Forty five patients aged <75 years old referred for a first STEMI or non STEMI AMI. Peripheral blood samples were drawn on admission. Isolated peripheral blood mononuclear cells were obtained by Hypaque-Ficoll density gradient centrifugation and cultured for 4 weeks. Cultured cells were phenotyped to assess the endothelial origin of ECFC. Genomic DNA was extracted in all patients and genotyping for allelic variations of KIF6 was performed.
Subjects were divided into two groups comparing the (Arg/Arg) homozygote variants with patients having a Trp allele. The genotype frequencies were 55 % , 31 % and 13 % for Arg/Arg, Arg/Trp and Trp/Trp respectively. Between groups, higher levels of TnI, CK and CK-MB wer observed in the Arg/Arg group (respectively p = 0.026, p = 0.001 and p = 0.031). ECFC were observed in 33 % of patients with AMI. The percentage of patients without ECFC was significantly higher in the Arg/Arg group (p = 0.033). No other significant differences were observed between groups.
In this report the Arg/Arg group showed a high number of ECFC-negative patients. A possible explanation might be the low mobilization of ECFC from bone marrow in this genotype since KIF6 is involved in cytokinesis. The altered amino acid Trp719Arg could decrease the ECFC released from the bone marrow in response to chemokines released at the onset of AMI.