Relevant Factors And Early Prognosis Of Significantlt Elevated Enzymes After Off-Pump Coronary Artery Bypass Grafting

Part 1 Relevant factors of significantly elevated enzymes after off-pump coronary artery bypass graftingObjectiveOff-pump coronary artery bypass grafting (OPCABG) is a very effective method of treatment for coronary artery heart disease (CAD). OPCABG can improve the patient's myocardial ischemia, and can also cause some injury to the patient's myocardium. These injury can cause arrhythmia, circulary instability and other complications during the early postoperative recovery period. Creatine kinase MB (CK-MB) can be used to evaluate the severity of myocardial injury, which has a high degree of sensitivity and specificity. We can detect the postoperative elevation level of CK-MB to reflect the severity of myocardial injury.In the case of grafts patency, postoperative CK-MB elevates slightly in most of the patients, and declines quickly; but CK-MB elevates significantly and declines slowly in a few patients whom are often associated with electrocardiograph (ECG) changes or hypotension. So it's very important to research the relevant factors of significantly elevated enzymes after OPCABG.214 cases were selected for this study, whom had underwent OPCABG in our hospital during the period from May 2014 to September 2015. Each graft flow of intraoperative detection was satisfied. This study is to investigate the relevant factors of significantly elevated enzymes after OPCABG, and to promote early recovery of the patients.Methods(1) 214 cases were selected for research, whom had underwent OPCABG in our hospital during the period from May 2014 to September 2015. Preoperative CK-MB was less than 4.55ng/ml. The preoperative clinical data were recorded.(2) All patients were used general anesthesia, and operated by the same surgeon. The incision was midline sternotomy. The left anterior descending artery (LAD) was bridged with the left internal mammary artery (LIMA), and the remaining target arteries was bridged with the sephenous vein (SV) sequentially.(3) The transit time flow measurement (TTFT) was used to measure the blood flow of the graft vessel. If the blood flow was mainly diastolic wave and satisfied, and the pulsate index (PI) was less than 5, the graft vessel was thought to be patency; otherwise the graft vessel should be adjusted.(4) The blood flow, PI, diameter of the LAD, graft location of the LAD, number of the grafts, bypass time (from the begaining of the first graft to the end of the last graft) and so on were recorded during the operation.(5) Postoperative CK-MB was detected at the time of 12h,24h and 48h. Patients with the CK-MB less than 5.31ng/ml were divided into group a (the enzyme was slightly elevated), and the other patients with the CK-MB more than 5.31ng/ml were divided into group b (the enzyme was significantly elevated).(6) SPSS 17.0 statistical software packages were used to deal with the data. Count data was presented as percentage, and was analyzed by X2 test; measurement data were presented as mean+standard deviation (x±s), and were analyzed by Paired-t test or Oneway Anova. If p<0.05, it exists significant difference.(7) By comparing the data of the two groups, the relevant factors of statistical significance were found. The significantly elevated CK-MB was used as the dependent variable, and the-relevant factors were used for the alternative independent variables. Multiple regression approaches were gradually introduced, and some alternative independent variables were rejected. The relevant factors of significantly elevated enzymes after OPCABG were dedermined by the multiple regression analysis.Results(1) Postoperative CK-MB was elevated in all patients (P<0.05), and the peak value occurred at the time of 12h.167 cases (78%) were divided into group a, whose peak values declined to the preoperative level at the time of 48h (P>0.05).47 patients (22%) were divided into group b, whose peak values were still more than the preoperative level at the time of 48h (P??0.05).(2) Compared with the preoperative clinical data of the two groups (a vs b):the proportion of the patients with angina pectoris of 24h-preoperation was 10% vs 32% (P<0.05); there was no statistical significance of age, sex, hypertension, diabetes, body mass index (BMI), left main coronary artery disease, previous myocardial infarction, previous percutaneous coronary intervention (PCI), left ventriclar ejection fraction (LVEF), and left ventricular end-diastolic diameter (LVEDD).(3) Compared with the operative clinical data of the two groups(a vs b):the proportion of the patients whose graft location was at the diatal or middle-distal segment of LAD was 17% vs 38%(P?0.05); the proportion of the patients whose diameter of LAD was less than 1.5mm was 7% vs 19% (P?0.05); bypass time was 57-159(82+21) min VS 63-178(93+24) min (P?0.05); there was no statistical significance of number of the grafts, blood flow, PI and readjusted grafts.(4) Multiple regression analysis:The significantly elevated CK-MB was used as the dependent variable, and the relevant factors such as angina pectoris of 24h-preoperation, the graft location at the diatal or middle-distal segment of LAD, the diameter of LAD less than 1.5mm, and bypass time were used for the alternative independent variables. Multiple regression approaches were gradually introduced, and the relevant factor of "the diameter of LAD less than 1.5mm" was rejected (P>0.05).The other relevant factors of significantly elevated enzymes after OPCABG were dedermined by the multiple regression analysis (P?0.05).Conclusions(1) In the case of grafts patency, CK-MB after OPCABG was elevated in all patients, and the peak value occurred at the time of 12h. The peak values elevated slightly (within the normal reference range) and declined quickly in most patients; but in a few patients, the peak values elevated significantly (more than the upper limit of normal reference values).(2) In the case of grafts patency, the relevant factors of significantly elevated CK-MB include:angina pectoris of 24h-preoperation, the graft location at the diatal and middle-distal segment of LAD, and bypass time; their relationship is positive correlation.(3) In the case of grafts patency, because of the limited clinical data, there is no significant correlation between significantly elevated CK-MB with "the diameter of LAD less than 1.5mm" and "readjusted grafts"; maybe we will find the positive results when the sample cases are increased.(4) In the case of grafts patency, there is no significant correlation between significantly elevated CK-MB with age, sex, hypertension, diabetes, BMI, left main coronary artery disease, previous myocardial infarction, previous PCI, and LVEF.(5) In the case of grafts patency, there is no significant correlation between significantly elevated CK-MB with number of the grafts, blood flow, and PI.Part 2 Early prognosis of patients with significantly elevated enzymes after off-pump coronary artery bypass graftingObjectiveIn patients of coronary artery disease (CAD) with myocardial infarction or myocardial ischemia, ventricular remodeling would occur at early stages,which could lead to the decline of the cardiac pump function, and cause the enlargement of the left ventricular end-diastolic diameter (LVEDD).Off-pump coronary artery bypass (OPCABG) can inhibit or reverse the ventricular remodeling by improving or restoring the function of remmant and dying cardiomyocytes.OPCABG can make some damage to the myocardium in the treatment ofmyocardial refusion, so ST segment changes of electrocardiograph (ECG), lower blood pressure,and severe perioperative myocardial infarction (PMI) may occur in some patients during the early postoperative recovery period.In addition, Early ventricular remodeling may be affected by the myocardial injury, and severely it will lead to the abnormal changes of ventricular size and left ventricular ejection fraction (LVEF).Creatine kinase MB (CK-MB) can be used to evaluate the severity of myocardial injury as one of the cardiac enzymes, and it has a high degree of sensitivity and specificity. We can detect the elevation level of CK-MB which can reflect the severity of postoperative myocardial injury and recovery. It is very important for the patient's good recovery to research the relationship between myocardial injury with early postoperative complications and ventricular remodeling.214 cases were selected for this study, whom had underwent OPCABG in our hospital during the period from May 2014 to September 2015. Each graft flow of intraoperative detection was satisfied. This study was to investigate the early prognosis of significantly elevated enzymes after OPCABG, which can promote early recovery of the patients and provide research data for patients in the long-term prognosis.Methods(1) 214 cases were selected for research, whom had underwent OPCABG in our hospital during the period from May 2014 to September 2015. The left internal mammary artery (LIMA) was bridged with the left anterior descending artery (LAD) as the graft vessel, and the sephenous vein (SV) was bridged with the remaining target vessels as the graft vessel sequentially. Each graft was patency.(2) Postoperative CK-MB was detected at the time of 12h,24h and 48h. Patients with the CK-MB less than 5.31ng/ml were divided into group A (the enzyme was slightly elevated), and the other patients with the CK-MB more than 5.31ng/ml were divided into group B(the enzyme was significantly elevated).(3) Continuous electrocardiograph monitoring was applied in the patients 3 days after surgery, and aspirin (100mg oral)+clopidogrel (50mg oral) were given 12h after surgery. Low molecular weight heparin (4100iu ih q12h) was also given for 3 days to the patients. Postoperative clinical data of two groups such as tracheal intubation time,patients with fever (more than 37.5 ?), pericardial drainage, patients used of dopamine (more than 3?g/Kg.min), and patients with ST segment changes of ECG, were recorded and compared.(4) Transthoracic echocardiography was performed at the time of 3rd day preoperation,7th day postoperation and 3 months after surgery. LVEDD and LVEF were recorded and compared between the two groups.(5) Bedside 12-lead ECG was performed at the time of 3rd day preoperation, 1st,2nd,3rd day postoperation. ST segment changes,Q wave and left bundle branch block (LBBB) were recorded.(6) SPSS 17.0 statistical software packages were used to deal with the data. Count data was presented as percentage, and was analyzed by X2 test; measurement data were presented as mean ± standard deviation (x ± s), and were analyzed by Paired-t test or Oneway Anova. If p<0.05, it exists significant difference.Results(1) There was no death in the two groups during the perioperative and follow-up periods, and the follow-up rate of the 3 months after surgery was 100%.(2) Compared the postoperative clinical data of the two groups(A vs B):the proportion of patients with ECG ST segment changes was 0% vs 9% (p<0.05); the proportion of patients used of dopamine was 5% vs 17% (p<0.05);the proportion of patients with perioperative myocardial infarction (PMI) was 0% vs 4% (p<0.05); there was no statistical significance of tracheal intubation time, fever (more than 37.5?), and pericardial drainage.(3) Compared the data of LVEDD pre-and post-operation between the two groups: the LVEDDs of patients in group A decreased significantly after surgery (7 days and 3 months later), p<0.05; the LVEDDs of patients in group B changed unsignificantly at the time of 7th day after surgery (p>0.05), but they decreased significantly at the time of 3 months after surgery (p<0.05).(4) Compared the data of LVEF pre-and post-operation between the two groups: the LVEF of patients in group A changed unsignificantly at the time of 7th day after surgery (p>0.05), but they increased significantly at the time of 3 months after surgery (p<0.05); the LVEF of patients in group B changed unsignificantly after surgery (7 days and 3 months later), p>0.05.Conclusions(1) In the case of grafts patency, ECG ST segment changes, hypotesion, and severe PMI were still more likely to occur after OPCABG in patients of significantly elevated enzymes than those of slightly elevated enzymes.(2) If the grafts flow is satisfied, in the patients of slightly elevated enzymes after OPCABG, ventricular remodeling will be inhibited or reversed, and cardiac pump function will be improved at early stages.(3) If the grafts flow is satisfied, in the patients of significantly elevated enzymes after OPCABG, the progressive trends of ventricular remodeling will be inhibited, but the speed of being reversed is slow, and cardiac pump function will not be improved at early stages.(4) CK-MB can be used as an important biomarker to reflect the early prognosis of OPCABG.