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Biomedical subjects

D de Bono

Publications and source records attributed to D de Bono.

34 records · Page 2Linked to original sources
PubMed1993

Complications of diagnostic cardiac catheterisation: results from 34,041 patients in the United Kingdom confidential enquiry into cardiac catheter complications. The Joint Audit Committee of the British Cardiac Society and Royal College of Physicians of London.

OBJECTIVES: To evaluate the frequency and nature of complications in patients undergoing diagnostic cardiac catheterisation and to assess the feasibility of a voluntary cooperative audit system. METHODS: 27 centres enrolled patients over a two year period. Each centre voluntarily reported numbers of patients catheterised every month. Complications were reported as they occurred. Feedback was provided in the form of newsletters and reports. RESULTS: 39,795 procedures were registered, of which 33,776 were diagnostic catheterisations in adults or adolescents, 1265 were paediatric catheter studies in patients under the age of 12 years, and 4754 were coronary angioplasties or balloon dilatation of valves. 83.3% of diagnostic catheter studies in adults were left heart studies with coronary arteriography. The overall complication rate for diagnostic studies was 0.80%, mortality rate 0.12%, emergency surgical intervention rate 0.08%. Complication rates varied between centres, but there was no correlation with case load. Different patterns of complication were associated with different technical approaches. CONCLUSIONS: Complication rates of diagnostic catheterisation are low but neither negligible nor irreducible. Voluntary audit of this kind has limitations, but it is useful and inexpensive.

Adult↗
PubMed1993

Use of a direct antithrombin, hirulog, in place of heparin during coronary angioplasty.

BACKGROUND: Since the inception of coronary angioplasty, heparin with or without aspirin has been routinely given intraprocedurally to avoid coronary thrombotic complications. Recently, the direct thrombin inhibitor hirulog has been demonstrated to inactivate clot-bound thrombin. The present study was a multicenter dose escalation of hirulog to determine its appropriate dose and feasibility as the sole anticoagulant during coronary angioplasty. METHODS AND RESULTS: At 11 participating centers, 291 patients undergoing elective coronary angioplasty and pretreated with 325 mg aspirin daily were enrolled in sequential groups of intravenously administered hirulog instead of heparin as follows: group 1: bolus, 0.15 mg/kg; infusion, 0.6 mg.kg-1.hr-1 (54 patients); group 2: bolus, 0.25 mg/kg; infusion, 1.0 mg.kg-1.hr-1 (53 patients); group 3: bolus, 0.35 mg/kg; infusion, 1.4 mg.kg-1.hr-1 (44 patients); group 4: bolus, 0.45 mg/kg; infusion, 1.8 mg.kg-1.hr-1 (74 patients); and group 5: bolus, 0.55 mg/kg; infusion, 2.2 mg.kg-1.hr-1 (54 patients). The hirulog infusion was maintained for 4 hours; the primary end point was abrupt vessel closure within 24 hours of the initiation of the procedure. Activated clotting times (ACT) and activated partial thromboplastin times (aPTT) were serially monitored. Abrupt vessel closure occurred in 18 patients (6.2%). By intention to treat, the abrupt closure event rate for groups 1-3 was 11.3% compared with 3.9% in groups 4 and 5 (p = 0.052). There were no significant bleeding complications except for one patient in group 1, who received a two-unit transfusion. A dose-response curve of both ACTs and aPTTs was noted; no coronary thrombotic closures occurred in the small number of patients with ACT > 300 seconds. CONCLUSIONS: The present study documents for the first time that it is possible to perform coronary angioplasty with an anticoagulant other than heparin in aspirin-pretreated patients. Hirulog was associated with a rapid onset, dose-dependent anticoagulant effect, minimal bleeding complications, and at doses of 1.8-2.2 mg/kg, a rate of 3.9% for abrupt vessel closure.

Adolescent↗
PubMed1992

Correlation between level of heparinization and patency of the infarct-related coronary artery after treatment of acute myocardial infarction with alteplase (rt-PA).

BACKGROUND AND OBJECTIVES: The conjunctive use of intravenous heparin may influence the efficacy of alteplase for coronary thrombolysis in patients with acute myocardial infarction. In this study we examined the relation between the level of intravenous anticoagulation with heparin and sustained coronary artery patency in a subgroup of patients of the European Cooperative Study Group (ECSG) trial. METHODS: In the ECSG trial, patients treated with alteplase and aspirin were randomized to concomitant fixed doses of intravenous heparin (a bolus dose of 5,000 U followed by a continuous infusion of 1,000 U/h or placebo). The current study group comprised 149 of 324 ECSG patients allocated to heparin therapy and 132 of 320 ECSG patients allocated to placebo administration who had both an interpretable coronary angiogram obtained within 6 days of treatment and sufficient plasma samples to assess the level of anticoagulation. Activated partial thromboplastin times, fibrinogen and D-dimer levels were determined on plasma samples at baseline and at 45 min and 3, 12, 24 and 36 h after the start of alteplase administration. RESULTS: The coronary artery patency rate was higher in patients allocated to heparin therapy than in those allocated to placebo (80% and 71%, respectively, p = 0.05). Patients allocated to heparin were classified into three subgroups: 48 patients (32%) with all activated partial thromboplastin times at least twice their own baseline value (optimal anticoagulation), 40 patients (27%) with the lowest activated partial thromboplastin time at 3, 12, 24 or 36 h between 130% and 200% of the baseline value (suboptimal anticoagulation) and 61 patients with at least one activated partial thromboplastin time less than 130% of baseline (inadequate anticoagulation). In the heparin group, coronary artery patency correlated with the level of anticoagulation: 90%, 80% and 72%, respectively, in patients with optimal, suboptimal and inadequate anticoagulation (p = 0.02, optimal vs. inadequate anticoagulation). Heparin administration was associated with a smaller reduction in fibrinogen and a smaller increase in D-dimer level during and after alteplase administration. No correlation was found between fibrinogen or D-dimer levels and coronary artery patency. No intracerebral hemorrhage occurred in these patients; however, bleeding was more frequent in the subgroup with optimal anticoagulation (p = 0.05). CONCLUSIONS: Intense anticoagulation with intravenous heparin enhances coronary artery patency after alteplase treatment of acute myocardial infarction.

Adult↗
PubMed1992

Plasma fibrinopeptide A levels in patients with acute myocardial infarction treated with alteplase. Correlation with concomitant heparin, coronary artery patency, and recurrent ischemia. The European Cooperative Study Group.

BACKGROUND: Fibrin 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. METHODS AND RESULTS: Serial 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 less than 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 (less than or equal to 4 ng/ml) at all time points compared with 12 (2-80), 16 (2-240), and 15 (2-240) ng/ml at 12, 24, and 36 hours, respectively, in heparin-assigned but inadequately anticoagulated patients (n = 102, p less than 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. CONCLUSIONS: During and after thrombolytic therapy with alteplase, the enhanced fibrin generation is suppressed by sustained concomitant anticoagulation with intravenous heparin. Adequate anticoagulation 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.

Coronary Vessels↗
PubMed1987

Ventricular septal defect after myocardial infarction: assessment by cross sectional echocardiography with pulsed wave Doppler scanning.

Eight patients who developed a ventricular septal defect after myocardial infarction were assessed by cross sectional echocardiography and pulsed wave Doppler scanning. Cross sectional echocardiography visualised the defect in four patients and gave an accurate assessment of global and regional left ventricular function in all eight. In all patients pulsed wave Doppler scanning detected turbulent flow at the apex of the right ventricle or adjacent to a wall motion abnormality affecting the interventricular septum. Pulsed wave Doppler detected coexisting mitral regurgitation in one patient and tricuspid regurgitation in another two. In all patients a left to right shunt was confirmed by oximetry and the location of the defect was identified by angiography or at operation or necropsy. Cross sectional echocardiography in combination with pulsed wave Doppler scanning is useful in the rapid bedside evaluation of patients with ventricular septal defect after myocardial infarction.

Aged↗
PubMed1983

Interaction between vascular endothelial cells and vascular intimal spindle-shaped cells in vitro.

The interactions between human or bovine vascular endothelial cells and fibroblast-like vascular intimal spindle-shaped cells have been studied in vitro, using species-specific antibodies to identify the different components in mixed cultures. Pure cultures of endothelial cells grow as uniform, nonoverlapping monolayers, but this growth pattern is lost after the addition of spindle cells, probably because the extracellular matrix secreted by the latter causes the endothelial cells to modify the way they are attached to the substrate. The result is a network of tubular aggregates of endothelial cells in a three-dimensional 'polylayer' of spindle-shaped cells. On the other hand, endothelial cells added to growth-inhibited cultures of spindle-shaped cells will grow in sheets over the surface of the culture. Human endothelial cells grown in contact with spindle-shaped cells have a reduced requirement for a brain-derived endothelial growth factor. The interactions of endothelial cells and other connective tissue cells in vitro may be relevant to the mechanisms of endothelial growth and blood vessel formation in vivo, and emphasize the potential importance of extracellular matrix in controlling endothelial cell behaviour.

Animals↗