Risk Factors and prediction model for mortality in octogenarians with off-pump coronary artery bypass grafting: Analysis of the Database from a Single Center of Anzhen hospital

Abstract

Objective To assess risk factors and establish prediction model for mortality in octogenarians with off-pump coronary artery bypass grafting(OPCABG), to supply help for medical decision and basis for medical strategy accordingly. Methods The clinical information was from the Anzhen Hospital. From June 2005 to July 2015 patients underwent OPCABG in our hospital, of whom 273 patients were aged 80 years or older. First of all the potential risk variables were identified through literature reviewing and referring other risk models. The data collection proceeded according to the potential risk factors. Univariate analysis and logistic regression were applied to find the potential risk factors. Risk factors and prediction model for mortality were confirmed. The calibration and discrimination of the prediction model were tested at last. Results 273 patients aged 80 years or older underwent isolated OPCABG were recruited. In hospital coronary operative mortality was 5.49% (15/273). Median follow-up duration was 6 years. All cause mortality rate was 21.61 %(59/273). Four variables: left main disease>50%, left ventricular ejection fraction (LVEF), acute myocardium infraction before surgery, operative status selective or emergent were independently correlated with OPCABG operative mortality. The results of Hosmer-Lemeshow test was χ2=5.871, P=0.662. The results of discrimination assessing by area under receiver-operating characteristic (ROC) curve was 0.877. Conclusions The following risk factors are associated with increased operative mortality of octogenarians with off-pump coronary artery bypass grafting in China: Left main disease> 50% LVEF, acute myocardium infraction before surgery, operative status selective or emergent. The prediction model established by the four potential risk factors was proven to perform well by some statistic tests. Key words: Octogenarians; Coronary heart disease; Off-pump coronary artery bypass grafting; Risk factor; Chronic obstructive pulmonary disease