Effects of Lipid Lowering by Pravastatin on Progression and Regression of Coronary Artery Disease in Symptomatic Men with Normal to Moderately Elevated Serum Cholesterol Levels. The Regression Growth Evaluation Statin Study (REGRESS) - REGRESS

Description:

REGRESS was a double-blind, placebo-controlled multicenter study that assessed the effects of pravastatin on progression and regression of coronary atherosclerosis in 885 men with known coronary artery disease (CAD) and normal to moderately elevated serum cholesterol levels

Hypothesis:

Therapy with pravastatin 40 mg once daily for 2 years will result in less progression of coronary atherosclerosis when compared to placebo, as manifested by smaller decrease in the average mean segment diameter (MSD) and average minimum obstruction diameter (MOD)

Study Design

Study Design:

Patients Screened: 1068
Patients Enrolled: 885
Mean Follow Up: 2 years
Mean Patient Age: mean age 56.2
Female: 0

Patient Populations:

(1) serum total cholesterol between 155 and 310 mg/dl
(2) scheduled to undergo a coronary angiogram because of symptoms of CAD

Primary Endpoints:

(1) change in average mean segment diameter on a per-patient basis
(2) change in average minimum obstruction diameter on a per-patient basis

Secondary Endpoints:

Clinical events: myocardial infarction, coronary

Drug/Procedures Used:

Lipid-lowering therapies were withdrawn prior to enrollment. Following enrollment, patients were divided into PTCA block (n=230), CABG block (n=282) and medical management block (n=373), in accordance with the primary treatment proposed at the enrolling center. In each block, patients were randomly assigned to receive either pravastatin 40 mg once daily, or a matching placebo.

Coronary angiography was reviewed by the central core laboratory. Dietary advice was dispensed by means of a brochure. Patients were asked to adhere to a stable diet and smoking status was monitored.

Follow-up lipid analyses were performed at 2,4,6,12,18 and 24 months. Follow-up coronary angiogram was scheduled for 24 months from the time of randomization.

Principal Findings:

A total of 1068 patients were initially included in the study and underwent qualifying coronary angiography. Of those, 183 were not randomized because of nonqualifying lipid levels or other laboratory tests, nonqualifying coronary angiography, or other reasons.

Among patients treated with pravastatin, 89% were clinical event-free at the end of 2 years, compared with 81% in the placebo group (p=0.02). This effect was independent of the study center (p=0.52).

At the end of follow-up, 778 patients (88%) had undergone a second angiogram. A total of 4209 coronary segment was analyzed by quantitative angiography. Both pravastatin and placebo groups demonstrated progression of coronary atherosclerosis over the course of the study. However, among patients treated with pravastatin, mean MSD decreased by 0.06 mm, compared to 0.10 mm in the placebo group (p=0.019). Median MOD decreased by 0.03 mm in the pravastatin group, compared to 0.09 mm in the placebo group (p=0.001).

The effect of pravastatin did not differ significantly between patients in the PTCA, CABG or medical management blocks (p=0.54 for MSD and p=0.34 for MOD).

Interpretation:

Among symptomatic men with coronary atherosclerosis and normal to moderately raised serum cholesterol, treatment with pravastatin 40 mg/day for 2 years was associated with less progression of coronary atherosclerosis and fewer new cardiovascular events, compared to placebo. This study supports earlier observations made in the MAAS, CCAIT and MARS studies.

References:

Jukema JW, Bruschke AV, van Boven AJ, et al. Effects of lipid lowering by pravastatin on progression and regression of coronary artery disease in symptomatic men with normal to moderately elevated serum cholesterol levels. The Regression Growth Evaluation Statin Study (REGRESS). Circulation;91:2528-40

Keywords: Cholesterol, Follow-Up Studies, Coronary Angiography, Hydroxymethylglutaryl-CoA Reductase Inhibitors, Pravastatin, Diet, Hypercholesterolemia, Smoking


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