Association of circulating leukocyte count with coronary atherosclerosis regression after pravastatin treatment

Epidemiological studies have demonstrated that the peripheral blood leukocyte count could be used as a marker of the progression of atherosclerosis. Few data exist regarding the relationship between inhibition of the progression of coronary atherosclerosis and the anti-inflammatory effects of statins, especially the drugs' effects on the leukocyte count in patients with coronary artery disease. A 6-month prospective study was, therefore, conducted in 50 patients treated with pravastatin. The plaque volume, as assessed by volumetric analysis using intravascular ultrasound, reduced significantly by 14% (p<0.0001, vs. baseline) following the treatment, furthermore, a corresponding decrease of the leukocyte count (8.9%, p<0.01, vs. baseline) was also seen. No correlation was found between the change in the leukocyte count and any of the changes in the lipid levels; changes in either of these are known to be associated with the rate of progression of atherosclerosis. A multivariate regression analysis using other traditional risk factors and medications as covariates revealed that the decrease in the leukocyte count was an independent predictor of inhibition of the progression of coronary atherosclerosis. In conclusion, a reduction of the leukocyte count as one of the non-lipid-lowering effects of pravastatin may be a novel marker of regression of coronary atherosclerosis.