Aim: Although high on-treatment platelet reactivity (HTPR) with dual antiplatelet therapy (DAPT) correlates with long-term adverse outcomes in patients undergoing percutaneous coronary intervention, the correlation in Japanese patients remains unclear. Therefore, we examined the relationship between platelet reactivity during DAPT with aspirin and clopidogrel and 1-year clinical outcomes following successful coronary stent implantation.

Methods: A prospective, multicenter registry study (j-CHIPS) was conducted in patients undergoing coronary stenting and receiving aspirin and clopidogrel at 16 hospitals in Japan. A VerifyNow point-of-care assay was used to assess platelet reactivity, and a cutoff value to define HTPR was established.

Results: Between February 2011 and May 2013, 1047 patients were prospectively enrolled, of which 854 patients with platelet function evaluation at 12–24 h after PCI were included in the final analysis. After 1 year of follow-up, the incidence of the primary endpoint (a composite of all-cause mortality, myocardial infarction, stent thrombosis, and ischemic stroke) was significantly higher in patients with HTPR than in those without (5.9% vs. 1.5%, p=0.008), and HTPR showed a modest ability to discriminate between patients who did and did not experience major adverse cardiac and cerebrovascular events (area under the curve, 0.60; 95% confidence interval, 0.511–0.688, p=0.039). HTPR status did not identify patients at risk for major or minor bleeding events.

Conclusion: HTPR was significantly associated with adverse ischemic outcomes at 1 year after PCI in Japanese patients receiving maintenance DAPT, indicating its potential as a prognostic indicator of clinical outcomes in this high-risk patient population.

Aim: Probucol is a controversial drug to inhibit ATP-binding cassette transporter A1 (ABCA1) and to exhibit some positive clinical effects such as regression of xanthomas. It reportedly rescues female infertility in scavenger receptor BI-deficient mice. Here, we investigated the effect of probucol on propagation in HDL-deficient mice as alternative models for impaired HDL-mediated cholesterol delivery.

Methods: Propagation of ABCA1-deficient (Abca1-/-) mice and lecithin: cholesterol acyltransferase (LCAT)-deficient (Lcat-/-) mice were quantitatively observed under the probucol treatment.

Results: Abca1-/- and Lcat-/- mice appear with negligible plasma HDL concentration. Upon backcrossing Abc1+/- with the Abc1-/- mice and cross-breeding between Abc1+/- mice, the numbers of Abc1-/- weaned pups were reduced to 54.7% and to 57.1% from those expected by Mendelian genetics, respectively. Similarly, Lcat-/- weaned pups decreased to 67.7% and to 35.9% but only in the male. Probucol severely reduced plasma HDL-cholesterol to 5% in the wild-type mice, but showed no effects on their propagation. Probucol corrected the deflections of the genotype distribution in the weaned pups recovery in the LCAT-deficient mice propagation but not in the ABCA1-deficient mice while plasma HDL was kept negligible. Probucol had no effect on cholesterol content in the steroidogenic organs of the HDL-deficient mice, while it somewhat increased plasma corticosterone and expression of adrenal cortex HMG-CoA reductase, StAR, cytochrome P450scc, and VKORC1 indicating increase in the synthesis of cholesterol and steroid hormones and in vitamin K turn-over. However, no evident mechanistic background was indicated.

Conclusions: Probucol corrected deflection of genotype distribution in propagation of the LCAT-deficient mice but not the ABCA1-deficient mice at the weaning stage, apparently not through normalization of hypoalphalipoproteinemia.

Aim: Carotid plaque score (cPS) reflecting throughout the carotid artery plaque burden may be a better marker than carotid intima–media thickness (cIMT) is. We aimed to compare the prognostic utility of these measurements in patients with atherosclerotic cardiovascular disease (ASCVD).

Methods: We retrospectively examined 2,035 Japanese patients with ASCVD who underwent carotid ultrasonography between January 2008 and December 2015 at Kanazawa University Hospital. Median follow-up period was 4 years. We used Cox models that adjusted for established risk factors of ASCVD, including age, gender, hypertension, diabetes, smoking, and serum lipids to assess the association of cIMT as well as cPS with major adverse cardiac events (MACE). MACE was defined as all-cause mortality or rehospitalization for a cardiovascular-related illness.

Results: During follow-up, 243 participants experienced MACE. After adjustment for established risk factors, cPS was associated with MACE (hazard ratio [HR]=3.38 for top quintile vs. bottom quintile of cPS; 95% confidence interval [CI] 1.82–6.27; P trend ＜0.001), while cIMT was not (HR=0.88, P=0.57). Addition of the cPS to established risk factors significantly improved risk discrimination (C-index 0.726 vs. 0.746; P=0.017).

Conclusion: These results suggest that cPS, rather than cIMT may be a better marker to identify increased risk for recurrence of MACE among patients with secondary prevention setting.

Aim: Menopause causes arterial senescence and atherosclerotic development through decrease of estrogen. Recently, histone deacetylase SIRT1 has been reported to have protective effects against arterial senescence and atherosclerosis. However, the relationship between estrogen and SIRT1 in the context of menopause-induced arterial senescence is not well understood. The present study aims to investigate whether SIRT1 is involved in the etiology of menopause-induced arterial senescence and atherosclerotic development.

Methods: Twelve-week old female apolipoprotein E-knockout (ApoE-KO) mice underwent ovariectomy (OVX) or sham surgery.

Results: SIRT1 expression and endothelial nitric oxide synthase (eNOS) activation in the aorta were significantly lower in OVX mice than they were in sham mice (OVX vs. sham, n=5 per group). Senescence-associated β-galactosidase activity, protein expression of Ac-p53 and PAI-1, and aortic atherosclerosis lesions were significantly greater in OVX mice than they were in sham mice. Administration of 17β-estradiol (E2) for eight weeks to OVX mice restored aortic SIRT1 expression, activated eNOS, and retarded OVX-induced arterial senescence and atherosclerotic development (E2 vs. control, n=5 per group). The effects of E2 on SIRT1 upregulation, anti-senescence and anti-atherosclerosis were attenuated by administration of a SIRT1 inhibitor, sirtinol. In vitro experiment using human endothelial cells demonstrated that E2 also increased SIRT1 expression and retarded oxidized low density lipoprotein-induced premature senescence, which were also abolished by sirtinol. These results suggested that estrogen modulated arterial senescence and atherosclerosis through SIRT1. Additionally a selective estrogen receptor modulator (SERM), bazedoxifene, also augmented SIRT1 and inhibited arterial senescence and atherosclerotic development (SERM vs. control, n=3 per group).

Conclusions: Downregulation of SIRT1 causes OVX-induced arterial senescence and atherosclerosis in ApoE-KO mice. Administration of estrogen or SERM enables OVX mice to restore these alterations by SIRT1 induction.

Aim: Lifetime risk (LTR) is a measure of disease burden, which presents the probability of occurrence of a specific disease in the remaining lifetime of a group of people for a given index age. This measure is useful for presenting the risk dynamics of a disease at the population level, which constitutes important public health information toward prevention. To date, there have been no studies investigating the LTR for coronary heart diseases (CHDs) in relation to hypercholesterolemia in Asian populations. Therefore, we estimated the LTR of CHDs according to serum low-density lipoprotein cholesterol (LDL-C).

Methods: The participants included in this study were 2,559 men and 2,848 women, enrolled in the Suita Cohort Study of urban residents followed up from 1989 to 2007 for a total of 69,823 person-years. We estimated the sex- and index-age-specific LTR for the first CHD event among participants with or without hypercholesterolemia (LDL-C ≥ 160 mg/dL), accounting for the competing risk for mortality.

Results: For men with hypercholesterolemia, the LTR was 47.2% (95% confidence interval [CI]: 29.3–65.1%) and 44.5% (95% CI: 21.4–68.5%) for those aged 45 and 75, respectively. The LTRs of women with hypercholesterolemia were also higher than of those without hypercholesterolemia. However, their LTRs were lower for all index ages compared to men. These results did not differ for hypercholesterolemia defined by non-high-density lipoprotein cholesterol.

Conclusions: The presence of hypercholesterolemia increases the LTR for CHDs in the Japanese population, especially in men. This estimate can be used in preventive knowledge translation efforts at the population level.

Aim: Studies have suggested that genetic and environmental factors do not account for all risks and mechanisms of intracranial atherosclerotic stenosis (ICAS). DNA methylation may play a role in the progression of ICAS.

Methods: DNA methylation profiles of peripheral blood leucocytes from 7 patients with early-onset ICAS and 7 perfectly matched controls were interrogated for the first time using the Illumina Infinium Human MethylationEPIC BeadChip. Afterward, functional analysis for differentially methylated genes was conducted. In addition, pyrosequencing verification was performed in an independent cohort comprising 21 patients with early-onset ICAS and 21 age- and gender-matched controls.

Results: A total of 318 cytosine-phosphate-guanine sites were found to be differentially methylated based on the established standards. Functional analysis annotated differentially methylated sites to atherosclerosis-related processes and pathways, such as the negative regulation of hydrolase activity (GO 0051346), type II diabetes mellitus (KEGG hsa04930), and the insulin signaling pathway (KEGG hsa04910). In addition, a differentially methylated site was also validated, cg22443212 in gene Rnf213, which showed significant hypermethylation in patients with early-onset ICAS compared with controls 59.56% (49.77%, 88.55%) vs. 44.65% (25.07%, 53.21%), respectively; P=0.010). Receiver operating characteristic curve analysis showed that the area under the curve value of cg22443212 was 0.744 (95% confidence interval, 0.586–0.866; P=0.002).

Conclusions: We revealed that altered DNA methylation may play a role in the occurrence and development of ICAS. These results provided new epigenetic insights into ICAS.

Thrombophilia increases the risk of venous thrombosis, but is rarely responsible for aortic thrombosis. Aortic mural thrombus (AMT) may be associated with a protein C deficiency. However, it is necessary to determine whether the protein C deficiency is congenital/hereditary or secondary/acquired (consumption of protein C during the process of thrombus formation). This study describes a 77-year-old Japanese woman with incidentally diagnosed AMT, who had a protein C deficiency (activity 54%, antigen 42%). Sequencing of the protein C gene revealed a heterozygous mutation of c.1268delG, p.Gly423Valfs^＊82 in exon 9, indicating a congenital protein C deficiency. These findings indicate that very late onset AMT can occur in an adult with congenital protein C deficiency.