TABLE 1.
Demographic and Clinical Characteristics of 1424 Patients Who Underwent CABG Surgery With or Without Valve Surgery, Olmsted County, Minnesota, 1993-2008a,b
| Characteristic | No. of patients | Patients without SSI (n=1324) | Patients with SSI (n=100) | P value |
|---|---|---|---|---|
| Age (y), mean ± SD | 1424 | 66.7±11.2 | 67.7±9.8 | .38 |
| Female | 1424 | 320 (24.2) | 32 (32.0) | .08 |
| Race/ethnicity | 1423 | .80 | ||
| White | 1286 (97.1) | 98 (99.0) | ||
| Black | 9 (0.7) | 1 (1.0) | ||
| Hispanic | 9 (0.7) | 0 | ||
| Asian | 16 (1.2) | 0 | ||
| Native American | 3 (0.2) | 0 | ||
| BMI, mean ± SD | 1424 | 28.8±4.9 | 31.4±6.5 | <.001 |
| Presurgery length of hospital stay (d), mean ± SD | 1420 | 2.1±3.5 | 2.8±3.3 | .06 |
| Length of hospital stay (d), mean ± SD | 1424 | 7.7±7.1 | 16.1±20.8 | <.001 |
| Smokers | 1423 | 892 (67.4) | 66 (66.0) | .77 |
| Diabetes mellitus | 1424 | 362 (27.3) | 39 (39.0) | .01 |
| Ejection fraction category | 1424 | .78 | ||
| >50% | 889 (67.2) | 64 (64.0) | ||
| 35-50% | 323 (24.4) | 26 (26.0) | ||
| <35% | 112 (8.5) | 10 (10.0) | ||
| Dialysis | 1424 | 13 (1) | 1 (1.0) | >.99 |
| Chronic obstructive lung disease | 1424 | 132 (10.0) | 13 (13.0) | .33 |
| Immunosuppressive treatment | 1424 | 48 (3.6) | 8 (8.0) | .03 |
| Peripheral vascular disease | 1424 | 248 (18.7) | 26 (26.0) | .08 |
| Cerebrovascular disease | 1424 | 183 (13.8) | 19 (19.0) | .15 |
| Cerebrovascular accident | 1424 | 97 (7.3) | 7 (7.0) | .90 |
| Previous CABG | 1424 | 72 (5.4) | 7 (7.0) | .51 |
| Preoperative myocardial infarction | 1424 | 596 (45.0) | 54 (54.0) | .08 |
| Preoperative unstable angina | 1422 | 455 (34.4) | 30 (30.0) | .37 |
| Congestive heart failure | 1424 | 191 (14.4) | 21 (21.0) | .08 |
| NYHA class | 1419 | .43 | ||
| I | 49 (3.7) | 4 (4.0) | ||
| II | 181 (13.7) | 8 (8.0) | ||
| III | 549 (41.6) | 46 (46.0) | ||
| IV | 540 (41.0) | 42 (42.0) | ||
| Emergency surgery | 1424 | 94 (7.1) | 5 (5.0) | .43 |
| American Society of Anesthesiologists physical status class | 1391 | .49 | ||
| 2 (mild systemic disease, no functional limitation) | 9 (0.7) | 1 (1.0) | ||
| 3 (severe systemic disease, definite functional limitation) | 1192 (92.2) | 87 (88.8) | ||
| 4 (severe systemic disease that is a constant threat to life) | 92 (7.1) | 10 (10.2) | ||
| Operative category | 1421 | .21 | ||
| CABG | 1110 (83.8) | 79 (79.0) | ||
| CABG + valve | 214 (16.2) | 21 (21.0) | ||
| Use of venous graft from the leg | 1417 | 1122 (85.2) | 98 (98.0) | <.001 |
| Radial artery use | 1417 | 89 (6.8) | 4 (4.0) | .28 |
| Use of skeletonization as the harvested method for IMA | 1424 | .58 | ||
| None | 1235 (93.3) | 95 (95.0) | ||
| Single | 54 (4.1) | 2 (2.0) | ||
| Both | 35 (2.6) | 3 (3.0) | ||
| IMA use | 1424 | .02 | ||
| None | 107 (8.1) | 15 (15.0) | ||
| Left | 1058 (79.9) | 77 (77.0) | ||
| Right | 8 (0.6) | 2 (2.0) | ||
| Both | 151 (11.4) | 6 (6.0) | ||
| No. of IMA grafts | 1424 | .02 | ||
| 0 | 108 (8.2) | 15 (15.0) | ||
| 1 | 1067 (80.6) | 80 (80.0) | ||
| 2 | 149 (11.3) | 5 (5.0) | ||
| Intraoperative cryoprecipitate transfusion | 1423 | 13 (1.0) | 3 (3.0) | .06 |
| Reexploration- | 1424 | .60 | ||
| For bleeding | 50 (3.8) | 5 (5.0) | ||
| For another reason | 9 (0.7) | 0 | ||
| Readmission within 30 d | 1412 | 182 (13.9) | 36 (36.4) | <.001 |
a
BMI = body mass index (calculated as weight in kilograms divided by height in meters squared); CABG = coronary artery bypass graft surgery; IMA = internal mammary artery; NYHA = New York Heart Association; SSI = surgical site infection.
b
Data are presented as No. (percentage) unless otherwise indicated.