Morgan Fu

Short- and long-term results of catheter balloon percutaneous transvenous mitral commissurotomy

Percutaneous transvenous mitral commissurotomy (PTMC) was performed in 219 patients with symptomatic, severe rheumatic mitral stenosis. There were 59 men and 160 women, aged 19 to 76 years (mean 43). Pliable, noncalcified valves were present in 139 (group 1), and calcified valves or severe mitral subvalvular lesions, or both, in 80 patients (group 2). Atrial fibrillation was present in 133 patients (61%) and 1+ or 2+ mitral regurgitation in 59 (27%). Technical failure occurred with 3 patients in our early experience. There was no cardiac tamponade or emergency surgery. The only in-hospital death occurred 3 days after the procedure in a group 2 premoribund patient in whom last-resort PTMC created 3+ mitral regurgitation. Mitral regurgitation appeared or increased in 72 patients (33%); 3+ mitral regurgitation resulted in 12 patients (6%). There were 3 systemic embolisms. Atrial left-to-right shunts measured by oximetry developed in 33 patients (15%). Immediately after PTMC, there were significantly reduced (p = 0.0001) left atrial pressure (24.2 +/- 5.6 to 15.1 +/- 5.1 mm Hg), mean pulmonary artery pressure (39.7 +/- 13.0 to 30.6 +/- 10.9 mm Hg) and mitral valve gradient (13.0 +/- 5.1 to 5.7 +/- 2.6 mm Hg). Mitral valve area increased from 1.0 +/- 0.3 to 2.0 +/- 0.7 cm2 (p = 0.0001) and cardiac output from 4.4 +/- 1.4 to 4.7 +/- 1.2 liters/min (p less than 0.01). The results mirrored clinical improvements in 209 patients (97%). Multivariate analysis showed an echo score greater than 8, and valvular calcification and severe subvalvular lesions as independent predictors for suboptimal hemodynamic results.(ABSTRACT TRUNCATED AT 250 WORDS)

Transradial coronary angiography and angioplasty in Chinese patients.

Radial artery punctures for diagnostic coronary angiography or coronary balloon angioplasty were performed in 211 patients with a success rate of 98% (207 patients). In the four failed transradial accesses, the procedure was accomplished via the transfemoral route. Major local vascular complications included one arteriovenous fistula, one pseudo-aneurysm, and one ischemic contracture of the right hand. Reduced radial pulses were noted in 25 (12%) patients at follow-up without ischemic manifestations. Transradial diagnostic coronary angiography was successfully completed in 184 (98%) of 187 patients. The technical success for balloon angioplasty was obtained in 73 (97%) of 75 patients. Clinical success was observed in 68 (91%) patients; balloon angioplasty resulted in one nonfatal myocardial infarction and four late deaths (3 cardiac and 1 stroke). We believe that transradial catheterization for diagnostic coronary angiography and balloon angioplasty in our relatively small built Chinese population is a safe and practical alternative approach.

Radiofrequency and Cryoablation of Atrial Fibrillation in Patients Undergoing Valvular Operations

BACKGROUND Previous studies have shown that the maze operation can restore sinus rhythm and atrial transport function in patients with chronic atrial fibrillation. The purpose of this study was to test the feasibility of the application of radiofrequency and cryoablation as an alternative to the classic maze operation. METHODS Twelve patients undergoing mitral valve procedures were included in this study. Radiofrequency and cryoablation were applied to create lesions in both atria to simulate the classic maze operation. RESULTS There were two surgical deaths. At the mean follow-up of 10.25 months for the remaining 10 patients; 6 were in sinus rhythm, 2 in atrial rhythm, 1 in paroxysmal atrial tachycardia, and 1 in atrial fibrillation. Doppler echocardiography at 6-month follow-up showed emergence of biatrial transport function in 3 patients and right atrial contractility in 8. At 12-month follow-up of 5 patients, Doppler echocardiography showed biatrial transport function in 3 and right atrial contractility in 4. CONCLUSIONS Our modified maze procedure during valvular operation is effective for achieving an acceptable success rate to restore sinus rhythm and atrial transport function in patients with chronic atrial fibrillation.

Autologous Transplantation of Adipose-Derived Mesenchymal Stem Cells Markedly Reduced Acute Ischemia-Reperfusion Lung Injury in a Rodent Model

BackgroundThis study tested the hypothesis that autologous transplantation of adipose-derived mesenchymal stem cells (ADMSCs) can effectively attenuate acute pulmonary ischemia-reperfusion (IR) injury.MethodsAdult male Sprague-Dawley (SD) rats (n = 24) were equally randomized into group 1 (sham control), group 2 (IR plus culture medium only), and group 3 (IR plus intravenous transplantation of 1.5 × 106 autologous ADMSCs at 1h, 6h, and 24h following IR injury). The duration of ischemia was 30 minutes, followed by 72 hours of reperfusion prior to sacrificing the animals. Blood samples were collected and lungs were harvested for analysis.ResultsBlood gas analysis showed that oxygen saturation (%) was remarkably lower, whereas right ventricular systolic pressure was notably higher in group 2 than in group 3 (all p < 0.03). Histological scoring of lung parenchymal damage was notably higher in group 2 than in group 3 (all p < 0.001). Real time-PCR demonstrated remarkably higher expressions of oxidative stress, as well as inflammatory and apoptotic biomarkers in group 2 compared with group 3 (all p < 0.005). Western blot showed that vascular cell adhesion molecule (VCAM)-1, intercellular adhesion molecule (ICAM)-1, oxidative stress, tumor necrosis factor-α and nuclear factor-κB were remarkably higher, whereas NAD(P)H quinone oxidoreductase 1 and heme oxygenase-1 activities were lower in group 2 compared to those in group 3 (all p < 0.004). Immunofluorescent staining demonstrated notably higher number of CD68+ cells, but significantly fewer CD31+ and vWF+ cells in group 2 than in group 3.ConclusionADMSC therapy minimized lung damage after IR injury in a rodent model through suppressing oxidative stress and inflammatory reaction.

Bone marrow-derived mononuclear cell therapy alleviates left ventricular remodeling and improves heart function in rat-dilated cardiomyopathy.

Objectives: This study hypothesized that bone marrow–derived mononuclear cell (BMDMNC) therapy may improve cardiac function through preventing cell death, alleviating left ventricular (LV) remodeling, and enhancing angio-/vasculo-genesis, as well as preserving LV contractility in a rat model of dilated cardiomyopathy (DCM). Design: A model of DCM in Sprague-Dawley rats was used to investigate the effects of BMDMNC therapy on inflammatory and oxidative response, energy depression, cellular apoptosis, expressions of protein kinase C-(PKC)-&egr;, and connexin43 protein (Cx43) in LV myocardium and heart function. Setting: An animal model research laboratory at Kaohsiung Chang Gung Memorial Hospital. Measurements: The rats were divided into group 1 (normal control, n = 8), group 2 (saline-treated DCM, n = 10), and group 3 (1.2 × 106 BMDMNC implanted into LV anterior wall on day 35 after DCM induction, n = 10). The DCM and normal control rats were killed on day 90 following DCM induction. Results: The results demonstrated that Cx43 protein expression and messenger RNA expressions of peroxisome proliferator-activated receptor-&ggr; coactivator 1 &agr;, endothelial nitric oxide synthase, and interleukin-10 were higher, whereas messenger RNA expressions of endothelin-1 and matrix metalloproteinase-9 were lower in groups 1 and 3 than in group 2 (all p < 0.05). Additionally, expressions of PKC-&egr; in plasma membrane and mitochondria and LV function were conserved in group 1 and improved in group 3, whereas cardiomyocyte apoptosis, mitochondrial oxidative stress, and fibrosis of LV myocardium were reduced in groups 1 and 3 than in group 2 (all p < 0.005). Conclusion: BMDMNC therapy in DCM significantly improves LV function by limiting cellular apoptosis, inflammatory and oxidative responses, and by up-regulating expressions of Cx43, PKC-&egr;, and energy transcription factors.

Autologous transplantation of bone marrow-derived endothelial progenitor cells attenuates monocrotaline-induced pulmonary arterial hypertension in rats

Objectives:Bone marrow–derived endothelial progenitor cells have been shown to circulate to damaged vascular endothelium and differentiate into mature endothelial cells. This study investigated whether bone marrow–derived endothelial progenitor cell therapy ameliorates monocrotaline (MCT)-induced pulmonary arterial hypertension in a rat model. Design:Male Sprague-Dawley rats were randomized to receive MCT (75 mg/kg) only (group 1), MCT plus autologous bone marrow–derived endothelial progenitor cell (1.2 × 106 cells) transplantation (group 2), and saline injection only (group 3). Mononuclear cells were obtained from femoral bone marrow of group 2 rats and isolated by Ficoll gradient centrifugation. The cells were cultured for 21 days in endothelial culture medium. Setting:An animal research laboratory at Kaohsiung Chang Gung Memorial Hospital. Measurements:Hemodynamics, ventricular weight, expressions of connexin43, endothelial nitric oxide synthase messenger RNA gene, Bcl-2, and number of alveolar sacs and small lung arterioles were measured. Results:Hemodynamic measurements on day 28 after MCT treatment revealed the development of significantly increased pulmonary arterial hypertension in MCT-treated groups (p < .0001). The bone marrow–derived endothelial progenitor cells were intravenously transplanted in group 2 on day 28 after MCT-induced pulmonary arterial hypertension. By day 90 after MCT treatment, the right ventricular systolic blood pressure and right ventricular hypertrophy were significantly increased in group 1 compared with groups 2 and 3 (all p values <.01). In addition, connexin43 and endothelial nitric oxide synthase messenger RNA gene expressions of lung and right ventricle and Bcl-2 protein expression of right ventricle were significantly lower in group 1 than in groups 2 and 3 (all p values <.01). Furthermore, the number of alveolar sacs and small lung arterioles were significantly lower in group 1 than in groups 2 and 3 (all p values <.01). Conclusions:Autologous bone marrow–derived endothelial progenitor cell transplantation effectively ameliorates MCT-induced pulmonary arterial hypertension.

Usefulness of intracardiac echocardiography in transseptal puncture during percutaneous transvenous mitral commissurotomy.

P ercutaneous transvenous mitral commissurotomy has become an effective and safe alternative to surgical treatment in well-selected patients.’ Transseptal catheterization is a vital component of the procedure. Because of its technical complexity and difEculty, transseptal catheterization is recommended to be restricted to highvolume catheterization laboratories equipped with biplane fluoroscopy.2 Recently, usefulness of transthoracic 2dimensional echocardiography and transesophageal echocardiography‘t in guiding transseptal puncture has been reported. However, transthoracic 2-dimensional echocardiography may be limited by suboptimal interatria1 septum visualization. In addition, placement of the transducer on the patient’s chest not only interferes with the fluoroscopic images, but also poses a radiation hazard to the echocardiographer. Space limitations in the catheterization laboratory and a need to preserve a sterile field also make this examination cumbersome. Transesophageal echocardiography allows high-quality visualization of the interatrial septum in relation to surrounding cardiac structures, thus facilitating a safe transseptal puncture. However, it adds discomfort and stress to the patients, aside from the possible risk of esophageal injury and lung aspiration. Because of the disadvantages and limitations of transthoracic and transesophageal echocardiography, we investigated the feasibility and usefulness of intracardiac echocardiography using a commercially available 10 MHz over-the-wire intravascular ultrasound catheter to perform transseptal puncture. Seven patients with symptomatic severe mitral stenosis were studied including 2 men and 5 women aged 36 to 55 years (mean 45). Informed consent was obtained from each patient. After diagnostic catheterization, a IOFr 10 MHz ultrasound catheter was inserted into the superior vena cava over a preplaced 0.025inch guidewire through a IlFr sheath in the lef femoral vein. The catheter was interfaced with a real-time ultrasound imaging system (CVIS Inc., Sunnyvale, California). The ultrasound catheter was withdrawn caudally from the superior vena cava to the midright atrium to image the interatrial septum and the atria (Figure IA, lef panel). A 7Fr Mullins transseptal catheter with a Brockenbrough needle was inserted through the right femoral vein and its tip was set at the optimal transseptal puncture site. The latter was determined under f?on-tal fluoroscopic view according to landmark selection guidelines previously described.‘a5 The position of the catheter ultrasound transducer was adjusted so that the

Usefulness of Intracardiac Echocardiography in Complex Transseptal Catheterization During Percutaneous Transvenous Mitral Commissurotomy

OBJECTIVE To examine the utility of intracardiac echocardiography in guiding complex transseptal catheterization of patients undergoing percutaneous transvenous mitral commissurotomy. DESIGN We assessed this procedure in high-risk patients in whom transseptal catheterization is technically complex and more demanding. MATERIAL AND METHODS Fifteen patients with mitral stenosis were studied. Twelve patients had giant left atria (70 mm or more), two had atrial septal aneurysms, and one had severe kyphoscoliosis. A newly developed 8-F 10-MHz intracardiac transducer catheter was placed in the right atrium through an 8-F Mullins sheath inserted from the left femoral vein. Echocardiographic images were used to confirm the septal position of the Brockenbrough needle tip before septal punctures. RESULTS Transseptal puncture was successful and uncomplicated in all 15 patients. Use of intracardiac echocardiography eliminated the need for atrial angiography. Before transseptal puncture, the needle tip was identified to be in contact with the atrial septum, as an echogenic point with its acoustic shadow and septal indentation. In addition, in the two patients with aneurysms, puncture of the thin-walled aneurysms was avoided. CONCLUSION Intracardiac echocardiography facilitates safe complex transseptal catheterization in patients with mitral stenosis and giant left atria, atrial septal aneurysms, or severe kyphoscoliosis.

Extracorporeal Shock Wave Therapy Reverses Ischemia-Related Left Ventricular Dysfunction and Remodeling: Molecular-Cellular and Functional Assessment

An optimal treatment for patients with diffuse obstructive arterial disease unsuitable for catheter-based or surgical intervention is still pending. This study tested the hypothesis that extracorporeal shock wave (ECSW) therapy may be a therapeutic alternative under such clinical situation. Myocardial ischemia was induced in male mini-pigs through applying an ameroid constrictor over mid-left anterior descending artery (LAD). Twelve mini-pigs were equally randomized into group 1 (Constrictor over LAD only) and group 2 (Constrictor over LAD plus ECSW [800 impulses at 0.09 mJ/mm2] once 3 months after the procedure). Results showed that the parameters measured by echocardiography did not differ between two groups on days 0 and 90. However, echocardiography and left ventricular (LV) angiography showed higher LV ejection fraction and lower LV end-systolic dimension and volume in group 2 on day 180 (p<0.035). Besides, mRNA and protein expressions of CXCR4 and SDF-1α were increased in group 2 (p<0.04). Immunofluorescence staining also showed higher number of vWF-, CD31-, SDF-1α-, and CXCR4-positive cells in group 2 (all p<0.04). Moreover, immunohistochemical staining showed notably higher vessel density but lower mean fibrosis area, number of CD40-positive cells and apoptotic nuclei in group 2 (all p<0.045). Mitochondrial protein expression of oxidative stress was lower, whereas cytochrome-C was higher in group 2 (all p<0.03). Furthermore, mRNA expressions of MMP-9, Bax and caspase-3 were lower, whereas Bcl-2, eNOS, VEGF and PGC-1α were higher in group 2 (all p<0.01). In conclusion, ECSW therapy effectively reversed ischemia-elicited LV dysfunction and remodeling through enhancing angiogenesis and attenuating inflammation and oxidative stress.

Intra-coronary administration of cyclosporine limits infarct size, attenuates remodeling and preserves left ventricular function in porcine acute anterior infarction

BACKGROUND We tested whether intra-coronary administration of cyclosporine effectively preserves left ventricular (LV) function in porcine acute anterior wall infarction (AMI). METHODS AND RESULTS Eighteen male mini-pigs were randomized into groups 1 (control), 2 (AMI alone), and 3 (AMI with cyclosporine treatment). AMI was induced by ligating middle left anterior descending artery (LAD). Fifteen minutes after ligation, saline and cyclosporine (2.5 mg) combination was injected into LAD beyond ligation in groups 2 and 3, respectively. Echocardiography was performed after 14 days, followed by animal sacrifice. Larger infarcted area (IA) was noted in group 2 than in group 3 (p < 0.001). In both IA and peri-IA, mRNA expressions of IL-8, MMP-9, caspase 3 and Bax were higher, whereas PGC-1α, eNOS and Bcl-2 were lower in group 2 than in groups 1 and 3 (p < 0.01). The mRNA expression of IL-10 was upregulated in both IA and peri-IA in group 3 compared with groups 1 and 2. Apoptotic nuclei and CD40-positive cells were higher in both peri-IA and non-IA in group 2 than in groups 1 and 3 (p < 0.001). Oxidative stress and cytosolic cytochrome C in IA were increased in group 2 than in groups 1 and 3 (p < 0.001). Mid-LV end-systolic areas were higher, whereas mid-LV wall fractional area change was lower in group 2 than in groups 1 and 3 (p < 0.001). CONCLUSIONS Intra-coronary administration of cyclosporine effectively limits infarct size, attenuates LV remodeling and preserves LV function.