Table 2.
Baseline, Operative, and Mortality Details by Center Volume (Tertiles of Latest 3‐Year Activity) (NACSA Cohort)
| Patient Factora | Low‐Volume Center (n=1308) | Medium‐Volume Center (n=2159) | High‐Volume Center (n=4591) |
|---|---|---|---|
| Demographics | |||
| Age at operation, y | 64 (52, 72) | 64 (52, 73) | 64 (51, 73) |
| BMI, kg/m2 | 27.2 (24.4, 30.2) | 27.0 (24.1, 30.4) | 26.7 (23.9, 29.9) |
| Female sex | 450 (34.4) | 715 (33.1) | 1526 (33.2) |
| Comorbidities | |||
| Unstable angina | 77 (5.9) | 114 (5.3) | 181 (3.9) |
| NYHA ≥III | 411 (31.4) | 721 (33.4) | 1184 (25.8) |
| MI within 90 days of operation | 58 (4.4) | 72 (3.3) | 138 (3.0) |
| Previous cardiac surgery | 150 (11.5) | 307 (14.2) | 795 (17.3) |
| Previous aortic surgery | 27 (2.1) | 71 (3.3) | 237 (5.2) |
| Diabetes mellitus | 102 (7.8) | 175 (8.1) | 276 (6.0) |
| Current smoker | 166 (12.7) | 236 (12.2) | 478 (10.4) |
| Hypertension | 838 (64.1) | 1419 (65.7) | 2779 (60.5) |
| Creatinine >200 μmol/L | 39 (3.0) | 62 (2.9) | 123 (2.7) |
| History of renal dysfunction | 16 (1.2) | 37 (1.7) | 81 (1.8) |
| History of pulmonary disease | 153 (11.7) | 267 (12.4) | 554 (12.1) |
| History of stroke | 119 (9.1) | 192 (8.9) | 350 (7.6) |
| Neurological dysfunction | 55 (4.2) | 91 (4.2) | 160 (3.5) |
| Peripheral vascular disease | 213 (16.3) | 452 (20.9) | 647 (14.1) |
| Preoperative nonsinus heart rhythm | 182 (13.9) | 278 (12.9) | 478 (10.4) |
| Triple vessel disease | 68 (5.2) | 134 (6.2) | 169 (3.7) |
| Left main stem disease | 30 (2.3) | 45 (2.1) | 77 (1.7) |
| Moderate ejection fraction (30–50%) | 308 (23.6) | 419 (19.4) | 857 (18.7) |
| Poor ejection fraction (<30%) | 57 (4.4) | 92 (4.3) | 179 (3.9) |
| PA systolic >60 mm Hg | 26 (2.0) | 26 (1.2) | 42 (0.9) |
| Preoperative IV nitrates | 62 (4.7) | 118 (5.5) | 231 (5.0) |
| Preoperative IV inotropes | 35 (2.7) | 58 (2.7) | 133 (2.9) |
| Preoperative ventilation | 22 (1.7) | 42 (2.0) | 102 (2.2) |
| Preoperative cardiogenic shock | 88 (6.7) | 100 (4.6) | 154 (3.4) |
| Nonelective priority | 497 (38.0) | 801 (37.1) | 1643 (35.8) |
| Urgent priority | 202 (15.4) | 396 (18.3) | 697 (15.2) |
| Emergency priority | 267 (20.4) | 355 (16.4) | 888 (19.3) |
| Salvage priority | 28 (2.1) | 50 (2.3) | 58 (1.3) |
| Dominant pathology | |||
| Aneurysm | 697 (53.3) | 1248 (57.8) | 2477 (54.0) |
| Dissection | 326 (24.9) | 481 (22.3) | 1012 (22.0) |
| Trauma | 7 (0.5) | 7 (0.3) | 36 (0.8) |
| “Other” | 166 (12.7) | 366 (17.0) | 702 (15.3) |
| Data N/A | 112 (8.6) | 57 (2.6) | 364 (7.9) |
| Aortic segment | |||
| Root/ascending aorta | 1211 (92.6) | 1798 (83.3) | 3839 (83.6) |
| Aortic arch | 75 (5.7) | 275 (12.7) | 412 (9.0) |
| Descending aorta | 17 (1.3) | 58 (2.7) | 245 (5.3) |
| Thoracoabdominal aorta | 5 (0.4) | 28 (1.3) | 95 (2.1) |
| Surgical data | |||
| Concomitant valve operation | 948 (72.5) | 1339 (62.0) | 3032 (66.0) |
| Concomitant CABG operation | 237 (18.1) | 399 (18.5) | 846 (18.4) |
| Concomitant “other” cardiac operation | 510 (39.0) | 728 (33.7) | 1408 (30.7) |
| CPB time, min | 178 (129, 240) | 152 (114, 208) | 162 (116, 229) |
| ACC time, min | 114 (82, 154) | 104 (74, 136) | 105 (75, 143) |
| Circulatory arrest time, min | 26 (18, 37) | 25 (17, 34) | 27 (18, 39) |
| Outcome | |||
| In‐hospital mortality | 138 (10.6) | 206 (9.5) | 404 (8.8) |
ACC indicates aortic cross‐clamp; BMI, body mass index; CABG, coronary artery bypass grafting; CPB, cardiopulmonary bypass; IV, intravenous; NACSA, National Adult Cardiac Surgery audit; N/A, not available; NYHA, New York Heart Association; PA, pulmonary artery.
a
Numerical data are expressed as median and interquartile range (IQR); categorical data as absolute number (percentage).