Objective To identify clinical significance of high level cardiac troponin I （cTnI） in the early postoperative period of off-pump coronary artery bypass grafting （OPCAB） and its predictive value for early clinical outcomes. Methods A total of 240 patients undergoing isolated OPCAB in the Department of Cardiac Surgery of People’s Hospitalof Peking University during 2011 were recruited in the study. There were 164 males and 76 females with their age of 36-83（62.07±8.24） years. Serum cTnI levels in 4-6 hours and 12-18 hours after OPCAB were monitored. Influential factors and its predictive value for early clinical outcomes of OPCAB were analyzed. Binary logistic regression analysis，correlation analysis and receiver operating characteristic （ROC） curve were performed for statistic analysis. Results Serum cTnI level in 4-6 hours after OPCAB （TNI0） was 1.28±0.40 ng/ml，and serum cTnI level in 12-18 hours after OPCAB （TNI1） was 3.60±0.74 ng/ml. Binary logistic regression analysis revealed that graft number was significant influential factors of TNI0 （P=0.000） and TNI1 （P=0.010）. Serum cTnI level in 12-18 hours after OPCAB was significantly correlated with early clinicaloutcomes of OPCAB （P＜0.05），but the correlational relationship was not b （correlation coefficient＜0.5）. ROC curveanalysis showed that serum cTnI level in 12-18 h after OPCAB had higher predictive value for patient prognosis （P＜0.05）. Serum cTnI level higher than 1.49 ng/ml in 12-18 h after OPCAB had good predictive value for postoperative ECG changes，use of intra-aortic balloon pump （IABP） and in-hospital mortality. Conclusions Serum cTnI level increases in varying degrees in the early postoperative period of OPCAB. Together with ECG changes，serum cTnI level can be used for early diagnosis of perioperative myocardial infarction with significant predictive value for early clinical outcomes of OPCAB.
Objective To investigate the effect of polyethylene glycolbovine hemoglobin (PEG-bHb), which was used as an oxygen carrier in cardioplegic solution, on the protection of isolated rat hearts. Methods The hearts of 32 male SD rats were harvested and transferred to Langendorff circuit. They were divided into 4 groups according to cardiocplegia: St.Thomas group (group A), 1∶2 PEG-bHb group (group B), 1∶4 PEG-bHb group (group C) and 1∶8 PEG-bHb group (group D). After 20min balance period, hearts were perfused with cold (4℃) cardioplegic solutions, and preserved at 30℃ for 60min, then reperfused. Levels of cardiac troponin I (cTn I) and adenosine triphosphate(ATP) contant in coronary effuent were detected, and ultrastructures of myocardium were observed. Results After reperfusion, cTn I contant of group A were higher (F=52.955,Plt;0.05) and ATP contant were lower (F=68.757,Plt;0.05) than those in group B, group C and group D. Myocardial water contant were lower in group B and group C(F=3.048,Plt;0.05). Conclusion PEG-bHb in cardioplegic solutions can provide better myocardial protection during ischemia.
Objective To investigate whether single cycle ischemic preconditioning （IP） improves the myocardial preservation in patients undergoing cardiac valve replacement. Methods From August 2002 to April 2006, 85 patients who had chronic heart valve disease and required cardiac valve replacement were randomly divided into two groups. IP group, 47 allocated to receive IP and arrested with 4 C St. Thomas＇ Hospital cardioplegic solution during cardiopulmonary bypass（CPB）, preconditioning was accomplished by using single cycle of 2 minutes occlusion of aorta followed by 3 minutes of reperfusion before cross-clamping. Control group, 38 allocated to receive 4 C St. Thomas＇ Hospital cardioplegic solution alone. Myocardial protective effects were assessed by determinations of creatinine kinase-MB isoenzyme （CK-MB） and cardiac troponin I（cTnI）, ST-T changes, ventricular arrhythmias and other clinical data in ICU. Results Serum CK-MB and cTnI concentrations were increased postoperatively in two groups. At 24, 48 and 72h after operation, values of CK-MB in IP group was significantly lower than that in control group （P〈0.05）, cTnI at 24 and 48h after operation also less in IP group （P〈0.05）. The duration for patients needed for antiarrhythmic drugs in IP group was lower than that in control group （P〈0.05）. Compared with control group, fewer inotropic drugs were used in IP group. As a result, ICU stay time in IP group was shorter than that in control group （P〈0.05）. Conclusion IP enhances the myocardial protective effect when it was used with hypothermic hyper kalemic cardioplegic solution in patients undergoing cardiac valve replacement, IP significantly reduces the postoperative increase of CK-MB, cTnI and plessens the severity of postoperative ventricular arrhythmias.
Objective To evaluate the influences of myocardial injury markers on the short-term and long-term mortality after coronary artery bypass grafting (CABG), so as to provide valuable references for clinical prognosis assessment. Methods Literature was electronically searched in CBM, PubMed, OVID, EMbase and CNKI from the date of their establishment to August 2011, meanwhile the manual searches were also performed to systemize the papers. According to the Cochrane Handbook for systematic reviews, the studies were screened by two reviewers independently, the quality of the included studies was evaluated, the data were extracted, and meta-analysis was conducted using RevMan5.0 software. Results A total of 10 observational studies including creatine kinase-myocardial band (CK-MB) and cardiac troponin I (cTnI), and the patients involved were 10 793 totally. Results of meta-analysis showed that the increasing release of CK-MB was associated with an increasing short-term mortality risk of both on-pump (RR=2.88, 95%CI 1.94 to 4.28, Plt;0.000 01) and off-pump group (RR=3.64, 95%CI 1.07 to 12.42), P=0.04). Also the increasing release of CK-MB was associated with an increasing long-term mortality risk of both on-pump (RR=2.55, 95%CI 1.91 to 3.40, Plt;0.000 01) and off-pump group (RR=3.36, 95%CI1.46 to 7.72, P=0.004). The increasing release of cTnI was also associated with an increasing risk of both short-term mortality (RR=6.45, 95%CI 2.50 to 16.66, Plt;0.1) and long-term mortality (RR=4.18, 95%CI 2.78 to 6.28, Plt;0.1). Conclusion The evidence shows that the increasing release of both CK-MB and cTnI is associated with an increasing risk of the short-term and long-term mortality.
ObjectiveTo compare early postoperative outcomes of Chinese patients undergoing off-pump coronary artery bypass grafting (OPCAB) with or without preoperative discontinuation of aspirin. MethodsClinical data of 354 patients who underwent elective OPCAB in Department of Cardiac Surgery, People's Hospital of Peking University from 2011 to 2012 were retrospectively analyzed. There were 132 patients during year 2011 who discontinued aspirin more than 5 days before OPCAB and were defined as a discontinuation group, including 93 males and 39 females with their age of 36-83 (61.70±8.74) years. There were 222 patients during year 2012 who continued aspirin treatment before OPCAB and were defined as an aspirin group, including 162 males and 60 females with their age of 37-82 (63.26±8.94) years. Postoperative chest drainage, incidence of reexploration for bleeding, in-hospital morbidity and mortality were compared between the 2 groups. Serum cardiac troponin I (cTnI) levels during 4-6 hours, 12-18 hours and 24-48 hours after OPCAB were also compared. ResultsPreoperative clinical characters were not statistically different between the 2 groups (P>0.05). Average number of grafts in the discontinuation group was significantly smaller than that in the aspirin group (3.00±0.89 vs. 3.43±0.93, P=0.001). There was no significant difference in postoperative chest drainage (1 063.75±511.50 ml vs. 1 131.35±460.13 ml, P=0.201), incidence of reexploration for bleeding(0 case vs. 1 case, P=1.000), perioperative myocardial infarction(2 cases vs. 1 case, P=0.647), postoperative acute renal failure(4 cases vs. 7 cases, P=1.000), stroke(1 case vs. 4 cases, P=0.726), mechanical ventilation time(41.46±85.50 hours vs. 52.07±143.59 hours, P=0.441), length of ICU stay(81.46±116.90 hours vs. 79.07±136.43 hours, P=0.867), or in-hospital mortality(0.8% vs. 0.9%, P=1.000)between the 2 groups. Serum cTnI levels during 4-6 hours after OPCAB were not statistically different between the 2 groups (P=0.506). Serum cTnI levels during 12-18 hours and 24-48 hours after OPCAB were statistically different between the 2 groups (P=0.002 and P=0.000). The percentages of patients with cTnI level higher than 4.0 ng/ml during 12-18 hours and 24-48 hours after OPCAB in the aspirin group were significantly lower than those in the discontinuation group (5.4% vs. 16.7%, P=0.001;5.9% vs. 17.4%, P=0.000). ConclusionOPCAB without preoperative discontinuation of aspirin does not increase the risk of postoperative bleeding, in-hospital morbidity or mortality, but can decrease postoperative myocardial injury of Chinese patients undergoing OPCAB.