Table 1. Baseline Characteristics of the Study Participants Stratified by Hospital Performance Status and Race.
| Characteristic | Patients, No. (%) | P Valuea | |||
|---|---|---|---|---|---|
| Low-Performing Hospitals (n = 354) | High-Performing Hospitals (n = 399) | ||||
| Black Patients (n = 6657) | Nonblack Patients (n = 56 661) | Black Patients (n = 4623) | Nonblack Patients (n = 87 456) | ||
| Age, median (IQR), y | 73.0 (68.0-80.0) | 75.0 (69.0-82.0) | 73.0 (68.0-80.0) | 75.0 (69.0-82.0) | <.001 |
| Female | 3487 (52.4) | 24 000 (42.4) | 2395 (51.8) | 35 564 (40.7) | <.001 |
| BMI, median (IQR) | 27.8 (24.2-32.3) | 27.4 (24.1-31.2) | 27.7 (24.0-32.1) | 27.4 (24.2-31.3) | <.001 |
| Socioeconomic status score, median (IQR) | −0.8 (−2.9 to 2.6) | −0.2 (−3.4 to 3.0) | −0.5 (−3.0 to 2.0) | −0.5 (−3.1 to 1.9) | <.001 |
| Hypertension | 6141 (92.2) | 46 955 (82.9) | 4243 (91.8) | 70 562 (80.7) | <.001 |
| Dyslipidemia | 4482 (67.4) | 38 657 (68.3) | 3046 (65.9) | 59 027 (67.5) | .004 |
| Diabetes mellitus | 3322 (49.9) | 20 271 (35.8) | 2313 (50.0) | 30 155 (34.5) | <.001 |
| Current/recent smoker (<1 y) | 1422 (21.4) | 9531 (16.8) | 954 (20.6) | 13 764 (15.7) | <.001 |
| Peripheral arterial disease | 1013 (15.2) | 7482 (13.2) | 677 (14.7) | 10 990 (12.6) | <.001 |
| Medical history | |||||
| Myocardial infarction | 1697 (25.5) | 14 831 (26.2) | 1247 (27.0) | 22 420 (25.7) | <.001 |
| PCI | 1523 (22.9) | 15 122 (26.7) | 1166 (25.2) | 23 425 (26.8) | <.001 |
| CABG | 916 (13.8) | 11 320 (20.0) | 686 (14.8) | 16 681 (19.1) | <.001 |
| Congestive heart failure | 1599 (24.1) | 9878 (17.5) | 1106 (23.9) | 13 383 (15.3) | <.001 |
| Stroke, overall | 1032 (15.5) | 6108 (10.8) | 765 (16.6) | 8646 (9.9) | <.001 |
| Presentation with STEMI | 1684 (25.3) | 17 505 (30.9) | 1142 (24.7) | 27 193 (31.1) | <.001 |
| Systolic blood pressure, median (IQR), mm Hg | 150.0 (128.0-174.0) | 147.0 (126.0-169.0) | 149.0 (126.0-173.0) | 146.0 (125.0-168.0) | <.001 |
| Heart rate on admission, median (IQR), beats per minute | 84.0 (70.0-100.0) | 82.0 (69.0-98.0) | 84.0 (71.0-99.0) | 80.0 (68.0-96.0) | <.001 |
| Cardiogenic shock at presentation | 160 (2.4) | 1437 (2.5) | 116 (2.5) | 2281 (2.6) | .73 |
| Signs of heart failure | 1588 (23.9) | 10 716 (18.9) | 947 (20.5) | 14 326 (16.4) | <.001 |
| Initial creatinine value, median (IQR), mg/dL | 1.2 (1.0-1.6) | 1.1 (0.9-1.4) | 1.2 (1.0-1.6) | 1.1 (0.9-1.4) | <.001 |
| Initial hemoglobin value, median (IQR), g/dL | 12.4 (11.0-13.6) | 13.4 (12.0-14.6) | 12.5 (11.1-13.8) | 13.5 (12.1-14.8) | <.001 |
| Left ventricular ejection fraction assessed, % | 6215 (93.4) | 53 075 (93.7) | 4313 (93.3) | 81 908 (93.7) | .03 |
| Interventions during index admission | |||||
| Primary PCI for STEMI | 1242 (93.9) | 13 961 (94.5) | 902 (96.5) | 21 113 (92.5) | <.001 |
| PCI (non-STEMI) | 1906 (38.4) | 17 236 (44.0) | 1334 (38.4) | 28 586 (47.5) | <.001 |
| CABG | 526 (7.9) | 5518 (9.8) | 302 (6.5) | 7540 (8.6) | <.001 |
| Discharge medication status | |||||
| Aspirin | 5839 (97.2) | 50 167 (97.6) | 4062 (97.1) | 77 909 (98.0) | <.001 |
| P2Y12 receptor inhibitors | 4466 (72.7) | 39 832 (75.9) | 3109 (72.8) | 62 197 (76.5) | <.001 |
| Statin | 5663 (93.3) | 47 717 (93.2) | 3912 (91.9) | 73 775 (93.3) | .002 |
| β-Blockers | 5703 (96.3) | 48 285 (96.5) | 3953 (96.4) | 74 801 (96.8) | .66 |
| ACE inhibitor or ARB | 4027 (72.2) | 34 225 (70.5) | 2777 (70.7) | 53 670 (70.9) | <.001 |
| Ideal patients for ACE inhibitor or ARB | 1047 (86.7) | 8618 (86.8) | 659 (85.0) | 11 968 (87.8) | .22 |
| Defect-free care | 4203 (65.2) | 37 395 (68.4) | 2909 (65.0) | 60 411 (71.6) | <.001 |
| In-hospital mortality risk score, median (IQR) | 34.0 (28.0-41.0) | 34.0 (28.0-40.0) | 34.0 (28.0-41.0) | 34.0 (28.0-40.0) | <.001 |
| In-hospital major bleeding risk score, median (IQR) | 32.0 (27.0-38.0) | 30.0 (25.0-35.0) | 32.0 (27.0-37.0) | 29.0 (24.0-34.0) | <.001 |
Abbreviations: ACE, angiotensin-converting enzyme; ARB, angiotensin-receptor blocker; BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); CABG, coronary artery bypass grafting; IQR, interquartile range; PCI, percutaneous coronary intervention; STEMI, ST-segment elevation myocardial infarction.
SI conversion factors: To convert creatinine to μmol/L, multiply by 88.4; hemoglobin to g/L, multiply by 10.0; and troponin to μg/L, multiply by 1.0.
a
P values are based on Pearson χ2 tests for all categorical row variables. P values are based on χ2 rank based group mean score statistics for all continuous or ordinal row variables. These are equivalent to Kruskal-Wallis tests.