The effect of simvastatin on progression of coronary artery disease. The Multicenter coronary Intervention Study (CIS)

BACKGROUND: In several angiographic trials, HMG-CoA reductase inhibitors have shown a beneficial effect on the progression of coronary artery disease. Using 20 mg simvastatin, day-1, a treatment period of up to 4 years was necessary to show a significant reduction in coronary artery disease progression. The question remains however whether higher dosages of simvastatin would be more advantageous in respect to the magnitude of the effect and the required time interval to demonstrate treatment efficacy. METHODS AND RESULTS: In the Coronary Intervention Study (CIS), a multicentre randomized double-blind placebo-controlled study, the effects of lipid-lowering therapy with simvastatin on progression of coronary artery disease in 254 men with documented coronary artery disease and hypercholesterolaemia were investigated. Following a period of lipid-lowering diet, treatment with 40 mg simvastatin or placebo was maintained for an average of 2.3 years. Two primary angiographic endpoints were chosen: the global change score (visual evaluation according to the method of Blankenhorn) and the per patient mean change of minimum lumen diameter (evaluated by the CAAS I system). The mean simvastatin dose was 34.5 mg day-1. In the placebo group, the serum lipids remained unchanged; in comparison to the placebo group the simvastatin group showed a 35% LDL-cholesterol decrease. Coronary angiography was repeated in 205 patients (81%) and 203 film pairs (80%,) were evaluable by quantitative coronary angiography. In the simvastatin and placebo groups, the mean global change scores were +0.20 and +0.58 respectively, demonstrating a significantly slower progression of coronary artery disease in the treatment group (P = 0.02). The change in minimum lumen diameter assessed by computer-assisted quantitative evaluation with the CAAS I system was -0.02 mm in the simvastatin group and -0.10 mm in the placebo group (P = 0.002). In the simvastatin group, there was a significant correlation between the LDL cholesterol levels achieved therapeutically and the per patient mean loss of minimum lumen diameter (r = 0.29; P = 0.003). During the study period, there was no significant difference in the incidence of serious cardiac events (15 of 129 patients in the simvastatin group and 19 of 125 patients in the placebo group, ns). CONCLUSION: Treatment with 40 mg simvastatin day-1 reduces serum cholesterol and slows the progression of coronary artery disease significantly within a short period of treatment time. In the treatment group, retardation of progression is inversely correlated to the LDL-cholesterol levels achieved

Lipid-Intervention und koronare Herzkrankheit bei Mannern unter 56 Jahren. Die Coronare Interventions-Studie: CIS. [Lipid intervention and coronary heart disease in men less than 56 years of age. The Coronary Intervention Study: CIS]

The CIS was undertaken with the aim to evaluate the effects of lipid modifications on angiographic progression and regression of CAD in patients with CAD and hypercholesterolemia. The design included a multicenter randomized, double-blind, parallel, placebo-controlled comparison, with target and safety limits for adjusting the trial medication depending on the LDL cholesterol level (LDL-C) achieved, i.e., up to 40 mg of simvastatin (S) or placebo (P) daily, add-on medication (up to 3 x 4 g Colestyramin), and diet counselling. Male patients, average age 49 (< or = 56) years, were included with angiographic CAD and a screening total cholesterol of 207-350 mg/dl, who were not due to undergo coronary bypass surgery or PTCA, who did not suffer from serious other disease (e.g., diabetes mellitus), and who had not undergone coronary bypass surgery previously. RESULTS: All baseline variables were comparable in the treatment groups, with 129 patients taking S and 125 taking P. Of these 254 patients 217 had their final study visit and 207 underwent a second angiography after an average treatment time of 2.3 years under an average daily dose of 37 mg S. 205 pairs of films were available for analysis. Vital information was obtained of all patients until closure of the data bank, half a year after the last study angiography. Five deaths occurred within the study period, 12 through March 15, 1995 (S: 1/6, P: 4/6). 37 patients (S: 18, P: 19) discontinued trial drug and protocol. Concomitant CAD medication was comparable in both groups, except lipid-lowering add-on medication which was significantly higher in the P group (38% versus 13%). Significant changes in lipid levels, on treatment, were observed in the S group amounting to a mean difference in LDL-C of -35%, in Apo-Protein B (ApoB) of -30%, in VLDL-C of -37%, and in triglycerides (TG) of -27%, and in HDL-C of +6%, in comparison to the control group; these differences were even greater in 137 fully compliant patients: -41, -36, -39, -31, and +7%, respectively. Progression in the S group was significantly less, as defined by the two primary target criteria: 1) the minimum obstruction diameter (MOD), determined by quantitative coronary angiography (QCA), decreased about five times less in comparison to the control group (S: by -0.017; P: -0.0954 mm), and 2) the standardized visual global change score (GCS) deteriorated almost three times less in the S group (by +0.20) than in the P group (+0.58). Of the secondary target criteria, the mean lumen diameter (QCA) also developed a significant difference (S: -0.20; P: +0.23 mm; p = 0.0006) with a trend toward regression in the S group. The QCA-%-stenosis deteriorated three- to four-times less in the S group as compared to the control group (S: by 0.69%; P: by 2.73%; p = 0.0022), and the number of patients with angiographic progression was nearly halved (S: 30%; P: 56%; p < 0.0000). These differences were determined by intention to treat analysis (ITT), and they were obtained in spite of lipid lowering add-on medication in 38% of the P patients; they turned out to be more pronounced in 137 fully compliant patients, in an analysis "as treated". The mean decrease in LDL-C serum level caused by S was significantly correlated to the decrease in progression, and multivariate regression analysis of both treatment groups identified LDL-C (or ApoB) and TG as independent predictors of progression. Progression appeared to be most pronounced in low and medium sized lesions, and the beneficial effect of lipid intervention dominated in lesions with 12-56% QCA stenosis severity. A small fraction of patients who suffered from exercise-induced angina, with ST-segment-depression at the beginning of the study, experienced a significant improvement under S as compared to P treatment. Although the study was not designed to show differences in clinical events, the combined number of all major cardiovascular events tended to be less frequent in the S than in the C g