Risk factors for mortality after coronary artery bypass grafting in patients with low left ventricular ejection fraction

Background We managed to assess and confirm the risk factors for mortality after coronary artery bypass grafting(CABG)operations so as to map out the proper guidance of surgical strategy especially in patients with low leftventricular ejection fraction(LVEF)in domestic polyclinic like ours.Methods Five hundred and forty-eight consecutive patients underwent CABG from December 1999 through August2005 were analyzed retrospectively.Eighty-nine cases had an LVEF of 40% or less.All together twenty-two candidatefactors were evaluated for their association with perioperative death using univariate and multivariate stepwise Logisticanalysis.Results When data from all the patients who had undergone CABG were taken into account,LVEF,left ventricular enddiastolic diameter(LVEDD),mitral regurgitation,aneurysm of the heart wall,mitral repair/replacement,resection ofaneurysm,concomitant aortic valve replacement,and perioperative intra-aortic balloon counter-pulsation(IABP),leftventricular assist device(LVAD)and cardiopulmonary bypass(CPB)all showed an association with perioperative deathin univariate analysis,while an LVEF of>40%,on the other hand,appeared to be a protective factor.In multivariateanalysis,moderate to severe mitral regurgitation,aneurysm of the heart wall,repair of septal perforation and aorticregurgitation were proved to be risk factors.When the analysis was restricted to patients with an LVEF of 40% or less,such variables as age,LVEDD,mitral regurgitation,mitral repair/replacement,IABP,and CPB were qualified as riskfactors in a univariate analysis.Age,moderate mitral regurgitation,aneurysm of the heart wall,CPB,left maJn coronaryartery disease and female were associated with perioperative death in a multivariate logistic regression analysis.Conclusions Concerning the prognosis,patients who undergo CABG would have different risk factors when data fromall the enrolled patients or data from patients with LVEF≤40% is compared.This is because low LVEF is itself animportant risk factor.Regarding the low LVEF patients,the aggressive treatments including correction of mitralregurgitation and resection of aneurysm of the heart wall concomitant with CABG should be taken into account whileplanning the operative strategy to ensure the perioperative safety and prognosis.Chin Med J 2007;120(4):317-322