Table E6.
Characteristics of 11,814 patients undergoing coronary artery bypass grafting over the study period: Michigan versus non-Michigan center comparison
| Variables | Non-Michigan centers | Michigan centers | P value |
|---|---|---|---|
| Patients | 1420 | 10,394 | |
| Preoperative | |||
| Age, y | 65.0 [58.0, 72.0] | 67.0 [60.0, 73.0] | <.001 |
| Body surface area, m2 | 2.0 [1.9, 2.2] | 2.1 [1.9, 2.2] | <.001 |
| Female | 300 (21.1) | 2385 (22.9) | .13 |
| Race | <.001 | ||
| Black | 165 (11.6) | 531 (5.1) | |
| Asian | 126 (8.9) | 92 (0.9) | |
| White and other | 1129 (79.5) | 9771 (94.0) | |
| Ejection fraction | 56.0 [45.0, 61.0] | 57.0 [48.0, 61.0] | .67 |
| Creatinine, mg/dL | 1.0 [0.83, 1.2] | 1.0 [0.83, 1.2] | .02 |
| Hematocrit | 40.4 [36.8, 43.8] | 40.4 [36.9, 43.7] | .95 |
| White blood cell count, thousands | 8.1 (2.9) | 8.0 (3.1) | .19 |
| Shock | 34 (2.4) | 194 (1.9) | .21 |
| Atrial fibrillation | 61 (4.3) | 613 (5.9) | .02 |
| Cardiac presentation at admission | <.001 | ||
| No symptom | 147 (10.4) | 437 (4.2) | |
| Stable angina | 356 (25.1) | 1289 (12.4) | |
| Unstable angina | 319 (22.5) | 3847 (37.0) | |
| Non-STEMI | 406 (28.6) | 2964 (28.5) | |
| Other (includes STEMI) | 192 (13.5) | 1857 (17.9) | |
| Cerebrovascular disease | 248 (17.5) | 2805 (27.0) | <.001 |
| Stroke | 109 (7.7) | 856 (8.2) | .50 |
| Diabetes and control method, % | .54 | ||
| Insulin diabetes | 287 (20.2) | 1993 (19.2) | |
| Noninsulin diabetes | 428 (30.1) | 3095 (29.8) | |
| Other or no diabetes | 705 (49.6) | 5306 (51.0) | |
| New York Heart Association class III/IV, % | 104 (7.3) | 1023 (9.8) | .00 |
| Home oxygen, % | 8 (0.6) | 161 (1.5) | .01 |
| Recent pneumonia, % | 53 (3.7) | 207 (2.0) | <.001 |
| Recent smoker, % | 231 (16.3) | 2282 (22.0) | <.001 |
| Hypertension, % | 1229 (86.5) | 9507 (91.5) | <.001 |
| Immunosuppressive therapy, % | 48 (3.4) | 430 (4.1) | .20 |
| Left main disease, % | 282 (19.9) | 2334 (22.5) | .03 |
| Liver disease, % | 29 (2.0) | 317 (3.0) | .04 |
| Myocardial infarction within 7 d, % | 423 (29.8) | 3016 (29.0) | .57 |
| Number of diseased vessels, % | .00 | ||
| One or fewer | 52 (3.7) | 253 (2.4) | |
| Two | 288 (20.3) | 1870 (18.0) | |
| Three | 1080 (76.1) | 8271 (79.6) | |
| Previous cardiac intervention, % | 412 (29.0) | 3620 (34.8) | <.001 |
| Percutaneous coronary intervention within 6 h, % | 10 (0.7) | 63 (0.6) | .79 |
| Preoperative intra-aortic balloon pump or inotropes, % | 86 (6.1) | 717 (6.9) | .26 |
| Peripheral arterial disease, % | 139 (9.8) | 1581 (15.2) | <.001 |
| Dialysis, % | 45 (3.2) | 257 (2.5) | .14 |
| Status, % | .00 | ||
| Elective | 621 (43.7) | 4032 (38.8) | |
| Urgent | 762 (53.7) | 6128 (59.0) | |
| Emergent | 37 (2.6) | 232 (2.2) | |
| Anticoagulants within 48 h, % | 669 (47.1) | 5144 (49.5) | .10 |
| Intraoperative | |||
| Perfusion, min | 92.0 [75.0, 114.0] | 97.0 [74.0, 126.0] | <.001 |
| Crossclamp, min | 70.0 [53.0, 88.0] | 76.0 [54.0, 100.5] | <.001 |
| Heparin management | |||
| Method of determining initial heparin dose | <.0001 | ||
| Fixed weight-based | 353 (25.0) | 8810 (85.1) | |
| Heparin dose response | 1060 (75.0) | 1547 (14.9) | |
| Total dose for CPB, units | 28,000 [23,000, 34,000] | 33,000 [30,000, 40,000] | <.0001 |
| Anticoagulation monitoring | |||
| Method for monitoring | |||
| ACT | 1241 (87.4) | 10,306 (99.7) | <.0001 |
| Heparin concentration | 1062 (74.8) | 617 (6.0) | <.0001 |
| PT/PTT | 0 (0) | 1 (0.01) | .99 |
| Other | 681 (48.0) | 4 (0.04) | <.0001 |
| Retrograde autologous priming | 1332 (93.8) | 8959 (86.2) | <.0001 |
| Static prime volume, mL | 1050.0 [850.0,1200.0] | 910.0 [820.0, 1053.0] | <.0001 |
| Use of antifibrinolytics | |||
| Coagulation monitoring | |||
| No | 575 (40.5) | 7054 (68.2) | <.0001 |
| Yes, before CPB | 704 (49.6) | 1959 (18.9) | <.0001 |
| Yes, during CPB | 5 (0.4) | 497 (4.8) | <.0001 |
| Yes, after CPB cessation | 2 (0.1) | 1955 (18.9) | <.0001 |
| Return to cardiopulmonary bypass | 30 (2.1) | 217 (2.1) | .95 |
| Hemodynamic instability | 13 (0.9) | 122 (1.2) | .39 |
| Technical | 16 (1.1) | 110 (1.1) | .81 |
| Other | 5 (0.4) | 7 (0.1) | .01 |
| Red cell transfusion | .00 | ||
| 0 | 1293 (91.1) | 9111 (87.7) | |
| 1-2 | 105 (7.4) | 1045 (10.1) | |
| ≥3 | 22 (1.5) | 238 (2.3) | |
| Hematocrit | |||
| Nadir on CPB | 26.7 [23.8, 30.0] | 26.0 [22.4, 29.4] | <.001 |
| Before first RBC transfusion | 21.0 [19.0, 22.0] | 20.0 [18.0, 22.0] | .24 |
| Before second RBC transfusion | 21.0 [20.0, 22.0] | 20.0 [19.0, 23.0] | .35 |
| Intra-aortic balloon pump | 20 (1.4) | 168 (1.6) | .64 |
| Conventional ultrafiltration | 442 (31.1) | 1842 (17.7) | <.001 |
| Ultrafiltration volume per kg, mL/kg | 16.9 [10.6, 27.4] | 14.1 [8.7, 24.1] | <.0001 |
| Cardiotomy suction | |||
| Not used | 249 (17.5) | 955 (9.2) | <.0001 |
| Used and stopped before protamine | 371 (26.1) | 7431 (71.5) | <.0001 |
| Protamine dosing, mg | 250.0 [200.0, 300.0] | 300.0 [250.0, 400.0] | <.0001 |
| Method for calculating initial protamine dose | <.0001 | ||
| Fixed dose | 2 (0.1) | 636 (6.1) | |
| Heparin protamine titration | 1057 (74.8) | 1461 (14.1) | |
| Ratio dose of heparin given | 354 (25.1) | 8125 (78.4) | |
| Protamine not given | 0 (0) | 0 (0) | |
| Other | 0 (0) | 136 (1.3) | |
| Non-RBC transfusion (amount in units) | |||
| In prime | 0 [0, 0] | 0 [0, 0] | |
| Fresh-frozen plasma | 0 [0, 0] | 0 [0, 0] | .56 |
| During CPB | |||
| Platelets | 0 [0, 0] | 0 [0, 0] | .002 |
| Fresh-frozen plasma | 0 [0, 0] | 0 [0, 0] | .44 |
| Non-CPB | |||
| Platelets | 2 [1, 2] | 1 [1, 2] | .81 |
| Fresh-frozen plasma | 2 [2, 2] | 2 [2, 2] | .11 |
| Autotransfusion device used | 1390 (97.9) | 10,165 (97.8) | .83 |
| Evidence of clot in circuit | 9 (0.6) | 50 (0.5) | .44 |
| Postoperative | |||
| Red cell transfusion | <.001 | ||
| 0 | 1161 (81.8) | 7973 (76.7) | |
| 1-2 | 197 (13.9) | 1752 (16.9) | |
| ≥3 | 62 (4.4) | 669 (6.4) | |
| Renal failure, % | 16 (1.1) | 202 (2.0) | .03 |
| Stroke, % | 14 (1.0) | 132 (1.3) | .38 |
| Reoperation for bleeding | 23 (1.6) | 184 (1.8) | .77 |
| Intensive care unit, h | 47.0 [24.1, 76.0] | 49.0 [26.5, 88.0] | <.001 |
| Ventilation time, h | 4.8 [3.5, 7.0] | 5.2 [3.7, 8.3] | <.001 |
| Operative mortality | 4 (0.3) | 57 (0.5) | .26 |
STEMI, ST-Segment elevation myocardial infarction; CPB, cardiopulmonary bypass; ACT, activated clotting time; PT/PTT, prothrombin time/partial thromboplastin time; RBC, red blood cell.