Abstract： Objective To observe the expression changes of microRNA 1 （miRNA-1） and microRNA 21（miRNA-21） after ischemic preconditioning （IPC）, ischemic postconditioning （IPO） and remote ischemic preconditioning （RIPC）in an ischemia-reperfusion rat heart model in vitro, as well as the expression of their target protein heat shock protein 70 （HSP70） and programmed cell death 4 （PDCD4）, and evaluate whether miRNA are involved in endogenous cardio-protective mechanism. Methods The Langendorff-perfused Sprague-Dawley rat hearts were randomly assigned into one of the four groups, control group （CON group, n=12）, ischemia preconditioning group （IPC group， n=12） , ischemia postconditioning group （IPO group， n=12） and remote ischemia preconditioning group （RIPC group，n=12）. Cardiac function was digitalized and analyzed. The expression of HSP70, PDCD4, B-cell lymphoma/leukemia-2 （Bcl-2） and Bax was detected by Western blotting. The expression of miRNA-1 and miRNA-21 was detected by real-time reverse transcriotion-polymerase chain reaction （RT-PCR）. Assessment of cardiac infarct size and myocardial apoptosis was determined using triphenyltetrazolium chloride （TTC） assay and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay （TUNEL） assay respectively. Results The expressions of miRNA-1 and miRNA-21 were up-regulated in IPC group, but the expression of miRNA-1 was down-regulated in RIPC group and IPO group （P＜0.05）. The expressionsof PDCD4, HSP70 and Bax were down-regulated in ‘conditioning’ groups compared with CON group （P＜0.05）. The expression of Bcl-2 was not statistically different among the four groups. The infarct size and the myocardial apoptosis in ‘conditioning’ hearts were significantly decreased compared with CON group （P＜0.05）. Conclusion The expressions of the miRNA-1 and miRNA-21 are different in IPC, RIPC and IPO groups, and their target proteins are not inversely correlated with the miRNAs in all the ‘conditioning’ groups.
ObjectiveTo investigate whether there is a protecting effect of remote ischemic preconditioning (RIPC) on patients underwent cardiac valvular surgery. MethodWe retrospectively analyzed the clinical data of 72 adult patients underwent cardiac valvular surgery in our hospital from Febuary 2014 through April 2015 year. There were 26 males and 46 females with an age ranging from 23-68 years. We devided 72 patients into a RIPC group and a control group. There were 14 males and 28 females with a mean age of 48.87±12.28 years in the RIPC group. After the induction of anesthesia, the RIPC group was induced by three cycles of right upper limb ischemia and reperfusion using a blood pressure cuff. The blood pressure cuff was inflated to 200 mm Hg and we held it on for 5 minutes, deflated to 0 mm Hg and maintained for 5 minutes, which was defined as one cycle. There were 10 males and 20 females with a mean age of 47.70±8.07 years in the control group. We placed a standard blood pressure gasbag on the right upper limb for 30 minutes without inflation in the control group. We recorded the clinical data including cardiopulmonary bypass (CPB) time, the cross-clamping time of ascending aorta, preoperative ejection fraction (EF), EF after discharging, postoperative complica-tion and mortality. Blood were sampled preoperatively (T0), 30 minutes after RIPC (T1), 30 minutes aftr the cardiopul-monary bypass finished (T2), 24 hours (T3), 48 hours (T4) and 72 hours (T5) after surgery to detect the concentration of troponin T (cTnT) and creatine kinase-MB (CK-MB). We counted the person-time used dopamine and norepinephrine. ResultThere was no death in both groups. The mechanical ventilation time, the time of ICU stay, the time of hospital stay, the number of person used vasoactive agent, and the EF when discharging showed no statistical difference between the two groups. Levels of cTNT in the RIPC group were statistically lower than those in the control group at T2 and T3 (P=0.001, P=0.001). Levels of CK-MB in the RIPC group were statistically lower than those in the control group at T2, T3, and T4 (P=0.011, P=0.010, P=0.033). ConclusionRIPC may have protective effect on myocardium for patients underwent cardiac valvular surgery.
Objective To systematically evaluate the clinical effect of remote ischaemic preconditioning (RIPC) in selective vascular surgery. Methods PubMed, The Cochrane Library, Web of Science, EMbase, CNKI, Wanfang Data, VIP and CBM were retrieved to gather relevant literatures. Relevant randomized controlled trials were screened according to inclusion and exclusion criteria. Meta-analysis was performed using RevMan 5.3 software. Results A total of 16 studies were included, involving 1 507 patients. There was no statistical difference between RIPC and non-RIPC in reducing perioperative mortality in elective vascular surgery. There were no statistical differences between the two groups in the incidence of myocardial infarction, kidney injury, postoperative stroke, postoperative length of hospital stay, the total duration of surgery or anesthesia, limb injury, arrhythmia, heart failure or pneumonia. Conclusion For patients undergoing elective vascular surgery, there may no statistical in perioperative mortality and other clinical endpoints between RIPC and non-RIPC patients.