Probucol Quantitative Regression Swedish Trial - PQRST

Description:

Lipid-lowering therapy for atherosclerosis in the femoral artery.

Hypothesis:

Probucol may reduce the atheroma volume.

Study Design

Study Design:

Patients Screened: 1,496
Patients Enrolled: 274
NYHA Class: not given
Mean Follow Up: 3 years
Mean Patient Age: 55
Female: 42
Mean Ejection Fraction: not given

Patient Populations:

<71 years of age at the time of referral
Cholesterol levels >265 mg/dL (6.88 mmol/L)
LDL cholesterol levels >175 mg/dL (4.53 mmol/L)
Total triglyceride levels <350 mg/dL (4.0 mmol/L)

Exclusions:

Type III hyperlipoproteinemia
Diabetes
Untreated thyroid disease
Hypertension (diastolic blood pressure >110 mmHg)
Chronic renal failure
Malignancy
Recent myocardial infarction

Primary Endpoints:

Change in atheroma volume estimated as the calculated difference from baseline in lumen volume for each of the one-year measurements (over three years).

Secondary Endpoints:

Edge roughness as a measure of the femoral artery wall irregularity, minimal and maximal diameters of the femoral artery wall, ST-segment depressions on exercise tests, ankle/arm blood pressure.

Drug/Procedures Used:

Cholestyramine, 8 to 16 g/day for 2 months; probucol, 0.5 g bid was then added to diet and cholestyramine for another 2 months; angiography only for responders (total serum cholesterol decreased by >8%).

Principal Findings:

At baseline, 17% 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 lipoprotein2 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 aorta-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.

In the control group, lumen volume increased (p < 0.001) and roughness of the femoral artery decreased (p < 0.05).

Interpretation:

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 the control group, there was statistically significant evidence of improvement.

References:

1. Am J Cardiol 1988;62:37B-43B. Study design
2. Am J Cardiol 1994;74:875-83. Final results

Clinical Topics: Diabetes and Cardiometabolic Disease, Dyslipidemia, Prevention, Vascular Medicine, Atherosclerotic Disease (CAD/PAD), Homozygous Familial Hypercholesterolemia, Lipid Metabolism, Nonstatins, Diet

Keywords: Intermittent Claudication, Plaque, Atherosclerotic, Blood Pressure, Hypercholesterolemia, Peripheral Vascular Diseases, Cholestyramine Resin, Diet, Triglycerides, Probucol, Exercise Test


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