Introduction: Ischemic-reperfusion injury/IRI/ plays major role for postoperative complications after cardiac surgery and demanding great costs of health care system. The phenomenon of ischemic preconditioning/IP/ may could be the most potent and affordable mechanisms to protect against myocardial IRI. In experimental studies shown that IP is reducing infarct size and attenuating the IRI, however the currently known few clinical data is still inadequate to convert animal studies protocol to clinical settings. Therefore we conducted the study to evaluate whether IP could reduce the IPI in patients having GABC surgery with cardiopulmonary bypass /CPB/ machine.
Method: The prospective, randomized study was conducted in a Medical College in China, from March 2012 to February 2013, total 268 patients were enrolled. All the patients were divided into either placebo or IP group which 3 cycles of 5 minutes remote IP is applied to limbs before surgery. All the clinical data including biomarkers of myocardial injuries /TnT, CK-MB/, were collected in 4, 12, 24 hours intervals after CPB. All the data were analyzed with SPSS18.
Results: Demographic characteristics and perioperative data did not differ between two groups. Standardized mean difference of TnT release showed a significant decrease (-0.48 (95% CI -0.58 to -0.18)) in IP group. Moreover the level of CK-MB level, was significantly lower in IP group (0.18(95%CI 0.63-0.03)) at 4 and 12h. A similar trend was also obtained of the length ICU stay and duration of mechanical ventilation with (-0.36 (95% CI -0.73to -0.1)) and (0.14 (95% CI 0.24 to 0.08)) respectively. Conclusion: This study showed that IP is clinically safe and potent cardioprotective method. IP reduced the IRI dramatically in patients undergoing CABG. However larger randomized trials are needed to clarify the protocol used for IP and follow-up checkups for long term outcome