Background：EndoPAT measurement has been reported to be well correlated with brachial artery flow-mediated vasodilatation (FMD) in coronary artery disease. However, this relation is still controversial in hypertensive patients or normal subjects and the pathophysiological mechanisms of EndoPAT index is still not completely clarified. Purpose：The purpose of this study is to investigate the correlation of EndoPAT index with FMD and the physiological role of EndoPAT index in hypertension. Methods：To study this aim, we simultaneously measured EndoPAT index (RHI) and FMD by forearm occlusion technique, that is reported to be nitric oxide (NO) dependent, in 47 hypertensive patients without hypertensive complication (62±11 years old). BaPWV and augmentation index (AI@75bpm) by EndoPAT were also measured at the same time. Results：RHI did not correlate with FMD nor baPWV (r= 0.17, NS) while FMD also did not correlate with baPWV (r=0.08, NS). However, baPWV significantly correlated with AI@75bpm by EndoPAT (r=0.50, p<0.01). In conclusion：Augmentation index expressed as AI@75bpm by EndoPAT was associated with arterial stiffness measured by baPWV. However, there is no correlation between EndoPAT index of RHI and FMD in hypertensive patients, suggesting that the indexes reflect partially different vascular functions.

Background: Clinical significance of central blood pressure (BP) in treated hypertensives has not been established. We tested the hypothesis that subjects with high central systolic BP (CBP) but normal office brachial BP (OBP) have high cardiovascular risk profile. Methods: All of the subjects were participants enrolled in the Antihypertensives and Blood pressure of Central artery study in Japan (ABC-J) II study. Radial applanation tonometry (Omron 9000AI) was performed in 4077 subjects, and they were classified as; Group 1: high OBP (>140/90 mmHg) and high CBP (>130 mmHg); Group 2: high OBP and normal CBP; Group 3: normal OBP and high CBP; and Group 4 as both normal. Plasma brain natriuretic peptide (BNP) was used as a measure of cardiovascular load. Results: The mean age was 65.9 ± 11.2 yrs, 49.2% were females, and 25.7% had diabetes. In both genders, subjects with Group 3 were oldest, and beta-blocker was most frequently used, but body mass index (BMI), rate of diabetes, and heart rate were lowest among the four groups. In ANOVA, Group 3 tended to have higher BNP levels in both genders. In multivariate analysis after adjusting for significant covariates, BNP in Group 3 tended to be high level in females, but not in males. Conclusion: In treated hypertensives, higher central SBP was associated with higher BNP levels regardless of office brachial BP levels, especially in females. The results imply that high central SBP (>130 mmHg) can be used to detect high risk hypertensives with cardiovascular overload.

Background：Activation of angiotensin receptor type1 (AT1R) and xanthine oxidase (XO) generates reactive oxygen species (ROS), that causes cardiac dysfunction after myocardial infarction (MI). However, it remains unknown whether its inhibition could restore the cardiac function after MI. In the present study, we examined effects of irbesartan and topiroxostat on cardiac function after MI. Methods and results：We studied blood pressure and cardiac function in a rat myocardial infraction model using tail cuff system and echocardiography. Irbesartan and topiroxostat as well as vehicle were orally administered for 35 days to rats 7 days before MI induction. Neither irbesartan nor topiroxostat altered mean blood pressure and heart rate after MI. Treatment with either drugs significantly improved cardiac function after MI. The potency of topiroxostat to restore the cardiac function was approximately half of that of irbesartan. Conclusions：A non-purine XO inhibitor, topiroxostat improved cardiac function after MI, suggesting that like irbesartan, topiroxostat may be a promising drug to treat congestive heart failure after MI.

Background: L-arginine and its related metabolites are associated with arginine bioavailability and subsequent nitric oxide production. The global L-arginine bioavailability ratio (GABR), defined as the ratio of the level of L-arginine to the sum of the levels of its major metabolites (L-arginine/[L-citrulline + L-ornithine]), has been reported as an index of arginine bioavailability. GABR in acute coronary syndrome (ACS) has not been fully investigated. Methods and results: The serum levels of L-arginine, L-citrulline, L-ornithine, asymmetric dimethylarginine (ADMA), and symmetric dimethylarginine (SDMA) were assessed in 134 patients who underwent coronary angiography. The patients were classified into the following three groups based on clinical presentation, electrocardiogram, and coronary angiogram: stable patients without coronary artery disease (CAD (−), n = 38), stable patients with CAD (CAD (+), n = 56), and patients with ACS (n = 40). The ACS patients included 13 with acute myocardial infarction and 27 with unstable angina pectoris. L-arginine and L-ornithine levels were not significantly different among the three groups, whereas L-citrulline levels were significantly increased in ACS patients (CAD (−): 135 ± 62, CAD (+): 148 ± 68, ACS: 174 ± 79 μmol/L; p = 0.043), resulting in a significant decrease in GABR (CAD (−): 0.51 ± 0.19, CAD (+): 0.49 ± 0.17, ACS: 0.39 ± 0.12; p = 0.003). Conclusion: Increased serum citrulline and decreased GABR were observed in patients with ACS, suggesting the presence of relative arginine deficiency in ACS.