Ridogrel in the setting of percutaneous transluminal coronary angioplasty

The safety of the combination of heparin and ridogrel therapy and its antiplatelet efficacy was examined in the setting of percutaneous transluminal coronary angioplasty (PTCA). In 32 patients without known aspirin intake for 10 days before PTCA, therapy with ridogrel (300-mg intravenous bolus) was begun just before PTCA and continued orally at a dose of 300 mg twice daily until discharge. Heparin was administered as a 10,000 IU bolus dose before PTCA and followed by an intravenous infusion at a rate of 1,000 IU/hour for 24 hours. Bleeding problems at the arterialentry site occurred in 13 patients, which required a blood transfusion in only 2 patients. One patient underwent emergency bypass surgery without specific problems of hemostasis. Ridogrel virtually eliminated thromboxane [B.sub.2] from the serum (29,2900 [+ or -] 6,555 pg/0.1 ml before vs 63 [+ or -] pg/0.1 ml at 2 hours after ridogrel), with a concomitant increase in serum 6-keto-prostaglandin [F.sub.1[alpha]] (511 [+ or -] 34 pg/0.1 ml before vs 1,190 [+ or -] 146 pg/0.1 ml at 24 hours after ridogrel). There were no acute reocclusions in the ridogrel-treated patients, whereas acute reocclusions occurred in 5.6% of the patients taking the standard aspirin + heparin regimen during the same period. Furthermore, at 6-month clinical follow-up patients treated with ridogrel compared favorably with those receiving standard treatment. (Am J Cardiol 1991;68:463-466)
Percutaneous transluminal coronary angioplasty (PTCA) is a technique used to dilate (widen) the coronary arteries, which supply blood to the heart. PTCA is used in the treatment of conditions such as atherosclerosis, in which cholesterol-rich deposits narrow the coronary arteries, diminishing the cardiac blood supply. While this therapy is quite effective, 2 to 11 percent of patients undergoing PTCA suffer reocclusion shortly after the procedure. One strategy for preventing reocclusion after PTCA has been the administration of drugs that prevent adhesion of blood platelets to the arterial wall (the precipitating factor in initiating reocclusion); however, the drugs currently available are not completely effective. A newly available drug, ridogrel, has been proposed as a more effective antiplatelet drug for use in this setting. This agent acts by inhibiting key enzymes involved in the platelet-initiated clotting process. To evaluate the utility and safety of ridogrel, a study involving 32 eligible patients (of 352 potential enrollees) referred for PTCA were administered either ridogrel and heparin or aspirin and heparin immediately after PTCA. (Aspirin and heparin are anticlotting medications.) Biochemical measurements indicated that ridogrel virtually eliminated blood levels of the enzymes on which it works. None of the patients treated with ridogrel suffered reocclusion after PTCA; 5.6 percent of the aspirin and heparin-treated patients did. At six-month follow-up, both groups of patients showed similar (low) levels of disease. (Consumer Summary produced by Reliance Medical Information, Inc.)