Objective:Percutaneous coronary intervention(PCI) triggers an acute inflammatory response,while sirolimus is known to have anti-inflammatory properties;the inflammatory system response to PCI after sirolimus-eluting stent placement remains unclear.The purpose of this study is to determine the changes in high sensitive C-reactive protein(hs-CRP) and apelin after PCI procedure and drug-eluting stent implantation in patients with and without reduced left ventricular systolic function.Methods:Forty-eight consecutive patients undergoing PCI at the Beijing Anzhen Hospital between July and September 2006 were recruited.Sirolimus-eluting stents were employed in all patients.Blood samples were drawn immediately before and 24 h after the procedure.Plasma hs-CRP and apelin levels were determined by enzyme immunoassay.Results:Paired t-test revealed a significant increase in both hs-CRP and apelin post-procedure(P=0.006 and P<0.0001,respectively).Patients with reduced left ventricular ejection fraction(LVEF) had significantly lower baseline apelin levels compared to those with normal ventricular function [(46.8±10.8) vs.(72.0±8.4) pg/ml,P<0.001].However,apelin increased to a level similar to the level of those with normal left ventricular systolic function 24 h after the PCI procedure [(86.7±11.6) vs.(85.1±6.1) pg/ml,P=0.72].Conclusions:hs-CRP and apelin levels increased after PCI and sirolimus-eluting stent implantation.Patients with impaired left ventricular systolic function had significantly lower baseline apelin levels,which increased significantly after PCI. Objective: Percutaneous coronary intervention (PCI) triggers an acute inflammatory response, while sirolimus is known to have anti-inflammatory properties; the inflammatory system response to PCI after sirolimus-eluting stent placement remains unclear. The purpose of this study is to determine the changes in high sensitive C-reactive protein (hs-CRP) and apelin after PCI procedure and drug-eluting stent implantation in patients with and without reduced left ventricular systolic function. Methods: Forty-eight consecutive patients undergoing PCI at the Beijing Anzhen Hospital between July and September 2006 were recruited in all patients. Blood samples were drawn immediately before and 24 h after the procedure. Plasmas hs-CRP and apelin levels were determined by enzyme immunoassay. Results: Paired t-test revealed a significant increase in both hs-CRP and apelin post-procedure (P = 0.006 and P <0.0001, respectively). Patients with reduced left ventricular ejection frac tion (LVEF) had significantly lower baseline apelin levels compared to those with normal ventricular function [(46.8 ± 10.8) vs. (72.0 ± 8.4) pg / ml, P <0.001] of those with normal left ventricular systolic function after 24 h after PCI procedure [(86.7 ± 11.6 vs. 85.1 ± 6.1) pg / ml, P = 0.72] .Conclusions: hs-CRP and apelin levels increased after PCI and sirolimus- eluting stent implantation. Patients with impaired left ventricular systolic function had significantly lower baseline apelin levels, which increased significantly after PCI.