Table 1. Baseline characteristics in the study population as a whole and in the subgroups of patients with normal and decreased pre-operative left ventricular ejection fraction.
| Variables | All patients (n=375) | LVEF ≥50% (n=203) | LVEF <50% (n=172) | P value* |
|---|---|---|---|---|
| Age, years | 66±9 | 67±9 | 66±9 | 0.85 |
| Male sex, % | 100 | 100 | 100 | 1.00 |
| Prior MI, % | 72 | 57 | 90 | <0.001 |
| Hypertension, % | 89 | 92 | 86 | 0.09 |
| Diabetes mellitus, % | 42 | 43 | 41 | 0.69 |
| Atrial fibrillation, % | 11 | 12 | 11 | 0.68 |
| Current smoker,% | 24 | 22 | 25 | 0.52 |
| Body mass index, kg/m2 | 30.2±5.8 | 30.6±6.2 | 29.7±5.4 | 0.12 |
| COPD, % | 33 | 30 | 37 | 0.15 |
| CVA, % | 28 | 31 | 25 | 0.23 |
| PAD, % | 47 | 46 | 48 | 0.71 |
| Prior cardiac surgery, % | 5 | 4 | 6 | 0.54 |
| Permanent pacemaker, % | 7 | 5 | 9 | 0.10 |
| Laboratory values | ||||
| GFR, mL/min/1.73 m2 | 85±36 | 86±38 | 83±34 | 0.40 |
| Hemoglobin, g/dL | 13.4±1.8 | 13.4±1.8 | 13.4±1.9 | 0.34 |
| Medications | ||||
| Beta blocker, % | 92 | 88 | 93 | 0.42 |
| ACEI/ ARB, % | 71 | 67 | 76 | 0.05 |
| Spironolactone, % | 6 | 2 | 12 | <0.001 |
| Hydralazine and ISDN, % | 4 | 2 | 8 | 0.004 |
| Digoxin, % | 8 | 4 | 14 | 0.001 |
| Diuretics, % | 44 | 31 | 59 | <0.001 |
| Operative parameters | ||||
| Number of grafts | 3.0±0.8 | 3.0±0.8 | 3.0±0.8 | 0.98 |
| Bypass time, minutes | 123±39 | 123±40 | 123±38 | 0.74 |
| Ischemic time, minutes | 80±27 | 82±27 | 78±26 | 0.87 |
| # diseased coronary vessels† | 0.35 | |||
| 1 vessel,% | 5 | 0 | 10 | |
| 2 vessels,% | 32 | 25 | 40 | |
| 3 vessels, % | 64 | 75 | 50 | |
| Left main disease, %‡ | 33 | 36 | 30 | 0.30 |
ACEI, angiotensin-converting enzyme inhibitor; ARB, angiotensin receptor blocker; COPD, chronic obstructive pulmonary disease; CVA, cerebrovascular accident; GFR, glomerular filtration rate (calculated using MDRD equation); ISDN, isosorbide dinitrate; LVEF, left ventricular ejection fraction; MI, myocardial infarction; PAD, peripheral arterial disease; *, LVEF ≥50% vs. LVEF <50%; †, defined as having ≥1 lesion(s) with ≥70% stenosis; ‡, defined as having ≥50% stenosis.