Diabetes and evidence of atherosclerosis are major risk factors for adverse outcome after elective thoracic aortic surgery

Background: To predict risk after elective repair of ascending aorta and aortic arch aneurysms, we studied 464 consecutive patients. Methods: Adverse outcome (stroke or hospital death) was analyzed in 372 patients who underwent proximal repair and 92 patients who underwent aortic arch replacement from 1986 to the present. Preoperative risk factors with a P value less than .2 in a univariate analysis were entered into a multivariate model, and an equation incorporating independent risk factors was derived separately for proximal aorta and arch surgery. Results: Age more than 65 years (P = .04), diabetes (P = .02), cause (P = .01), and prolonged total cerebral protection time (duration of hypothermic circulatory arrest and selective cerebral perfusion, P = .001) were significant univariate risk factors for elective proximal aortic repair. Diabetes (P = .005, odds ratio 5.1), atherosclerosis (P = .003, odds ratio 4.0), and dissection (P = .048, odds ratio 2.5) were independent factors. For elective arch surgery, female sex (P = .07), age more than 65 years (P = .04), coronary artery disease (P = .02), diabetes (P = .06), cause (P = .07), and prolonged total cerebral protection time (P = .025) were univariate risk factors. Female sex (P = .05, odds ratio 4.7), coronary artery disease (P = .02, odds ratio 6.5), diabetes (P = .13, odds ratio 4.0), and total cerebral protection time (P = .03, odds ratio 1.02/min) were independent factors. To calculate risk of adverse outcome (P), enter 1 if factor is present, 0 if absent, and estimate total cerebral protection time (in minutes). P-proximal aorta = {1 + exp [3.06 - 1.62 (diabetes) - 1.37 (atherosclerosis) - 0.91 (dissection)]}(-1) P-aortic arch = {1 + exp [4.93 - 1.55 (female) - 1.87 (coronary artery disease) - 1.38 (diabetes) - 0.024 (total cerebral protection time)]}(-1) Conclusion: In this large series of patients, the presence of diabetes and manifestations of atherosclerosis emerge as extremely important risk factors for adverse outcome after ascending aorta or arch surgery, displacing age. Multivariate equations derived from these data allow more precise calculation of risk for each individual contemplating elective surgery.