Assessment of Endothelial Vasomotricity After Treatment by Nicotinic Acid in Acute Coronary Syndrome

The investigators' work proposes to evaluate the effectiveness of the Acid Nicotinique (Niaspan®), only molecule currently marketed, ready to raise the plasmatic levels of HDL-c. This effectiveness will be tested among patients having presented recently an acute coronary syndrome. The effectiveness of the molecule will be appreciated versus placebo after randomization. The technique of evaluation of this effectiveness will be the analysis of the vasodilatation endothelial-dependent measured on the level huméral (by echography high resolution). The awaited result is an improvement of 2% in value absolute of this vasodilatation between the initial test and the end of study for the patients receiving the acid nicotinic versus those receiving the placebo (3 months of treatment after inclusion). The calculation of the sample necessary to achieve this goal envisages 70 patients led at the end of the study, divided into two groups of treatment (acid nicotinic or Placebo). Such a result if it were obtained would be higher than that found in studies evaluating the effect on the vasomotricity endothelial statins or inhibitors of the enzyme of conversion.