Ultrathin-strut versus thin-strut stent healing and outcomes in preclinical and clinical subjects.

BACKGROUND: Compared with thin-strut durable-polymer drug-eluting stents (DP-DES), ultrathin-strut biodegradable-polymer sirolimus-eluting stents (BP-SES) improve stent-related clinical outcomes in patients undergoing percutaneous coronary intervention (PCI). Reduced stent strut thickness is hypothesised to underlie these benefits, but this conjecture remains unproven. AIMS: We aimed to assess the impact of strut thickness on stent healing and clinical outcomes between ultrathin-strut and thin-strut BP-SES. METHODS: First, we performed a preclinical study of 8 rabbits implanted with non-overlapping thin-strut (diameter/thickness 3.5 mm/80 µm) and ultrathin-strut (diameter/thickness 3.0 mm/60 µm) BP-SES in the infrarenal aorta. On day 7, the rabbits underwent intravascular near-infrared fluorescence optical coherence tomography (NIRF-OCT) molecular-structural imaging of fibrin deposition and stent tissue coverage, followed by histopathological analysis. Second, we conducted an individual data pooled analysis of patients enrolled in the BIOSCIENCE and BIOSTEMI randomised PCI trials treated with ultrathin-strut (n=282) or thin-strut (n=222) BP-SES. The primary endpoint was target lesion failure (TLF) at 1-year follow-up, with a landmark analysis at 30 days. RESULTS: NIRF-OCT image analyses revealed that ultrathin-strut and thin-strut BP-SES exhibited similar stent fibrin deposition (p=0.49) and percentage of uncovered stent struts (p=0.63). Histopathological assessments corroÂborated these findings. In 504 pooled randomised trial patients, TLF rates were similar for those treated with ultrathin-strut or thin-strut BP-SES at 30-day (2.5% vs 1.8%; p=0.62) and 1-year follow-up (4.3% vs 4.7%; p=0.88). CONCLUSIONS: Ultrathin-strut and thin-strut BP-SES demonstrate similar early arterial healing profiles and 30-day and 1-year clinical outcomes.

Coronary Aneurysm after Excimer Laser Catheter Ablation and Plain Balloon Angioplasty for Chronic Total Occlusion in a Patient with Kawasaki Disease.

A 37-year-old man with a history of Kawasaki disease presented with total occlusion of the right coronary artery. The patient underwent percutaneous coronary intervention (PCI) with excimer laser coronary angioplasty (ELCA) and plain balloon angioplasty (POBA). Three months after PCI, a coronary aneurysm with restenosis was detected at the PCI site, and PCI was performed again using a small balloon. The aneurysm healed three months after the second PCI procedure. This is the first report describing the long-term outcome after an aneurysm caused by PCI with ELCA and POBA.

Efficacy of Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitor Treatment for Repeated In-stent Restenosis in a Coronary Artery.

A 57-year-old woman experienced chest pain. A coronary angiogram revealed middle left anterior descending artery stenosis. Despite receiving adequate anti-hyperlipidemia treatment and undergoing percutaneous coronary intervention (PCI), she experienced angina and required PCI six more times for in-stent restenosis. As she had high lipoprotein (a) [LP-(a)] levels at the seventh PCI procedure, proprotein convertase subtilisin/kexin type 9 inhibitor (PCSK9i) was administered, and a reduction in the LP-(a) and low-density lipoprotein cholesterol (LDL-C) values was observed. She experienced no recurrence of angina for five years with PCSK9i treatment. PCSK9i can reduce not only LDL-C but also LP-(a) levels, resulting in cardiac event risk reduction.

Correlation Between the Japanese Version of the High Bleeding Risk (J-HBR) Criteria and the PRECISE-DAPT Score, and Optimal J-HBR Cut-Off Score to Predict Major Bleeding.

Background: The correlation between the Japanese version of high bleeding risk (J-HBR) criteria and the Predicting Bleeding Complications in Patients Undergoing Stent Implantation and Subsequent Dual Antiplatelet Therapy (PRECISE-DAPT) score is unknown, as is the relationship of both risk scores with ischemic events. Methods and Results: This study enrolled 842 patients who underwent percutaneous coronary intervention (PCI) between January 2016 and December 2020. The 2 bleeding risk scores at the time of PCI and the subsequent risk of bleeding and ischemic events over a 1-year follow-up were examined. The J-HBR score was significantly correlated with the PRECISE-DAPT score (r=0.731, P<0.001). However, 1 year after PCI, the J-HBR was not significantly associated with the incidence of major bleeding and ischemic events (log-rank, P=0.058 and P=0.351, respectively), whereas the PRECISE-DAPT score predicted both the incidence of major bleeding and ischemic events (log-rank, P=0.006 and P=0.019, respectively). According to receiver operating characteristic curve analysis, a J-HBR score ≥1.5 was significantly associated with a higher cumulative incidence of major bleeding, but not ischemic events (log-rank, P=0.004 and P=0.513, respectively). Conclusions: The J-HBR score is highly correlated with the PRECISE-DAPT score. A J-HBR score ≥1.5 can identify high bleeding risk patients without an increased risk of ischemic events.

Coagulation factors promote brown adipose tissue dysfunction and abnormal systemic metabolism in obesity.

Brown adipose tissue (BAT) has a role in maintaining systemic metabolic health in rodents and humans. Here, we show that metabolic stress induces BAT to produce coagulation factors, which then-together with molecules derived from the circulation-promote BAT dysfunction and systemic glucose intolerance. When mice were fed a high-fat diet (HFD), the levels of tissue factor, coagulation Factor VII (FVII), activated coagulation Factor X (FXa), and protease-activated receptor 1 (PAR1) expression increased significantly in BAT. Genetic or pharmacological suppression of coagulation factor-PAR1 signaling in BAT ameliorated its whitening and improved thermogenic response and systemic glucose intolerance in mice with dietary obesity. Conversely, the activation of coagulation factor-PAR1 signaling in BAT caused mitochondrial dysfunction in brown adipocytes and systemic glucose intolerance in mice fed normal chow. These results indicate that BAT produces endogenous coagulation factors that mediate pleiotropic effects via PAR1 signaling under metabolic stress.

Empagliflozin maintains capillarization and improves cardiac function in a murine model of left ventricular pressure overload.

Patients with type 2 diabetes treated with Sodium glucose transporter 2 (SGLT2) inhibitors show reduced mortality and hospitalization for heart failure (HF). SGLT2 inhibitors are considered to activate multiple cardioprotective pathways; however, underlying mechanisms are not fully described. This study aimed to elucidate the underlying mechanisms of the beneficial effects of SGLT2 inhibitors on the failing heart. We generated a left ventricular (LV) pressure overload model in C57BL/6NCrSlc mice by transverse aortic constriction (TAC) and examined the effects of empagliflozin (EMPA) in this model. We conducted metabolome and transcriptome analyses and histological and physiological examinations. EMPA administration ameliorated pressure overload-induced systolic dysfunction. Metabolomic studies showed that EMPA increased citrulline levels in cardiac tissue and reduced levels of arginine, indicating enhanced metabolism from arginine to citrulline and nitric oxide (NO). Transcriptome suggested possible involvement of the insulin/AKT pathway that could activate NO production through phosphorylation of endothelial NO synthase (eNOS). Histological examination of the mice showed capillary rarefaction and endothelial apoptosis after TAC, both of which were significantly improved by EMPA treatment. This improvement was associated with enhanced expression phospho-eNOS and NO production in cardiac endothelial cells. NOS inhibition attenuated these cardioprotective effects of EMPA. The in vitro studies showed that catecholamine-induced endothelial apoptosis was inhibited by NO, arginine, or AKT activator. EMPA activates the AKT/eNOS/NO pathway, which helps to suppress endothelial apoptosis, maintain capillarization and improve systolic dysfunction during LV pressure overload.

Conservative treatment with an intra-aortic balloon pump to treat acute myocardial infarction due to spontaneous coronary artery dissection.

Spontaneous coronary artery dissection (SCAD) is a rare cause of acute coronary syndrome. Treatment for SCAD includes conservative approaches, percutaneous coronary intervention (PCI), and coronary artery bypass graft surgery. Although the success rate of PCI is low, conservative treatment often leads to a good clinical course. Three patients with SCAD who were conservatively treated with intra-aortic balloon pumping without coronary intervention are presented. All three patients continue to do well. .

Near-Infrared Autofluorescence in Atherosclerosis Associates With Ceroid and Is Generated by Oxidized Lipid-Induced Oxidative Stress.

[Figure: see text].

Cardiac mitofusin-1 is reduced in non-responding patients with idiopathic dilated cardiomyopathy.

Prognosis of severe heart failure remains poor. Urgent new therapies are required. Some heart failure patients do not respond to established multidisciplinary treatment and are classified as "non-responders". The outcome is especially poor for non-responders, and underlying mechanisms are largely unknown. Mitofusin-1 (Mfn1), a mitochondrial fusion protein, is significantly reduced in non-responding patients. This study aimed to elucidate the role of Mfn1 in the failing heart. Twenty-two idiopathic dilated cardiomyopathy (IDCM) patients who underwent endomyocardial biopsy of intraventricular septum were included. Of the 22 patients, 8 were non-responders (left ventricular (LV) ejection fraction (LVEF) of < 10% improvement at late phase follow-up). Electron microscopy (EM), quantitative PCR, and immunofluorescence studies were performed to explore the biological processes and molecules involved in failure to respond. Studies in cardiac specific Mfn1 knockout mice (c-Mfn1 KO), and in vitro studies with neonatal rat ventricular myocytes (NRVMs) were also conducted. A significant reduction in mitochondrial size in cardiomyocytes, and Mfn1, was observed in non-responders. A LV pressure overload with thoracic aortic constriction (TAC) c-Mfn1 KO mouse model was generated. Systolic function was reduced in c-Mfn1 KO mice, while mitochondria alteration in TAC c-Mfn1 KO mice increased. In vitro studies in NRVMs indicated negative regulation of Mfn1 by the ß-AR/cAMP/PKA/miR-140-5p pathway resulting in significant reduction in mitochondrial respiration of NRVMs. The level of miR140-5p was increased in cardiac tissues of non-responders. Mfn1 is a biomarker of heart failure in non-responders. Therapies targeting mitochondrial dynamics and homeostasis are next generation therapy for non-responding heart failure patients.

Senolytic vaccination improves normal and pathological age-related phenotypes and increases lifespan in progeroid mice.

Elimination of senescent cells (senolysis) was recently reported to improve normal and pathological changes associated with aging in mice1,2. However, most senolytic agents inhibit antiapoptotic pathways3, raising the possibility of off-target effects in normal tissues. Identification of alternative senolytic approaches is therefore warranted. Here we identify glycoprotein nonmetastatic melanoma protein B (GPNMB) as a molecular target for senolytic therapy. Analysis of transcriptome data from senescent vascular endothelial cells revealed that GPNMB was a molecule with a transmembrane domain that was enriched in senescent cells (seno-antigen). GPNMB expression was upregulated in vascular endothelial cells and/or leukocytes of patients and mice with atherosclerosis. Genetic ablation of Gpnmb-positive cells attenuated senescence in adipose tissue and improved systemic metabolic abnormalities in mice fed a high-fat diet, and reduced atherosclerotic burden in apolipoprotein E knockout mice on a high-fat diet. We then immunized mice against Gpnmb and found a reduction in Gpnmb-positive cells. Senolytic vaccination also improved normal and pathological phenotypes associated with aging, and extended the male lifespan of progeroid mice. Our results suggest that vaccination targeting seno-antigens could be a potential strategy for new senolytic therapies.

Peptide vaccine for semaphorin3E ameliorates systemic glucose intolerance in mice with dietary obesity.

We previously demonstrated that cellular aging signals upregulated a secreted class 3 semaphorin E (Sema3E) and its receptor plexinD1 in the adipose tissue of a murine model of dietary obesity and that Sema3E was a chemoattractant, mediating its biological effects by inducing infiltration of plexinD1-positive inflammatory macrophages into the visceral white adipose tissue. This study was performed to develop a peptide vaccine for Sema3E and test its therapeutic potential in a murine model of dietary obesity. Two antigenic peptides were selected to generate neutralizing antibodies for a vaccine. These peptides were conjugated to keyhole limpet hemocyanin (KLH), and were administered with Freund's adjuvant to obese wild-type male mice. The Sema3E antibody titer was analyzed by ELISA, and the biological effects of the peptides were tested in mice with dietary obesity. Among the two candidate peptides, the Sema3E antibody titer was significantly increased by injection of KLH-conjugated HKEGPEYHWS (Sema3E vaccine). Administration of Sema3E vaccine suppressed the infiltration of plexinD1-positive cells, ameliorated chronic inflammation in visceral white adipose tissue, and improved systemic glucose intolerance in mice with dietary obesity, suggesting that Sema3E vaccine has the potential to become a next generation therapy for obesity and diabetes.

p53 plays a crucial role in endothelial dysfunction associated with hyperglycemia and ischemia.

p53 is a guardian of the genome that protects against carcinogenesis. There is accumulating evidence that p53 is activated with aging. Such activation has been reported to contribute to various age-associated pathologies, but its role in vascular dysfunction is largely unknown. The aim of this study was to investigate whether activation of endothelial p53 has a pathological effect in relation to endothelial function. We established endothelial p53 loss-of-function and gain-of-function models by breeding endothelial-cell specific Cre mice with floxed Trp53 or floxed Mdm2/Mdm4 mice, respectively. Then we induced diabetes by injection of streptozotocin. In the diabetic state, endothelial p53 expression was markedly up-regulated and endothelium-dependent vasodilatation was significantly impaired. Impairment of vasodilatation was significantly ameliorated in endothelial p53 knockout (EC-p53 KO) mice, and deletion of endothelial p53 also significantly enhanced the induction of angiogenesis by ischemia. Conversely, activation of endothelial p53 by deleting Mdm2/Mdm4 reduced both endothelium-dependent vasodilatation and ischemia-induced angiogenesis. Introduction of p53 into human endothelial cells up-regulated the expression of phosphatase and tensin homolog (PTEN), thereby reducing phospho-eNOS levels. Consistent with these results, the beneficial impact of endothelial p53 deletion on endothelial function was attenuated in EC-p53 KO mice with an eNOS-deficient background. These results show that endothelial p53 negatively regulates endothelium-dependent vasodilatation and ischemia-induced angiogenesis, suggesting that inhibition of endothelial p53 could be a novel therapeutic target in patients with metabolic disorders.

Role of smooth muscle cell p53 in pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is characterized by remodeling and narrowing of the pulmonary arteries, which lead to elevation of right ventricular pressure, heart failure, and death. Proliferation of pulmonary artery smooth muscle cells (PASMCs) is thought to be central to the pathogenesis of PAH, although the underlying mechanisms are still being explored. The protein p53 is involved in cell cycle coordination, DNA repair, apoptosis, and cellular senescence, but its role in pulmonary hypertension (PH) is not fully known. We developed a mouse model of hypoxia-induced pulmonary hypertension (PH) and found significant reduction of p53 expression in the lungs. Our in vitro experiments with metabolomic analyses and the Seahorse XF extracellular flux analyzer indicated that suppression of p53 expression in PASMCs led to upregulation of glycolysis and downregulation of mitochondrial respiration, suggesting a proliferative phenotype resembling that of cancer cells. It was previously shown that systemic genetic depletion of p53 in a murine PH model led to more severe lung manifestations. Lack of information about the role of cell-specific p53 signaling promoted us to investigate it in our mouse PH model with the inducible Cre-loxP system. We generated a mouse model with SMC-specific gain or loss of p53 function by crossing Myh11-Cre/ERT2 mice with floxed Mdm4 mice or floxed Trp53 mice. After these animals were exposed to hypoxia for 4 weeks, we conducted hemodynamic and echocardiographic studies. Surprisingly, the severity of PH was similar in both groups of mice and there were no differences between the genotypes. Our findings in these mice indicate that activation or suppression of p53 signaling in SMCs has a minor role in the pathogenesis of PH and suggest that p53 signaling in other cells (endothelial cells, immune cells, or fibroblasts) may be involved in the progression of this condition.

Gamma-Aminobutyric Acid Signaling in Brown Adipose Tissue Promotes Systemic Metabolic Derangement in Obesity.

Brown adipose tissue (BAT) is a metabolically active organ that contributes to the maintenance of systemic metabolism. The sympathetic nervous system plays important roles in the homeostasis of BAT and promotes its browning and activation. However, the role of other neurotransmitters in BAT homeostasis remains largely unknown. Our metabolomic analyses reveal that gamma-aminobutyric acid (GABA) levels are increased in the interscapular BAT of mice with dietary obesity. We also found a significant increase in GABA-type B receptor subunit 1 (GABA-BR1) in the cell membranes of brown adipocytes of dietary obese mice. When administered to obese mice, GABA induces BAT dysfunction together with systemic metabolic disorder. Conversely, the genetic inactivation or inhibition of GABA-BR1 leads to the re-browning of BAT under conditions of metabolic stress and ameliorated systemic glucose intolerance. These results indicate that the constitutive activation of GABA/GABA-BR1 signaling in obesity promotes BAT dysfunction and systemic metabolic derangement.

Boysenberry polyphenol inhibits endothelial dysfunction and improves vascular health.

Endothelial cells have an important role in maintaining vascular homeostasis. Age-related disorders (including obesity, diabetes, and hypertension) or aging per se induce endothelial dysfunction that predisposes to the development of atherosclerosis. Polyphenols have been reported to suppress age-related endothelial cell disorders, but their role in vascular function is yet to be determined. We investigated the influence of boysenberry polyphenol on vascular health under metabolic stress in a murine model of dietary obesity. We found that administration of boysenberry polyphenol suppressed production of reactive oxygen species (ROS) and increased production of nitric oxide (NO) in the aorta. It has been reported that p53 induces cellular senescence and has a crucial role in age-related disorders, including heart failure and diabetes. Administration of boysenberry polyphenol significantly reduced the endothelial p53 level in the aorta and ameliorated endothelial cell dysfunction in iliac arteries under metabolic stress. Boysenberry polyphenol also reduced ROS and p53 levels in cultured human umbilical vein endothelial cells (HUVECs), while increasing NO production. Uncoupled endothelial nitric oxide synthase (eNOS monomer) is known to promote ROS production. We found that boysenberry polyphenol reduced eNOS monomer levels both in vivo and in vitro, along with an increase of eNOS dimerization. To investigate the components of boysenberry polyphenol mediating these favorable biological effects, we extracted the anthocyanin fractions. We found that anthocyanins contributed to suppression of ROS and p53, in association with increased NO production and eNOS dimerization. In an ex vivo study, anthocyanins promoted relaxation of iliac arteries from mice with dietary obesity. These findings indicate that boysenberry polyphenol and anthocyanins, a major component of this polyphenol, inhibit endothelial dysfunction and contribute to maintenance of vascular homeostasis.

Catecholamine-Induced Senescence of Endothelial Cells and Bone Marrow Cells Promotes Cardiac Dysfunction in Mice.

Previous studies have suggested that cellular senescence plays a central role in the progression of pathologic changes in the failing heart. It is well known that the sympathetic nervous system is activated in patients with heart failure, and this change is associated with poor clinical outcomes. Sympathetic activation increases the levels of various catecholamines, such as epinephrine and norepinephrine, but the contribution of these catecholamines to cellular senescence associated with heart failure remains to be determined. We found that catecholamine infusion induced senescence of endothelial cells and bone marrow cells, and promoted cardiac dysfunction in mice. In C57BL/6NCr mice, the continuous infusion of isoproterenol-induced cardiac inflammation and cardiac dysfunction. Expression of p53, a master regulator of cellular senescence, was increased in the cardiac tissue and bone marrow cells of these mice. Suppression of cellular senescence by genetic deletion of p53 in endothelial cells or bone marrow cells led to improvement of isoproterenol-induced cardiac dysfunction. In vitro studies showed that adrenergic signaling increased the expression of p53 and adhesion molecules by endothelial cells and macrophages. Our results indicate that catecholamine-induced senescence of endothelial cells and bone marrow cells plays a pivotal role in the progression of heart failure. Suppression of catecholamine-p53 signaling is crucial for inhibition of remodeling in the failing heart.

Amlodipine Inhibits Vascular Cell Senescence and Protects Against Atherogenesis Through the Mechanism Independent of Calcium Channel Blockade.

Vascular cells have a finite lifespan and eventually enter irreversible growth arrest called cellular senescence. We have previously suggested that vascular cell senescence contributes to the pathogenesis of human atherosclerosis. Amlodipine is a mixture of two enantiomers, one of which (S- enantiomer) has L-type channel blocking activity, while the other (R+ enantiomer) shows ~1000-fold weaker channel blocking activity than S- enantiomer and has other unknown effects. It has been reported that amlodipine inhibits the progression of atherosclerosis in humans, but the molecular mechanism of this beneficial effect remains unknown. Apolipoprotein E-deficient mice on a high-fat diet were treated with amlodipine, its R+ enantiomer or vehicle for eight weeks. Compared with vehicle treatment, both amlodipine and the R+ enantiomer significantly reduced the number of senescent vascular cells and inhibited plaque formation to a similar extent. Expression of the pro-inflammatory molecule interleukin-1ß was markedly upregulated in vehicle-treated mice, but was inhibited to a similar extent by treatment with amlodipine or the R+ enantiomer. Likewise, activation of p53 (a critical inducer of senescence) was markedly suppressed by treatment with amlodipine or the R+ enantiomer. These results suggest that amlodipine inhibits vascular cell senescence and protects against atherogenesis at least partly by a mechanism that is independent of calcium channel blockade.

Percutaneous Coronary Intervention for a Patient with Left Main Coronary Compression Syndrome.

Left main coronary compression syndrome rarely occurs in patients with severe pulmonary hypertension. A 65-year-old woman with severe pulmonary hypertension due to an atrial septal defect suffered from angina on effort. Cardiac computed-tomography and coronary angiography revealed considerable stenosis of the left main coronary artery (LMA) caused by compression between the dilated main pulmonary artery trunk and the sinus of valsalva. Stenting of the LMA under intravascular ultrasound imaging was effective for the treatment of angina. We herein report the diagnosis and management of this condition with a brief literature review.