Vascular risk factors correlate to the extent as well as the severity of coronary atherosclerosis

Because most acute coronary events result from thrombosis at sites of minor plaque, the extent of non-obstructive coronary artery disease (CAD), rather than simply the number of severe stenoses, might be clinically relevant.

To examine the relationship between vascular risk factors and a novel extent score for CAD that measures the percentage of the coronary tree involved with atheromatous plaque, as judged by coronary angiography.

We assessed the extent and severity of CAD and the presence of vascular risk factors of 429 consecutive eligible patients (296 men, aged 61 +/- 11 years) who presented for elective coronary angiography. Detailed analyses of lipid levels were performed for 126 subjects.

The mean extent score was 54 (range 0-100). The presence of diabetes (P < 0.001), current or former smoking (P < 0.005) and a history of hypertension (P < 0.001) were all strongly associated with the CAD extent score, as was severity of disease. For the 283 patients with one or no severe stenosis, diabetes was associated with a greater extent score (57 versus 41%, P < 0.005), as was smoking (49 versus 34%, P < 0.005). For the 126 patients with detailed data on lipid levels, extent of coronary artery disease was independently correlated to age (P < 0.005), male sex (P < 0.05), presence of diabetes (P < 0.05), hypertension (P < 0.05), level of lipoprotein (a) (P < 0.005) and low-density:high-density lipoprotein ratio (P < 0.01) in multivariable analysis.

Extent of CAD, as well as its severity, is significantly associated with traditional vascular risk factors. Because most acute coronary events occur at sites of minor plaque, this might explain the mechanism whereby risk factors confer adverse prognostic significance.