Effect of Late Reperfusion on Caspase-3 Activityin Ischemic Myocardium after Myocardial Infarction

Objectives To study the effect of late reperfusion on caspase-3 activity of ischemic myocardium in rabbit and its significance. Methods 24 adult rabbits were randomly divided into3 groups: Sham (S) without ligation of coronary artery, Late Reperfusion (LR) with ligation for 3 hours following release for 3 hours and Persistent Ischemia (PI) with persistent ligation of coronary artery for 6 hours. All animals were sacrificed 6 hours after the beginning of the experiments. Border region of infarcted myocardium were incised for analyzing the concentration of SOD, MDA, GR and the expression of FADD, Caspase-3 and the apoptosis index (AI). Results Compared with the Sham group, LR and PI group exhibited much higher MDA, FADD, Caspase-3, AI and much lower SOD, GR(all P<0.01). Compared with the PI group, LR group exhibited higher MDA, FADD, Caspase-3, AI and lower SOD, GR (all P<0.05). Conclusions Late reperfusion markedly enhanced the Caspase-3 activity and then the number of apoptotic cardiomyocyte in border region of infracted myocardium, which indicated the existence of late reperfusion injury. The mechanism may involve the high oxidative stress state and expression of FADD.

Effect of late reperfusion therapy on cardiac function and prognosis in patients with acute ST elevation myocardial infarction

Background The suitable time for treating patients with acute ST elevation myocardial infarction （STEMI） is unclear. This study was to investigate the effects of reperfusion therapy at different late times on patients with acute STEMI, in order to decide the best time for late reperfusion therapy by providing evidence-based treatment in clinical practice. Methods We enrolled 1372 patients with STEMI and receiving selective percutaneous coro- nary intervention therapy between January 1st, 2010 to December 30th, 2014. According to the time receiving PCI, these patients were divided into 3 groups： 〈3 d（n=66） ,3-6 d（n=388） and/〉7 d （n=918）. The demograph- ic, clinical and coronary angiography data, and in-hospital major adverse clinical events （MACEs） were com- pared. Results The mortality rates among 3 groups were not statistically different （0 vs. 2.6% vs. 2.0%, P= 0.375）. The incidence rate of in-hospital MACEs in 3-6 d group was lower than the other two groups, but not sta- tistic difference （25.8% vs. 16.8% vs. 21.6%, P=0.077）. By comparing the cost of hospitalization, we found that the 3-6 d group was slight lower. For patients with non-occlusive culprit vessels, although the mortality rate still had no statistic difference, the incidence rates of in-hospital MACEs were different （33.3% vs. 11.7% vs. 15.9%, P=0.003）. However, the same conclusion was not driven in patients with occlusive target vessels. Conclusions For patients with STEMI receiving late reperfusion therapy, intervention during 3-6 d might have a trend to improve prognosis.