Assessment of plasma aminothiol levels and the association with recurrent atherothrombotic events in patients hospitalized for an acute coronary syndrome: a prospective study

Abstract

Abstract Background: The aminothiols homocysteine and, to a lesser extent, cysteine have been associated with adverse cardiovascular outcome, whereas glutathione, as an antioxidant, may protect against atherosclerosis and thrombosis. Potentially, the combined assessment of these aminothiols may provide a more accurate association with future cardiovascular outcome. We evaluated the association between recurrent atherothrombotic events and the concentration of total plasma cysteine, homocysteine, and glutathione and their combination. Methods: Respective aminothiols were measured by high-performance liquid chromatography in blood plasma of consecutive first-day survivors admitted for an acute coronary syndrome between April 2002 and January 2004. The combined score was calculated using the combination of the individual aminothiols. The end point was the composite of cardiovascular death, myocardial infarction, and/or stroke. Results: A cohort of 375 consecutive patients (median age 66 years, 66% male) were followed for a median duration of 2.7 years. The end point occurred in 82 patients (22%). In univariate analyses, all aminothiols were significantly associated with the composite end point. After correction for possible confounders, only cysteine and glutathione remained significantly associated. The strongest association with the end point was observed for the combined score (adjusted hazard ratio, 1.40 per standard deviation increase; p=0.005). Conclusions: Although homocysteine is generally considered the aminothiol of interest with respect to cardiovascular disease, in our prospective study, only cysteine and glutathione appeared independently associated with recurrent atherothrombotic events. Moreover, we showed that an imbalance in the combination of aminothiols could be of more importance than investigating the individual metabolites.