Reza Ghiassi | Islamic Azad Universty (original) (raw)
Papers by Reza Ghiassi
Myxomatous mitral valve disease is by far the most common cardiac disease in small to medium bree... more Myxomatous mitral valve disease is by far the most common cardiac disease in small to medium breeds of dogs. Diagnosis is based on physical examination and diagnostic imaging findings. In this study, 37 dogs with myxomatous mitral valve disease, older than 4 years were evaluated by the means of clinical findings (including history, physical examination, and auscultation), radiographic, echocardiographic, and electrocardiographic signs. Based on modified New York heart association 7 dogs were categorized to class I, 11 dogs to class II, 15 dogs to class III, and 4 dogs to class IV of congestive heart failure. Exercise intolerance, cough, dyspnea, and syncope were seen in 78.3%, 40.5%, 37.8%, and 24.3% of dogs, respectively. Eighty-one percent of dogs had radiographic signs related to disease while 88.7% and 27% of dogs had echocardiographic and electrocardiographic signs of disease, respectively. Left atrial enlargement (75.6%) and increased atrial to aorta ratio (78.3%) were among t...
Objectives: Determination of serum cardiac troponin I (cTnI) levels in cats with lower respirator... more Objectives: Determination of serum cardiac troponin I (cTnI) levels in cats with lower respiratory diseases (LRDs) and evaluation of clinical variables associated with increased serum cTnI concentrations in cats with LRDs. Materials and Methods: 46 cats. Serum cTnI concentrations were measured in 23 cats with LRDs and compared with 23 healthy normal cats. Results: Sixty-nine percent of cats (16 of 23) with LRDs had elevated cTnI levels (cTnI > 0.16 ng/mL). The mean and range of plasma cTnI in cats with LRDs were significantly (P < 0.001) greater than healthy control cats. There was no correlation between respiratory signs, type of LRDs, and radiographic patterns of LRDs with plasma cTnI concentrations in cats with LRDs. Conclusion: Serum cardiac troponin I concentration was significantly increased in cats suffering from LRDs when compared to control group. Measurement of cTnI levels in cats could not be used as a stand-alone test to differentiate LRDs from cardiac disease in c...
Sections Abstract Methods Results Discussion Acknowledgements
Background: The study was designed to evaluate the severity of mitral regurgitation by cardiac ma... more Background: The study was designed to evaluate the severity of mitral regurgitation by cardiac magnetic resonance imaging (MRI). We proposed a new measurement of signal void by MRI and tried to define threshold values for the severity of regurgitation with different sequences. Methods: Twenty-one patients with mitral regurgitation were evaluated by echocardiography and MRI. We measured the length, width, and the area of jet flow void from long-axis and four-chamber views. The regurgitant area was measured with TrueFISP, FLASH sequences, and phase images by tracing the signal-void area in left atrium parallel to mitral annulus. This new parameter for grading of the severity of mitral regurgitation by cine MRI was called regurgitant area from short axis (RAFSA). Results: All methods (EROA, vena contracta) were correlated for determining the regurgitation severity (P < 0.01). There was a correlation between EROA by echocardiography and RAFSA by MRI with the TrueFISP, FLASH sequences, and phase images (P < 0.01). Stepwise regression analysis revealed that EROA was significantly correlated with RAFSA by phase images (P < 0.001). After regression analysis, threshold values of RAFSA by phase imaging were calculated and found to be 0.27 cm 2 and 0.92 cm 2 between mild, moderate, and severe mitral regurgitations (100% sensitivity, 67% specificity, and 100% sensitivity, 78% specificity, respectively) (P < 0.01, P < 0.05). Conclusions: MRI is an alternative method for evaluating mitral regurgitation. Our study suggests a new parameter, RAFSA by cine MRI, to grade the severity of mitral regurgitation and provides threshold values in order to define mild, moderate, and severe regurgitations.
OBJECTIVES This phase I trial was designed to assess the feasibility and safety of autologous ske... more OBJECTIVES This phase I trial was designed to assess the feasibility and safety of autologous skeletal myoblast transplantation in patients with severe ischemic cardiomyopathy. BACKGROUND Experimentally, myoblast grafting into postinfarction myocardial scars improves left ventric-ular function. METHODS Ten patients were included on the basis of the following criteria: 1) severe left ventricular dysfunction (ejection fraction 35%); 2) the presence of a postinfarction akinetic and nonviable scar, as assessed by dobutamine echocardiography and 18-fluorodeoxyglucose positron emission tomography; and 3) an indication of coronary bypass in remote areas. Skeletal myoblasts were grown from a biopsy taken at the thigh. RESULTS An average of 871 10 6 cells (86% of myoblasts) were obtained after a mean period of 16 days and implanted uneventfully across the scar at the time of bypass. Except for one patient whose early death was unrelated to the cell transplantation, all patients had an uncomplicated postoperative course. Four patients showed delayed episodes of sustained ventricular tachy-cardia and were implanted with an internal defibrillator. At an average follow-up of 10.9 months, the mean New York Heart Association functional class improved from 2.7 0.2 preoperatively to 1.6 0.1 postoperatively (p 0.0001), and the ejection fraction increased from 24 1% to 32 1% (p 0.02). A blinded echocardiographic analysis showed that 63% of the cell-implanted scars (14 of 22) demonstrated improved systolic thickening. One noncardiac death occurred 17.5 months after transplantation. CONCLUSIONS These preliminary data suggest the feasibility and safety of autologous skeletal myoblast transplantation in severe ischemic cardiomyopathy, with the caveat of an arrhythmogenic potential. New-onset contraction of akinetic and nonviable segments suggests a functional efficacy that requires confirmation by randomized studies. (J Am Coll Cardiol 2003;41: 1078 – 83)
Objectives: Cellular cardiomyoplasty with isolated skeletal myoblasts and bone marrow mononuclear... more Objectives: Cellular cardiomyoplasty with isolated skeletal myoblasts and bone marrow mononuclear cells is an encouraging therapeutic strategy for heart failure. We investigated the achievements accomplished with combined cell therapy of skeletal myoblast and bone marrow mononuclear cell transplantation to the ischemic canine myocardium.
Objective: A key challenge to applying cell transplantation to treat severely damaged myocardium ... more Objective: A key challenge to applying cell transplantation to treat severely damaged myocardium is in delivering large numbers of cells with minimum cell loss. We developed a new implantation method using skeletal myoblast (SMB) sheets, wrapped with an omentum flap as a blood supply to deliver huge numbers of SMBs to the damaged heart. We examined whether this method could be used to deliver a large amount of cells to deteriorated porcine myocardium. Methods: Cell sheets were obtained by culturing mini-pig autologous SMB cells on temperature-responsive culture dishes. Myocardial infarction was induced by placing an ameroid constrictor around the left anterior descending artery. The mini-pigs were divided into 4 treatment groups (n ¼ 6 in each): cell sheets with omentum, cell sheets only, omentum only, and sham operation. Each animal implant consisted of 30 cell sheets (1.5 3 10 7 cells per sheet). Six 5-layer constructs were each placed on a different area, immediately adjacent to but not overlapping one another, to cover the infarct and border regions. Results: The new regenerative cell delivery system using SMB sheets covered and wrapped with omentum resulted in (1) a significantly reduced infarct size causing, at least in part, a thin scar with thick well-vascularized cardiac tissue; (2) increased angiogenesis, as determined by a significantly higher vascular density; and (3) improved cardiac function, as determined by echocardiography, compared with the conventional method (SMB sheet implantation). Conclusions: This cell delivery system shows potential for repairing the severely failed heart. (J Thorac Cardiovasc Surg 2011;142:1188-96) Heart failure is a frequent and life-threatening disorder, despite recent medical and surgical advances. Myocardial re-generative therapy is gaining interest as a means for improving left ventricular (LV) function in patients with end-stage heart disease. 1-3 However, a recent clinical trial of cell transplantation by needle injection reported slightly disappointing results. 2-4 The main drawbacks of cell transplantation by needle injection appear to be poor retention and survival of the injected cells, local mechanical myocardial damage owing to injury by the needle itself, and the potential for lethal arrhythmias. We have been investigating cell-sheet techniques for delivering cells to severely damaged myocardium more efficiently, without damaging the myocardium, and, consequently, more effectively. This technique provides better improvement of cardiac function than obtained with the needle cell-injection method. 5-7 The greatest advantage of the cell-sheet technique is that the sheet consists only of cells, which produce an extracel-lular matrix without requiring an artificial scaffold. The cell sheet has a high ability to integrate with native tissues, because the adhesion molecules on its surface are preserved. 5-7 The layered grafts must be carefully prepared to avoid tearing, but they themselves are strong, flexible, and easy to work with. It has been suggested that an increased number of implanted skeletal myoblast (SMB) sheets is related to better results, such as improved cardiac function and angiogene-sis, less fibrosis, and less hypertrophy, with the amounts of secreted cytokines dependent on the number of cell sheets used. 7 However, cell sheets with more than 5 layers show areas with disorganized vasculature, presumably because of insufficient supplies of blood, oxygen, and nutritients. 7,8 Thus, in applying cell transplantation to the severely damaged myocardium, a key challenge is in improving the blood perfusion of the implanted cells so
Myxomatous mitral valve disease is by far the most common cardiac disease in small to medium bree... more Myxomatous mitral valve disease is by far the most common cardiac disease in small to medium breeds of dogs. Diagnosis is based on physical examination and diagnostic imaging findings. In this study, 37 dogs with myxomatous mitral valve disease, older than 4 years were evaluated by the means of clinical findings (including history, physical examination, and auscultation), radiographic, echocardiographic, and electrocardiographic signs. Based on modified New York heart association 7 dogs were categorized to class I, 11 dogs to class II, 15 dogs to class III, and 4 dogs to class IV of congestive heart failure. Exercise intolerance, cough, dyspnea, and syncope were seen in 78.3%, 40.5%, 37.8%, and 24.3% of dogs, respectively. Eighty-one percent of dogs had radiographic signs related to disease while 88.7% and 27% of dogs had echocardiographic and electrocardiographic signs of disease, respectively. Left atrial enlargement (75.6%) and increased atrial to aorta ratio (78.3%) were among t...
Objectives: Determination of serum cardiac troponin I (cTnI) levels in cats with lower respirator... more Objectives: Determination of serum cardiac troponin I (cTnI) levels in cats with lower respiratory diseases (LRDs) and evaluation of clinical variables associated with increased serum cTnI concentrations in cats with LRDs. Materials and Methods: 46 cats. Serum cTnI concentrations were measured in 23 cats with LRDs and compared with 23 healthy normal cats. Results: Sixty-nine percent of cats (16 of 23) with LRDs had elevated cTnI levels (cTnI > 0.16 ng/mL). The mean and range of plasma cTnI in cats with LRDs were significantly (P < 0.001) greater than healthy control cats. There was no correlation between respiratory signs, type of LRDs, and radiographic patterns of LRDs with plasma cTnI concentrations in cats with LRDs. Conclusion: Serum cardiac troponin I concentration was significantly increased in cats suffering from LRDs when compared to control group. Measurement of cTnI levels in cats could not be used as a stand-alone test to differentiate LRDs from cardiac disease in c...
Sections Abstract Methods Results Discussion Acknowledgements
Background: The study was designed to evaluate the severity of mitral regurgitation by cardiac ma... more Background: The study was designed to evaluate the severity of mitral regurgitation by cardiac magnetic resonance imaging (MRI). We proposed a new measurement of signal void by MRI and tried to define threshold values for the severity of regurgitation with different sequences. Methods: Twenty-one patients with mitral regurgitation were evaluated by echocardiography and MRI. We measured the length, width, and the area of jet flow void from long-axis and four-chamber views. The regurgitant area was measured with TrueFISP, FLASH sequences, and phase images by tracing the signal-void area in left atrium parallel to mitral annulus. This new parameter for grading of the severity of mitral regurgitation by cine MRI was called regurgitant area from short axis (RAFSA). Results: All methods (EROA, vena contracta) were correlated for determining the regurgitation severity (P < 0.01). There was a correlation between EROA by echocardiography and RAFSA by MRI with the TrueFISP, FLASH sequences, and phase images (P < 0.01). Stepwise regression analysis revealed that EROA was significantly correlated with RAFSA by phase images (P < 0.001). After regression analysis, threshold values of RAFSA by phase imaging were calculated and found to be 0.27 cm 2 and 0.92 cm 2 between mild, moderate, and severe mitral regurgitations (100% sensitivity, 67% specificity, and 100% sensitivity, 78% specificity, respectively) (P < 0.01, P < 0.05). Conclusions: MRI is an alternative method for evaluating mitral regurgitation. Our study suggests a new parameter, RAFSA by cine MRI, to grade the severity of mitral regurgitation and provides threshold values in order to define mild, moderate, and severe regurgitations.
OBJECTIVES This phase I trial was designed to assess the feasibility and safety of autologous ske... more OBJECTIVES This phase I trial was designed to assess the feasibility and safety of autologous skeletal myoblast transplantation in patients with severe ischemic cardiomyopathy. BACKGROUND Experimentally, myoblast grafting into postinfarction myocardial scars improves left ventric-ular function. METHODS Ten patients were included on the basis of the following criteria: 1) severe left ventricular dysfunction (ejection fraction 35%); 2) the presence of a postinfarction akinetic and nonviable scar, as assessed by dobutamine echocardiography and 18-fluorodeoxyglucose positron emission tomography; and 3) an indication of coronary bypass in remote areas. Skeletal myoblasts were grown from a biopsy taken at the thigh. RESULTS An average of 871 10 6 cells (86% of myoblasts) were obtained after a mean period of 16 days and implanted uneventfully across the scar at the time of bypass. Except for one patient whose early death was unrelated to the cell transplantation, all patients had an uncomplicated postoperative course. Four patients showed delayed episodes of sustained ventricular tachy-cardia and were implanted with an internal defibrillator. At an average follow-up of 10.9 months, the mean New York Heart Association functional class improved from 2.7 0.2 preoperatively to 1.6 0.1 postoperatively (p 0.0001), and the ejection fraction increased from 24 1% to 32 1% (p 0.02). A blinded echocardiographic analysis showed that 63% of the cell-implanted scars (14 of 22) demonstrated improved systolic thickening. One noncardiac death occurred 17.5 months after transplantation. CONCLUSIONS These preliminary data suggest the feasibility and safety of autologous skeletal myoblast transplantation in severe ischemic cardiomyopathy, with the caveat of an arrhythmogenic potential. New-onset contraction of akinetic and nonviable segments suggests a functional efficacy that requires confirmation by randomized studies. (J Am Coll Cardiol 2003;41: 1078 – 83)
Objectives: Cellular cardiomyoplasty with isolated skeletal myoblasts and bone marrow mononuclear... more Objectives: Cellular cardiomyoplasty with isolated skeletal myoblasts and bone marrow mononuclear cells is an encouraging therapeutic strategy for heart failure. We investigated the achievements accomplished with combined cell therapy of skeletal myoblast and bone marrow mononuclear cell transplantation to the ischemic canine myocardium.
Objective: A key challenge to applying cell transplantation to treat severely damaged myocardium ... more Objective: A key challenge to applying cell transplantation to treat severely damaged myocardium is in delivering large numbers of cells with minimum cell loss. We developed a new implantation method using skeletal myoblast (SMB) sheets, wrapped with an omentum flap as a blood supply to deliver huge numbers of SMBs to the damaged heart. We examined whether this method could be used to deliver a large amount of cells to deteriorated porcine myocardium. Methods: Cell sheets were obtained by culturing mini-pig autologous SMB cells on temperature-responsive culture dishes. Myocardial infarction was induced by placing an ameroid constrictor around the left anterior descending artery. The mini-pigs were divided into 4 treatment groups (n ¼ 6 in each): cell sheets with omentum, cell sheets only, omentum only, and sham operation. Each animal implant consisted of 30 cell sheets (1.5 3 10 7 cells per sheet). Six 5-layer constructs were each placed on a different area, immediately adjacent to but not overlapping one another, to cover the infarct and border regions. Results: The new regenerative cell delivery system using SMB sheets covered and wrapped with omentum resulted in (1) a significantly reduced infarct size causing, at least in part, a thin scar with thick well-vascularized cardiac tissue; (2) increased angiogenesis, as determined by a significantly higher vascular density; and (3) improved cardiac function, as determined by echocardiography, compared with the conventional method (SMB sheet implantation). Conclusions: This cell delivery system shows potential for repairing the severely failed heart. (J Thorac Cardiovasc Surg 2011;142:1188-96) Heart failure is a frequent and life-threatening disorder, despite recent medical and surgical advances. Myocardial re-generative therapy is gaining interest as a means for improving left ventricular (LV) function in patients with end-stage heart disease. 1-3 However, a recent clinical trial of cell transplantation by needle injection reported slightly disappointing results. 2-4 The main drawbacks of cell transplantation by needle injection appear to be poor retention and survival of the injected cells, local mechanical myocardial damage owing to injury by the needle itself, and the potential for lethal arrhythmias. We have been investigating cell-sheet techniques for delivering cells to severely damaged myocardium more efficiently, without damaging the myocardium, and, consequently, more effectively. This technique provides better improvement of cardiac function than obtained with the needle cell-injection method. 5-7 The greatest advantage of the cell-sheet technique is that the sheet consists only of cells, which produce an extracel-lular matrix without requiring an artificial scaffold. The cell sheet has a high ability to integrate with native tissues, because the adhesion molecules on its surface are preserved. 5-7 The layered grafts must be carefully prepared to avoid tearing, but they themselves are strong, flexible, and easy to work with. It has been suggested that an increased number of implanted skeletal myoblast (SMB) sheets is related to better results, such as improved cardiac function and angiogene-sis, less fibrosis, and less hypertrophy, with the amounts of secreted cytokines dependent on the number of cell sheets used. 7 However, cell sheets with more than 5 layers show areas with disorganized vasculature, presumably because of insufficient supplies of blood, oxygen, and nutritients. 7,8 Thus, in applying cell transplantation to the severely damaged myocardium, a key challenge is in improving the blood perfusion of the implanted cells so