ISSN:0009-7322    

出版商:OVID    

年代:1992

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

BackgroundRisk factors for pure coronary spasm are not known. Clinical observations have pointed to cigarette smoking, a known risk factor for obstructive coronary artery disease.Methods and ResultsWe conducted a case-neighborhood control study of premenopausal women, a population segment with the lowest prevalence of obstructive coronary artery disease. The cases were 21 premenopausal women (age range, 36–41 years) with angiographically proven coronary spasm. All coronary arteriograms were analyzed by two independent experienced cardiologists on two occasions. There were no differences between analyses; all cases had normal baseline coronary angiogram except for two, who had less than 20% coronary luminal stenosis in segments other than the site of the focal vasospasm. All cases had normal hemodynamics at rest, normal left ventricular function, and were in sinus rhythm. Ascertainment of the cases was done by angiographic demonstration of focal coronary spasm spontaneously or by ergonovine provocation. Six cases developed spontaneous coronary spasm before catheter engagement, and in 15, coronary spasm was induced by ergonovine provocation. Each case was asked to name as many as possible female neighborhood acquaintances of similar age and racial background who were willing to answer the same standardized questionnaire. The same standardized questionnaire was completed for each case and each control (n= 63). The standardized questionnaire was designed to obtain information on health characteristics, habits, socioeconomic status, and education. Only cigarette smoking was significantly more prevalent among coronary spasm cases. Cigarette smokers were 13 cases (62%) and 11 controls (17.5%) (p<0.001). The odds ratio was 7.7, with a 95% confidence interval of 2.6–23.1.ConclusionsThese findings suggest that there is a very strong association between cigarette smoking and pure coronary spasm in young women.

ISSN:0009-7322    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

BackgroundSeveral epidemiological studies have shown light-to-moderate alcohol consumption to have a net protective effect on the incidence of coronary heart disease (CHD).Methods and ResultsMajor components of this effect, both positive and negative, may be explored using models that include both alcohol and variables expected to mediate the observed alcohol effect. Such modeling in a cohort of men of Japanese descent followed in the Honolulu Heart Program indicates that about half of the observed protection against CHD afforded by moderate alcohol consumption is mediated by an increase in high density lipoprotein cholesterol. An additional 18% of this protection is attributable to a decrease in low density lipoprotein cholesterol, but it is counterbalanced by a 17% increase in risk due to increased systolic blood pressure. The explanation for the residual 59% benefit attributable to alcohol is unknown but may include interference with thrombosis. The results in this population replicate those in the Lipid Research Clinics cohort studied earlier with the same analytic technique.ConclusionsThe consistency of these findings across populations, along with the demonstration of reasonable biological pathways for this effect of alcohol, provides strong support for the hypothesis that light-to-moderate alcohol intake is protective against heart disease in men.

ISSN:0009-7322    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

BackgroundAcute closure remains a significant limitation of percutaneous transluminal coronary angioplasty (PTCA) and underlies the majority of ischemic complications. This study details the clinical and angiographic characteristics of a series of patients receiving an intracoronary stent device to manage acute and threatened closure and presents the early clinical results.Methods and ResultsFrom October 1989 through June 1991, 115 patients undergoing PTCA received intracoronary stents to treat acute or threatened closure in 119 vessels. Sixty-three percent had multivessel coronary disease, 33 (29%) had undergone prior coronary artery bypass grafting (CABG), and 52 (45%) had had previous PTCA. Using the American College of Cardiology/American Heart Association (ACC/AHA) classification, 15% of lesions were class A, 55% were class B, and 30% were class C. Eight patients were referred with severe coronary dissection and unstable angina after PTCA at other institutions. Acute closure was defined as occlusion of the vessel with TIMI (Thrombolysis in Myocardial Infarction) 0 or 1 flow immediately before stent placement. Threatened closure required two or more of the following criteria: 1) a residual stenosis greater than 50%, 2) TIMI grade 2 flow, 3) angiographic dissection comprising extraluminal dye extravasation and/or a length of greater than 15 mm, 4) evidence of clinical ischemia (either typical angina or ECG changes). Twelve vessels (10%) met the criteria for acute closure, and 87 vessels (73%) satisfied the criteria for threatened closure. Twenty vessels (17%) failed to meet two criteria. Stenting produced optimal angiographic results in 111 vessels (93%), with mean diameter stenosis (±1 SD) reduced from 83±12% before to 18±29% after stenting. Overall, in-hospital mortality was 1.7% and CABG was required in 4.2%; Q wave myocardial infarction (MI) occurred in 7% and non-Q wave MI in 91%. Stent thrombosis occurred in nine patients (7.6%). For the 108 patients who presented to the catheterization laboratory without evolving MI, Q wave MI occurred in 4% and non-Q wave MI occurred in 7%. Angiographic follow-up has been performed in 81 eligible patients (76%), and 34 patients (41%) had a lesion of .50%.ConclusionsThis stent may be a useful adjunct to balloon dilatation in acute or threatened closure. Randomized studies comparing this stent with alternative technologies are required.

ISSN:0009-7322    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

BackgroundFibrin generation during and after therapy with alteplase may depend on the level of concomitant anticoagulation. The hypothesis that fibrinopeptide A (FPA) levels, as markers of ongoing in vivo fibrin formation, correlate with the angiographic and clinical outcome of thrombolysis is tested.Methds and ResultsSerial plasma FPA levels were determined in 334 patients of the randomized European Cooperative Study Group trial comparing heparin versus placebo plus alteplase and aspirin in patients with acute myocardial infarction. Median FPA levels (with the 10th to 90th percentiles) were 21 ng/ml (2–390 ng/ml) before treatment in placebo-allocated patients (n= 166) and increased to 49 (15–580), 34 (4–320), 27 (2–240), 29 (2–430), and 30 (3–390) ng/ml after 0.75, 3, 12, 24, and 36 hours, respectively. In heparin-allocated patients (n= 168), median baseline FPA values were 18 ng/ml (2–210 ng/ml) and decreased to 6 (1–110), 5 (1–75), 5 (1–60), 7 (1–100), and 10 (1–170) ng/ml at corresponding time points (p<0.0001 for the difference at each time point). Adequate anticoagulation, defined as no activated partial thromboplastin time value below twice the pretreatment value at 3, 12, 24, and 36 hours after initiation of treatment, was obtained in 48 patients assigned to heparin. It was associated with normal median FPA levels (≤4 ng/ml) at all time points compared with 12 (2–80), 16 (2–240), and 15 (2–240) nglml at 12, 24, and 36 hours, respectively, in heparin-assigned but inadequately anticoagulated patients (n= 102,p<0.001 for each time point). In the heparin-treated group, median FPA values tended to be lower at all time points in patients with patent vessels than in patients with occluded arteries, but the difference was significant only at 24 hours (p= 0.04). FPA levels did not correlate with clinically apparent recurrent ischemia or with left ventricular thrombosis on two-dimensional echocardiography.ConclusionsDuring and after thrombolytic therapy with alteplase, the enhanced fibrin generation is suppressed by sustained concomitant anticoagulation with intravenous heparin. Adequate anticoagula-tion warrants individual titration of the heparin dose. High plasma FPA levels 24 hours after alteplase therapy are specific but insensitive markers of vessel occlusion in anticoagulated patients. They do not correlate with clinical outcome.

ISSN:0009-7322    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

BackgroundPlasmin has been reported both to activate platelets and to inhibit platelet functions. The latter effect was thought to be caused by proteolysis of the main membrane glycoproteins.Methods and ResultsWe found that incubation of citrated human platelet-rich plasma with streptoki-nase (SK) (300 IU/ml) does not produce any detectable activation but leads to a time-dependent inhibition of ADP-induced aggregation accompanied by substantial fibrinogenolysis. These effects were abrogated by previous addition of a plasmin inhibitor, aprotinin. Crossover experiments (SK-treated or control platelets mixed with SK-treated or control plasma) demonstrated that the platelets remained functional and that the aggregation defect was caused by fibrinogenolysis. Further experiments (addition of purified fibrinogen to fibrinogen-depleted plasma with either SK or thrombin) suggested that in addition to the low residual level of fibrinogen, fibrinogen degradation products had an inhibitory effect. Under the same conditions, tissue-type plasminogen activator (t-PA) (3,000 ng/ml) had no effect on platelet aggregation, and plasma fibrinogen was not significantly lowered. The effects on glycoproteins IIb-IIIa of incubation with SK, t-PA, or plasmin were assessed with immunoblots with murine monoclonal antibodies directed against either part of the complex, which is the receptor for fibrinogen. Proteolysis was detected only in the presence of EDTA, a potent chelator of divalent cations.ConclusionsThe incubation of human platelets in citrated plasma with SK concentrations obtained during therapy leads to an aggregation defect that is related to the decrease in fibrinogen, the adhesive protein involved in this function, and to the impeding effect of fibrinogen degradation products on its binding onto platelets but not to an alteration of the corresponding platelet receptor, the heterodimer glycoproteins IIb-IIIa.

ISSN:0009-7322    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

BackgroundThis multicenter trial was conducted to determine the efficacy and safety of pimobendan, an inotropic agent with calcium-sensitizing properties and activity as a phosphodiesterase inhibitor, in patients with heart failure.Methods and ResultsOne hundred ninety-eight ambulatory patients with symptoms of moderate to severe heart failure despite therapy with digitalis and diuretics with or without a single vasodilator were randomly assigned to receive either placebo (n= 49) or pimobendan (n= 149) in a double-blind fashion for 12 weeks. A dose range of pimobendan was used including 2.5 (n= 49), 5 (n= 51), or 10 mg/day (n= 49). One hundred fifty-eight (80%) patients were taking a converting enzyme inhibitor (CEI) and 28 (14%) patients were taking a non-CEI vasodilator. At end point, the 5-mg dose of pimobendan significantly increased exercise duration compared with placebo (121.6±19.1 seconds,p<0.001), whereas the 10-mg dose produced an increase of borderline significance (81.1±19.5 seconds,p= 0.05). Peak Vo2was significantly increased by 2.23±0.58 ml/kg/min in the 5-mg group (p<0.01 versus placebo). Furthermore, quality of life measured with the Minnesota Living With Heart Failure Questionnaire improved by 8.5±2.3 units in the 5-mg group compared with 1.3±2.2 units in the placebo group (p<0.01). There were a total of 23 all-cause hospitalizations in the placebo group, which was significantly greater compared with 33 in the three groups treated with pimobendan (p<0.01). There were no significant differences between the placebo and pimobendan groups with respect to changes in ejection fraction and plasma norepinephrine measured at baseline and at the completion of the 12-week study, proarrhythmic effect, or the number of patients with a significant adjustment in background therapy. Eleven patients died, including three (6%) on placebo and eight (5%) on pimobendan (p= NS). Among all adverse events, headache tended to be more common in the pimobendan groups compared with placebo, with the incidence increasing with dose (p<0.05).ConclusionsThese data demonstrate that pimobendan significantly increases exercise duration, peak Vo2, and quality of life in patients with heart failure. Pimobendan appears to be useful adjunctive therapy when added to digitalis, diuretics, and vasodilators.

ISSN:0009-7322    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

BackgroundPrevious studies suggest that recurrence of coronary stenosis after percutaneous transluminal coronary angioplasty (PTCA) might be prevented with dietary supplements rich in ω-3 fatty acids. The purpose of the present study was to evaluate this hypothesis. In addition, the relation between usual dietary consumption of ω-3 fatty acids and restenosis was assessed.Methods and ResultsA double-blind, randomized, controlled trial was conducted in which 205 patients undergoing a first PTCA received 15 capsules per day containing 1 g of either fish oil (2.7 g/day of eicosapentaenoic acid, 1.8 g/day of docosahexaenoic acid) or olive oil. The treatment was started 3 weeks before PTCA and continued for 6 months thereafter. Dietary intake was assessed by food frequency questionnaire. At 6 months after PTCA, patients underwent a control angiography. All angiographic lesions were measured by quantitative computer analysis. Four criteria were used to define restenosis. Restenosis occurred less often in the fish oil group (22.0–35.6% depending on the definition) than in the control group (40.0–53.3%). After controlling for other risk factors of restenosis, the association of fish oil supplementation with a lower frequency of restenosis was statistically significant (p= 0.03) for three of four definitions. After adjustment, a dietary intake of ω-3 fatty acids of more than 0.15 g/day was also associated with a lower frequency of restenosis (p≤0.03).ConclusionsThis trial documented the protective effect of fish oil supplements on the recurrence of coronary stenosis 6 months after PTCA. The study results suggest that a dietary intervention could be useful in preventing restenosis.

ISSN:0009-7322    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

BackgroundPercutaneous ablation of accessory pathways with the use of a defibrillator can be accomplished with high-energy direct-current (DC) shocks of 150–400 J, but complications include cardiac tamponade and sudden cardiac death, mostly resulting from significant electrical arcing and barotrauma. A new low-energy DC power source with a brief time-constant capacitive discharge delivers shocks of 2–40 J and eliminates or greatly reduces arcing. This report describes our initial experience with this device in 60 consecutive patients (mean age, 34 years; range, 9–67 years) with Wolff-Parkinson-White syndrome. Accessory pathways were located in the left free wall in 36 patients, in the right free wall in two, were posteroseptal in 18, and anteroseptal in four. Most patients (77%) had their initial diagnostic electrophysiological study and catheter ablation during the same session.Methods and ResultsSelective ablation of accessory pathways was successful in 55 patients (92%). The mean cumulative energy was 312±284 J and the mean creatine kinase MB peak (normal, 0–30 units) was 42±27 units. Patients with left free wall accessory pathways required less procedure time for ablation (2.7±0.8 versus 3.6±1.5 hours,p<0.0007) and less fluoroscopy time (46±24 versus 66±33 minutes,p<0.002). Complications were limited to transient pericarditis (three patients), one iliac artery dissection, and cardiac tamponade probably caused by catheter repositioning in the coronary sinus (one patient). An electrophysiological study was repeated in 50 of the 55 successful cases at a mean of 9±5 months. This study was normal in 48 of 50 (96%) patients.ConclusionsLow-energy DC ablation is safe and effective treatment for accessory pathways in children and adults. The long-term outcome is excellent as documented by electrophysiological restudy.

ISSN:0009-7322    

出版商:OVID    

年代:1992

数据来源: OVID