Comparison Of Graft Patency Between OPCAB And CCABG And Analysis Of Relative Risk Factor

OBJECTIVES:1. To access the accuracy of 64-MSCT for evaluation of grafts patency, based on the results of Coronary Artery Angiography.2. To compare the patency between OPCAB and CCABG by 64-MSCT.3. To search the risk factors correlated with the occlusion of grafts.4. To compare the Quality of Life of patients post OPCAB vs. CCABG, and find out the causes that result in the limitation.MATERIALS and METHODS:1. There were 31 patients post CABG underwent both MSCT and CAG because of angina or graft disease. Based with the golden standard results of CAG, the sensitivity, specificity, positive predictive valve, negative predictive valve and accuracy were accessed.2. The patients were chosen for the reason that their simple CABG surgeries were carried by Prof. GaoChang-qing with a permanent operation team, anesthesia group and Extracorporeal Circulation group in the PLA General Hospital from Jan 2002 to Aug 2006. 91 post CCABG patients were chosen according to the surgery year randomly, and then 137 matched post OPCAB patients were chosen according to the clinical characteristics of the CCABG patients. The comparing analysis of grafts patency between LIMA and SVG post OPCAB vs. CCABG at 1 month, 1 year, 2 years, 3 years and 4 years were executed by 64-MSCT respectively.3. The risk factors including pre-operation, on-operation and post-operation data which were correlated with graft lesions were collected and analyzed by chi square test, t test or rank sum test for the mono-factor analysis, and then sieved by the standard of p value is less than 0.1, the factors left wereanalyzed by Logistic regress analysis, and the true factors affecting the graftsocclusion were searched out. 4. The Quality of Life of patients post OPCAB and CCABG were invested bythe EQ-5D questionnaire, comparing analysis were carried out by chi squaretest, reasons resulted in the limitation were surveyed and found out. RESULTS:1. Diagnostic accuracy of 64-MSCTA for the assessment of grafts patency: All 228 patients were checked by 64-MSCTA successfully. There were 31 patients were checked by both 64-MSCTA and CAG because of angina or graft lesions; all 82 grafts were evaluable. The 5 occlude artery grafts and 8 occlude vein grafts were checked out by 64-MSCTA and confirmed by CAG, the sensitivity, specificity, positive predictive valve, negative predictive valve and accuracy for the assessment of graft occlusion were 100% all. 64-MSCTA found 14 stenosis (include 2 stenotic LIMA grafts, 7 SVG grafts and 5 stenotic proximal anastomosis) which were proved by CAG, but as to the distal stenosis located in the RCA, MSCTA missed one and miss diagnosed one, the sensitivity, specificity, positive predictive valve, negative predictive valve and accuracy for the assessment of graft stenosis were 93.3%, 98.1%, 93.3%, 98.1% and 97.1%, respectively. The sensitivity, specificity, positive predictive valve, negative predictive valve and accuracy for assessment of graft disease were 96.4%, 98.1%, 96.4%, 98.1% and 97.6%.2. Grafts patency post CABG operation: There were 137 patients in the OPCAB group which occupied 22.6% of the contemporaneous OPCAB surgeries, 91 patients in the CCABG group which occupied 52.3% of the contemporaneous CCABG surgeries from Jan 2002 to Aug 2006. The total number of grafts was 612, including 337 grafts in the OPCAB group and 275 grafts in the CCABG group. The median time was 22 months (7-38months) post OPCAB and 22 months (6-43 months) post CCABG; The distal anstomosis of OPCAB (2.47±0.75 per patient vs 3.01±0.90 per patient p=0.0000) were less than thatof CCABG, mainly because SVG (1.45±0.79 per patient vs. 2.06±0.91per patient p=0.0000) in OPCAB were less than CCABG The 58 occluded grafts were composed of 33 grafts in the OPCAB group (7 LIMA grafts 1 radial graft and 25 SVG) and 25 grafts in the CCABG group (5 LIMA grafts 1 radial grafts and 19 SVG). LIMA patency were higher than SVG in both groups, p<0.05. There was no difference in LIMA and SVG patency compared between OPCAB and CCABG at the plot time of 1 month, 1 year, 2 years, 3 years and 4 years post-operation, p>0.05, the LIMA patency post OPCAB vs. CCABG were 99.2% vs. 100%, 98.4% vs. 98.9%, 98.9% vs. 98.3%, 98.2% vs. 97.6%,and 96.4% vs. 95.8%, respectively; the SVG patency were 98.5% vs. 99.5%, 96.3% vs. 96.9% , 95.3% vs. 96.1% , 93.6% vs. 94.6% and 90.9% vs. 92.3% respectively, p>0.05.3. Relative risk factor: the result of mono-factor analysis showed that the risk factors relative to graft occlusion were pre-PCI, diffused coronary artery disease, pre-operative and post-operative blood glucose, pre-operative and post-operative blood HDL-C level, the diameter of the target vessel, LIMA Flow (correlated with LIMA occlusion), post-operative TC blood level, antiplatelet drugs (clopidgrel and/or asprin) taken post CABG and postoperative fibrinogen blood level. Logistic regress analysis told us that diffused coronary artery disease, pre-PCI and post-operative TC blood level were risk factors; antiplatlet drugs and post operative blood HDL-C level were protective factors. Further analysis were taken according the graft category: the risk factors correlated with LIMA occlusion were the stenotic degree of target and LIMA flow; the risk factors correlated with SVG occlusion were diffused coronary artery disease, pre-PCI, post-operative TC blood level, antiplatlet drugs and post operative blood HDL-C level.4. Quality of Life post CABG: the quality of life post CABG was satisfactory, the ratio of no-limitation on mobility, self-care, usual activities, pain and anxiety/distress were 82.0%, 93.9%, 94.7%, 80.7%和 78.9%, respectively.There was no-difference between the OPCAB group and CCABG group; the main factors that caused the limitations of Quality of Life were grafts lesions and cardiac arrhythmia. CONCLUSION:1. 64-MSCTA is suitable for the assessment of graft patency with high sensitivity, specificity and accuracy.2. Graft patency post CABG:2.1 LIMA patency was higher than SVG in both groups;2.2 There was no difference on the patency between OPCAB group and CCABG group;2.3 The distal anastomoses in OPCAB were less than that of CCABG.3. The risk factors relative to occlusion were diffused coronary artery disease, pre-PCI, post-operative TC level, antiplatlet drugs and post operative blood HDL-C level by Logistic regress analysis. As to LIMA: the risk factors include stenotic degree of target vessel and LIMA flow. Pre-PCI, diffused coronary artery disease, oral antiplatelet drugs and post-operative HDL-C and TC level were correlated with SVG occlusion.4. The Quality of Life post CABG was satisfactory; there was no difference between the two groups, the main factors that caused the limitations were graft lesions and arrhythmia.