Background —Dual therapy with ticlopidine and aspirin has been shown to be as effective as or more effective than conventional anticoagulation in patients with an optimal result after implantation of intracoronary metallic stents. However, the safety and efficacy of antiplatelet therapy alone in an unselected population has not been evaluated. Methods —Patients were randomized to conventional anticoagulation or to treatment with antiplatelet therapy alone. Indications for stenting were classified as elective (decided before the procedure) or unplanned (to salvage failed angioplasty or to optimize the results of balloon angioplasty). After stenting, patients received aspirin and either ticlopidine or conventional anticoagulation (heparin or oral anticoagulant). The primary end point was the occurrence of bleeding or peripheral vascular complications; secondary end points were cardiac events (death, infarction, or stent occlusion) and duration of hospitalization. Results —In 13 centers, 236 patients were randomized to anticoagulation and 249 to antiplatelet therapy. Stenting was elective in 58% of patients and unplanned in 42%. Stent implantation was successfully achieved in 99% of patients. A primary end point occurred in 33 patients (13.5%) in the antiplatelet group and 48 patients (21%) in the anticoagulation group (odds ratio=0.6 [95% CI 0.36 to 0.98], P =0.03). Major cardiac-related events in electively stented patients were less common (odds ratio=0.23 [95% CI 0.05 to 0.91], P =0.01) in the antiplatelet group (3 of 123, 2.4%) than the anticoagulation group (11 of 111, 9.9%). Hospital stay was significantly shorter in the antiplatelet group (4.3±3.6 versus 6.4±3.7 days, P =0.0001). Conclusions —Antiplatelet therapy after coronary stenting significantly reduced rates of bleeding and subacute stent occlusion compared with conventional anticoagulation.

Single coronary artery is a rare congenital anomaly of the coronary arteries where only one coronary artery arises from the aortic trunk by a single coronary ostium, supplying the entire heart. A database consisting of the angiographic reports of 50,000 consecutive coronary angiographies performed in adult patients in the University Hospital of Leuven between March 1973 and August 1991 was searched for the diagnosis of single coronary artery. All films concerned were reviewed and classified according to their anatomical type. Thirty-three cases of single coronary artery were retrieved, yielding an incidence of 0.066%. Patient characteristics and clinical data are described, with a discussion on the pathological importance of this finding.

The effect of phosphorylation by cyclic GMP-dependent protein kinase (G-kinase) on the activity of the plasmalemmal Ca2+-transport ATPase was studied on isolated plasma membranes and on the ATPase purified from pig erythrocytes and from the smooth muscle of pig stomach and pig aorta. Incubation with G-kinase resulted, in both smooth-muscle preparations, but not in the erythrocyte ATPase, in a higher Ca2+ affinity and in an increase in the maximal rate of Ca2+ uptake. Cyclic AMP-dependent protein kinase (A-kinase) did not exert such an effect. The stimulation of the (Ca2+ + Mg2+)-dependent ATPase activity of the purified Ca2+ pump reconstituted in liposomes depended on the phospholipid used for reconstitution. The stimulation of the (Ca2+ + Mg2+)-ATPase activity by G-kinase was only observed in the presence of phosphatidylinositol (PI). G-kinase, but not A-kinase, stimulated the phosphorylation of PI to phosphatidylinositol phosphate (PIP) in a preparation of (Ca2+ + Mg2+)-ATPase obtained by calmodulin affinity chromatography from smooth muscle, but not in a similar preparation from erythrocytes. Adenosine inhibited both the phosphorylation of PI and the stimulation of the (Ca2+ + Mg2+)-ATPase by G-kinase. In the absence of G-kinase the (Ca2+ + Mg2+)-ATPase was stimulated by the addition of PIP, but not by PI. In contrast with previous results of Furukawa & Nakamura [(1987) J. Biochem (Tokyo) 101, 287-290], no convincing evidence for a phosphorylation of the (Ca2+ + Mg2+)-ATPase was found. Evidence is presented showing that the apparent phosphorylation occurs in a contaminant protein, possibly myosin light-chain kinase. It is proposed that G-kinase stimulates the plasmalemmal Ca2+ pump of smooth-muscle cells indirectly via the phosphorylation of an associated PI kinase.

The purpose of this study was to determine the feasibility, safety, and efficacy of elective stenting with heparin-coated Wiktor stents in patients with coronary artery disease. In experimental studies, heparin coating has been shown to prevent subacute thrombosis and restenosis. Recently, a new method of heparin coating was developed, resulting in a more stable and predictable heparin layer on stent devices. This trial constitutes the first in-human use of this coating procedure, applied on the well-known Wiktor stent device. Heparin-coated Wiktor stent implantation was performed in 132 consecutive patients (132 lesions) in a multicenter international trial from September 1996 to February 1997. Forty-three percent of patients had unstable angina, 33% had previous myocardial infarction, and 10% had diabetes mellitus. Patients were followed for 12 months for occurrence of major adverse cardiovascular events, and 96% of the eligible patients underwent quantitative angiographic control at 6 months. Stent deployment was successful in 95.5% of lesions. Minimal lumen diameter increased by 1.67 +/- 0.48 mm (from 1.02 +/- 0.38 mm before to 2.69 +/- 0.37 mm after the stent implantation). Mean percent diameter stenosis decreased from 67.4 +/- 11.3% before to 18.9 +/- 7.7% after the intervention. A successful intervention (<50% diameter stenosis and no major adverse cardiac events within 30 days) occurred in 97% of the patients. The subacute thrombosis rate was 0.8%, which compares favorably with historical controls of this stent, and a low incidence of postprocedural increase in creatine kinase-MB was noted. At 6 months, event-free survival was 85% and angiographic restenosis rate was 22% with late loss of 0.78 +/- 0.69 mm and a loss index of 0.48 +/- 0.44. Heparin-coated Wiktor stents appeared to be an efficacious device to treat Benestent-like lesions, yielding angiographic and clinical results comparable to a heparin-coated Palmaz-Schatz stent. Despite its use in more complex lesions, the incidence of subacute thrombosis appeared to be lower than historical controls with a similar noncoated stent.

The aim of the present work was to investigate the stimulation of the plasma-membrane Ca2+-transporting ATPase by negatively charged phospholipids. The Ca2+-transporting ATPase was purified from pig stomach smooth muscle and from pig erythrocytes, and was reactivated with phosphatidylcholine (PC) in the presence and absence of negatively charged phospholipids. The substitution of phosphatidylinositol (PI), phosphatidylinositol 4-phosphate (PIP), phosphatidylinositol 4,5-bisphosphate (PIP2), phosphatidic acid (PA) or phosphatidylserine (PS) for PC induced profound changes in the Vmax, the K0.5 and the Hill coefficient of the Ca2+-activation curves for both ATPases. Low concentrations of each of the negatively charged phospholipids increased the Vmax., but high ratios of PIP, PIP2 or PA to PC decreased this parameter. PI, PA and PS increased the Vmax. of the erythrocyte enzyme to a larger extent than that of the smooth-muscle enzyme. This difference was less pronounced for PIP and absent for PIP2. PI (greater than 20% PC substituted), PIP, PIP2, PA and PS all increased the affinity of the two Ca2+-transporting ATPases for Ca2+ in the following order of potency: PIP2 greater than PIP greater than PI approximately PS approximately PA. PI, PA and PS increased the Ca2+ affinity of the smooth-muscle enzyme more than that of the erythrocyte enzyme; this difference was less pronounced for PIP and absent for PIP2. Even in the presence of calmodulin, all of the negatively charged phospholipids were still able to increase the Vmax. of the erythrocyte enzyme, whereas only PIP and PIP2 increased the affinity for Ca2+. The effect of PI at low concentrations (less than 20%) on the erythrocyte enzyme was peculiar in that it caused a decrease in the Ca2+ affinity instead of an increase. This effect was not observed for the smooth-muscle enzyme. All of the negatively charged phospholipids slightly increased the Hill coefficient for Ca2+ of both ATPases, and this effect was additive to that of calmodulin. The stimulation of the erythrocyte enzyme exhibited positive co-operativity towards PI and PIP, whereas that of the smooth-muscle enzyme did not. It is concluded (1) that there is a correlation between the number of negative charges on the phospholipids (PIP2 greater than PIP greater than PA approximately PI approximately PS) and the magnitude of their effect on the Vmax. and the K0.5 for Ca2+, and (2) that the action of the lipids on the smooth-muscle enzyme differs from that on the erythrocyte enzyme, indicating that these two Ca2+-transporting ATPases are not the same.