Standard versus low-dose weight-adjusted heparin in patients treated with the platelet glycoprotein IIb/IIIa receptor antibody fragment abciximab (c7E3 Fab) during percutaneous coronary revascularization. PROLOG Investigators.

Blockade of the platelet glycoprotein IIb/IIIa receptor by abciximab (c7E3 Fab) during coronary intervention reduces the incidence of ischemic complications, but has been associated with a doubling of the risk for bleeding complications. The present pilot study investigated whether modification of heparin dosing and/or early sheath removal would reduce the hemorrhagic complications associated with abciximab. One hundred three patients undergoing coronary intervention received abciximab (0.25 mg/kg bolus, 10 microg/min infusion for 12 hours) and aspirin and were randomized by a 2 x 2 factorial design to 1 of 2 weight-adjusted heparin doses and to 1 of 2 strategies for heparin discontinuation and vascular sheath removal. In the "standard-dose heparin" group, an initial bolus of 100 U/kg was administered to achieve a procedural activated clotting time (ACT) > or = 300 seconds; in the "low-dose heparin" group, an initial bolus of 70 U/kg was administered without adjustment for ACT. In the "late sheath removal" arm, heparin infusion was continued for the 12-hour duration of abciximab infusion, followed by sheath removal; in the "early sheath removal" group, heparin was stopped after the interventional procedure and sheaths were removed during the abciximab infusion. There were no apparent differences between patients randomized to the different treatment groups with regard to the occurrence of ischemic end points. Rates of bleeding and blood transfusion were reduced by low-dose heparin and early sheath removal and were lowest when both strategies were combined. Reduction and weight adjustment of heparin dose and early sheath removal in the setting of platelet inhibition with abciximab during coronary intervention may be useful in diminishing the incidence of hemorrhagic complications without loss of clinical efficacy.

An apparatus for measuring volumes of small objects.

An apparatus for measuring volumes of small objects such as tissue blocks is described. The apparatus measures volumes by fluid displacement and consists of a micropipette adapted to fit the month of an Erlenmeyer flask, a Luer adaptor fused to the side of the flask, and a glass syringe. When assembled with fluid enclosed, the fluid rises to a low level in the micropipette. Withdrawal of fluid into the syringe lowers the fluid level below the mouth of the flask. The micropipette is raised, the object to be measured is placed in the flask, and the micropipette is joined to the flask again. Fluid returned to the flask from the syringe rises to a higher level in the micropipette. The difference between the two fluid levels equals the volume of the object measured. This apparatus gives reproducible measurements and can be calibrated for absolute volume determination. It is inexpensive to construct and easy to use.

Comparison of 7 and 8 French guiding catheters for elective PTCA: results of a prospective randomized trial.

A prospective randomized trial was performed to detect technical and clinical differences of 7F compared to 8F guiding catheters (GC) used in elective coronary angioplasty (PTCA). One hundred and fifteen patients undergoing elective PTCA with standard balloon dilatation catheters were randomized to 7F (55 pts) or 8F (58 pts) guiding catheters. The endpoints were primarily coronary artery and peripheral vascular complications; and secondarily, technical details and quantitative and qualitative angiographic quality. There was no difference between 7F or 8F GC for development of coronary or peripheral vascular complications. With 7F GC there was less blood loss (Hct, 3.5 +/- 3.4% vs. 6.5 +/- 9.6%, P = .033), and less contrast medium (160 +/- 88 mL vs. 200 +/- 119 mL, P = .049) used. Angiographic quality was similar, although visualization of lesions in the left anterior descending coronary artery in the left anterior oblique projection was improved with the 8F GC. There is no advantage of 7F GC for the prevention of coronary or peripheral vascular complications, although there was less blood loss and contrast medium used with the 7F systems.