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We investigated whether change in coronary artery atherosclerosis as measured by quantitative coronary angiography is related to cardiovascular event risk. Although many studies have demonstrated the effectiveness of statins in decreasing atherosclerotic progression and cardiovascular event risk, a relation between coronary atherosclerotic progression and event risk has not been documented in clinical trials that have evaluated statin therapy. The Monitored Atherosclerosis Regression Study (MARS) was a randomized, double-blind, placebo-controlled trial designed to test whether lovastatin would decrease coronary atherosclerotic progression as measured by quantitative coronary angiography. We followed 173 subjects in the MARS who had minimum luminal diameter and percent diameter stenosis measured at the beginning and end of a 2-year intervention. Postintervention follow-up events over a mean period of 9.4 years were reported by subjects and verified by medical records. Two-year percent stenosis and minimum luminal diameter changes were tested in relation to clinical event risk in multivariate Cox's regression models. Events ascertained were (1) coronary death and myocardial infarction, (2) coronary death, myocardial infarction, coronary artery bypass grafting, and percutaneous transluminal coronary angioplasty, and (3) any cardiovascular event. Increased percent stenosis was associated with significantly increased hazard ratios (HRs) in all event categories (category 1 HR 1.55 per SD percent stenosis, p

Few studies have examined the correlation between change in carotid artery intima-media thickness (IMT) and change in coronary artery disease. In the Cholesterol Lowering Atherosclerosis Study, current nonsmoking men with coronary artery disease were randomized to colestipol-niacin or placebo. Among 133 subjects with baseline and on-trial coronary angiography and carotid ultrasonography, colestipol-niacin treatment significantly reduced progression of atherosclerosis by both end point measures (2-year average change in percent diameter stenosis by coronary angiography and rate of change in carotid IMT). Significant correlations between change in common carotid artery IMT and quantitative coronary angiographic measures of change were evident over all coronary artery lesions, and in mild:moderate (B 50% diameter stenosis), but not severe (] 50% diameter stenosis) coronary artery lesions. In mild:moderate lesions, correlations with change in common carotid IMT were: percent diameter stenosis (r0.28, P0.002), minimum lumen diameter (r 0.28, P 0.002), and vessel edge roughness (r0.25, P0.003). While measures obtained by carotid ultrasonography and coronary angiography are correlated, they each assess different aspects of atherosclerosis change. © 2000 Elsevier Science Ireland Ltd. All rights reserved.

Background Although assessment of progression of atherosclerosis by quantitative coronary angiography (QCA) is used as a surrogate for coronary events, no validation study has compared the several QCA measures used. Methods and Results The Cholesterol Lowering Atherosclerosis Study was a clinical trial testing the efficacy of colestipol-niacin on the progression of coronary atherosclerosis. Baseline/2-year coronary angiograms were obtained on 156 men with prior coronary artery bypass graft surgery. Changes in percent diameter stenosis and minimum lumen diameter (both measured in coronary lesions and segments) and coronary segment measures of average diameter, percent involvement, and vessel edge roughness were measured by QCA. Coronary events ascertained over 12 years of follow-up included myocardial infarction (MI), coronary death, and coronary artery revascularizations. Proportional hazards models evaluated the relation between QCA change measures and coronary events. Changes in percent diameter stenosis and minimum lumen diameter of coronary artery lesions were significantly related to the risk of MI/coronary death. All QCA measures were significantly related to the risk of any coronary event. Relative risks for each QCA measure were of similar magnitude when estimated separately within each treatment group. Change in minimum lumen diameter of lesions was the only measure independently associated with the risk of coronary events. Conclusions All QCA measures of progression of coronary artery disease were related to all coronary events (including revascularizations). Only QCA measures of lesion progression were related to MI/coronary death. QCA measures of lesion change may be better surrogate end points for "hard" coronary events than measures of change in coronary segments. (Am Heart J 2000;139:993-9.)

Common carotid artery (CCA) intima-media thickness (IMT) from B-mode ultrasound is a widely used measure of early atherosclerosis. This study evaluated within- and between-sonographer reproducibility of automated edge-tracking IMT using a low-cost mobile scanner. B-mode images of the left and right CCA were acquired on two occasions (interval of 2–14 days) by two sonographers for 38 subjects, aged 31–75 y. Reproduciblity error was measured as the mean absolute difference (MAD ± SEM) and the standard deviation of differences (SDΔ) between repeated measurements. Within-sonographer (MAD = 0.027 ± 0.006 mm; SDΔ = 0.044 mm) and between-sonographer errors (MAD = 0.041 ± 0.008 mm; SDΔ = 0.064) in IMT (mean = 0.74, SD = 0.14) of a single artery were small compared to those of other protocols. Combined averaging across both body positions and arteries reduced intersonographer MAD by 47% (MAD = 0.022 ± 0.003 mm; SDΔ = 0.029 mm). These data demonstrate that the proposed IMT protocol reduces reproducibility error by more than 50% relative to several protocols used in other major studies.

Atherosclerosis has been studied by femoral angiography in men with myocardial infarction. Smoking history recorded at entry was the strongest variable asssociated with degree of atherosclerosis at the first angiogram. This correlation was significant at the 1% level in two out of three femoral segments. Fifty-four men had two angiograms; 28 of these men had one additional angiogram. Two variables recorded in the interval between angiograms were significantly correlated with atherosclerosis change in one femoral segment; α-lipoprotein level determined by electrophoresis (a negative correlation, p < 0.01) and maximum systolic blood pressure occurring during an exercise tolerance test (a positive correlation, p < 0.01). An estimate of angiographic atherosclerosis assessment error has been obtained (S.D. = 8.28; in a scale of 1–128) and used to calculate sample size for future clinical trials which employ this endpoint. Testing the effect of therapy on lesion change with angiography requires fewer study subjects observed for a shorter period than is necessary to test a commensurate effect on atherosclerosis-related morbidity or mortality rates. For example, an angiographic study with design features comparable to those of the Coronary Drug Project could require a 1-yr observation period and 132 subjects per test group.

This system allows for efficient use of professional time and immediate availability of nutrient analysis for use in counseling.

Documentation of nutrition counseling effectiveness is essential to reinforce its value in an era of escalating health care costs. Counseling effectiveness can be determined definitively only if dietary assessment is made both before and after intervention. Unfortunately, methods currently available have drawbacks that limit feasibility of routine use. A directly computer-readable Quantitative Food Frequency Analysis method, which eliminates the need for manual data entry, has been developed and instituted at the University of Southern California School of Medicine, Los Angeles, for outpatient counseling. A 1-hour interview, focusing upon "usual" intake, is conducted using pictorial menus for food items. Feedback is available to the patient and health care team immediately. The data base is derived from the National Heart, Lung, and Blood Institute Food Table; the intake of 61 nutrients, including 23 fatty acids, is computed. The computer printout consists of four components: a summary; an alert for foods high in fat, cholesterol, sucrose, alcohol, and/or sodium; a listing of all foods consumed by frequency, accompanied by their nutrient contribution to daily intake; and a bar graph relating current nutrient intake to recommended levels. This document serves as a counseling tool and can support claims for third-party payment.

The application of digital image processing techniques to medical problems has been under development at the Jet Propulsion Laboratory, California Institute of Technology, since 1966. The initial research concentrated on medical X-ray films and include (1) image restoration, i.e., using digital techniques to retrieve information partially lost in the imaging system which generated the pictures, (2) image enhancement to emphasize features or remove useless data, and (3) image mensuration to provide more quantitative measurements and analyses than are available through visual inspection techniques. From the initial concern with X-ray image processing, this research in image processing as applied to biomedicine has been expanded to include a system for the automated analysis of images from light and electron microscopes. The Automated Light Microscope System (ALMS), around which the chromosome analysis system has been developed, allows direct scanning of specimen images into a computer for subsequent analysis. The applications of digital image processing to biomedicine at the Jet Propulsion Laboratory encompass 15 separate research projects. The areas selected for discussion in this paper give some indication of the types of picture analysis that are being performed. The current trend in biomedical image processing is toward more human interaction in the research setting.

Femoral angiograms were made in 21 cadavers under conditions which simulated clinical films. Then these arteries were excised, laid open, and color photographed along side of corresponding casts of the arterial lumen. Twenty-seven segments, 5 cm long, were classified as exemplary of normal vessel, uncomplicated stenosis, or hemorrhagic ulceration. The corresponding angiogram images of these arterial segments were digitized and processed to yield outlines of the vessel edges, and from these, computer measures were developed which described how these outlines deviated from ideal ones. Six of these measures were selected by means of stepwise discriminant analysis to distinguish the type of disease along the 27 exemplary segments, and 96% were correctly classified. Computer processing of angiograms shows promise for discriminating the nature of atherosclerotic lesions.

Comparison of coronary atherosclerosis change in a pilot angiographic study of retrospectively matched smokers and controls indicates more rapid progression in smokers. The findings indicate the feasibility of small-scale angiographic trials of treatment designed to ameliorate arterial damage in atherosclerotic smokers who cannot quit.