ISSN:0009-7322    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Background—Although pulmonary thromboendarterectomy is increasingly successful for the definitive treatment of chronic thromboembolic pulmonary hypertension (CTEPH), not all patients have surgically accessible disease. Others are poor surgical candidates because of comorbid illness. Therefore, for selected patients, we defined and implemented an alternative interventional strategy of balloon pulmonary angioplasty (BPA).Methods and Results—Eighteen patients (mean age, 51.8 years; range, 14 to 75 years) with CTEPH underwent BPA; they averaged 2.6 procedures (range, 1 to 5) and 6 dilations (range, 1 to 12). Selection of pulmonary artery segments for dilation required (1) complete occlusion, (2) filling defects, or (3) signs of intravascular webs. After an average of 36 months of follow-up (range, 0.5 to 66 months), the average New York Heart Association class improved from 3.3 to 1.8 (P<0.001), and 6-minute walking distances increased from 209 to 497 yards (P<0.0001). Pulmonary artery mean pressures decreased from 43.0±12.1 to 33.7±10.2 mm Hg (P=0.007). Eleven patients developed reperfusion pulmonary edema; 3 required mechanical ventilation.Conclusions—BPA reduces pulmonary artery hypertension in patients with CTEPH and is associated with long-term improvement in New York Heart Association class and 6-minute walking distances. BPA is a promising interventional technique that warrants randomized comparison with medical therapy in CTEPH patients who are not surgical candidates.

ISSN:0009-7322    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Background—Restenosis after conventional stenting is almost exclusively caused by neointimal hyperplasia. &bgr;-Particle–emitting radioactive stents decrease in-stent neointimal hyperplasia at 6-month follow-up. The purpose of this study was to evaluate the 1-year outcome of32P radioactive stents with an initial activity of 6 to 12 &mgr;Ci using serial quantitative coronary angiography and volumetric ECG-gated 3D intravascular ultrasound (IVUS).Methods and Results—Of 40 patients undergoing initial stent implantation, 26 were event-free after the 6-month follow-up period and 22 underwent repeat catheterization and IVUS at 1 year; they comprised half of the study population. Significant luminal deterioration was observed within the stents between 6 months and 1 year, as evidenced by a decrease in the angiographic minimum lumen diameter (−0.43±0.56 mm;P=0.028) and in the mean lumen diameter in the stent (−0.55±0.63 mm;P=0.001); a significant increase in in-stent neointimal hyperplasia by IVUS (18.16±12.59 mm3at 6 months to 27.75±11.99 mm3at 1 year;P=0.001) was also observed. Target vessel revascularization was performed in 5 patients (23%). No patient experienced late occlusion, myocardial infarction, or death. By 1 year, 21 of the initial 40 patients (65%) remained event-free.Conclusions—Neointimal proliferation is delayed rather than prevented by radioactive stent implantation. Clinical outcome 1 year after the implantation of stents with an initial activity of 6 to 12 &mgr;Ci is not favorable when compared with conventional stenting.

ISSN:0009-7322    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Background—Interferon-&ggr; (IFN-&ggr;) is an essential cytokine in the regulation of inflammatory responses in autoimmune diseases. Little is known about its role in inflammatory heart disease.Methods and Results—We showed that IFN-&ggr; receptor–deficient mice (IFN-&ggr;R–/–) on a BALB/c background immunized with a peptide derived from cardiac &agr;-myosin heavy chain develop severe myocarditis with high mortality. Although myocarditis subsided in wild-type mice after 3 weeks, IFN-&ggr;R–/–mice showed persistent disease. The persistent inflammation was accompanied by vigorous in vitro CD4 T-cell responses and impaired inducible nitric oxide synthase expression, together with evidence of impaired nitric oxide production in IFN-&ggr;R–/–hearts. Treatment of wild-type mice with the nitric oxide synthetase inhibitorN-nitro-l-arginine-methyl-ester enhanced in vitro CD4 T-cell proliferation and prevented healing of myocarditis.Conclusions—Our data provide evidence that IFN-&ggr; protects mice from lethal autoimmune myocarditis by inducing the expression of inducible nitric oxide synthase followed by the downregulation of T-cell responses.

ISSN:0009-7322    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Background—Long-term rapid atrial pacing may result in atrial fibrillation (AF) in dogs. Whether there is histological evidence for neural remodeling is unclear.Method and Results—We performed rapid right atrial pacing in 6 dogs for 111±76 days to induce sustained AF. Tissues from 6 healthy dogs were used as controls. Immunocytochemical staining of cardiac nerves was performed using anti–growth-associated protein 43 (GAP43) and anti–tyrosine hydroxylase (TH) antibodies. In dogs with AF, the density of GAP43-positive and TH-positive nerves in the right atrium was 470±406 and 231±126 per mm2, respectively, which was significantly (P<0.001) higher than the nerve density in control tissues (25±32 and 88±40 per mm2, respectively). The density of GAP43-positive and TH-positive nerves in the atrial septum was 317±36 and 155±85 per mm2, respectively, and was significantly (P<0.001) higher than the nerve density in control tissues (9±13 and 30±7 per mm2, respectively). Similarly, the density of GAP43-positive and TH-positive nerves in the left atrium of dogs with AF was 119±61 and 91±40 per mm2, respectively, which was significantly (P<0.001) higher than the nerve density in control tissues (10±15 and 38±39 per mm2, respectively). Furthermore, in dogs with AF, the right atrium had a significantly higher nerve density than the left atrium. Microscopic examinations revealed an inhomogeneous distribution of cardiac nerves within each sampling site.Conclusions—Significant nerve sprouting and sympathetic hyperinnervation are present in a canine model of sustained AF produced by prolonged right atrial pacing. The magnitude of nerve sprouting and hyperinnervation was higher in the right atrium than in the left atrium.

ISSN:0009-7322    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Background—Enoxaparin inhibits smooth muscle cell proliferation in experimental models. Intimal hyperplasia has been found to be the principal cause of restenosis after coronary stent implantation. We sought to determine whether the intramural delivery of enoxaparin before stenting of de novo lesions decreases restenosis.Methods and Results—One hundred patients who were undergoing stenting were randomly assigned to either local administration of enoxaparin during predilation with reduced systemic heparinization or stenting with standard, systemic heparinization. All patients were treated with the same type of stent (NIR). The primary study end point was late luminal loss. The secondary end points were major adverse cardiac events, target lesion revascularization, and angiographic restenosis at 6 months. Angiographic follow-up at 6 months was completed in all except 1 patient. Late luminal loss was reduced to 0.76±0.42 mm in the local enoxaparin delivery group versus 1.07±0.49 mm in the systemic heparinization group (P<0.001). Restenosis, using a binary definition, occurred in 10% of patients in the enoxaparin group and in 24% of patients in the systemic heparinization group (P<0.05). Target lesion revascularization rates occurred in 8% of the enoxaparin group and 22% of the systemic heparinization group (P<0.05). There were no deaths and no emergent CABGs were performed. The only subacute stent closure and non–Q-wave infarction occurred in a patient assigned to the systemic heparinization group.Conclusions—This is the first prospective randomized trial in which the local delivery of a drug, enoxaparin, resulted in significant reduction in late luminal loss and restenosis after stent implantation in de novo coronary lesions.

ISSN:0009-7322    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Background—The Women’s Healthy Lifestyle Project Clinical Trial tested the hypothesis that reducing saturated fat and cholesterol consumption and preventing weight gain by decreased caloric and fat intake and increased physical activity would prevent the rise in LDL cholesterol and weight gain in women during perimenopause to postmenopause.Methods and Results—There were 275 premenopausal women randomized into the assessment only group and 260 women into the intervention group. The mean age of participants at baseline was 47 years, and 92% of the women were white. The mean LDL cholesterol was 115 mg/dL at baseline, and mean body mass index was 25 kg/m2. The follow-up through 54 months was excellent. By 54 months, 35% of the women had become postmenopausal. At the 54-month examination, there was a 3.5-mg/dL increase in LDL cholesterol in the intervention group and an 8.9-mg/dL increase in the assessment-only group (P=0.009). Weight decreased 0.2 lb in the intervention and increased 5.2 lb in the assessment-only group (P=0.000). Triglycerides and glucose also increased significantly more in the assessment-only group than in the intervention group. Waist circumference decreased 2.9 cm in the intervention compared with 0.5 cm in the assessment-only group (P=0.000).Conclusions—The trial was successful in reducing the rise in LDL cholesterol during perimenopause to postmenopause but could not completely eliminate the rise in LDL cholesterol. The trial was also successful in preventing the increase in weight from premenopause to perimenopause to postmenopause. The difference in LDL cholesterol between the assessment and intervention groups was most pronounced among postmenopausal women and occurred among hormone users and nonusers.

ISSN:0009-7322    

出版商:OVID    

年代:2001

数据来源: OVID