Miyuki Yokoyama

Impact of serum omentin-1 levels on cardiac prognosis in patients with heart failure

BackgroundVarious adipokines are reported to be associated with the development of heart failure (HF) through insulin resistance and chronic inflammation. Omentin-1 is a novel adipokine and is associated with incident coronary artery disease. However, it remains unclear whether serum omentin-1 levels are associated with cardiac prognosis in patients with HF.MethodsWe measured serum omentin-1 levels at admission in 136 consecutive patients with HF, and 20 control subjects without signs of significant heart disease. We prospectively followed patients with HF to endpoints of cardiac death or re-hospitalization for worsening HF.ResultsSerum omentin-1 levels were markedly lower in HF patients with cardiac events compared with to without. The patients who were in New York Heart Association (NYHA) functional class IV showed significantly lower serum omentin-1 levels compared to those in class II and III, whereas serum omentin-1 levels did not correlate with serum brain natriuretic peptide levels (r = 0.217, P = 0.011). We divided the HF patients into three groups based on the tertiles of serum omentin-1 level (low T1, middle T2, and high T3). Multivariate Cox hazard analysis showed that the lowest serum omentin-1 level (T1) was independently associated with cardiac events after adjustment for confounding factors (hazard ratio 5.78, 95% confidence interval 1.20-12.79). We divided the HF patients into two groups according to the median serum omentin-1 levels. Kaplan-Meier analysis revealed that the patients with low serum omentin-1 levels had a higher risk of cardiac events compared with those with high serum omentin-1 levels (log-rank test p < 0.001).ConclusionDecreased serum omentin-1 levels were associated with a poor cardiac outcome in patients with HF.

Sarcopenia evaluated by fat-free mass index is an important prognostic factor in patients with chronic heart failure.

BACKGROUND AND AIM Chronic heart failure (CHF) is a major cause of morbidity and mortality, and cardiac cachexia and sarcopenia are serious complications associated with weight loss and increased catabolism. Fat-free mass index (FFMI) is an indicator of resting energy expenditure and is used for the clinical diagnosis of sarcopenia. In the present study, we investigated the impact of sarcopenia, as evaluated by FFMI, on cardiac prognosis in patients with CHF. METHODS AND RESULTS We calculated FFMI in 267 CHF patients who were prospectively followed until they died due to cardiac event, or until they were re-hospitalized. Fat-free mass (FFM) was estimated by the formula [FFM (kg)=7.38+0.02908×urinary creatinine (mg/day)] and normalized by the square of the patients height in meters to calculate FFMI. During the follow-up periods, there were 83 cardiac events, including 19 cardiac deaths. FFMI was lower in patients with cardiac events than in those without (17.0 kg/m(2) vs. 17.6 kg/m(2), P=0.045). Multivariate Cox hazard analysis revealed that decreased FFMI was associated with an unfavorable outcome (adjusted hazard ratio 0.68, 95% confidence interval 0.47-0.98). The patients were divided into two groups according to their median FFMI. The Kaplan-Meier analysis revealed that significantly higher cardiac event rate was observed in the low-FFMI group (log-rank test, P=0.017). CONCLUSIONS Decreased FFMI was associated with an unfavorable prognosis in patients with CHF.

High-mobility group box 1-mediated heat shock protein beta 1 expression attenuates mitochondrial dysfunction and apoptosis

AIMS Apoptosis of cardiomyocytes is thought to account for doxorubicin cardiotoxicity as it contributes to loss of myocardial tissue and contractile dysfunction. Given that high-mobility group box 1 (HMGB1) is a nuclear DNA-binding protein capable of inhibiting apoptosis, we aimed to clarify the role of HMGB1 in heat shock protein beta 1 (HSPB1) expression during doxorubicin-induced cardiomyopathy. METHODS AND RESULTS Mitochondrial damage, cardiomyocyte apoptosis, and cardiac dysfunction after doxorubicin administration were significantly attenuated in mice with cardiac-specific overexpression of HMGB1 (HMGB1-Tg) compared with wild type (WT) -mice. HSPB1 levels after doxorubicin administration were significantly higher in HMGB1-Tg mice than in WT mice. Transfection with HMGB1 increased the expression of HSPB1 at both the protein and mRNA levels, and HMGB1 inhibited mitochondrial dysfunction and apoptosis after exposure of cardiomyocytes to doxorubicin. HSPB1 silencing abrogated the inhibitory effect of HMGB1 on cardiomyocyte apoptosis. Doxorubicin increased the binding of HMGB1 to heat shock factor 2 and enhanced heat shock element promoter activity. Moreover, HMGB1 overexpression greatly enhanced heat shock element promoter activity. Silencing of heat shock factor 2 attenuated HMGB1-dependent HSPB1 expression and abrogated the ability of HMGB1 to suppress cleaved caspase-3 accumulation after doxorubicin stimulation. CONCLUSIONS We report the first in vivo and in vitro evidence that cardiac HMGB1 increases HSPB1 expression and attenuates cardiomyocyte apoptosis associated with doxorubicin-induced cardiomyopathy. Cardiac HMGB1 increases HSPB1 expression in cardiomyocytes in a heat shock factor 2-dependent manner.

Association of plasma xanthine oxidoreductase activity with severity and clinical outcome in patients with chronic heart failure

BACKGROUND Oxidative stress due to purine degradation is associated with the development of chronic heart failure (CHF). Xanthine oxidoreductase (XOR) is a rate-limiting enzyme of purine degradation that plays a key role in uric acid (UA) production with a resultant increase in reactive oxygen species. However, the relationship between plasma XOR activity and CHF severity and clinical outcome remains unclear. METHODS AND RESULTS We measured XOR activity in 440 patients with CHF and 44 control subjects. Abnormally high and low XOR activities were identified based on the results for 95% of the control subjects (high and low XOR activities ≥120 and <33pmol/100μL/h, respectively). The prevalence rates of high and low XOR activities increased with advancing New York Heart Association functional class. There were 158 cardiac events during a median follow-up period of 1034days. Multivariate Cox proportional hazard regression analysis showed that both high and low XOR activities were significantly associated with cardiac events in patients with CHF after adjustment for confounding risk factors including serum UA and loop diuretic use. Kaplan-Meier analysis revealed that the cardiac event rate was significantly higher in patients with either high or low XOR activity. The net reclassification index was significantly improved by adding XOR activity to the basic risk factors. CONCLUSIONS We provide the first evidence of an association of plasma XOR activity with CHF severity and clinical outcome. Plasma XOR activity could be used to identify high-risk CHF patients and could be a therapeutic target for XOR inhibitors.

The role of macrophage transcription factor MafB in atherosclerotic plaque stability

BACKGROUND AND AIMS Macrophage differentiation is associated with the development of atherosclerosis and plaque vulnerability and is regulated by transcription factor MafB. We previously reported that MafB attenuates macrophage apoptosis, which is associated with atherosclerotic plaque instability. The aim of this study was to elucidate the role of MafB in the progression of atherosclerotic plaque. METHODS We generated macrophage-specific dominant-negative (DN) MafB transgenic mice and intercrossed DN-MafB mice with apolipoprotein E (ApoE) knockout (KO) mice. RESULTS There was no significant difference in advanced atherosclerotic lesion area between DN-MafB/ApoE KO mice and littermate control ApoE KO mice 9 weeks after high-cholesterol diet. However, DN-MafB/ApoE KO mice showed significantly larger necrotic cores and lower collagen content in atherosclerotic plaques than ApoE KO mice. Although there was no difference in intraplaque macrophage infiltration and efferocytosis, DN-MafB/ApoE KO mice showed significantly more apoptotic macrophages at the plaque edges than did ApoE KO mice. Real-time PCR analysis revealed that peritoneal macrophages of DN-MafB/ApoE KO mice had a greater increase in matrix metalloproteinase-9 and mRNA expression of inflammatory/M1 macrophage markers (tissue necrosis factor-α, interleukin-6, CD11c, and p47phox) after lipopolysaccharide stimulation than those of ApoE KO mice. CONCLUSION Macrophage-specific inhibition of MafB may destabilize atherosclerotic plaques in advanced lesions.

Impact of restrictive lung disorder on cardiovascular mortality in a general population: The Yamagata (Takahata) study

BACKGROUND Obstructive lung disorder (OLD) is known to be associated with cardiovascular disease. However, the impact of restrictive lung disorder (RLD) on cardiovascular mortality has not been fully investigated in the apparently healthy general population. OBJECTIVES To clarify whether RLD is associated with cardiovascular mortality in the general population. METHODS AND RESULTS This community-based cohort study included 3247 subjects who participated in an annual health check in Takahata. We performed spirometry in registered subjects and found that 194 (6%) had RLD, 262 (8%) had OLD, and 73 (2%) had RLD and OLD (Mixed). During a 10-year follow-up, there were 210 deaths, including 57 cardiovascular deaths. Cardiovascular mortality of subjects with RLD was significantly higher than that of subjects with normal lung function. Although the subjects with RLD were younger, comprised fewer smokers, and were more likely to be female than those with OLD, cardiovascular mortality of subjects with RLD was comparable to that of subjects with OLD. Subjects with RLD had a higher prevalence of atrial fibrillation (AF) than those with OLD, and the prevalence of AF was increased with advanced severity of RLD. Multivariate Cox proportional hazard analysis revealed that RLD was an independent predictor of cardiovascular death (hazard ratio 2.61, 95% confidence interval, 1.22-5.21) after adjustment for confounders, but OLD was not. The net reclassification improvement and integrated discrimination improvement were significantly increased by the addition of RLD to conventional cardiovascular risk factors. CONCLUSION The presence of RLD was associated with cardiovascular mortality in the general population.

Association of the Aspartate Aminotransferase to Alanine Aminotransferase Ratio with BNP Level and Cardiovascular Mortality in the General Population: The Yamagata Study 10-Year Follow-Up

Background. Early identification of high risk subjects for cardiovascular disease in health check-up is still unmet medical need. Cardiovascular disease is characterized by the superior increase in aspartate aminotransferase (AST) to alanine aminotransferase (ALT). However, the association of AST/ALT ratio with brain natriuretic peptide (BNP) levels and cardiovascular mortality remains unclear in the general population. Methods and Results. This longitudinal cohort study included 3,494 Japanese subjects who participated in a community-based health check-up, with a 10-year follow-up. The AST/ALT ratio increased with increasing BNP levels. And multivariate logistic analysis showed that the AST/ALT ratio was significantly associated with a high BNP (≥100 pg/mL). There were 250 all-cause deaths including 79 cardiovascular deaths. Multivariate Cox proportional hazard regression analysis revealed that a high AST/ALT ratio (>90 percentile) was an independent predictor of all-cause and cardiovascular mortality after adjustment for confounding factors. Kaplan-Meier analysis demonstrated that cardiovascular mortality was higher in subjects with a high AST/ALT ratio than in those without. Conclusions. The AST/ALT ratio was associated with an increase in BNP and was predictive of cardiovascular mortality in a general population. Measuring the AST/ALT ratio during routine health check-ups may be a simple and cost-effective marker for cardiovascular mortality.

Impact of Objective Malnutrition Status on the Clinical Outcomes in Patients With Peripheral Artery Disease Following Endovascular Therapy

BACKGROUND Peripheral artery disease (PAD) is an athero-occlusive disease and a known risk factor for cardiovascular events. The controlling nutritional status (CONUT) score and geriatric nutritional risk index (GNRI) are objective tools for evaluating malnutrition and are reportedly associated with poor clinical outcomes in patients with fatal diseases. However, the effect of malnutrition on the clinical outcomes in patients with PAD remains unclear.Methods and Results:We enrolled 357 patients with PAD who underwent endovascular therapy. Malnutrition was diagnosed by CONUT score and GNRI as in previous reports. During a median follow-up period of 1,071 days, there were 67 major adverse cardiovascular and leg events (MACLEs). The CONUT score- and GNRI-based malnutrition statuses were identified in 56% and 46% of the patients, respectively. Proportion of malnutrition increased with advancing Fontaine class. The multivariate Cox proportional hazard regression analysis demonstrated that both the CONUT score- and GNRI-based malnutrition status was an independent predictor of MACLEs. The Kaplan-Meier analysis demonstrated that the MACLE ratio increased with deteriorating malnutrition. Finally, the addition of the CONUT score or GNRI to the known risk factors significantly improved the net reclassification index and integrated discrimination index. CONCLUSIONS Malnutrition was common and closely associated with the clinical outcomes in patients with PAD, indicating that it is a novel therapeutic target in the management of these patients.

Ventricular wall stress and silent myocardial damage are associated with pulse pressure in the general population

Pulse pressure (PP) is a risk factor for cardiovascular diseases and is associated with increased afterload and myocardial oxygen demand. Brain natriuretic peptide (BNP) and heart‐type fatty acid–binding protein (H‐FABP) are known as biomarkers indicating ventricular wall stress and silent myocardial damage. However, the association between PP and ventricular wall stress and silent myocardial damage in the general population is unclear. The authors enrolled 3504 patients who participated in a community‐based annual health check. Serum levels of BNP and H‐FABP were measured as markers of ventricular wall stress and silent myocardial damage. Patients were divided into four groups according to the quartiles of PP. Patients in the highest PP group showed higher serum BNP and H‐FABP levels than that of the other groups. Multivariate logistic analysis showed that high PP was independently associated with ventricular wall stress and silent myocardial damage on the basis of BNP and H‐FABP levels. Compared with systolic blood pressure, diastolic blood pressure, and mean blood pressure, PP was superior in predicting ventricular wall stress and silent myocardial damage evaluated according to BNP and H‐FABP levels, which was reflected by the receiver operating characteristic analysis. Screening of healthy patients revealed that high PP was related to high BNP and H‐FABP levels, suggesting that an asymptomatic general population with high PP may be exposed to ventricular wall stress and myocardial damage and might be susceptible to silent heart failure.

Increased plasma xanthine oxidoreductase activity deteriorates coronary artery spasm

Increased reactive oxygen species (ROS) contributes to the development of endothelial dysfunction, which is involved in coronary artery spasm (CAS). Xanthine oxidoreductase (XOR) plays a pivotal role in producing both uric acid and ROS. However, the association between plasma XOR activity and CAS has not been elucidated. The aim of this study was to investigate whether plasma XOR activity is associated with CAS. We measured XOR activity in 104 patients suspected for CAS, who presented without significant coronary artery stenosis and underwent intracoronary acetylcholine provocation tests. CAS was provoked in 44 patients and they had significantly higher XOR activity as compared with those without CAS. The patients were divided into three groups based on the XOR activity. The prevalence rate of CAS was increased with increasing XOR activity. A multivariate logistic regression analysis showed that the 3rd tertile group exhibited a higher incidence of CAS as compared with the 1st tertile group [odds ratio (OR) 6.9, P = 0.001) and the 2nd tertile group (OR 3.2, P = 0.033) after adjustment for conventional CAS risk factors, respectively. The C index was significantly improved by the addition of XOR activity to the baseline model based on CAS risk factors. Furthermore, the 3rd tertile group had the highest incidence of severe spasm defined as total obstruction, flow-limiting stenosis, diffuse spasm, multivessel spasm, and/or lethal arrhythmia. This is a first report to elucidate the association of plasma XOR activity with CAS. Increased plasma XOR activity is significantly associated with CAS.