Progression of coronary atherosclerosis is a unpredictable process. It follows a nonlinear course, and information derived from sequential coronary angiograms is of little value in predicting future progression. This study was designed to evaluate the changing patterns of coronary artery disease(CAD) and to determine possible factors for progression.

We analyzed progression and regression of CAD in 22 patients(group I : patients with progression of the coronary lesion, group II : patients with regression or no significant change of the coronary lesion) who underwent coronary arteriography two times. Progression was defined either as an increase in percent stenosis of preexisting stenoses by ≥20% including occlusions or as formation of new stenoses ≥20%. The results were compared with clinical findings to determine the nature of the progression of coronary atherosclerosis.

Progression of the coronary artery lesion was found in 14 of 22 patients, regression in 4 and no significant changes in 4. New lesions occured in 22 of 156 segments in previously normal segments of arteries. The highest progression percentage was shown by the proximal right coronary artery. Progression occured most frequently in segments with stenosis of 50% to 74% at initial arteriogram. There were no significant differences in mean values for age, blood pressure, total serum cholesterol and blood sugar between two groups.

The coronary arterial lesions are more frequently progressive rather than regressive of stationary. The progression follows nonlinear course. Many new lesions occurred in segments with previously normal segments of arteries.