Apolipoprotein concentrations during treatment and recurrent coronary artery disease events

Abstract

The effect of untreated total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) as cardiovascular risk factors in both primary and secondary prevention has been extensively investigated. The predictive value of on-treatment lipid and apolipoprotein levels on subsequent cardiovascular events is as yet uncertain. Eight hundred forty-eight patients (675 men and 173 women) with angiographically proven coronary artery disease (CAD) who received effective statin therapy (≥30% decrease of baseline TC) were studied. We analyzed the predictive value of on-treatment levels of TC, LDL-C, triglycerides (TG), apolipoprotein A-I (apoA-I) and apolipoprotein B (apoB) on subsequent myocardial infarction (MI) and all cause mortality. On-treatment LDL-C levels were 2.55±0.55 mmol/L and 2.58±0.62 mmol/L for men and women respectively. Age-adjusted Cox regression analysis showed that only on-treatment apoA-I was predictive for future CAD events in both men and women, whereas on-treatment HDL-C was exclusively predictive in women. On-treatment apoB levels were predictive for recurrent CAD events in the total population but not after separate analysis for men and women. On-treatment levels of TC, LDL-C, and TG did not predict subsequent events. Multivariate analysis showed that on-treatment apoA-I and apoB were the only significant predictors for future cardiovascular events. On-treatment levels of TC, LDL-C, and TG were no longer associated with increased risk of recurrent cardiovascular events in CAD patients treated to target levels, which justifies the current guidelines. However, on-treatment levels of apoB and in particular apoA-I (and HDL-C in women) were significantly predictive for MI and all-cause mortality and may therefore be more suitable for cardiovascular risk assessment in this population.