(+) CABG (-) CABG  
  N=88 N=28 p
Age, yr 68±8 69±8 0.41
Education, yr 12±2 13±2 0.49
Caucasian (%) 80(91) 23(8) 0.30
Married (%) 55(63) 17(61) 0.87
Current smoker (%) 20(23) 2(7) 0.07
Hypertension (%) 80(91) 22(79) 0.08
Hypercholesterolemia (%) 79(90) 26(93) 1.00
Angina (%) 35(40) 6(21) 0.08
Arrhythmia (%) 8(9) 5(18) 0.21
Myocardial infarction (%) 14(16) 9(32) 0.06
Peripheral vascular disease (%) 10(11) 2(7) 0.73
Diabetes (%) 49(56) 15(54) 0.84
Congestive heart failure (%) 12(14) 2(7) 0.51
Anxiety disorder (%) 6(7) 1(4) 1.00
Stroke (%) 5(6) 1(4) 1.00
Sleep disorder (%) 33(38) 15(54) 0.13
Depression (%) 17(19) 8(29) 0.30
Geriatric depression score (GDS-15) 3±3 4±4 0.17
Antihypertensive drug (%) 68(77) 25(89) 0.28
Diuretic drug (%) 33(38) 6(21) 0.12
Lipid lowering drug (%) 74(84) 25(89) 0.76
Hachinski score >=4, baseline (%) 0(0) 0(0)  
The p values are from t-test for continuous variables and Chi-square or Fisher's exact test for dichotomous variables, Data are expressed as number (%) or mean±SD, CABG: coronary artery bypass graft
Table 1: Demographics and medical data in two patient groups.