OBJECTIVETo observe serum C4a and platelet aggregation rates changes in acute myocardial infarction (AMI) patients before and after percutaneous coronary intervention (PCI) and association with the development of no-reflow phenomenon.

METHODSFrom June 2006 to August 2009, 119 AMI patients underwent PCI (28 cases of no-reflow group, 91 cases of reflow group) and 30 subjects with suspected coronary heart diseases and normal coronary angiography results (control group) were enrolled in this study. C4a and platelet aggregation rate were measured at 30 minutes before PCI, immediately after PCI, 30 minutes, 1 hour, 2 hour, and 6 months post PCI in AMI patients and at before coronary angiography in control subjects.

RESULTSThe levels of serum C4a at 30 minutes prior to PCI in control, no-reflow, and reflow groups were similar (P > 0.05). Platelet aggregation rate at 30 minutes prior to PCI was significantly higher in no-reflow group and reflow group than in control group (all P < 0.05). Serum C4a and platelet aggregation rates were significantly higher in no-reflow group at immediate, 30 minutes and 1 hour after PCI than at 30 minutes prior to PCI, two hours and 6 months after PCI (all P < 0.05), and were significantly higher than in reflow group at immediate, 30 minutes and 1 hour after PCI (all P < 0.05). Serum C4a and platelet aggregation rates were similar at different time points in reflow group (all P > 0.05). The levels of C4a in no-reflow group at immediate, 30 minutes and 1 hour after PCI were positively correlated with platelet aggregation rates (r = 0.91, 0.79, 0.60, respectively, all P < 0.01).

CONCLUSIONThe transient increase on levels of C4a and platelet aggregation rate early post PCI are verified in no-reflow patients with AMI undergoing PCI.

Aged ; Angioplasty, Balloon, Coronary ; Case-Control Studies ; Complement C4a ; metabolism ; Humans ; Middle Aged ; Myocardial Infarction ; blood ; No-Reflow Phenomenon ; Platelet Aggregation ; Postoperative Period