Table 1.
Patient and Operative Characteristics and Unadjusted Risk Ratios (Major Infection)*
| Infected (N = 237) | Not Infected (N = 4,921) | Overall (N = 5158) | Unadjusted HR | P-value† | |
|---|---|---|---|---|---|
| Demographics | |||||
| Age, mean (SD) | 65.6 (13.8) | 64.3 (13.2) | 64.4 (13.2) | 1.01 | 0.13 |
| Male | 157 (66.2) | 3293 (66.9) | 3450 (66.9) | 0.97 | 0.81 |
| White | 181 (76.4) | 4141 (84.2) | 4322 (83.9) | 0.61 | 0.001 |
| BMI | 28.5 (24.4, 33.2) | 28.2 (25.1, 32.2) | 28.2 (25.1, 32.3) | 1.01 | 0.34 |
| Insurance | 0.11 | ||||
| Medicaid | 14 (5.9) | 219 (4.5) | 233 (4.5) | 1.90 | |
| Medicare | 103 (43.5) | 1825 (37.2) | 1928 (37.5) | 1.69 | |
| Government (Other) | 20 (8.4) | 606 (12.3) | 626 (12.2) | 1.00 (ref) | |
| Private | 87 (36.7) | 2012 (41.0) | 2099 (40.8) | 1.30 | |
| None/Self | 13 (5.5) | 247 (5.0) | 260 (5.1) | 1.58 | |
| Baseline Laboratories | |||||
| WBC, x103/ml | 7.2 (5.8, 8.7) | 6.9 (5.7, 8.4) | 7.0 (5.7, 8.4) | 1.03 | 0.11 |
| Creatinine, mg/dL | 1.1 (0.9, 1.4) | 1.0 (0.8, 1.2) | 1.0 (0.8, 1.2) | 1.18 | <.001 |
| Hemoglobin, g/dL | 12.5 (11.0, 13.9) | 13.4 (12.1, 14.6) | 13.4 (12.0, 14.5) | 0.80 | <.001 |
| Cardiac morbidity | |||||
| Heart failure | 110 (46.4) | 1395 (28.4) | 1505 (29.2) | 2.16 | <.001 |
| Ejection fraction | 50.0 (35.0, 60.0) | 55.0 (49.0, 60.0) | 55.0 (48.0, 60.0) | 0.97 | <.001 |
| Previous cardiac surgery | 74 (31.2) | 884 (18.0) | 958 (18.6) | 2.03 | <.001 |
| Noncardiac morbidity | |||||
| Diabetes‡ | 66 (27.9) | 1103 (22.4) | 1169 (22.7) | 1.33 | 0.05 |
| COPD | <.001 | ||||
| None | 178 (75.1) | 4234 (86.0) | 4412 (85.5) | 1.00 (ref) | |
| Mild or moderate | 47 (19.8) | 597 (12.1) | 644 (12.5) | 1.84 | |
| Severe | 12 (5.1) | 90 (1.8) | 102 (2.0) | 3.04 | |
| Operative | |||||
| Surgery time, hours | 4.8 (3.9, 6.4) | 4.2 (3.3, 5.2) | 4.2 (3.3, 5.2) | 1.38 | <.001 |
| Bypass time, minutes§ | 129.0 (94.0, 180.0) | 104.0 (77.0, 138.0) | 105.0 (78.0, 140.0) | 1.01 | <.001 |
| Sternotomy | 218 (92.0) | 4451 (90.5) | 4669 (90.5) | 1.20 | 0.45 |
| Surgery Type | 0.01 | ||||
| Elective | 155 (65.4) | 3651 (74.2) | 3806 (73.8) | 1.00 (ref) | |
| Urgent | 72 (30.4) | 1142 (23.2) | 1214 (23.5) | 1.47 | |
| Emergent | 10 (4.2) | 128 (2.6) | 138 (2.7) | 1.82 | |
| Procedure | <.001 | ||||
| Isolated CABG | 54 (22.8) | 1623 (33.0) | 1677 (32.5) | 1.00 (ref) | |
| Isolated valve | 72 (30.4) | 1806 (36.7) | 1878 (36.4) | 1.20 | |
| CABG + valve | 39 (16.5) | 653 (13.3) | 692 (13.4) | 1.79 | |
| LVAD/Tx | 29 (12.2) | 93 (1.9) | 122 (2.4) | 8.07 | |
| Thoracic aortic | 23 (9.7) | 405 (8.2) | 428 (8.3) | 1.72 | |
| Other|| | 20 (8.4) | 341 (6.9) | 361 (7.0) | 1.75 | |
Abbreviations: BMI, body mass index; CABG, coronary artery bypass grafting; COPD, chronic obstructive pulmonary disease; HR, hazard ratio; LVAD/Tx, left ventricular assist device or transplant surgery; SD, standard deviation.
Continuous variables are expressed as median (IQR) and categorical variables as count (%).
Based on Cox proportional hazards model where outcome is time to infection and predictor is baseline or patient characteristic.
Insulin or oral medications.
91.1% of patients had on-pump surgical procedures.
Other: ventricular septal defect repairs, atrial septal defect repairs, aneurysmectomies, PFO closures, ablations, septal myectomies, excision of cardiac tumors, pericardiectomies, and limited other procedures