DIABETES ATHEROSCLEROSIS INTERVENTION STUDY (DAIS) - QUANTITATIVE CORONARY ANGIOGRAPHIC ANALYSIS OF CORONARY-ARTERY ATHEROSCLEROSIS

The primary objective of the Diabetes Atherosclerosis Intervention Stu dy (DAIS) is to determine by quantitative coronary angiography whether long-term correction of the dyslipoproteinemia of diabetes with micro nized fenofibrate results in evidence of decreased progression or regr ession of angiographically measured obstructive coronary atheroscleros is. The purpose of this communication is to describe the angiographic methodology for the DAIS project, and to present data documenting the reproducibility of measurements that will determine the primary outcom e of DAIS. Four hundred eighteen subjects between the ages of 40 and 6 5 were entered from 11 centers in Canada, France, Finland, and Sweden, with 305 males and 113 females. Thirty-two percent of subjects had un dergone a previous coronary artery intervention, either PTCA or bypass grafting, Subjects underwent coronary arteriography at baseline accor ding to a strictly defined protocol. The coronary tree was divided int o AHA segments and quantitative analysis of segments was performed usi ng the cardiovascular measurement system described by Reiber. Geometri c parameters including mean lumen diameter, minimum lumen diameter, ma ximum lumen diameter, and segment length were determined. In 15 studie s, measurements were carried out on the same frame by two observers, a nd at least 1 week apart by the same observer. In 13 studies, measurem ents were performed by the same observer on two separate injections of the same coronary artery. The mean of the standard deviation of the d ifferences of measurements of all segments for the primary study analy st was 0.029 mm, with a mean of correlation coefficients of 1.00. Betw een two observers, the mean of the standard deviations of segmental me an lumen diameters was 0.347 mm with a mean of coefficients of variati on of 0.78. The mean of standard deviations for measurements of segmen tal mean lumen diameter from two separate coronary injections was 0.12 2, with a mean of correlation coefficients of 0.94. The mean of correl ation coefficients for minimum lumen diameter were 0.98 for intraobser ver variability, 0.77 for inter-observer variability, and 0.96 for int er-angiogram variability. For segment length the corresponding values were 0.99, 0.79, and 0.94. These data demonstrate that a high level of reproducibility and precision may be achieved in a multicenter study in assessment of the coronary tree in carefully performed studies usin g this methodology. We anticipate the results will provide a statistic ally powerful conclusion with new and unique data to answer the questi on of the effect of long-term correction of dyslipoproteinemia on coro nary atherosclerosis in type II diabetic patients with dyslipoproteine mia. (C) 1998 Wiley-Liss, Inc.