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Objective To study the effect of myocardial bridge oppression on blood flow, positive pressure, circumferential stress and shear stress of the coronary artery. Methods The original myocardial bridge simulative device was greatly improved to be able to measure multi-hemodynamic parameters, such as normal stress, circumferential stress and shear stress, so as to exactly simulate real blood dynamics environment with the common effect of several stresses, and comprehensively investigate the relationship between hemodynamics and atherosclerosis of mural coronary artery under the combined effects of several stresses. Results The results from the myocardial bridge simulative device indicated that the hemodynamic abnormalities were mainly located in the proximal end of mural coronary artery, and the mean and oscillation values of normal stress at the proximal end were increased by 27.8% and 139%, respectively, showing a significant increase with the intensification of myocardial bridge oppression. Conclusions It is myocardial oppression that causes the hemodynamic abnormity of proximal coronary artery, which is quite important for understanding the hemodynamic mechanism of coronary atherosclerotic diseases and valuable for studying pathological effects and treatments of the myocardial bridge in clinic.
ABSTRACT
<p><b>OBJECTIVE</b>We aimed to perform a meta-analysis of clinical trials on the efficacy of autologous bone marrow-derived cells (BMCs) transfer for patients with chronic ischemic heart disease.</p><p><b>METHODS</b>We searched MEDLINE, EMBASE, and Cochrane database through September 2009. Eligible studies were randomized controlled trials of autologous BMCs infusion in patients with chronic ischemic heart disease. We gathered information about left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV) and death, and did a random-effect meta-analysis to obtain summary effect estimates for outcomes. The pooled analyses were performed and forest plots were generated with RevMan 5.0 software. Heterogeneity was assessed by meta-regression with STATA 10.0 software. Additionally, subgroup analysis was performed to compare the effect of intracoronary BMCs transfer with intramyocardial cell injection on LVEF.</p><p><b>RESULTS</b>Eleven trials with 490 participants were identified. There were 268 patients in BMCs group, and 222 in control group. In control group, the patients received saline injection or autologous plasma injection or no injection. BMCs transfer was performed via intracoronary transfer or intramyocardial injection. Compared with controls, BMCs transfer significantly improved LVEF by 4.63% (95%CI 2.42 to 6.84; P < 0.01). BMCs transfer was also associated with significant reductions in LVEDV (standardized mean difference -0.55, 95%CI -0.94 to -0.17, P = 0.005) and LVESV (standardized mean difference -0.45, 95%CI -0.73 to -0.17, P = 0.002). In addition, BMCs treatment was associated with a significant effect on death (OR 0.42, 95%CI 0.18 to 1.01, P = 0.05). Subgroup analysis indicated that intramyocardial cell injection was preferred due to its more significant improvement of LVEF than intracoronary cell therapy. Meta-regression suggested the existence of a negative association between baseline LVEF and LVEF change.</p><p><b>CONCLUSION</b>BMCs infusion is associated with a significant improvement in LVEF, and an attenuation of left ventricular remodeling.</p>
Subject(s)
Humans , Bone Marrow Transplantation , Myocardial Ischemia , General Surgery , Randomized Controlled Trials as Topic , Transplantation, AutologousABSTRACT
<p><b>OBJECTIVES</b>To compare the efficacy and feasibility between intracoronary and hypodermic injection of granulocyte colony-stimulating factor (G-CSF) on improving cardiac function in a Swine model of chronic myocardial ischemia.</p><p><b>METHODS</b>Eighteen Swine underwent placement of ameroid constrictor on left circumflex coronary artery. The presence of myocardial ischemia was verified at four weeks after the operation, and the animals were then randomly assigned into three groups (n = 6 each): (1) administration of vehicle (control), (2) hypodermic injection of G-CSF (5 microgxkg(-1)x;d(-1)) for five days (IH), and (3) intracoronary injection of a bonus G-CSF (60 microg/kg) (IC). Coronary angiogram, cardiac MRI, and (18)F-FDG-SPECT/(99m)Tc-SPECT (DISA-SPECT) measurements were performed at pre-administration and at 4 weeks post administration. Global heart function such as left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVSDV) and left ventricular ejection fraction (LVEF), myocardial perfusion, myocardial viability and myocardial infarct area were evaluated. Myocardial vWF, Bcl-2 and Bax expressions were detected by Western blot and RT-PCR.</p><p><b>RESULTS</b>MRI data showed that left ventricular dilation and dysfunction were similarly prevented in IH and IC G-CSF treated animals at eight weeks after the operation. SPECT revealed that both IH and IC G-CSF equally improved the regional contractility of chronic myocardial ischemia and increased myocardial viability. Myocardial infarct size was also reduced after both G-CSF treatments as detected by MRI. Intracoronary injection of G-CSF did not lead to angiogenesis in other organs. G-CSF treatments were also associated with a significant reduction in myocardial apoptosis and significant increase in angiogenesis.</p><p><b>CONCLUSIONS</b>Both intracoronary and hypodermic injection of G-CSF were safe and feasible and could equally improve cardiac function and increase angiogenesis in this Swine model of chronic myocardial ischemia.</p>
Subject(s)
Animals , Female , Male , Coronary Vessels , Disease Models, Animal , Granulocyte Colony-Stimulating Factor , Myocardial Ischemia , Therapeutics , Recombinant Proteins , SwineABSTRACT
<p><b>OBJECTIVE</b>To estimate the safety of intracoronary autologous bone marrow stem cells (BMSC) transfer in patients with acute myocardial infarction.</p><p><b>METHODS</b>A systematic literature search of PubMed, MEDLINE, Cochrane EBM, BIOSIS, EMBASE and Chinese Journal Full-text Database between January 1990 and May 2007, was performed. Inclusion criteria required that patients received intracoronary BMSC transfer after coronary reperfusion therapy for primary acute myocardial infarction; study design involved patient randomization and matching placebo group as well as detailed safety data with more than 3 months follow-up results.</p><p><b>RESULTS</b>A total of 5 trials with 620 patients were available for analysis. The pooled statistics showed similar results between BMSC and placebo groups in terms of occurrence of the individual clinical adverse events and the combined endpoint death, recurrence of myocardial infarction, or revascularization procedures. The combined endpoint death, recurrence of myocardial infarction, revascularization procedures, or rehospitalization for heart failure was significantly reduced in the BMSC group compared with the control group at more than one year follow-up (OR = 0.45, 95%CI 0.28 - 0.74, P = 0.002). Likewise, the occurrence of revascularization and the combined endpoint death, recurrence of myocardial infarction, or revascularization procedures were significantly reduced when BMSC transplantation was performed between 4 and 7 days after primary percutaneous coronary intervention (PCI) (OR = 0.60, 95%CI 0.37 - 0.97, P = 0.04; OR = 0.58, 95%CI 0.37 - 0.91, P = 0.02, respectively). In contrast, there was a significant increase in the combined endpoint revascularization and recurrence of myocardial infarction when BMSC transplantation was performed within 24 hours after PCI (OR = 2.56, 95%CI 1.03 - 6.34, P = 0.04).</p><p><b>CONCLUSIONS</b>Post PCI intracoronary autologous BMSC transplantation in patients with acute myocardial infarction is safe, especially in patients received BMSC transplantation between 4 and 7 days after primary PCI than patients received BMSC transplantation within 24 hours post PCI.</p>