Table II.
Balance of risk factors between propensity-matched cohorts of patients undergoing CEA; transfused one or two units vs nontransfused controls (n = 240)
| Risk variable | Nontransfused, No. (%) or mean ± SD |
Transfused (1–2 units), No. (%) or mean ± SD |
Standardized difference |
|---|---|---|---|
| No. of patients in cohort | 160 | 80 | |
| Age, mean years ± SD | 75.1 ± 8.1 | 74.3 ± 8.7 | −0.01 |
| Male | 83 (51.9) | 43 (53.8) | 0.04 |
| Hx hemiplegia, No. (%) | 4 (2.5) | 2 (2.5) | 0 |
| Hx TIA, No. (%) | 49 (30.6) | 25 (31.3) | 0.01 |
| Hx CVA w/neurologic deficit, No. (%) | 15 (9.4) | 8 (10.0) | 0.02 |
| Hx CVA w/o neurologic deficit, No. (%) | 14 (8.8) | 7 (8.8) | 0 |
| Preop hematocrit group | |||
| >40.0, No. (%) | 18 (11.0) | 9 (11.0) | 0 |
| 35.1–40.0, No. (%) | 34 (20.7) | 17 (20.7) | 0 |
| 30.1–35.0, No. (%) | 44 (26.8) | 22 (26.8) | 0 |
| 25.1–30.0, No. (%) | 56 (35.0) | 28 (35.0) | 0 |
| ≤25, No. (%) | 8 (4.9) | 4 (4.9) | 0 |
| Operative duration quintile | |||
| ≤80 minutes, No. (%) | 28 (17.5) | 11 (13.8) | −0.1 |
| 81–99 minutes, No. (%) | 14 (8.8) | 9 (11.3) | 0.08 |
| 100–119 minutes, No. (%) | 27 (16.9) | 13 (16.3) | −0.02 |
| 120–147 minutes, No. (%) | 20 (12.5) | 10 (12.5) | 0 |
| >147 minutes, No. (%) | 71 (44.4) | 37 (46.3) | 0.04 |
CEA, Carotid endarterectomy; CVA, cerebrovascular accident; SD, standard deviation; TIA, transient ischemic attack.