Objective: To compare the efifcacy between emergent and delayed stent implantation in patients with ST-elevation myocardial infarction (STEMI) after thrombus extraction.
Methods: A total of 82 STEMI patients who received thrombus extraction and intracoronary injection of tiroifban, sodium nitroprusside, nitroglycerin via thrombus extraction catheter and with recovered TIMI 3 lfow from 2012-11 to 2014-01 were retrospectively studied. The patients were randomized into 2 groups by SAS software: Emergent group, the patients received stent implantation immediately upon diagnosis and Delayed group, the patients were treated by anti-platelet and anticoagulant medication for 10-14 days, and then received stent implantation. n=41 in each group. The primary and secondary indicators were compared between 2 groups which including ST-segment resolution (STR), the occurrence rate of no-relfow/slow-relfow, myocardial blush grade (MBG) 3, parameters of stent, ventricular remodeling condition, the incidence of major adverse cardiac events (MACE).
Results: ①Delayed group had the post PCI STR at (68.2 ± 9.2)%, TIMI 3 grade at 97.5%, MBG 3 at 69.0%and corrected TIMI frame count (CTFC) at (19.5 ± 5.2), compared with Emergent group, P<0.05. The occurrence rate of no-relfow/slow-relfow in Delayed group and Emergent group were 2.5% and 31.0%, P<0.01. ②The parameters of stents in Delayed group and Emergent group were as the number at (1.21 ± 0.32) vs. (1.76 ± 0.76), the mean length at (28.3 ± 11.7) mm vs. (33.7 ± 12.9) mm, the mean diameter at (3.17 ± 0.76) mm vs. (2.82 ± 0.87) mm, all P<0.01. Delayed group had the higher dilating pressure than that in Emergent group, (18.5 ± 6.2) atm vs (13.6 ± 7.1) atm, P<0.01, and more patients in Delayed group receive high-pressure non-compliant balloon dilation 75% vs 23.8%, P<0.01. ③With 6 months of follow-up study, there were slightly declining trend for LVEF and LVSF in both groups than that at 1 week condition, P>0.05, while LVEDV and LVEDD increased than 1 week, P<0.05, the changes were more obvious in Emergent group, P<0.05. Delayed group had less MACE occurrence, P<0.05.
Conclusion: Delayed stent implantation in STEMI patients after thrombus extraction had reduced incidence of post PCI no-relfow/slow-relfow phenomenon, improved myocardial reperfusion and less MACE occurrence.

In order to investigate the association of G+1688A (Ser563Asn) polymorphism of platelet endothelial cell adhesion molecule-1 (PECAM-1) gene with myocardial infarction (MI) in the Chi- nese Han population, the G+1688A polymorphism in PECAM-1 gene was detected by polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) method among 502 subjects, including 218 patients with MI and 284 controls. The results showed that there was significant dif-ference in AA frequencies of genotype G+1688A polymorphism between case and control groups (39% vs 24%, P<0.001). A similar trend was observed on the allele frequencies (A/G: 62% vs 49%, P<0.001). Among the subjects with high serum total cholesterol level or high systolic blood pressure level, the variant AA genotype was associated with high risk of MI (adjusted OR, 2.13; 95% CI, 1.08-4.41 and adjusted OR, 2.53; 95%CI, 1.63-3.63). The single nucleotide polymorphism (SNP) at position +1688 in the exon 8 of PECAM-1 gene was associated with MI and the allele A might be a risk factor for MI in the Chinese Han population.