Correlates of Angiographic Changes and Coronary Events

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00005433
Recruitment Status : Completed
First Posted : May 26, 2000
Last Update Posted : April 24, 2017
National Heart, Lung, and Blood Institute (NHLBI)
Information provided by (Responsible Party):
Wendy Mack, University of Southern California

Brief Summary:
To examine the appropriateness of angiographic and ultrasound endpoints as predictors of subsequent clinical coronary events. Follow-up data from the Cholesterol Lowering in Atherosclerosis Study (CLAS) were used.

Condition or disease
Cardiovascular Diseases Coronary Disease Coronary Arteriosclerosis Heart Diseases

Detailed Description:


A multitude of coronary angiographic trials have been conducted using various endpoint measures based on repeated coronary angiograms. Relative to coronary event trials, angiographic trials require both a smaller sample size and reduced trial length. While such trials have assumed that angiographic endpoints are valid surrogate measures for clinical coronary events, this assumption has not been completely tested. Although several coronary angiographic endpoints are available for trial outcomes, no single method has been uniformly accepted as optimal. Because of this, the utility and validity of coronary angiographic progression for predicting future clinical coronary events remains unsettled.

The recent advent of carotid ultrasonography to assess arterial intima-media thickness (IMT) offers the exciting potential for a noninvasive measure of atherosclerosis. Because of its noninvasiveness, carotid IMTallows the extension of anti-atherosclerotic trials to both asymptomatic and frail subjects, for whom coronary angiography might be medically unethical. Because there is currently only limited support for the association of carotid IMT with clinical events or coronary atherosclerosis, the validity of carotid IMT as a potential surrogate for either endpoint has not been established.

The Cholesterol Lowering Atherosclerosis Study (CLAS) was a coronary angiographic trial testing the efficacy of colestipol-niacin therapy in 188 nonsmoking, 40-59 year old men with previous coronary artery bypass graft surgery. Coronary artery atherosclerosis change was evaluated both by human consensus panel and by quantitative coronary angiography (QCA). In addition, B-mode ultrasounds of the common carotid artery was conducted every six months to provide measures of carotid IMT. Since the competion of the two-year CLAS study, subjects have been followed for up to 12 years. This long term follow-up of the CLAS cohort permits examination of the appropriateness of angiographic and ultrasound arterial endpoints as predictors of subsequent clinical coronary events. Angiographic and ultrasound (carotid IMT) endpoints also allow for testing of the associations between these various serial measures of atherosclerotic progression.

The results of these analyses will provide important information on the validity of these measures, which are in current use as trial endpoints, as surrogates for clinical coronary events.


The study used angiographic and ultrasound carotid intima medial thickness endpoints for testing the associations between these various serial measures of atherosclerotic progression and subsequent coronary heart disease.

Study Type : Observational
Actual Enrollment : 188 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: Correlates of Angiographic Changes and Coronary Events: The Cholesterol-Lowering Atherosclerosis Study (CLAS)
Study Start Date : April 1996
Actual Primary Completion Date : April 1997
Actual Study Completion Date : April 1997

Information from the National Library of Medicine

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Ages Eligible for Study:   40 Years to 100 Years   (Adult, Older Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
188 nonsmoking, 40-59 year old men with previous coronary artery bypass graft surgery
Male Nonsmoker Prior coronary artery bypass graft surgery

Responsible Party: Wendy Mack, Professor, University of Southern California Identifier: NCT00005433     History of Changes
Other Study ID Numbers: 4351
R03HL054532 ( U.S. NIH Grant/Contract )
First Posted: May 26, 2000    Key Record Dates
Last Update Posted: April 24, 2017
Last Verified: April 2017
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No

Additional relevant MeSH terms:
Cardiovascular Diseases
Heart Diseases
Coronary Disease
Coronary Artery Disease
Myocardial Ischemia
Vascular Diseases
Arterial Occlusive Diseases