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The Probucol Quantitative Regression Swedish Trial tested whether treatment of hypercholesterolemic persons with probucol for 3 years affected femoral atherosclerosis. The primary end point was the change in atheroma volume estimated as change in lumen volume of the femoral artery assessed by quantitative arteriography. Three hundred three patients with visible atherosclerosis were randomized to probucol 0.5 g, twice daily, or to placebo. All patients were given diet and cholestyramine, 8 to 16 g/day. Twenty-nine patients were excluded because of inadequate primary end point measurements. The mean age of the remaining 274 subjects (158 were men) was 55 years. Seventeen percent had intermittent claudication and 24% had angina pectoris. After 3 years, the probucol-treated patients had 17% lower serum cholesterol, 12% lower low-density lipoprotein cholesterol, 24% lower total high-density lipoprotein cholesterol, and 34% lower high-density [lipoprotein.sub.2] cholesterol levels than control subjects. All lipoprotein differences between the treatment groups remained highly significant during the trial. There was no statistically significant change in lumen volume between the probucol and the control group. Furthermore, there was no difference between the treatment groups with regard to change in arterial edge roughness or amount of aorto-femoral atherosclerosis; neither were there any differences between the treatment groups with regard to change in ST-segment depressions on exercise tests or ankle/arm blood pressure (secondary end points). In the control group, lumen volume increased (p [less than] 0.001) and roughness of the femoral artery decreased (p [less than] 0.05). It is concluded that the addition of probucol to diet and cholestyramine did not result in any significant regression of atherosclerosis compared with that found in patients treated only with diet and cholestyramine. However, in this control group there was statistically significant evidence of improvement. (Am J Cardiol 1994;74:875-883)

The effect of prebucol on the development of atherascleresis is being Investigated in the Probucol Quantitative Regression Swedish Trial (PQRST). Hypercholosterolemic patients are randomIzed to receive either probucol 0.5 g twice daily or placebo in a double-blind manner, in combination with dietary therapy and choleatyramine 8-:1.6 g daily for a 3-year period. The primary endpoint of the trial is the change in atheroma volume, asseseecl by annual quantitative angiography involving 20-cm segments of the femoral artery. Data from the open diet and prerandomization phase indicate that probucol added to dietary intervention plus cholestyramine produced highly significant reductions in total (-17%), low-donslty lipopratein (LDL; -10%), and high-donsity lipopratein (-30%) cholesterol. From a subpopulatlon, LDL levels were isolated during different stages of the prerandomization phase. LDL was exposed to the oxidant Cu2+ and binding to fibroblasts as well as degradation by macrophages was measured. The generation of thlobarbRuric acid-reactive substances (TBARS) was also moasered. Probucol prevented degradation of copper-exposed LDL by macrophages and also reducad the formation of TBARS, indicating that probucol protected LDL from oxidation. After the tdal concludes in December 1992, statistical models will he used to investigate how much of the change in atheresclerosis is explained by changes in lipoprotein concentrations and how much is explained by probucors antioxidative effects. Thus, other matabolic factors such as dietary intake and circulating levels of lipid soluble vitamins and fatty acids that may modify the possible antioxldative effects of probucal are also measured and will he related to change in atheresclerosis. (Am J Cardiol 1993;71:15B-19B)

The effects of single doses of felodipine (5 and 10 mg) and nifedipine (10 and 20 mg) on chronic stable effort angina pectoris were assessed in a placebo-controlled, double-blind, crossover study of 24 patients receiving [beta] blockers and short. acting nitroglycerin. The effects were measured by repeated bicycle ergometer tests. The total work, and time until 1 mm of ST depression increased significantly by 9 to 31% after both active drugs at both dose levels in comparison with placebo. The differences were not. significant between drugs or doses. At rest, blood pressure decreased (10 to 15%) and heart rate increased (S to 10%) significantly after both active drugs. During exercise at the highest comparable work load, systolic blood pressure decreased significantly (23 to 26%), whereas heart rate was not affected after felodipine and nifedipine compared with placebo. The 2 drugs were well tolerated, and side effects were mild. Therefore, single doses of 5 and 10 mg of felodipine, and 10 and 20 mg of nifedpine have similar antiaginal and anti-ishemic properties. However, felodipine has a longer duration of action, which may improve compliance.