EFFECTIVENESS OF AN ANTIOXIDANT IN PREVENTING RESTENOSIS AFTER PERCUTANEOUS TRANSLUMINAL CORONARY ANGIOPLASTY - THE PROBUCOL ANGIOPLASTY RESTENOSIS TRIAL

Objectives. The Probucol Angioplasty Restenosis Trial was a prospectiv e, randomized, controlled study that investigated the effectiveness of probucol therapy in reducing the rate of restenosis after percutaneou s transluminal coronary angioplasty (PTCA). Background. Antioxidants h ave an inhibitory effect on smooth muscle cell growth in experiments i n vitro and in vivo, which suggests a possible pharmacologic effect on restenosis after PTCA. Methods. One hundred one patients were randoml y assigned to receive 1,000 mg/day of probucol or control (no lipid-lo wering) therapy 4 weeks before PTCA. After 4 weeks of premedication, b oth groups underwent PTCA. Probucol was continued until follow-up angi ography 24 weeks after PTCA. Angiographic results were analyzed at a c ore laboratory by quantitative coronary angiography. Results. Dilation was successful in 46 of 50 patients in the probucol group and 45 of 5 1 in the control group. At follow-up angiography 24 weeks after angiop lasty, angiographic restenosis occurred in 9 (23%) of 40 patients in t he probucol group and 22 (58%) of 38 in the control group (p = 0.001). Minimal lumen diameter was 1.49 +/- 0.75 mm (mean +/- SD) in the prob ucol group and 1.13 +/- 0.65 mm in the control group (p = 0.02). Perce nt diameter stenosis at follow up angiography in the probucol group wa s significantly lower than that in the control group (43.9% vs. 56.4%, p = 0.009). The late loss was 0.37 +/- 0.69 mm in the probucol group and 0.60 +/- 0.62 mm in the control group (p = 0.13). The loss/gain ra tio was 0.32 +/- 0.74 in the probucol group and 0.56 +/- 0.81 in the c ontrol group (p = 0.059). Net gain was greater in the probucol group t han in the control group (0.77 +/- 0.70 vs. 0.48 +/- 0.59 mm, p = 0.05 3). Conclusions. Probucol administered beginning 4 weeks before PTCA a ppears to reduce restenosis rates.