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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The vitamin D(3) and nicotine (VDN) model is a model of isolated systolic hypertension (ISH) due to arterial calcification raising arterial stiffness and vascular impedance similar to an aged and stiffened arterial tree. We therefore analyzed the impact of this aging model on normal and diseased hearts with myocardial infarction (MI). Wistar rats were treated with VDN (n = 9), subjected to MI by coronary ligation (n = 10), or subjected to a combination of both MI and VDN treatment (VDN/MI, n = 14). A sham-treated group served as control (Ctrl, n = 10). Transthoracic echocardiography was performed every 2 wk, whereas invasive indexes were obtained at week 8 before death. Calcium, collagen, and protein contents were measured in the heart and the aorta. Systolic blood pressure, pulse pressure, thoracic aortic calcium, and end-systolic elastance as an index of myocardial contractility were highest in the aging model group compared with MI and Ctrl groups (P(VDN) < 0.05, 2-way ANOVA). Left ventricular wall stress and brain natriuretic peptide (P(VDNxMI) = not significant) were highest, while ejection fraction, stroke volume, and cardiac output were lowest in the combined group versus all other groups (P(VDNxMI) < 0.05). The combination of ISH due to this aging model and MI demonstrates significant alterations in cardiac function. This model mimics several clinical phenomena of cardiovascular aging and may thus serve to further study novel therapies.
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PMID:Effects of an aging vascular model on healthy and diseased hearts. 1761 50

A stress response consisting of elevated levels of cortisol and catecholamines is common after acute stroke. The plasma levels of natriuretic peptides are known to be elevated after ischemic stroke, but the relations of these neurohormonal systems in the acute phase of stroke and their impact on long-term prognosis have not been studied previously. A series of 51 consecutive patients (mean age 68+/-11 years) with an ischemic first-ever stroke underwent a comprehensive clinical investigation, scoring of their neurologic deficit by Scandinavian Stroke Scale (SSS), Barthel Index (BI) and Modified Ranking Scale (MRS) as well as measurements of plasma cortisol, norepinephrine, epinephrine, ACTH and atrial (N-ANP) and brain (N-BNP) natriuretic peptides on the 2nd and 7th days after ischemic stroke. The patients were followed up for 44+/-21 months. Higher levels of cortisol, ACTH and natriuretic peptides were observed in the stroke patients who died (n=22) during the follow-up than in the stroke survivors. Cortisol levels associated significantly with the 2nd and 7th day N-ANP and N-BNP levels, catecholamine levels (r= 0.55 - 0.94, p<0.01 for all) and measures of neurologic deficit (r= 0.36 - -0.44, p<0.05). High acute phase cortisol levels assessed either in the morning (RR=5.4, p<0.05) or in the evening (RR=5.8, p<0.05) predicted long-term mortality after stroke in multivariate analysis. Activation of the hypothalamus-pituitary-adrenal axis in ischemic stroke is associated with elevated levels of natriuretic peptides. High cortisol and natriuretic peptide values predict long-term mortality after ischemic stroke, suggesting that this profound neurohumoral disturbance is prognostically unfavourable.
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PMID:Neurohormonal activation in ischemic stroke: effects of acute phase disturbances on long-term mortality. 1769 70

Purpose. To examine cardiovascular function and risk profile of postmenopausal women treated with chemoendocrine therapy (CET) for hormone receptor-positive operable breast cancer. Methods. Forty-seven breast cancer patients and 11 age-matched healthy controls were studied. Participants performed a cardiopulmonary exercise test with expired gas analysis and impedance cardiography to assess peak aerobic power (VO(2peak)) and cardiovascular function (stroke volume, cardiac output, cardiac power output, and cardiac reserve). Traditional (i.e., body mass index, lipid profile, and fasting insulin and glucose) and novel (i.e., C-reactive protein, brain natriuretic peptide) cardiovascular risk biochemical factors were also assessed. Results. Breast cancer patients had significantly lower peak exercise stroke volume (68 +/- 9 versus 76 +/- 11 ml/beat), cardiac output (10.4 +/- 1.5 versus 11.7 +/- 2.4 l/minute), cardiac power output (3.0 +/- 0.5 versus 3.5 +/- 0.9 Watts), cardiac power output reserve (1.7 +/- 0.6 versus 2.4 +/- 0.8 Watts), and VO(2peak) (1.3 +/- 0.3 versus 1.6 +/- 0.2 l x min(-1)) than control subjects (p-values < .05). Patients with the greatest impairment in VO(2peak) had the worse cardiovascular risk profile. Exploratory analyses revealed several differences in study outcomes between the 26 patients receiving hormonal therapy with tamoxifen (TAM) and the 21 patients receiving aromatase inhibitor (AI) therapy. Conclusion. Breast cancer patients treated with adjuvant CET have a significantly and markedly lower cardiorespiratory fitness and cardiac functional reserve compared with age- and sex-matched controls. AI therapy may be associated with a more unfavorable cardiovascular risk profile than TAM. Prospective studies are required to further investigate the clinical value of these findings.
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PMID:Cardiovascular reserve and risk profile of postmenopausal women after chemoendocrine therapy for hormone receptor--positive operable breast cancer. 1796 9

Beneficial effects of thiazolidinediones, peroxisome proliferator-activated receptor gamma (PPARgamma) agonists, on cardiovascular injuries have been reported. However, the effects of these agonists on left ventricular (LV) hypertrophy have not been clarified. To investigate whether pioglitazone improves LV hypertrophy, we used 32-week-old stroke-prone spontaneously hypertensive rats (SHR-SP) that had been treated or not treated with pioglitazone (10 mg/kg/day) for 8 weeks, and Wistar Kyoto rats (WKY). We evaluated LV geometry by echocardiography; myocyte hypertrophy, tissue fibrosis, and appearance of myofibroblasts by histological examination; mRNA expression by real-time polymerase chain reaction (PCR); protein expression by Western blot; activities of matrix metalloproteinase (MMP) by zymography; and production of reactive oxygen species (ROS) by electron spin resonance spectroscopy or thiobarbituric acid reactive substances (TBARS). SHR-SP showed concentric hypertrophy of the LV, but WKY did not. The myocyte diameter, fraction of tissue fibrosis, and number of myofibroblasts were greater in SHR-SP. mRNA expressions of collagen type I and type III, tissue growth factor (TGF)-beta1, and brain natriuretic peptide (BNP); protein expression of connective tissue growth factor (CTGF); activities of MMP2 and MMP9; and ROS were increased in SHR-SP. Pioglitazone did not decrease blood pressure, but partially normalized LV geometry in addition to decreasing myocyte diameter, interstitial fibrosis and number of myofibroblasts; mRNA levels of collagen type I and BNP; MMP2 activity; and protein level of CTGF. However, the mRNA level of collagen type III and TGF-beta1, MMP9 activity, and ROS production were not improved. In conclusion, pioglitazone reversed the concentric LV remodeling independently from blood pressure or oxidative stress in chronic hypertension.
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PMID:Beneficial effects of pioglitazone on left ventricular hypertrophy in genetically hypertensive rats. 1803 80

This study was designed to determine the effect of all-trans retinoic acid (RA) on the development of cardiac remodeling in a pressure overload rat model. Male Sprague-Dawley rats were subjected to sham operation and the aortic constriction procedure. A subgroup of sham control and aortic constricted rats were treated with RA for 5 mo after surgery. Pressure-overloaded rats showed significantly increased interstitial and perivascular fibrosis, heart weight-to-body weight ratio, and gene expression of atrial natriuretic peptide and brain natriuretic peptide. Echocardiographic analysis showed that pressure overload induced systolic and diastolic dysfunction, as evidenced by decreased fractional shortening, ejection fraction, stroke volume, and increased E-to-E(a) ratio and isovolumic relaxation time. RA treatment prevented the above changes in cardiac structure and function and hypertrophic gene expression in pressure-overloaded rats. RA restored the ratio of Bcl-2 to Bax, inhibited cleavage of caspase-3 and -9, and prevented the decreases in the levels of SOD-1 and SOD-2. Pressure overload-induced phosphorylation of ERK1/2, JNK, and p38 was inhibited by RA, via upregulation of mitogen-activated protein kinase phosphatase (MKP)-1 and MKP-2. The pressure overload-induced production of angiotensin II was inhibited by RA via upregulation of expression of angiotensin-converting enzyme (ACE)2 and through inhibition of the expression of cardiac and renal renin, angiotensinogen, ACE, and angiotensin type 1 receptor. Similar results were observed in cultured neonatal cardiomyocytes in response to static stretch. These results demonstrate that RA has a significant inhibitory effect on pressure overload-induced cardiac remodeling, through inhibition of the expression of renin-angiotensin system components.
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PMID:All-trans retinoic acid prevents development of cardiac remodeling in aortic banded rats by inhibiting the renin-angiotensin system. 1817 13

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether it is worth performing aortic valve replacement in patients with severe aortic stenosis and poor left ventricular function but no contractile reserve on dobutamine stress testing. Altogether 251 papers were identified using the below mentioned search and all major international guidelines were included. Fourteen presented the best evidence to answer the clinical question. The author, journal, date and country of publication, patient group, relevant outcomes and weaknesses were tabulated. We conclude that patients with severe aortic stenosis and a contractile reserve of <20% improvement in stroke volume on dobutamine stress testing have a very poor prognosis of only 10-20% at two years. Heart transplant would offer the best chance of survival to those eligible but for those not eligible, a surgical option should not be discounted for selected patients. The American Heart Association guidelines state that prognosis is very poor for either medical or surgical treatment, but the European Society of Cardiology guidelines state that surgery can be performed in these patients but should take into account the clinical condition of the patient. The operative mortality is around 30% and the French Multicentre study on low gradient aortic stenosis has shown that if the patient survives there is likely to be an improvement in symptoms and ejection fraction. Thus, absence of contractile reserve on stress testing does not exclude myocardial recovery after surgery, although it is a strong predictor for operative mortality. It should be noted that surgery has only been reported in very few of these patients to date. B-natriuretic peptide has also been suggested as a further marker of better prognosis in these high-risk patients in one small study.
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PMID:Is it ever worth contemplating an aortic valve replacement on patients with low gradient severe aortic stenosis but poor left ventricular function with no contractile reserve? 1821 45

Diminished constriction of arteries and veins following exposure to microgravity or bed rest is associated with a reduced ability to augment peripheral vascular resistance (PVR) and stroke volume during orthostasis. We tested the hypothesis that small mesenteric arteries and veins, which are not exposed to large pressure shifts during simulated microgravity via head-down tail suspension (HDT), will exhibit decrements in adrenergic constriction after HDT in rats. Small mesenteric arteries and veins from control (Con; n = 41) and HDT (n = 35) male Sprague-Dawley rats were studied in vitro. Vasoactive responsiveness to norepinephrine (NE) in arteries (10(-9) to 10(-4) M) and veins (pressure-diameter responses from 2 to 12 cmH(2)O after incubation in 10(-6) or 10(-4) M NE) were evaluated. Plasma concentrations of atrial (ANP) and NH(2)-terminal prohormone brain (NT-proBNP) natriuretic peptides were also measured. In mesenteric arteries, sensitivity and maximal responsiveness to NE were reduced with HDT. In mesenteric veins there was a diminished venoconstriction to NE at any given pressure in HDT. Plasma concentrations of both ANP and NT-proBNP were increased with HDT, and maximal arterial and venous constrictor responses to NE after incubation with 10(-7) M ANP or brain natriuretic peptide (BNP) were diminished. These data demonstrate that, in a vascular bed not subjected to large hydrodynamic differences with HDT, both small arteries and veins have a reduced responsiveness to adrenergic stimulation. Elevated levels of circulating ANP or NT-proBNP could adversely affect the ability of these vascular beds to constrict in vivo and conceivably could alter the intrinsic constrictor properties of these vessels with long-term exposure.
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PMID:Diminished mesenteric vaso- and venoconstriction and elevated plasma ANP and BNP with simulated microgravity. 1827 2

1. The measurement of plasma levels of B-type natriuretic peptide (BNP) and amino-terminal pro-BNP (NT-proBNP) provides useful diagnostic information in patients with suspected heart failure and valuable prognostic information in patients with heart failure, acute coronary syndrome, valvular heart disease and other cardiac pathologies. 2. BNP- and NT-proBNP-guided heart failure therapy improves patient outcomes. 3. An increasing number of studies shows plasma BNP and NT-proBNP levels predict all-cause mortality and cardiovascular events including heart failure, myocardial infarction, stroke, atrial fibrillation and cardiovascular death in stable patients with or without known cardiovascular disease and provide information about cardiovascular risk additional to that provided by traditional risk factors. 4. Antihypertensive therapy reduces elevated NT-proBNP levels in individuals at increased cardiovascular risk, thereby suggesting that change in NT-proBNP levels provides a measure of risk reduction. 5. Thus, monitoring of BNP and NT-proBNP levels offers the possibilities of improved targeting of individuals with increased cardiovascular risk and optimization of strategies for primary and secondary prevention of cardiovascular disease. 6. There is need for an outcome study to determine whether BNP- or NT-proBNP-guided therapy improves cardiovascular disease prevention.
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PMID:Can measurement of B-type natriuretic peptide levels improve cardiovascular disease prevention? 1830 38

Stroke is sometimes seen in patients with congestive heart failure (CHF). The factors that best predict incident stroke in hospitalized CHF patients are not well known. We performed this pilot study to explore the clinical markers of incident stroke in CHF patients. We studied 111 hospitalized patients with CHF (mean age, 67+/-11 years). Ambulatory blood pressure (BP) monitoring, blood tests, and echocardiography were performed in these patients just before they left the hospital, and all cardiovascular events during the study period were followed for an average of 18+/-9 months. Cox regression analysis was performed to explore the predictors of incident stroke using age, sex, body mass index (BMI), casual and ambulatory systolic BP (SBP), and brain-type natriuretic peptide (BNP). There were 10 stroke events (9%) during the follow-up period. The stroke group had higher nocturnal SBP and plasma BNP levels than the non-stroke group. With Cox regression analysis, both nocturnal SBP and BNP were significant predictors of incident stroke independent of other covariates. When nocturnal BP of 120 mmHg and BNP of 600 pg/mL (75th percentile) were used as cutoffs, nocturnal SBP > or =120 mmHg was associated with a 7-fold increase in the risk of incident stroke, while BNP > or =600 pg/mL was associated with a 46.6-fold increase. However, abnormal circadian BP patterns were not associated with incident stroke. In this pilot study, elevated nocturnal BP and high plasma BNP just before patients left the hospital were significant predictors of stroke events in CHF patients. Further study is needed to confirm this hypothesis.
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PMID:Factors associated with incident ischemic stroke in hospitalized heart failure patients: a pilot study. 1836 49

The natriuretic peptide system includes three known peptides: atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP). They contribute to the regulation of cardiovascular homeostasis through diuretic, natriuretic, and vasodilatory properties. Among them, ANP has received particular attention because of its effects on blood pressure regulation and cardiac function. Although the potential for its therapeutic application in the treatment of hypertension and heart failure has been evaluated in several experimental and clinical investigations, no pharmacological approach directly targeted at modulation of ANP levels has ever reached the stage of being incorporated into clinical practice. Recently, ANP has also received attention as being a possible cardiovascular risk factor, particularly in the context of hypertension, stroke, obesity, and metabolic syndrome. Abnormalities in either peptide levels or peptide structure are thought to underlie its implied role in mediating cardiovascular diseases. Meanwhile, BNP has emerged as a relevant marker of left ventricular (LV) dysfunction and as a useful predictor of future outcome in patients with heart failure. This review deals with the major relevant findings related to the cardiovascular and metabolic effects of natriuretic peptides, to their potential therapeutic use, and to their role in mediating cardiovascular diseases.
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PMID:Natriuretic peptides: an update on bioactivity, potential therapeutic use, and implication in cardiovascular diseases. 1846 48


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