaded hearts by gelatin zymography. Formation of MMP-9/NGAL complex was shown to enhance the enzymatic activity of MMP-9. We found that early growth response (Egr)-1 was upregulated in the heart in both compensatory and HF phases. In neonatal cardiomyocytes, Egr-1 overexpression induced the gene expression of NGAL, which was dose-dependently suppressed by an interleukin-1 receptor antagonist. Conclusions: During the development of HF due to VO, NGAL was upregulated in the heart but not in the kidney in both compensatory and HF phases, with a similar expression level. Myocardial NGAL upregulation enhanced MMP-9 activity through formation of the MMP-9/NGAL complex. The expression of myocardial NGAL was regulated by Egr-1.

Development of Interstitial Lung Disease Among Patients With Atrial Fibrillation Receiving Oral Anticoagulants in Taiwan.

Importance: There are emerging concerns from case reports and pharmacovigilance analyses of a possible risk of interstitial lung disease (ILD) associated with the use of factor Xa (FXa) inhibitors. Objective: To evaluate the risk of incident ILD associated with the use of oral anticoagulants (OACs) in patients with nonvalvular atrial fibrillation (NVAF). Design, Setting, and Participants: This nationwide retrospective cohort study used data from the Taiwan National Health Insurance Research Database. Patients with NVAF without preexisting lung disease who received OACs from June 1, 2012, to December 31, 2017, were included. Propensity score stabilized weighting (PSSW) was used to balance covariates across the medication groups (FXa inhibitors, dabigatran, and warfarin, with warfarin as the reference). Patients were followed up from the drug index date until the onset of ILD, death, or end of the study (December 31, 2019), whichever occurred first. Data were analyzed from September 11, 2021, to August 3, 2022. Exposures: Patients with NVAF were treated with FXa inhibitors, dabigatran, or warfarin. Main Outcomes and Measures: New-onset idiopathic ILD. Results: Among the 106 044 patients (mean [SD] age, 73.4 [11.9] years; 59 995 men [56.6%]) included in the study, 64 555 (60.9%) received FXa inhibitors (apixban [n = 15 386], edoxaban [n = 12 413], and rivaroxaban [n = 36 756]), 22 501 (21.2%) received dabigatran, and 18 988 (17.9%) received warfarin at baseline. The FXa inhibitors were associated with a higher risk of incident ILD (0.29 vs 0.17 per 100 patient-years; hazard ratio, 1.54 [95% CI, 1.22-1.94]; P < .001), whereas dabigatran was associated with a nonsignificant difference in risk of incident ILD compared with warfarin (reference) after PSSW. The higher risk of incident ILD for FXa inhibitors vs warfarin was consistent with several high-risk subgroups. Conclusions and Relevance: Results of this study suggest that FXa inhibitors were associated with lung injury among patients with NVAF who were treated with OACs. Physicians should be vigilant in monitoring for any potential adverse lung outcomes associated with the use of these drugs.

Different Renal Function Equations and Dosing of Direct Oral Anticoagulants in Atrial Fibrillation.

Background: Randomized trials of direct oral anticoagulants (DOACs) adopted the Cockcroft-Gault (CG) formula to calculate estimated glomerular filtration rate (eGFR) to determine the dosages of DOACs. Objectives: The authors aimed to investigate the agreements/disagreements of eGFRs calculated using different equations (CG, Modified Diet in Renal Disease [MDRD], and Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI] formulas), and their impacts on the dosages of DOACs and clinical outcomes. Methods: Medical data from a multicenter health care provider in Taiwan including 39,239 patients with atrial fibrillation were used. Among these patients, there were 11,185 and 2,323 patients treated with DOACs and warfarin, respectively. Results: At the cutoff values of eGFR of <15, 15-50, and >50 mL/min, the agreements were 78% between MDRD and CG and 81% between CKD-EPI and CG. The disagreements among the different equations were largely due to overestimations, especially for patients aged >75 years and with a body weight of <50 kg (58.8% for MDRD and 50.9% for CKD-EPI). Among patients receiving DOACs whose dosages were defined as "on label" based on MDRD or CKD-EPI, only those whose dosages were "truly on label" based on CG were associated with a lower risk of major bleeding (adjusted HR: 0.34; 95% CI: 0.26-0.45) compared to warfarin. Conclusions: The adoptions of MDRD or CKD-EPI rather than CG would result in inappropriate dosing of DOACs (mainly overdosing), which would attenuate the advantages of DOACs compared to warfarin. The CG equation should be used as the gold standard to calculate eGFRs and guide the DOAC dosages.