Mutsuharu Hayashi

Smoking Cessation Rapidly Increases Circulating Progenitor Cells in Peripheral Blood in Chronic Smokers

Objective—Circulating endothelial progenitor cells (EPCs) contribute to postnatal angiogenesis. The number of circulating EPCs has an inverse correlation with coronary risk scores. However, the effect of smoking on the number of circulating EPCs is not well-known. Methods and Results—We examined the effects of chronic smoking and of smoking cessation on EPC levels. Circulating EPCs were quantified by flow cytometry as CD45lowCD34+CD133+ (progenitor cells [PCs]) or CD45lowCD34+CD133+VEGFR2+ (EPCs) in 14 nonsmokers and in 15 smokers. All smokers quit smoking. Eight quit smoking with nicotine patch and 7 without nicotine patch. PC/EPC levels were inversely correlated with the number of cigarettes smoked. Circulating PCs/EPCs increased rapidly after cessation (P < 0.0001) and decreased again after resumption of smoking to the level similar to that before cessation (P = 0.0031). The magnitude of increase in EPCs was greater in light smokers than in heavy smokers. Conclusions—The number of circulating PCs/EPCs was reduced in chronic smokers. Smoking cessation led to a rapid restoration of PC/EPC levels. The recovery of EPC levels was greater in light smokers than in heavy smokers. The decreased number of circulating EPCs would make smokers susceptible to cardiovascular disease, and even short-time cessation of smoking may be an effective means to reduce cardiovascular risk.

Increased Expression of Plasminogen Activator Inhibitor-1 in Cardiomyocytes Contributes to Cardiac Fibrosis after Myocardial Infarction

Plasminogen activator inhibitor-1 (PAI-1) plays a critical role in tissue fibrosis by inactivating matrix metalloproteinases, which might effect on the progression of left ventricular dysfunction. However, little has been known about the expression of PAI-1 during cardiac remodeling. We used a mouse model of myocardial infarction (MI) by coronary ligation, in which the progression of left ventricular remodeling was confirmed by echocardiography. Histological examination showed that interstitial and perivascular fibrosis progressed in the post-MI (PMI) heart at 4 weeks after the procedure. We observed the dramatic induction of cardiac PAI-1 mRNA and PAI-1 antigen in plasma in the PMI mice, as compared with the sham-operated (sham) mice. In situ hybridization analysis demonstrated that strong signals for PAI-1 mRNA were localized to cardiomyocytes in the border of infarct area and around fibrous lesions, and to perivascular mononuclear cells, which seemed to be mast cells, only in hearts of the PMI mice. Importantly, less development of cardiac fibrosis after MI was observed in mice deficient in PAI-1 as compared to wild-type mice. The mRNA expression of cytokines, transforming growth factor-beta, and tumor necrosis factor-alpha, was also increased in hearts of the PMI mice, but not in the sham mice. These observations suggest that cardiomyocytes and mast cells contribute to the increased PAI-1 expression, resulting in the development of interstitial and perivascular fibrosis in the PMI heart, and that the regional induction of cytokines may be involved in this process.

Prognostic Value of Reduced Left Ventricular Ejection Fraction at Start of Hemodialysis Therapy on Cardiovascular and All-Cause Mortality in End-Stage Renal Disease Patients

BACKGROUND AND OBJECTIVES Cardiac failure is directly affected by left ventricular (LV) dysfunction, and particularly LV systolic dysfunction is strongly associated with survival in ESRD patients. The aim of this study was to determine the prognostic value of reduced LV ejection fraction (LVEF) measured at the time of initiation of hemodialysis (HD) in incident HD patients. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS 1254 consecutive ESRD patients who electively started HD therapy were screened by echocardiography within 1 month after its inception. They were divided into five groups according to LVEF levels with a decrease of 0.1 each and were followed up for up to 7 years. Survival was examined with the Kaplan-Meier method and compared using the log-rank test. RESULTS Among the 1254 patients, LVEF levels ≥0.6, 0.5 to 0.6, 0.4 to 0.5, 0.3 to 0.4, and <0.3 were seen in 842 (67.1%), 247 (19.7%), 107 (8.5%), 41 (3.3%), and 17 (1.4%) patients, respectively. On Kaplan-Meier analysis, 7-year event-free rates from cardiovascular death were 84.2, 83.7, 73.6, 59.4, and 30.9% in order of groups with decreasing LVEF of 0.1 each, respectively. Seven-year event-free rates from all-cause death were 69.2, 61.7, 57.1, 45.9, and 23.1% in the respective groups. Even after adjustment for other risk factors, decreasing LVEF was a strong independent predictor for cardiovascular death. CONCLUSIONS Reduced LVEF on starting HD therapy could stratify risk of cardiovascular and all-cause mortality in ESRD patients. Screening by echocardiography at start of HD therapy might be recommended to predict prognosis in patients with ESRD.

Comparison of Atorvastatin 5 and 20 mg/d for Reducing F-18 Fluorodeoxyglucose Uptake in Atherosclerotic Plaques on Positron Emission Tomography/Computed Tomography: A Randomized, Investigator-Blinded, Open-Label, 6-Month Study in Japanese Adults Scheduled for Percutaneous Coronary Intervention

BACKGROUND F-18 fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) is a useful tool for the detection of local inflamed atherosclerotic lesions. OBJECTIVE This study used hybrid PET/computed tomography (CT) to examine the effects of 2 doses of atorvastatin on (18)F-FDG uptake in atherosclerotic plaques in Japanese adults with stable angina pectoris who were scheduled to undergo percutaneous coronary intervention (PCI). METHODS This was a prospective, randomized, investigator-blinded, open-label study in patients with dyslipidemia (total cholesterol ≥ 220 mg/dL and/or LDL-C ≥ 140 mg/dL) who were scheduled to undergo PCI for stable angina pectoris and had not received any lipid-lowering drugs within 1 year before enrollment. Patients were randomly allocated to receive atorvastatin 5 or 20 mg/d for 6 months. At baseline (the day after PCI), (18)F-FDG uptake in the ascending aorta and femoral artery was determined using PET/CT imaging, and the mean target-to-background ratio (TBR) was calculated in individual plaques. The same regions were assessed by PET/CT after 6 months of treatment. Changes from baseline to follow-up in the lipid profile, serum malondialdehyde-modified LDL-C (MDA-LDL-C), and serum high-sensitivity C-reactive protein (hs-CRP) were also examined. Drug adherence, adverse events, and changes in medications were monitored at monthly outpatient visits. RESULTS Of 32 patients initially screened, 2 were excluded due to newly diagnosed cancer; thus, 30 patients were randomly assigned to treatment, 15 in each group. Patients were predominantly male (18 [60%]), with a mean (SD) age of 54 (11) years, mean body weight of 65 (12) kg, and mean total cholesterol, HDL-C, and triglyceride concentrations of 240 (29), 48 (14), and 180 (102) mg/dL, respectively. After 6 months, the 20-mg group had significant reductions from baseline in mean (SD) TBR in the ascending aorta (from 1.15 [0.14] to 1.05 [0.12]; percent change, -7.9% [9.4%]; P = 0.007) and the femoral artery (from 1.12 [0.11] to 1.02 [0.11]; percent change, -9.9% [13.8%]; P = 0.012). The corresponding changes from baseline were not statistically significant in the 5-mg group. The differences in percent change in TBR in the 2 locations were not significant between groups. When data from the 2 groups were combined, the overall reduction in TBR from baseline to 6 months was significant in both the ascending aorta (P = 0.003) and the femoral artery (P = 0.021). The decreases in TBR in both arteries were significantly correlated with reductions in LDL-C (ascending aorta: r(2) = 0.230 [P = 0.012]; femoral artery: r(2) = 0.338 [P = 0.003]), MDA-LDL-C (ascending aorta: r(2) = 0.183 [P = 0.028]; femoral artery: r(2) = 0.247 [P = 0.010]), and hs-CRP (ascending aorta: r(2) = 0.132 [P = 0.048]; femoral artery: r(2) = 0.271 [P = 0.007]). One patient in the 5-mg group and 2 patients in the 20-mg group had ∼2-fold increases in serum aminotransferases on a single occasion; however, no specific musculoskeletal or hepatic adverse events were observed, and aminotransferase values decreased to within normal ranges without changes in the atorvastatin dose. CONCLUSION Six months of treatment with atorvastatin 20 mg, but not 5 mg, was associated with a significant reduction in TBR in the ascending aorta and femoral artery in these Japanese adults with dyslipidemia undergoing PCI for stable angina pectoris. University Hospital Medical Information Network Clinical Trials Registry identifier: C000000371.

Impact of renal function on coronary plaque composition

BACKGROUND Recent studies have demonstrated that patients with chronic kidney disease are at high risk of atherosclerosis. Recently it has been found that coronary plaque components can be evaluated by integrated backscatter intravascular ultrasound (IB-IVUS), and lipid-rich plaque is associated with vulnerable plaque. The aim of the study was to investigate the relationship between renal function and tissue characterization of coronary plaque composition at the target stenotic site for percutaneous coronary intervention (PCI). METHODS We prospectively performed IB-IVUS before elective PCI in 89 consecutive patients with stable angina. According to estimated glomerular filtration rate (eGFR), they were divided into two groups (eGFR <60 ml/min/ 1.73 m(2) or eGFR > or =60 ml/min/1.73 m(2)). The tissue characteristics of the coronary plaque at each target stenotic site were evaluated by three-dimensional (3D) IB-IVUS just before PCI procedure. RESULTS The patients with eGFR <60 ml/min/1.73 m(2) had higher percentage of lipid volume and lower percentage of fibrous volume compared to the patients with eGFR > or = 60 ml/min/1.73 m(2) on the 3D IB-IVUS images (36.7 +/- 10.6% versus 28.7 +/- 9.3%, P < 0.001 and 59.1 +/- 8.7% versus 66.3 +/- 8.3%, P < 0.001, respectively). eGFR showed a significant negative correlation with lipid volume and had a significant positive correlation with fibrous volume in coronary plaques (r = -0.44, P < 0.0001, and r = 0.46, P < 0.0001, respectively). CONCLUSIONS Impaired renal function was related to higher percentage of lipid volume and lower percentage of fibrous volume in coronary plaque. Our findings may explain the increasing risk of cardiovascular events in patients with renal dysfunction.

Platelet activation and induction of tissue factor in acute and chronic atrial fibrillation: Involvement of mononuclear cell-platelet interaction

BACKGROUND Atrial fibrillation (AF) is associated with a prothrombotic state. The aim of this study was to analyze platelet activation and tissue factor (TF) induction in mononuclear cells (MNCs) and granulocytes downstream of cell-cell interactions in AF patients. METHODS Blood samples were obtained from patients with paroxysmal AF (n=14) at sinus rhythm and at 15 min after induction of AF during an electrophysiological study, and from control subjects (n=13) and patients with chronic AF (n=14) in the outpatient clinic. The expression of CD41a, CD42b, P-selectin, and P-selectin glycoprotein ligand-1 (PSGL-1) on platelets and microparticles in platelet-rich plasma (PRP), and on MNCs and granulocytes in whole blood were examined by flow cytometry. MNC-platelet interaction was investigated ex vivo. RESULTS The expression of CD41a and CD42b on platelets and microparticles was comparable between the control and chronic AF groups, and unchanged after AF induction. Acute induction of AF significantly increased the expression of P-selectin on platelets and microparticles, and to a similar extent, P-selectin-positive MNCs and granulocytes and P-selectin/PSGL-1-double positive MNCs. However, AF induction had no effect on platelet-MNC interactions ex vivo or TF expression on MNCs and granulocytes. Only patients with chronic AF showed platelet-MNC interaction ex vivo and TF overexpression on MNCs. CONCLUSIONS Acute-onset AF activates platelets within minutes to initiate platelet-MNC interaction. The subsequent platelet binding induced TF expression in patients with chronic AF. These findings support the efficacy of anticoagulant therapeutics in chronic AF and suggest the underlying utility of antiplatelet therapeutics in early phase of AF occurrence.

Prognostic Values of C-Reactive Protein Levels on Clinical Outcome After Implantation of Sirolimus-Eluting Stents in Patients on Hemodialysis

Background—Percutaneous coronary intervention (PCI) using drug-eluting stents significantly reduces the risk of restenosis in the general population. However, in patients on hemodialysis, adverse cardiac events are frequently seen even if treated with drug-eluting stents. Recent studies suggest that C-reactive protein (CRP) reflects vascular wall inflammation and can predict adverse cardiac events. We evaluated possible prognostic values of CRP on outcomes in patients on hemodialysis undergoing PCI with drug-eluting stents. Methods and Results—A total of 167 patients undergoing PCI with sirolimus-eluting stents for stable angina (322 lesions) were enrolled. They were divided into tertiles according to serum CRP levels. We analyzed the incidence of major adverse cardiovascular events including cardiovascular death, nonfatal myocardial infarction, and target lesion revascularization after PCI as well as quantitative coronary angiographic data. The mean follow-up was 31 months (SD, 14). Major adverse cardiac events occurred in 11 patients (19.6%) of the lowest tertile, in 22 patients (39.3%) of the middle tertile, and in 28 patients (50.9%) of the highest tertile during follow-up period (P=0.0009). There was a progressive increase in neointimal growth after sirolimus-eluting stent implantation during follow-up because preprocedural CRP levels were higher, despite similar angiographic data just after PCI. Angiographic restenosis at 6 to 8 months after PCI was seen in 10.6% in the lowest tertile, 17.9% in the middle tertile, and 32.0% in the highest tertile (P=0.0007). Conclusions—Increased preprocedural serum CRP levels would predict higher major adverse cardiac events and restenosis rates after sirolimus-eluting stents implantation in patients on hemodialysis.

Relation of Plasma Indoxyl Sulfate Levels and Estimated Glomerular Filtration Rate to Left Ventricular Diastolic Dysfunction

The prognosis of patients with diastolic heart failure (HF) is as poor as that of patients with systolic HF. Greater chronic kidney disease-associated mortality occurs in patients with left ventricular (LV) diastolic HF than in those with systolic HF. Indoxyl sulfate (IS), a uremic toxin, directly affects cardiac cells adversely in in vitro experiments. We investigated the association of IS, a uremic toxin, and chronic kidney disease with LV diastolic dysfunction in the clinical setting. The present study included 204 consecutive patients with preserved LV systolic function. To evaluate LV function, all patients underwent echocardiography. To measure the plasma IS levels and estimated glomerular filtration rate (eGFR), blood samples were obtained. Of the 204 patients, 75 (37%) had LV diastolic dysfunction. A significantly lower prevalence of LV diastolic dysfunction was present in patients with lower plasma IS levels (≤1.0 μg/ml) than those with greater plasma IS levels (38 [29%] vs 37 [51%], p <0.001). Furthermore, a significantly lower prevalence of LV diastolic dysfunction was present in patients with lower plasma IS levels and preserved eGFR than those with greater plasma IS levels and preserved eGFR, those with lower plasma IS levels and a reduced eGFR, or those with greater plasma IS levels and reduced eGFR (20 [21%] vs 18 [53%], p = 0.001; 20 [21%] vs 18 [46%], p = 0.004; and 20 [21%] vs 19 [56%], p <0.001, respectively). In conclusion, greater plasma IS levels or a reduced eGFR, or both, represent an increased risk of LV diastolic dysfunction.

Accuracy of 64-slice multidetector computed tomography for classification and quantitation of coronary plaque: Comparison with integrated backscatter intravascular ultrasound

BACKGROUND Noninvasive assessment of coronary plaque is important for coronary risk stratification. Whereas integrated backscatter intravascular ultrasound (IB-IVUS) has proven effective for analysis of the tissue components of coronary plaque, plaque assessment by 64-slice multidetector computed tomography (MDCT) has not been established. We therefore evaluated the accuracy of MDCT compared with IB-IVUS for identification of coronary plaque components and determination of plaque volume. METHODS Thirty-one sites in 17 coronary vessels (7 left anterior descending, 5 left circumflex, and 5 right coronary arteries) with substantial stenosis were visualized by both 64-slice MDCT and IB-IVUS. Coronary plaque was evaluated by MDCT and the findings were compared with those of IB-IVUS at the same sites and for the same vessel lengths. Plaque was classified as low-attenuated, fibrous, or calcified, and the volume of each plaque component and total plaque volume were calculated. RESULTS Total plaque volume per vessel determined by MDCT was significantly correlated with that determined by IB-IVUS (r=0.704, P<0.05, n=17). However, the volumes of individual plaque components determined by the two approaches were not correlated. The predominant plaque morphology as determined by the two approaches was consistent in 12 of the 17 vessels (70.6%), whereas calcified and low-attenuated plaques were overestimated by MDCT in the remaining vessels. CONCLUSIONS MDCT is a promising approach for noninvasive detection of different types of coronary plaque and may therefore contribute to coronary risk stratification. The ability of MDCT to determine the volume of individual plaque components, however, is limited.

Renin inhibition reduces atherosclerotic plaque neovessel formation and regresses advanced atherosclerotic plaques

OBJECTIVE The interaction between the renin-angiotensin system and toll-like receptors (TLRs) in the pathogenesis of advanced atherosclerotic plaques is not well understood. We studied the effects of the renin inhibitor aliskiren on the progression of advanced atherosclerotic plaque in apolipoprotein E-deficient (ApoE(-/-)) mice with a special focus on plaque neovessel formation. METHODS AND RESULTS Four-wk-old ApoE(-/-) mice were fed a high-fat diet for 8 wks, and the mice were randomly assigned to one of three groups and administered a vehicle, hydralazine, or aliskiren for an additional 12 wks. Aliskiren reduced the atherosclerotic plaque area and plaque neovessel density. It increased the plaque collagen and elastin contents, and reduced plasma angiotensin II levels and plaque macrophage infiltration and cathepsin S (CatS) protein. Aliskiren also decreased the levels of AT1R, gp91phox, TLR2, monocyte chemotactic protein-1, and CatS mRNAs in the aortic roots. Hydralazine had no beneficial vascular effects, although its administration resulted in the same degree of blood pressure reduction as aliskiren. CatS deficiency mimicked the aliskiren-mediated vasculoprotective effect in the ApoE(-/-) mice, but aliskiren showed no further benefits in ApoE(-/-) CatS(-/-) mice. In vitro, TLR2 silencing reduced CatS expression induced by angiotensin II. Moreover, aliskiren or the inhibition of CatS impaired the endothelial cell angiogenic action in vitro or/and ex vivo. CONCLUSION Renin inhibition appears to inhibit advanced plaque neovessel formation in ApoE(-/-) mice and to decrease the vascular inflammatory action and extracellular matrix degradation, partly by reducing AT1R/TLR2-mediated CatS activation and activity, thus regressing advanced atherosclerosis.