Cholesterol-Lowering Atherosclerosis Study (CLAS)
|First Received Date ICMJE||October 27, 1999|
|Last Updated Date||December 12, 2013|
|Start Date ICMJE||June 1980|
|Primary Completion Date||Not Provided|
|Current Primary Outcome Measures ICMJE||Not Provided|
|Original Primary Outcome Measures ICMJE||Not Provided|
|Change History||Complete list of historical versions of study NCT00000599 on ClinicalTrials.gov Archive Site|
|Current Secondary Outcome Measures ICMJE||Not Provided|
|Original Secondary Outcome Measures ICMJE||Not Provided|
|Current Other Outcome Measures ICMJE||Not Provided|
|Original Other Outcome Measures ICMJE||Not Provided|
|Brief Title ICMJE||Cholesterol-Lowering Atherosclerosis Study (CLAS)|
|Official Title ICMJE||Not Provided|
To determine whether combined therapy with the lipid lowering agents colestipol hydrochloride plus niacin would produce significant change in coronary, carotid, and femoral artery atherosclerosis and coronary bypass graft lesions as determined by angiography. Also, to determine possible correlations between lesion changes and plasma lipid and lipoprotein cholesterol levels and to explore interrelationships of atherosclerosis change in femoral, coronary, and carotid arteries.
The Lipid Research Clinics Coronary Primary Prevention Trial and the Coronary Drug Project had shown that morbidity and mortality from ischemic heart disease were reduced by blood cholesterol-lowering therapy. Although blood cholesterol reduction ameliorated experimental atherosclerosis in animal models, the two largest human studies with angiographic observation of arterial lesion change, the NHLBI Type II Coronary Intervention Study and a study by Cohn et al, had not demonstrated significant treatment effects. Favorable, but inconclusive, treatment trends were observed in four unrandomized angiographic trials and one trial too small for evaluation of randomized groups.
The clinical trial was supported by a subproject within a program project grant.
CLAS-I was randomized and selectively-blinded. Screening for the trial consisted of five clinic visits, at which baseline data, including angiographic data, were obtained and a prerandomization trial of the study drugs was conducted. One hundred eighty-eighty subjects were randomized to either 30 grams (g) of colestipol hydrochloride plus 3 to 12 g of niacin daily or to placebo. Both groups received diet intervention. The drug group received less than 125 milligrams (mg) of cholesterol daily, 22 percent of energy as fat, 10 percent as polyunsaturated fat, and 4 percent as saturated fat. The placebo group received less than 250 mg of cholesterol per day, 26 percent of energy as fat, 10 percent as polyunsaturated fat, and 5 percent as saturated fat. The different diet composition for drug and placebo groups was to enhance the differential in blood cholesterol responses between the two groups. Study subjects and clinic staff were blinded to the prerandomization study drug trial lipid responses. Subjects were blinded to treatment assignments. Subjects and staff were not blinded to on-trial lipid values. The primary endpoint, the global change score, was change in atherosclerosis observed by angiography of native coronary arteries and aorta coronary bypass grafts. Evaluation of study end-points was performed by staff and consultants who were blinded to treatment group assignments, as well as to the temporal ordering of angiographic data. Subjects were seen monthly for the first six months and then at two-month intervals. A repeat angiogram was performed at two years. Of the 188 randomized subjects, 162 completed the study.
On completion of CLAS-I, participants not requiring further bypass surgery were invited to continue in CLAS-II for an additional two years on their previously assigned treatment. Blinded study methods were maintained; there was no crossover between treatments. One hundred thirty-eight subjects continued in CLAS-II; 103 completed a third angiogram before the CLAS-I outcome was known and CLAS-II terminated. The CLAS-II clinical procedures, lipid, lipoprotein-cholesterol, and apolipoprotein analyses were the same as in CLAS-I. The CLAS-II angiographic and file evaluation procedures exactly replicated those in CLAS-I.
The study completion date listed in this record was obtained from the Query/View/Report (QVR) System.
|Study Type ICMJE||Interventional|
|Study Phase||Phase 3|
|Study Design ICMJE||Allocation: Randomized
Primary Purpose: Treatment
|Study Arm (s)||Not Provided|
* Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
|Recruitment Status ICMJE||Completed|
|Enrollment ICMJE||Not Provided|
|Completion Date||November 1994|
|Primary Completion Date||Not Provided|
|Eligibility Criteria ICMJE||
Non-smoking men, ages 40 to 59, with progressive atherosclerosis confirmed by angiography, who had coronary bypass surgery at least three months prior to the study admission date, and who had entry fasting blood cholesterol levels in the range of 185
|Ages||40 Years to 59 Years|
|Accepts Healthy Volunteers||No|
|Contacts ICMJE||Contact information is only displayed when the study is recruiting subjects|
|Location Countries ICMJE||Not Provided|
|NCT Number ICMJE||NCT00000599|
|Other Study ID Numbers ICMJE||502, P01HL023619|
|Has Data Monitoring Committee||Not Provided|
|Responsible Party||Not Provided|
|Study Sponsor ICMJE||National Heart, Lung, and Blood Institute (NHLBI)|
|Collaborators ICMJE||Not Provided|
|Information Provided By||National Heart, Lung, and Blood Institute (NHLBI)|
|Verification Date||May 2000|
ICMJE Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP