Table 1.
Characteristics of Canadian cardiac intensive care unit patients requiring mechanical ventilation stratified by annual institutional mechanical ventilation volume
| CICU MV volume |
Total (n = 47 173) | P-value | |||
|---|---|---|---|---|---|
| ≤100 (n = 17 702) | 101–300 (n = 24 351) | >300 (5120) | |||
| Age at admission | |||||
| Median (IQR) | 70.0 (60.0–78.0) | 68.0 (59.0–77.0) | 68.0 (59.0–77.0) | 69.0 (59.0–78.0) | <0.0001 |
| Female sex (%) | 6884 (38.9) | 8431 (34.6) | 1605 (31.3) | 16 920 (35.9) | <0.0001 |
| MV type | |||||
| Invasive (%) | 15 405 (87.0) | 21 180 (87.0) | 4710 (92.0) | 41 295 (87.5) | <0.0001 |
| Non-invasive (%) | 2047 (11.6) | 2613 (10.7) | 313 (6.1) | 4973 (10.5) | |
| Both invasive and non-invasive (%) | 250 (1.4) | 558 (2.3) | 97 (1.9) | 905 (1.9) | |
| Admission categories | |||||
| Transferred (%) | 7555 (42.7) | 15 134 (62.1) | 4211 (82.2) | 26 900 (57.0) | <0.0001 |
| ED (%) | 10 147 (57.3) | 9217 (37.9) | 909 (17.8) | 20 273 (43.0) | |
| PCI capability | |||||
| Not capable (%) | 8471 (47.9) | 5274 (21.7) | 0 (0.0) | 13 745 (29.1) | <0.0001 |
| Capable (%) | 9231 (52.1) | 19 077 (78.3) | 5120 (100.0) | 33 428 (70.9) | |
| Hospital type | <0.001 | ||||
| Academic (%) | 8915 (50.4) | 19 820 (81.4) | 5120 (100.0) | 0 | |
| All community (%) | 8783 (49.6) | 4531 (18.6) | 0 | 0 | |
| Large community (%) | 7993 (91.0) | 4531 (100.0) | 0 | 0 | |
| Medium community (%) | 781 (8.9) | 0 | 0 | 0 | |
| Small community (%) | 9 (0.1) | 0 | 0 | 0 | |
| Comorbidities | |||||
| Diabetes (%) | 2981 (16.8) | 4021 (16.5) | 779 (15.2) | 7781 (16.5) | 0.0221 |
| Hypertension (%) | 2925 (16.5) | 4385 (18.0) | 867 (16.9) | 8177 (17.3) | 0.0003 |
| Dyslipidaemia (%) | 672 (3.8) | 1025 (4.2) | 216 (4.2) | 1913 (4.1) | 0.0867 |
| Myocardial infraction (%) | 1672 (9.4) | 2806 (11.5) | 760 (14.8) | 5238 (11.1) | <0.0001 |
| PCI (%) | 281 (1.6) | 342 (1.4) | 67 (1.3) | 690 (1.5) | 0.1895 |
| CABG (%) | 154 (0.9) | 147 (0.6) | 20 (0.4) | 321 (0.7) | 0.0001 |
| Heart failure (%) | 2336 (13.2) | 3081 (12.7) | 683 (13.3) | 6100 (12.9) | 0.17 |
| Atrial fibrillation (%) | 1321 (7.5) | 1772 (7.3) | 368 (7.2) | 3461 (7.3) | 0.7021 |
| Cerebrovascular disease (%) | 454 (2.6) | 530 (2.2) | 107 (2.1) | 1091 (2.3) | 0.0174 |
| Peripheral vascular disease (%) | 551 (3.1) | 667 (2.7) | 116 (2.3) | 1334 (2.8) | 0.0027 |
| Chronic obstructive pulmonary disease (%) | 1237 (7.0) | 1476 (6.1) | 210 (4.1) | 2923 (6.2) | <0.0001 |
| Renal disease (%) | 1033 (5.8) | 1381 (5.7) | 186 (3.6) | 2600 (5.5) | <0.0001 |
| Cancer (%) | 600 (3.4) | 636 (2.6) | 78 (1.5) | 1314 (2.8) | <0.0001 |
| Dementia (%) | 207 (1.2) | 182 (0.7) | 21 (0.4) | 410 (0.9) | <0.0001 |
| Charlson Comorbidity Index, mean (IQR) | 3 (1–4) | 2 (1–4) | 2 (1–4) | 3 (1–4) | <0.001 |
| Discharge diagnosis | |||||
| NSTEMI (%) | 1499 (8.5) | 1454 (6.0) | 203 (4.0) | 3156 (6.7) | <0.0001 |
| STEMI and complications (%) | 2780 (15.7) | 3849 (15.8) | 646 (12.6) | 7275 (15.4) | <0.0001 |
| Unstable angina (%) | 37 (0.2) | 78 (0.3) | 16 (0.3) | 131 (0.3) | 0.0891 |
| CAD and chest pain (%) | 680 (3.8) | 5009 (20.6) | 2012 (39.3) | 7701 (16.3) | <0.0001 |
| Valve disease (%) | 262 (1.5) | 1292 (5.3) | 717 (14.0) | 2271 (4.8) | <0.0001 |
| Shock (%) | 3898 (22.0) | 5606 (23.0) | 1056 (20.6) | 10 560 (22.4) | 0.0003 |
| HF and cardiomyopathies (%) | 2570 (14.5) | 2555 (10.5) | 377 (7.4) | 5502 (11.7) | <0.0001 |
| Cardiac arrest and ventricular arrhythmias (%) | 796 (4.5) | 961 (4.0) | 110 (2.2) | 1867 (4.0) | <0.001 |
| Supra ventricular arrhythmias (%) | 348 (2.0) | 305 (1.3) | 42 (0.8) | 695 (1.5) | <0.0001 |
| Syncope and conduction disease (%) | 390 (2.2) | 345 (1.4) | 49 (1.0) | 784 (1.7) | <0.001 |
| Aortic and arterial (%) | 301 (1.7) | 295 (1.2) | 95 (1.9) | 691 (1.5) | <0.0001 |
| Critical care therapies | |||||
| Resuscitation (%) | 2191 (12.4) | 2524 (10.4) | 343 (6.7) | 5058 (10.7) | <0.0001 |
| Dialysis including haemodialysis (%) | 2327 (13.1) | 3528 (14.5) | 435 (8.5) | 6290 (13.3) | <0.0001 |
| Catheterization (%) | 4991 (28.2) | 10 825 (44.5) | 2417 (47.2) | 18 233 (38.7) | <0.0001 |
| PCI (%) | 2737 (15.5) | 5116 (21.0) | 893 (17.4) | 8746 (18.5) | <0.001 |
| Catheterization or PCI (%) | 5223 (29.5) | 11 070 (45.5) | 2470 (48.2) | 18 763 (39.8) | <0.0001 |
| Intra-aortic balloon pump (%) | 1028 (5.8) | 2744 (11.3) | 521 (10.2) | 4293 (9.1) | <0.001 |
CABG, coronary artery bypass grafting; CAD, coronary artery disease; CICU, cardiac intensive care unit; ED, emergency department; ED, emergency department; HF, heart failure; IQR, interquartile range; MV, mechanical ventilation; NSTEMI, non-ST-elevation myocardial infarction; PCI, percutaneous coronary intervention; SD, standard deviation; STEMI, ST-elevation myocardial infarction.