Factors associated with progression of coronary artery disease in patients with normal or minimally narrowed coronary arteries.

This study was performed to identify the subset of patients with normal or with minimal (49% or less) stenosis of the coronary vessels who may be prone to progressive coronary artery disease (CAD). Data were collected from 51 patients (19 men, 32 women, mean age 48 years) with normal coronary arteries (20 patients) or with minimal narrowing (31 patients) on a first angiogram, who underwent repeat catheterization 4 to 120 months later (mean 52) because of persistent chest pain. Three classic lifestyle-related risk factors (systemic hypertension, cigarette smoking status and hypercholesterolemia) were noted; the number of diseased segments on the first angiogram was counted according to a 15-segment coding system. Progression of CAD required the consensus of 3 observers on a 30% or greater decrease in luminal diameter. Progression was recorded in 16 of 31 patients with minimal CAD and in 3 of 20 patients with normal coronary arteries (p less than 0.01). By multivariate logistic regression, progression was predicted by (1) number of diseased segments (p = 0.001), (2) age (p less than 0.01), (3) smoking status (p less than 0.05) and (4) initial cholesterol level (p less than 0.05). Using the probability computed by the logistic model, we could separate the 51 patients in groups with low (0 of 18), medium (9 of 23) and high (10 of 10) risk of progression. Thus, patients with normal or minimally narrowed coronary arteries at angiography form a heterogeneous population including both normal or borderline subjects and patients with CAD at its early stage. The latter condition was associated with presence of risk factors and to the angiographic extent of the disease.