A Follow-up Study Of Mid & Long-Term Results After Coronary Artery Bypass Graft Surgery And Analysis Of Influence Factors

Purpose.To analyze the mid- and long-term results after coronary artery bypass graft surgery (CABG),and evaluate the effect of multi-detector CT coronary angiography(MDCTA) on the patency status of conduits during following up after CABG,and investigate the patency difference among different conduits and the influence factors to the mid & long term results of CABG primarily.Material and methods.One hundred and one cases underwent CABG from June 1992 to March 2008 were followed up by searching the database of CTA(42 cases) and SCA(59 cases) in Beijing Hospital.The mean following up period is 66.79±44.27(1-174) months.We investigated the history of hypertension,diabetes mellitus,hyperlipidemia,smoking,preoperative myocardial infarction and coronary artery status;graft details,surgery manner,recurrent angina pectoris or not,cardiac function status as well as detailed results of CTA and SCA.The most involved patients suffered from angina pectoris or other symptoms in different degrees after CABG,such as chest distress, palpation,dyspnea and so on.310 conduits,115 arterial and 195 venous grafts,were analyzed.A comparison of the patency rate between different conduits was also carried out.The involved patients were divided into two groups according to with or without recurrent angina pectoris after CABG.χ2 test was used to check the difference of the long term patency between the two groups. The conduit lesion is defined as a luminal reduction≥50%in diameter,we divided the investigated cases into two groups again according to if there is conduit lesion,and made univariate analysis at first,then did a Logistic regression analysis of the variates which had statistical significance (P＜0.05).When the confounding factors were excluded stepwisely,the risk factors leading to conduit lesion were screened.Results.At the following up period of 53.93±36.80 months,the patency rate of LIMA,RA,SV and CV rechecked by MDCTA is 94.7%,92.0%,85.9%and 60.0%respectively.The total patency rate is 89.9%(125/139),which is 83.5%(81/97) in the angina group,and 95.2%(40/42) in the angina-free group,with a statistically significant difference between the two groups(P=0.046).At the following up period of 75.95±47.09 months,the patency rate of LIMA,RA,SV and CV rechecked by SCA is 87.1%,81.0%,53.6%and 57.1%respectively.The total patency rate is 63.2%(108/171),which is 62.0%(101/163)in the angina group,and 100%(8/8)in the angina-free group,also with a statistically significant difference between them(P=0.025).On the Logistic regression analysis,only the postoperative period is statistically related to the conduit lesion([β_j =-0.021,P=0.000,OR_j=0.979),other variates are without statistical significance.Conclusion.1.MDCT can find out the occlusions and obvious stenoses of the conduits after CABG, which may be as a noninvasive method to evaluate the grafts patency postoperatively.2.The mid-and long-term patency of arterial grafts is better than venous grafts.3.Conduit lesion is an important factor that leading to postoperative recurrent angina pectoris.4.The severity of the conduit lesion has a strong relation to the postoperative period.