Among patients with unstable angina or myocardial infarction without ST-segment elevation, prasugrel did not significantly reduce the frequency of the primary end point, as compared with clopidogrel, and similar risks of bleeding were observed. (Funded by Eli Lilly and Daiichi Sankyo; TRILOGY ACS ClinicalTrials.gov number, NCT00699998.).
The HIF-1alpha/VP16 hybrid transcription factor is able to promote significant improvement in perfusion of an ischemic limb. These results confirm the feasibility of a novel approach for therapeutic angiogenesis in which neovascularization may be achieved indirectly by use of a transcriptional regulatory strategy.
Ang1 but not Ang2 gene transfer produces anatomic and physiological evidence of enhanced collateral vessel formation. Ang1 may modulate neovascularization in adult animals and thus represents a feasible therapeutic strategy for patients with tissue ischemia. The role of Ang2 in postnatal neovascularization remains to be clarified.
Vascular smooth muscle cells (VSMCs) are exposed to hormonal and mechanical stress in vivo. Hormonal factors have been shown to affect hypoxia-inducible factor-1alpha (HIF-1alpha). How mechanical stress affects the regulation of HIF-1alpha in VSMCs has not been reported previously, and therefore we sought to investigate the regulation of HIF-1alpha by cyclical mechanical stretch in cultured rat VSMCs. Rat VSMCs grown on a flexible membrane base were stretched by vacuum to 20% of the maximum elongation at 60 cycles/min. The levels of HIF-1alpha protein began to increase as early as 2 h after stretch was applied and reached a maximum of 2.8-fold over the control by 4 h. Real-time PCR showed that the levels of HIF-1alpha mRNA increased 2.1-fold after cyclical stretch for 4 h. Cyclical mechanical stretch also increased the immunohistochemical labelling of HIF-1alpha in VSMCs after cyclical stretch for 4 h. The phosphorylation of p42/p44 mitogen-activated protein kinase (MAP kinase) increased after stretch and this was inhibited by the MAP kinase kinase inhibitors PD98059 and U0126. PD98059 and U0126 also blocked HIF-1alpha gene expression induced by cyclical stretch. In conclusion, cyclical mechanical stretch activates the gene expression of HIF-1alpha in cultured VSMCs and this mechanical effect is possibly mediated by the p42/p44 MAP kinase kinase pathway.
CHADS2 and CHA2DS2-VASc scores were predictive of postoperative atrial fibrillation after cardiac surgery and may be helpful for identifying high-risk patients.
Cells in the cardiovascular system are permanently subjected to mechanical forces due to the pulsatile nature of blood flow and shear stress, created by the beating heart. These haemodynamic forces play an important role in the regulation of vascular development, remodelling, wound healing and atherosclerotic lesion formation. Mechanical stretch can modulate several different cellular functions in VSMCs (vascular smooth muscle cells). These functions include, but are not limited to, cell alignment and differentiation, migration, survival or apoptosis, vascular remodelling, and autocrine and paracrine functions. Laminar shear stress exerts anti-apoptotic, anti-atherosclerotic and antithrombotic effects on ECs (endothelial cells). Mechanical stretch of cardiac myocytes can modulate growth, apoptosis, electric remodelling, alterations in gene expression, and autocrine and paracrine effects. The aim of the present review is primarily to summarize the cellular and molecular effects of mechanical stretch on vascular cells and cardiac myocytes, emphasizing the molecular mechanisms underlying the regulation. Knowledge of the impact of mechanical stretch on the cardiovascular system is vital to the understanding of the pathogenesis of cardiovascular diseases, and is also crucial to provide new insights into the prevention and therapy of cardiovascular diseases.
Background: There have been few studies done regarding young patients with ST-elevation myocardial infarction (STEMI). The purpose of this study was to investigate the clinical characteristics and coronary angiographic features in young patients with STEMI. Methods: We collected data on 849 consecutive patients with STEMI from 1992 to 2006. Baseline clinical characteristics, coronary anatomy, and outcome were compared in young (≤45 yrs) and older patients (>45 yrs). Results: Young patients presented 11.6% of all patients with STEMI. These patients were predominantly male (92.9% vs 80.3%, P < 0.001), more likely to smoke (75.8% vs 47.2%, P < 0.001), obese (48.2% vs 27.9%, P = 0.002), have higher triglyceride levels (176.9 ± 153.8 mg/dL vs 140.7 ± 112.7 mg/dL, P = 0.005), and lower high-density lipoprotein cholesterol (37.1 ± 7.9 mg/dL vs 42.8 ± 14.3 mg/dL, P = 0.005) than older patients. Also, younger patients had a shorter hospital stay (7.1 ± 4.9 d vs 8.5 ± 6.7 d, P = 0.04), less in-hospital morbidity (29.3% vs 39.7%, P = 0.02), and mortality (3.0% vs 12.3%, P = 0.002). Killip class III or IV could predict in-hospital morbidity and mortality in young patients. Both groups had similar rates of repeated percutaneous coronary intervention (PCI; 45.5% vs 41.5%, P = 0.23) and reinfarction (6.1% vs 3.2%, P = 0.32). Mortality rate during follow-up was significantly lower in younger patients (3.0% vs 19.6%, P < 0.001). Conclusion: Cigarette smoking, obesity, and dyslipidemia were the most important modifiable risk factors in young patients with STEMI. These patients had a better outcome than older patients without differences in repeated PCI and reinfarction between them. Only Killip class III or IV could predict in-hospital morbidity and mortality in young patients with STEMI.
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