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ABSTRACT: Irbesartan, an angiotensin II receptor blocker (ARB), acts as a selective PPAR-γ (peroxisome proliferator-activated receptor-γ) modulator, and thus may have anti-inflammatory and antioxidative effects, as well as beneficial effects on glucose and lipid metabolism. We enrolled 118 high-risk hypertensive outpatients, defined as those with the presence of at least one complication such as coronary artery disease, cerebrovascular disease or diabetes, and who were receiving any ARB except for irbesartan (67±10 years, 80% male subjects). After a 4-week control period, all ARBs were switched to an equivalent dose of irbesartan. We evaluated changes in lipid parameters, inflammatory markers and derivatives of reactive oxygen metabolites (d-ROMs) as an oxidative stress index. After 12 weeks of irbesartan, there were significant decreases in triglycerides (138±73 versus 123±65 mg dl(-1), P<0.05), high-sensitivity C-reactive protein (hs-CRP) (2.80±0.53 versus 2.66±0.50, log (ng ml(-1)), P<0.05) and d-ROMs (338±74 versus 305±62 U.CARR, P<0.001). There were significant increases in high-density lipoprotein cholesterol (50±13 versus 52±14 mg dl(-1), P<0.01) and adiponectin (9.4±6.2 versus 16.6±13.4 ng ml(-1), P<0.05). There were no significant changes in systolic and diastolic blood pressure. The change in d-ROMs from baseline to 12 weeks was positively correlated with the change in hs-CRP (R=0.34, P<0.01). Irbesartan appears to exert beneficial effects on oxidative stress, inflammation, lipid metabolism and metabolic syndrome, indicating that it may be useful in high-risk hypertensive patients.Hypertension Research advance online publication, 21 February 2013; doi:10.1038/hr.2013.3.
Hypertension Research 02/2013; · 2.58 Impact Factor
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ABSTRACT: To elucidate left ventricular function in pulmonary hypertension, we measured parameters of left ventricular as well as right ventricular function by echocardiography in 11 patients with pulmonary hypertension (idiopathic pulmonary artery hypertension in 4, chronic thromboembolic pulmonary hypertension in 5, and other pulmonary hypertension in 2). The percent change in these parameters 6 months after treatment with pulmonary artery vasodilators (beraprost in 8 and sildenafil in 3) was assessed. There was a correlation between the relative change in right ventricular systolic pressure (RVSP) and the relative changes in left ventricular outflow tract velocity-time integral (r = -0.730, P = 0.011) and mitral valve velocity-time integral (r = -0.621, P = 0.041). However, there was no correlation between the relative change in RVSP and the relative changes in left ventricular ejection fraction, left ventricular diastolic dimension, and systolic blood pressure. The relative change in RVSP was also correlated with the relative change in early diastolic myocardial velocity at the medial mitral annulus (r = -0.675, P = 0.023). Reduction of RVSP by pulmonary artery vasodilators might increase left ventricular preload, leading to an increase in stroke volume. Right ventricular load reduction might improve left ventricular diastolic function in patients with pulmonary hypertension, possibly through altered interventricular septal performance.
Heart and Vessels 11/2012; · 2.05 Impact Factor
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Ryoichi Sohma,
Teruo Inoue,
Shichiro Abe,
Isao Taguchi,
Migaku Kikuchi,
Shigeru Toyoda, Takuo Arikawa,
Yutaka Hikichi,
Shoji Sanada,
Hiroshi Asanuma,
Masafumi Kitakaze,
Koichi Node
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ABSTRACT: Statins attenuate angiotensin II-induced myocyte hypertrophy and this might increase the cardioprotective effects of renin-angiotensin system inhibition in the ischemic heart. In this study, we investigated the cardioprotective effects of combination therapy with low-dose simvastatin and low-dose losartan using a rat myocardial infarction model.
Myocardial infarction was created in rats by left anterior descending artery ligation, and the animals were randomly allocated to one of four groups: control (n=8), losartan 3 mg/kg/day (n=8), simvastatin 2 mg/kg/day (n=8), and losartan 3 mg/kg/day plus simvastatin 2 mg/kg/day (n=8). Each treatment was started on the day of coronary ligation, and hemodynamics, myocardial blood flow, and infarct size were measured after 28 days.
Blood pressure, heart rate, and left ventricular systolic and end-diastolic pressures were not significantly different comparing the control group with the 3 other treatment groups. The peak positive first derivative of left ventricular pressure (peak LV dP/dt) was equivalent comparing the control group with the losartan and simvastatin groups. However, the peak LV dP/dt was greater in the losartan plus simvastatin group than in the control group (p<0.05). Myocardial blood flow, left ventricular weight, and infarct size were not significantly altered by the 3 treatments.
Treatment with 3 mg/kg/day losartan plus 2 mg/kg/day simvastatin but not losartan or simvastatin alone improved left ventricular systolic function in a rat myocardial infarction model. The result suggests that statins given in combination with angiotensin receptor blockers might have beneficial cardioprotective effects, even at low-doses for each agent.
Journal of Cardiology 09/2011; 59(1):91-6. · 1.28 Impact Factor
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ABSTRACT: Angiotensin II type 1 (AT1) receptor blockers (ARBs), widely used in the treatment of hypertension, have cardiovascular, cerebral, and renal protective effects beyond blood pressure control. In addition to direct end-organ protection, some ARBs have been suggested to improve abnormalities of glucose and lipid metabolisms, resulting in an anti-atherosclerotic effect in patients with hypertension. In several clinical trials, the effects of ARBs on lipid metabolism have been emerged, although the effects are heterogeneous. Certain subgroups of ARBs such as telmisartan have been identified as partial agonists for the peroxisome proliferators activated receptor (PPAR)-γ, and thus, this class of ARBs has been mostly focused on their effects on lipid metabolism. Based on the pleiotropic effects on lipid metabolism, we can envision that ARBs would provide the promising outcome for hypertensive patients aggregating metabolic risk factors, including dyslipidemia.
Current Vascular Pharmacology 03/2011; 9(2):129-35. · 2.90 Impact Factor
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ABSTRACT: A 65-year-old woman who had previously undergone aortic root replacement with a bioprosthetic valve (Bentall operation) in treatment of annuloaortic ectasia became feverish after developing dental caries and was admitted to our hospital. Transesophageal echocardiography showed an 18 × 4-mm vegetation on her prosthetic valve. Campylobacter fetus was isolated on blood cultures, and she was diagnosed with infectious endocarditis. Aggressive combined antibiotic treatment was effective for her recovery. C. fetus infection is a rarely reported cause of prosthetic valve endocarditis.
Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital 01/2011; 38(5):584-7. · 0.65 Impact Factor
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Noboru Kaneko,
Ryuko Matsuda,
Naoyuki Ohtani,
Takahide Nakajima, Takuo Arikawa,
Hidehiko Suzuki,
Shigeru Toyoda,
Migaku Kikuchi,
Yoshihito Hata,
Shichiro Abe,
Isao Taguchi,
Ken Shimamoto
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ABSTRACT: Heart failure with preserved ejection fraction differs from systolic heart failure in pathogenesis, underlying disease, and prognosis; however, the onset mechanism of this type of heart failure remains unknown and there is no proven therapy. Recently, we showed that norepinephrine (NE) under Ca2+ loading induces severe diastolic dysfunction without a significant change in the left ventricular ejection fraction (LVEF), that is, increased left ventricular end-diastolic pressure (LVEDP), norepinephrine-induced diastolic contracture (NEIDC), and diastolic opening of the aortic valve. In this study, the effects of two benzothiazepine derivatives, K201 (JTV519) and diltiazem, on diastolic dysfunction were examined using this model. K201 significantly suppressed the increase in LVEDP, reduced the incidence of NEIDC, and significantly improved the Ea wave and DCT in a dose-dependent manner, as well as reducing pulmonary hemorrhage. In contrast, diltiazem did not improve diastolic dysfunction and the mortality in the diltiazem group was 57%, compared to 0% in the K201 group. These results suggest that reduction of intracellular Ca2+ alone does not inhibit diastolic heart failure; in contrast, blocking of α-adrenoceptors and regulation of proteins such as troponin I via protein kinase C are required for treatment of diastolic heart failure. These results also suggest that K201 may be an agent for treatment of diastolic heart failure. Drug Dev. Res. 67:852–861, 2006. © 2007 Wiley-Liss, Inc.
Drug Development Research 02/2007; 67(11):852 - 861. · 1.19 Impact Factor
