Groups 1 and 2 were similar in preoperative characteristics including age ( 65.3 6.8 vs 70.7 7.0 , P = 0.191 ) New York Heart Association class ( 2.3 0.5 vs 1.8 0.7 , P = 0.218 ) , EuroSCORE ( 2.8 2.0 vs 3.6 2.3 , P = 0.547 ) , the degree of carotid stenosis ( 79 12 vs 87 13 % , P = 0.224 ) and average left ventricular ejection fraction ( 44.3 12.4 vs 43.4 13.3 % , P = 0.896 ) .