Table 2.
Baseline Characteristics of the Final Study Population, Patients With M-CARS Less Than 2 and M-CARS Greater Than or Equal to 2
| Variable | Final study population (n=12,428) | M-CARS <2 (n=5890) | M-CARS ≥2 (n=6538) | P value |
|---|---|---|---|---|
| Baseline characteristics | ||||
| Age (years, mean) | 67.6±15.2 | 65.2±15.3 | 69.8±14.7 | <.001 |
| Female, n (%) | 4686 (37.7) | 2134 (36.2) | 2552 (39.0) | .0013 |
| Caucasian, n (%) | 11,466 (92.2) | 5436 (92.3) | 6030 (92.2) | .89 |
| Hospital days before CICU (mean) | 0.7±2.7 | 0.4±1.5 | 1.0±3.4 | <.001 |
| Comorbidities | ||||
| Charlson comorbidity index | 2.4±2.6 | 1.6±2.2 | 3.1±2.8 | <.001 |
| Previous myocardial infarction, n (%) | 2300 (18.5) | 962 (16.4) | 1338 (20.5) | <.001 |
| Previous heart failure, n (%) | 2521 (20.3) | 604 (10.3) | 1917 (29.4) | <.001 |
| Previous stroke, n (%) | 1483 (11.9) | 519 (8.83) | 964 (14.8) | <.001 |
| Previous diabetes mellitus, n (%) | 3544 (28.6) | 1247 (21.2) | 2297 (35.2) | <.001 |
| Previous cancer, n (%) | 2623 (21.1) | 1042 (17.7) | 1581 (24.2) | <.001 |
| Previous lung disease, n (%) | 2410 (19.4) | 881 (15.0) | 1529 (23.4) | <.001 |
| Previous chronic kidney disease, n (%) | 2561 (20.7) | 538 (9.15) | 2023 (31.0) | <.001 |
| Previous dialysis, n (%) | 620 (4.9) | 73 (1.2) | 547 (8.4) | <.001 |
| Admission diagnosesa | ||||
| Acute coronary syndrome | 5238 (42.5) | 2780 (47.8) | 2458 (37.8) | <.001 |
| Heart failure | 6008 (48.8) | 1659 (28.5) | 4349 (66.8) | <.001 |
| Shock | 1859 (15.9) | 0 (0) | 1859 (28.6) | <.001 |
| Cardiogenic shock | 1498 (12.2) | 0 (0) | 1498 (23.0) | <.001 |
| Cardiac arrest | 1479 (12.0) | 0 (0) | 1479 (22.7) | <.001 |
| VF arrest | 753 (6.1) | 0 (0) | 753 (11.6) | <.001 |
| Non-VF arrest | 726 (5.9) | 0 (0) | 726 (11.2) | <.001 |
| Respiratory failure | 2986 (24.2) | 137 (2.4) | 2849 (43.8) | <.001 |
| Sepsis | 780 (6.3) | 59 (1.0) | 721 (11.1) | <.001 |
| Severity of illness | ||||
| APACHE-III score (mean) | 60.7±25.1 | 48.0±16.2 | 72.2±26.2 | <.001 |
| APACHE-IV predicted hospital mortality (%) | 16.8±19.7 | 7.5±8.0 | 25.2±23.1 | <.001 |
| Day 1 SOFA score (mean) | 3.5±3.2 | 1.8±1.5 | 5.1±3.5 | <.001 |
| Maximum week 1 SOFA score | 21 | 16 | 21 | <.001 |
| Mean week 1 SOFA score | 3.0 | 1.7 | 4.2 | <.001 |
| Procedures and therapies | ||||
| Any critical care therapy | 5260 (42.3%) | 1129 (19.2%) | 4131 (63.2%) | <.001 |
| Inpatient coronary angiogram, n (%) | 7254 (58.4) | 3859 (65.5) | 3395 (51.9) | <.001 |
| Inpatient PCI, n (%) | 4320 (34.8) | 2567 (43.6) | 1753 (26.8) | <.001 |
| Any invasive line, n (%) | 5503 (44.3) | 2038 (34.6) | 3465 (53.0) | <.001 |
| Central venous line, n (%) | 2507 (20.2) | 584 (9.9) | 1923 (29.4) | <.001 |
| Arterial line, n (%) | 3985 (32.1) | 1513 (25.7) | 2472 (37.8) | <.001 |
| Pulmonary artery catheter, n (%) | 1198 (9.6) | 236 (4.0) | 962 (14.7) | <.001 |
| IABP in CICU, n (%) | 1051 (8.5) | 242 (4.1) | 809 (12.4) | <.001 |
| Impella (Abiomed, Danvers, MA) in hospital, n (%) | 73 (0.6) | 9 (0.2) | 64 (1.0) | <.001 |
| ECMO in CICU, n (%) | 30 (0.2) | 2 (0.0) | 28 (0.4) | <.001 |
| Any mechanical ventilation, n (%) | 3483 (28.0) | 470 (8.0) | 3013 (46.1) | <.001 |
| Duration of mechanical ventilation, days | 2.1±3.0 | 1.0±1.9 | 2.1±2.9 | <.001 |
| Invasive ventilator use, n (%) | 2034 (16.4) | 108 (1.8) | 1924 (29.4) | <.001 |
| Duration of invasive ventilation, days | 1.9±2.8 | 0.9±1.8 | 2.2±3.0 | <.001 |
| Duration of invasive ventilation <1 day, n (%) | 948 (46.6) | 90 (83.3) | 858 (44.6) | <.001 |
| Noninvasive ventilator use, n (%) | 1923 (15.5) | 377 (6.4) | 1546 (23.7) | <.001 |
| Duration of noninvasive ventilation, days | 1.2±1.8 | 1.0±1.9 | 1.3±1.8 | <.001 |
| Vasoactive drug use, n (%) | 3131 (25.5) | 592 (10.1) | 2539 (38.8) | <.001 |
| Vasopressor use, n (%) | 2672 (21.5) | 443 (7.5%) | 2229 (34.1) | <.001 |
| Inotrope use, n (%) | 1150 (9.3) | 223 (3.8) | 927 (14.2) | <.001 |
| Blood transfusion, n (%) | 1393 (11.2) | 258 (4.4) | 1135 (17.4) | <.001 |
| Dialysis, n (%) | 594 (4.8) | 59 (1.0) | 535 (8.2) | <.001 |
| New dialysis start, n (%) | 393 (3.2) | 50 (0.9) | 343 (5.3) | <.001 |
| CRRT, n (%) | 244 (2.0) | 1 (0.0) | 243 (3.7) | <.001 |
| In-hospital CPR, n (%) | 317 (2.6) | 17 (0.3) | 300 (4.6) | <.001 |
| Length of stay | ||||
| CICU length of stay (days) | 2.5±4.3 | 1.8±3.8 | 3.1±4.6 | <.001 |
| CICU length of stay <1 day, n (%) | 3515 (28.3) | 1997 (33.9) | 1518 (23.2) | <.001 |
| CICU length of stay >7 days, n (%) | 593 (4.8) | 53 (0.9) | 540 (8.3) | <.001 |
| Hospital length of stay (days, mean) | 8.0±13.4 | 4.9±6.9 | 10.7±16.8 | <.001 |
| Hospital length of stay <3 days, n (%) | 3844 (30.9) | 2575 (43.7) | 1269 (19.4) | <.001 |
| Hospital length of stay >14 days, n (%) | 1565 (12.6) | 238 (4.0) | 1327 (20.3) | <.001 |
APACHE, Acute Physiology and Chronic Health Evaluation; CICU, cardiac intensive care unit; CPR, cardiopulmonary resuscitation; CRRT, continuous renal replacement therapy; ECMO, extracorporeal membrane oxygenation; IABP, intra-aortic balloon pump; M-CARS, Mayo Clinic Intensive Care Unit Admission Risk Score; PCI, percutaneous coronary intervention; SOFA, Sequential Organ Failure Assessment; VF, ventricular fibrillation.
Data displayed as n (%) for categorical variables or mean ± standard deviation for continuous variables. Reported P value is for between-group comparison of patients with M-CARS less than 2 and M-CARS greater than or equal to 2, using χ2 test (categorical variables) or Wilcoxon rank-sum test (continuous variables).
a
Admission diagnoses are not mutually exclusive and may add up to more than 100%.