769-2 Progression and Regression of Coronary Atherosclerosis Occur within the Same Patient During Placebo Treatment and During Lipid-Lowering Therapy with Pravastatin

Abstract

REGRESS (Regression Growth Evaluation Statin Study) is a placebo controlled multicenter study to asses the effect of 2-yr treatment with Pravastatin (PRAV) on progression and regression of angiographically documented coronary atherosclerosis (CA) in patients with a serum cholesterol between 4–8 mmol/l (155-310 mg/dl). Analyses of the coronary arteriograms were performed by quantitative computer analysis. The primary endpoints of the study, change in Mean Segment Diameter and Minimum Obstruction Diameter (MOD) averaged per patient, showed significant retardation of mean progression of CA in the PRAY-group as compared to the placebo (PLAC)-group. However, these mean changes per treatment group are hardly informative about individual CA-behavior. Therefore we determined for all 641 patients included in the primary MOD-analysis: 1. a mean progression score (MPS)-cumulative value of all >0.4 mm progressing obstructions divided by the number of contributing obstructions-, and 2. a mean regression score (MRS)-cumulative value of all >0.4 mm regressing obstructions divided by the number of contributing obstructions. Obstructions changing ≤0.4 mm were considered stable and do not contribute to the scores. Thus, each patient is characterized by a MPS and a MRS. An overview of the patient MPS and MRS is presented in the figure below. significant progression and regression of CA within the same patient occurred in 41 (13%) PRAY-patients and in 27 (9%) PLAC-patients. Thus, although pravastatin slows mean progression of CA, progression and regression of CA within the same patient still occurs in a considerable number of patients during lipid lowering therapy.