Table 1.
Baseline/operative characteristics
| HMOX1 Genotype | |||||
|---|---|---|---|---|---|
| Characteristic | All (n=2377) | SS (n=304) | SL (n=1102) | LL (n=971) | P Valuea |
| Demographics | |||||
| Age, yr | 65 [58–74] | 64 [57–73] | 65 [58–74] | 66 [58–74] | 0.49 |
| Female | 529 (22) | 69 (23) | 231 (21) | 229 (24) | 0.35 |
| Preoperative renal function | |||||
| SCr, mg/dl | 1.0 [0.9–1.2] | 1.0 [0.9–1.2] | 1.0 [0.9–1.2] | 1.0 [0.9–1.2] | 0.43 |
| eGFR, ml/min per 1.73 m2 | 72 [58–87] | 74 [59–87] | 72 [58–86] | 73 [57–87] | 0.56 |
| eGFR<60 ml/min per 1.73 m2 | 692 (29) | 83 (27) | 315 (29) | 294 (30) | 0.53 |
| eGFR=30–59 ml/min per 1.73 m2 | 652 (27) | 79 (26) | 298 (27) | 275 (28) | 0.67 |
| eGFR=15–29 ml/min per 1.73 m2 | 40 (2) | 4 (1) | 17 (2) | 19 (2) | 0.66 |
| Comorbidities | |||||
| Hypertension | 1764 (74) | 217 (71) | 834 (76) | 713 (73) | 0.21 |
| Diabetes mellitus | 739 (31) | 88 (29) | 341 (31) | 310 (32) | 0.61 |
| Chronic lung disease | 260 (11) | 35 (12) | 130 (12) | 95 (10) | 0.30 |
| Atrial fibrillation/flutter | 193 (8) | 28 (9) | 91 (8) | 74 (8) | 0.65 |
| Operative characteristics | |||||
| Type of procedure | 0.77 | ||||
| CABG alone | 1822 (77) | 241 (79) | 845 (77) | 736 (76) | |
| Valve alone | 323 (14) | 38 (13) | 151 (14) | 134 (14) | |
| Combined CABG and valve | 232 (10) | 25 (8) | 106 (10) | 101 (10) | |
| Urgent procedure | 1138 (48) | 141 (46) | 522 (47) | 475 (49) | 0.65 |
| Previous cardiac surgery | 109 (5) | 14 (5) | 50 (5) | 45 (5) | 0.99 |
| CPB time, min | 103 [75–137] | 102 [75–129] | 103 [75–137] | 104 [75–138] | 0.54 |
| Crossclamp time, min | 76 [55–101] | 76 [58–98] | 77 [55–102] | 76 [56–103] | 0.94 |
| Intraoperative pRBCs, no. of units | 0 [0–1] | 0 [0–1] | 0 [0–0] | 0 [0–1] | 0.66 |
| Intraoperative cellsaver, ml | 3 [2–197] | 3 [2–47] | 3 [2–130] | 3 [2–220] | 0.59 |
Data are presented as n (%) or median [interquartile range, 25th–75th percentile]. The S allele represents a short (<27) number of repeats, and the L allele represents a long (≥27) number of (GT)n repeats in the HMOX1 gene promoter. Shorter repeats are associated with greater HMOX1 mRNA expression and enzyme activity. eGFR was determined using the Chronic Kidney Disease Epidemiology Collaboration equation.32
a
P values for comparisons among the three groups were calculated using Kruskal–Wallis and Χ2 tests for continuous and categorical variables, respectively.