ISSN:0009-7322    

出版商:OVID    

年代:2000

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:2000

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundFetal cardiac interventions by direct ultrasound-guided approaches or open fetal cardiac surgery have been fraught with technical difficulties, as well as with significant maternal and fetal morbidity in humans. Therefore, the purpose of our study in sheep was to assess the feasibility and potential of fetoscopic direct fetal cardiac access.Methods and ResultsIn 15 anesthetized pregnant ewes (88 to 109 days of gestation; term, 145 days), 3 to 4 trocars were percutaneously placed in the uterus. Using videofetoscopic equipment, we assessed the feasibility of achieving direct fetal cardiac access. Minimally invasive direct fetal cardiac access by operative fetoscopy was achieved in 10 of the 15 fetal sheep. In 7 fetuses, the approach was successfully tested for fetal cardiac pacing (n=5) or antegrade fetal cardiac catheterization (n=2). Access was not achieved in 5 fetuses because of bleeding complications (n=2) or because the fetoscopic setup could not be established (n=3). All but 2 fetal sheep were alive at the end of the procedure. Acute fetal demise resulted from maternal hypotension or kinking of the fetal inferior caval vein by sternal suspension. Six ewes continued gestation; 3 of these went to term, with a normal fetal outcome. Two ewes died from septicemia 3 and 7 days after the procedure, and 1 ewe aborted 1 month after the procedure.ConclusionsMinimally invasive direct fetal cardiac access by operative fetoscopy is feasible in fetal sheep. The fetoscopic approach carries important potential for fetal cardiac pacing, antegrade fetal valvuloplasties, and resection of fetal intrapericardial teratomas in human fetuses.

ISSN:0009-7322    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundWe report the effects of the administration of recombinant fibroblast growth factor-2 (rFGF-2) protein on myocardial perfusion using single photon emission computed tomography imaging in humans with advanced coronary disease.Methods and ResultsA total of 59 patients with coronary disease that was not amenable to mechanical revascularization underwent intracoronary (n=45) or intravenous (n=14) administration of rFGF-2 in ascending doses. Changes in perfusion were evaluated at baseline and again at 29, 57, and 180 days after rFGF-2 administration. In this uncontrolled study, perfusion scans were analyzed by 2 observers who were blinded to patient identity and test sequence; scans were displayed in random order, with scans from nonstudy patients randomly interspersed to enhance blinding. Combining all dose groups, a reduction occurred in the per-segment reversibility score (reflecting the magnitude of inducible ischemia) from 1.7±0.4 at baseline to 1.1±0.6 at day 29 (P<0.001), 1.2±0.7 at day 57 (P<0.001), and 1.1±0.7 at day 180 (P<0.001). The 37 patients with evidence of resting hypoperfusion had evidence of improved resting perfusion: their per-segment rest perfusion score of 1.5±0.5 at baseline decreased to 1.0±0.8 at day 29 (P<0.001), 1.0±0.8 at day 57 (P=0.003), and 1.1±0.9 at day 180 (P=0.11).ConclusionsThese preliminary data suggest that the administration of rFGF-2 to patients with advanced coronary disease resulted in an attenuation of stress-induced ischemia and an improvement in resting myocardial perfusion; these findings are consistent with a favorable effect of therapeutic angiogenesis.

ISSN:0009-7322    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundIn patients with acute myocardial infarction (AMI) undergoing thrombolytic therapy, an elevated troponin level on admission is associated with a lower reperfusion rate and a complicated clinical course. Whether an elevated troponin level on admission similarly predicts an adverse outcome in patients undergoing primary angioplasty is currently unknown and was investigated in the present study.Methods and ResultsCardiac troponin I (cTnI) was determined on admission in 110 consecutive patients with AMI associated with ST-segment elevation or left bundle branch block who underwent primary angioplasty. Fifty-four patients (49%) had an elevated cTnI (≥0.4 ng/mL) on admission. In patients with elevated cTnI, primary angioplasty was less likely to achieve TIMI 3 flow (as classified by the Thrombolysis in Myocardial Infarction trial) in univariate (76% versus 96%,P=0.03) or in multivariate (odds ratio 0.1, 95% CI 0.02 to 0.54) analysis. Patients with elevated cTnI were more likely to develop congestive heart failure (23% versus 9%,P<0.05) and death, heart failure, or shock (30% versus 9%,P=0.006). Elevated cTnI remained a significant predictor of the composite end point after controlling for other clinical data that were available early in the course, including time to presentation and angiographic results (relative risk 5.2, 95% CI 1.03 to 26.3). During a follow-up of 426±50 days, elevated admission cTnI was a predictor of cardiac mortality (11% versus 0%,P=0.012), adverse cardiac events (cardiac mortality or nonfatal reinfarction; 19% versus 5.4%,P=0.04), and adverse cardiac events plus target vessel revascularization (32% versus 14%,P=0.054).ConclusionsIn patients with ST-segment elevation AMI, an elevated cTnI on admission is associated with an increased risk of primary angioplasty failure and a more complicated clinical course.

ISSN:0009-7322    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundEstrogen reverses acetylcholine-induced coronary vasoconstriction via the possible facilitation of endothelium-derived NO. Estrogen also affects endothelium-derived constrictor factors. We therefore investigated the effects of 17&bgr;-estradiol on coronary vasomotor responses to substance P (SP), and coronary sinus endothelin-1 and NO metabolite levels in postmenopausal women with coronary heart disease.Methods and ResultsWe studied 20 women; 14 received estrogen (mean age 65±2 years) and 6 served as ethanol control subjects (age 63±3 years). Intracoronary infusions of papaverine (8 mg) and SP were administered before and 20 minutes after 50 pg/min 17&bgr;-estradiol or 0.2 &mgr;L/min control. Coronary blood flow was calculated from the diameter, as measured with quantitative coronary angiography, and flow velocity, as measured with intracoronary Doppler. Coronary sinus plasma endothelin-1 and nitrite/nitrate (NO2/NO3) were measured at baseline, at peak velocity response to each infusion, and every 5 minutes during the estradiol infusion. Endothelin-1 levels were decreased after 20 minutes of estradiol (1.12±0.18 versus 0.86±0.17 pmol/L baseline2 versus estradiol,P=0.05). Endothelin-1 levels to SP decreased after 17&bgr;-estradiol (1.29±0.18 versus 1.04±0.15 and 1.3±0.16 versus 0.99±0.17 pmol/L for before versus after estradiol, 10 and 25 pmol/min SP; bothP<0.05). NO2/NO3levels did not change. There was no change in vasomotor responses to estradiol alone or to papaverine or SP before versus after estradiol.ConclusionsShort-term intracoronary 17&bgr;-estradiol administration decreases coronary endothelin-1 levels. There was no enhancement of vasomotor responses to SP after the administration of estrogen, suggesting that the effects of estrogen on coronary acetylcholine responses may be a specific and not a generalized effect on coronary vasoreactivity.

ISSN:0009-7322    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundCardiorespiratory fitness is favorably associated with most modifiable coronary heart disease (CHD) risk factors. Findings are limited, however, by few data for women, persons with existing CHD, and low-risk populations. In the present study, we described cross-sectional associations between cardiorespiratory fitness and CHD risk factors in a large cohort of middle-aged men and women, of whom the majority were LDS Church members (Mormons), with and without existing CHD.Methods and ResultsComprehensive health examinations were performed on 3232 men (age 45.9±10.8 years) and 1128 women (age 43.8±12.8 years) between 1975 and 1997. Maximal treadmill exercise testing was used to categorize those with (12% of the men and 10% of the women) and those without CHD into age- and sex-specific cardiorespiratory fitness quintiles. After adjustments for age, body fat, smoking status, and family history of CHD, favorable associations were observed between fitness and most CHD risk factors among men and women, regardless of CHD status.ConclusionsThese data indicate that enhanced levels of cardiorespiratory fitness may confer resistance to elevations in CHD risk factors even in a low-risk sample of middle-aged men and women. Furthermore, these findings reinforce current public health recommendations that advocate increased national levels of physical activity and cardiorespiratory fitness for primary and secondary CHD prevention.

ISSN:0009-7322    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundRaised triglyceride-rich lipoproteins significantly increase the risk for cardiovascular disease. Variation in the activity of the enzyme lipoprotein lipase (LPL), which is crucial in the removal of these lipoproteins, may therefore modulate this risk.Methods and ResultsPostheparin levels of LPL activity and mass were measured in a large cohort of male coronary artery disease patients participating in the Regression Growth Evaluation Statin Study (REGRESS), a lipid-lowering regression trial. In addition, the relationships between LPL activity and mass and severity of angina pectoris according to the NYHA classification and silent ischemia on 24-hour ambulatory ECG monitoring were assessed. Patients in different LPL activity quartiles and mass had different severities of angina; a total of 47% of patients in the lowest LPL quartile reported class III or IV angina. In contrast, only 29% in the highest activity quartile (P=0.002) had severe angina. These parameters were supported by ambulatory ECG results, for which the total ischemic burden in the lowest LPL activity quartile was 36.5±104.1 mm×min compared with 14.8±38.8 mm×min in the highest quartile of LPL activity (P=0.001). LPL activity levels were strongly correlated with LPL mass (r=0.70,P<0.0001). A significant association between the LPL protein mass and NYHA class (P=0.012) was also demonstrated.ConclusionsWe have demonstrated a significant relationship between LPL mass and activity and severity of ischemia as defined by angina class and ambulatory ECG. These results suggest that LPL influences risk for coronary artery disease by both catalytic and noncatalytic mechanisms.

ISSN:0009-7322    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundFibrinogen has been identified as an independent risk factor for cardiovascular disease and associated with traditional cardiovascular risk factors. Also, the role of elevated fibrinogen in thrombosis suggests that it may be on the causal pathway for certain risk factors to exert their effect. These associations remain incompletely characterized. Moreover, the optimal fibrinogen assay for risk stratification is uncertain.Methods and ResultsIn 2632 subjects from cycle 5 of the Framingham Offspring Population, fibrinogen levels were determined with a newly developed immunoprecipitation test (American Biogenetic Sciences) and the functional Clauss method. With the immunoprecipitation method, there were significant linear trends across fibrinogen tertiles (P<0.001) for age, body mass index, smoking, diabetes mellitus, total cholesterol, HDL cholesterol, and triglycerides in men and women. The Clauss method had significant results (P<0.030), except for triglycerides in men. Fibrinogen levels were higher for those with compared with those without cardiovascular disease. After covariate adjustment, fibrinogen remained significantly higher in those with cardiovascular disease with the use of the immunoprecipitation test (P=0.035 andP=0.018 for men and women, respectively) but not with the Clauss method.ConclusionsFibrinogen was associated with traditional cardiovascular risk factors. Elevation of fibrinogen may provide a mechanism for risk factors to exert their effect. Also, fibrinogen levels were higher among subjects with cardiovascular disease compared with those without disease. The immunoprecipitation test showed a stronger association with cardiovascular disease than the Clauss method, suggesting that it may be a useful screening tool to identify individuals at increased thrombotic risk.

ISSN:0009-7322    

出版商:OVID    

年代:2000

数据来源: OVID