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Description / Table of Contents: Summary Even in the era of coronary stenting, acute coronary artery occlusion continues to represent a significant limitation of percutaneous transluminal coronary angioplasty (PTCA). Despite application of heparin and aspirin, abrupt vessel closure still occurs in 2–8%, depending on the definition applied. Especially patients receiving PTCA for acute coronary syndromes are at high risk for abrupt vessel closure. The formation of an intracoronary thrombus plays a central role in the pathogenesis of abrupt vessel closure. Dipyridamole induces dilatation of coronary arteries and prevents platelet aggregation by a mechanism that differs from that of aspirin. The primary purpose of the study was to evaluate whether adjunctive local intracoronary therapy with dipyridamole could reduce the incidence of coronary artery occlusion following PTCA. Secondary endpoints were defined as myocardial infarction, necessity for bypass grafting, and death. In 939 PTCA procedures performed for stable angina and in 155 angioplasty procedures for acute coronary syndromes (unstable angina, acute myocardial infarction), patients were randomized to receive conventional pretreatment consisting of heparin 15000 I.E. and aspirin 500 mg i.v. or additional intracoronary infusion of dipyridamole (0.5 mg/kg body weight). Dipyridamole was applied in 550 interventions (455 interventions in men, 95 interventions in women, age = 59.2 ± 8.4; 74 emergency procedures); conventional pretreatment was performed in 544 interventions (444 interventions in men, 100 interventions in women, age 58.3 ± 7.9; 81 emergency procedures). Intracoronary application of dipyridamole resulted in a significant reduction in the incidence of abrupt vessel closure following PTCA. This significant reduction was observed in patients presenting with stable ischemia as well as in patients receiving PTCA for acute coronary syndromes. Concerning secondary end points, intracoronary application of dipyridamole did not affect the need for bypass grafting or the incidence of death following PTCA. Intracoronary application of dipyridamole was associated with a reduction in the incidence of myocardial infarction following PTCA which, however, failed to reach significance.

Description / Table of Contents: Summary Diagnostic and interventional heart catheterization in peripheral vascular disease often requires due to iliacal disease additional methods of arterial approach besides the Judkin's technique. The percutaneous catheterization of the brachial artery finds widespread use. A major complication linked with this method is an increased rate of thrombotic occlusions at the puncture site. Thus, we investigated in a prospective set-up the ability of duplex ultrasound to identify predictive risk factors for vascular complications. Over a period of 20 months, 8000 patients referred to heart catheterization were studied. Routine catheterization via the femoral route was contraindicated in 34 out of 8000 mostly due to severe peripheral vascular disease with multiple vascular risk factors (diabetes, hypertention, and smoking). 53 patients who had a comparable low riskprofile served as the control group. The brachial artery was examined by ultrasound duplex for vessel anatomy and diameter at the puncture site before coronary angiography. Both groups (patient and control group) showed in 15% a variable anatomy with a premature division of the brachial artery in 6% proximal of the elbow and in 9% already distal to the axillary artery. Because of reduced diameters of these variable vessels no procedure was carried out at these arms. In all cases the opposite arm was successfully used instead, because the variants were always located only at one arm. The diameter of the brachial artery measured in average 5.0±0.8 mm and 4.8±0.7 mm in patients and controls, respectively. Women had a significantly smaller vessel diameter than men, measuring a difference of 0.4 and 0.6 mm, respectively (p〈0.05). For coronary angiography 6F and 7F arterial sheats were used equally, and in 32% of all cases a coronary intervention was performed. 31 (91%) procedures were carried out without complications; there was a false aneurysm in 1 patient (3%) and an occlusion of the brachial artery at the puncture site in 2 patients (6%). The occluded vessels of two diabetic women had a reduced diameter at the level of 10% of the standard distribution and an unfavorable ratio of sheat-to-vessel-diameter which lead initially to an obstruction of nearly 50% of the vessel lumen during catheterization. Screening of the brachial artery by ultrasound duplex before a percutaneous catheterization for coronary angiography and intervention showed reproducibly the variable anatomy and differences in vessel diameter, which can be risk factors for thrombotic occlusion. Important details for the location of the puncture site and the possible size of the arterial sheat can be obtained, so that coronary interventions with 7F catheter systems are still practicable. This technique is a simple and efficient method to estimate the relative risk of arterial occlusion prior to percutaneous puncture of the brachial artery, especially in a group of patients with severe atherosclerosis and elevated vascular risk-factors.