Plasma apoproteins and the severity of coronary artery disease.

Plasma levels of lipids, lipoproteins, and apoproteins in 281 patients undergoing cardiac catheterization were correlated with the incidence and severity of coronary artery disease (CAD) to determine if measurements of apoprotein levels are more predictive of the presence and severity of CAD than the corresponding levels of lipoprotein lipids. In 156 men with CAD among 194 men in the study the only variable other than age that correlated with the severity of CAD, defined by the number of lesions and percent stenosis, was the ratio of apoprotein AI to apoprotein B (r = .1908, p less than .03). The ratio of apoprotein AI to apoprotein B was a more accurate predictor of the severity of CAD than was the ratio of the corresponding high-density to low-density lipoprotein levels (coefficients of partial determination of .07 and .035; p less than .001 and p less than .07, respectively). Multivariate analysis confirmed the independent effect of the ratio of apoprotein AI to apoprotein B on the severity of CAD even after adjustments were made for lipid levels, age, presence of hypertension or diabetes, and therapy with beta-blockers or diuretics. Among men with total occlusion of a coronary artery apoprotein E and apoprotein B levels were significantly higher than in control subjects with a similar extent of CAD (p less than .03). The lipid profiles of the 37 women with CAD were very different from those of the men.(ABSTRACT TRUNCATED AT 250 WORDS)