Table 2.
Baseline characteristics of patients.
| Overall population | AMI subpopulation | UA subpopulation | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Discharged with β-blockers (n = 5,043) | Discharged without β-blockers (n = 588) | P value | Discharged with β-blockers (n = 1,444) | Discharged without β-blockers (n = 116) | P value | Discharged with β-blockers (n = 3,599) | Discharged without β-blockers (n = 472) | P value | |
| Clinical characteristics (%) | |||||||||
| Age (years) | 58.0 (50.0, 65.0) | 59.0 (53.0, 67.0) | 0.027 | 58.0 (50.0, 67.0) | 56.0 (48.0, 63.0) | 0.009 | 59.0 (52.0, 66.0) | 59.0 (53.0, 67.0) | 0.687 |
| Male | 3,844 (76.2) | 473 (80.4) | 0.022 | 1,220 (84.5) | 100 (86.2) | 0.621 | 2,624 (72.9) | 373 (79.0) | 0.005 |
| BMI (kg/m2) | 26.0 (23.9, 27.8) | 25.4 (23.5, 27.3) | <0.001 | 26.0 (23.9, 27.8) | 25.6 (23.2, 27.1) | 0.200 | 25.9 (23.8, 27.8) | 25.3 (23.5, 27.3) | 0.002 |
| Diabetes | 1,499 (29.7) | 127 (21.6) | <0.001 | 388 (26.9) | 21 (18.1) | 0.039 | 1,111 (30.3) | 106 (22.5) | <0.001 |
| Hypertension | 3,226 (64.0) | 356 (60.5) | 0.102 | 832 (57.6) | 65 (56.0) | 0.740 | 2,394 (66.5) | 291 (61.7) | 0.036 |
| Dyslipidemia | 3,380 (67.0) | 357 (60.7) | 0.002 | 892 (61.8) | 60 (51.7) | 0.033 | 2,488 (69.1) | 297 (62.9) | 0.006 |
| Prior MI | 639 (12.7) | 72 (12.2) | 0.768 | 92 (6.4) | 9 (7.8) | 0.559 | 547 (15.2) | 63 (13.3) | 0.289 |
| Prior PCI | 1,014 (20.1) | 125 (21.3) | 0.511 | 247 (17.1) | 29 (25.0) | 0.032 | 767 (21.3) | 96 (20.3) | 0.627 |
| Prior CABG | 198 (3.9) | 17 (2.9) | 0.215 | 31 (2.1) | 2 (1.7) | 1.000 | 167 (4.6) | 15 (3.2) | 0.148 |
| Stroke | 531 (10.5) | 61 (10.4) | 0.908 | 125 (8.7) | 15 (12.9) | 0.121 | 406 (11.3) | 46 (9.7) | 0.318 |
| PAD | 104 (2.1) | 14 (2.4) | 0.61 | 19 (1.3) | 3 (2.6) | 0.221 | 85 (2.4) | 11 (2.3) | 0.966 |
| COPD | 112 (2.2) | 21 (3.6) | 0.041 | 33 (2.3) | 4 (3.4) | 0.349 | 79 (2.2) | 17 (3.6) | 0.058 |
| Current smoking | 2,896 (57.4) | 373 (63.4) | 0.005 | 942 (65.2) | 91 (78.4) | 0.004 | 1954 (54.3) | 282 (59.7) | 0.025 |
| Presenting characteristics | |||||||||
| SBP (mmHg) | 125 (116, 140) | 125 (117, 140) | 0.978 | 120 (110, 130) | 120 (105, 130) | 0.119 | 130.0 (120.0, 140.0) | 129.0 (120.0, 140.0) | 0.892 |
| Heart rate (bpm) | 70 (63, 76) | 62 (57, 70) | <0.001 | 70.0 (64.0, 78.0) | 61.5 (56.0, 73.8) | <0.001 | 69.0 (63.0, 76.0) | 62.0 (57.0, 69.0) | <0.001 |
| CCr < 60 mL/min (%) | 1,939 (38.4) | 237 (40.3) | 0.382 | 521 (36.5) | 51 (44.0) | 0.109 | 1,412 (39.2) | 186 (39.4) | 0.942 |
| CK-MB (U/L) | 12.0 (9.0, 16.0) | 12.0 (9.0, 15.0) | 0.209 | 12.0 (9.0, 17.0) | 12.0 (8.0, 15.5) | 0.146 | 11.0 (9.0, 15.0) | 12.0 (9.0, 15.0) | 0.796 |
| LVEF | 63.0 (60.0, 67.0) | 64.6 (60.0, 68.0) | 0.002 | 60.0 (55.0, 64.0) | 60.0 (55.0, 65.0) | 0.659 | 65.0 (60.2, 68.0) | 65.0 (61.0, 68.3) | 0.135 |
| 40-49% | 217 (4.3) | 16 (2.7) | 0.068 | 125 (8.7) | 10 (8.6) | 0.989 | 92 (2.6) | 6 (1.3) | 0.087 |
| Procedure characteristics (%) | |||||||||
| SYNTAX score | 10 (6, 16) | 8 (5, 14) | <0.001 | 11.0 (7.0, 17.5) | 12.0 (7.0, 18.4) | 0.435 | 9.5 (5.0, 16.0) | 7.0 (4.3, 12.4) | <0.001 |
| Residual SYNTAX score | 0.001 | 0.178 | 0.001 | ||||||
| 0 | 2,576 (52.7) | 350 (60.8) | 752 (52.7) | 66 (57.4) | 1,824 (52.7) | 284 (61.6) | |||
| 0-8 | 1,622 (33.2) | 157 (27.3) | 463 (32.4) | 28 (24.3) | 1,159 (33.5) | 129 (28.0) | |||
| >8 | 688 (14.1) | 69 (12.0) | 212 (14.9) | 21 (18.3) | 476 (13.8) | 48 (10.4) | |||
| Left main lesion | 122 (2.4) | 7 (1.2) | 0.058 | 25 (1.7) | 3 (2.6) | 0.459 | 97 (2.7) | 4 (0.8) | 0.015 |
| LAD | 4,588 (91.0) | 537 (91.3) | 0.779 | 1,309 (90.7) | 103 (88.7) | 0.511 | 3,279 (91.1) | 434 (91.9) | 0.544 |
| IABP use | 49 (1.0) | 4 (0.7) | 0.489 | 27 (1.9) | 3 (2.6) | 0.485 | 22 (0.6) | 1 (0.2) | 0.508 |
| IVUS use | 276 (5.5) | 21 (3.6) | 0.051 | 53 (3.7) | 2 (1.7) | 0.274 | 223 (6.2) | 19 (4.0) | 0.061 |
| GPIIb/IIIa inhibitor use | 792 (15.7) | 85 (14.5) | 0.429 | 256 (17.7) | 21 (18.1) | 0.919 | 536 (14.9) | 64 (13.6) | 0.442 |
| Medication at discharge | |||||||||
| Aspirin | 4,993 (99.0) | 568 (96.6) | <0.001 | 1,437 (99.5) | 105 (90.5) | <0.001 | 3,556 (98.8) | 463 (98.1) | 0.195 |
| Clopidogrel | 4,963 (98.4) | 573 (97.4) | 0.086 | 1,427 (98.8) | 109 (94.0) | <0.001 | 3,536 (98.6) | 464 (98.3) | 0.931 |
| Statin | 4,871 (96.6) | 547 (93.0) | <0.001 | 1,395 (96.6) | 96 (82.8) | <0.001 | 3,476 (96.6) | 451 (95.6) | 0.254 |
| ACEI/ARB | 2,742 (54.4) | 272 (46.3) | <0.001 | 1,051 (72.8) | 71 (61.2) | 0.008 | 1,691 (47.0) | 201 (42.6) | 0.071 |
| CCB | 2,547 (50.5) | 314 (53.4) | 0.184 | 406 (28.1) | 33 (28.4) | 0.939 | 2,141 (59.5) | 281 (59.5) | 0.985 |
Values are presented as n (%), mean ± SD, or median (IQR). ACEI: angiotensin-converting enzyme inhibitors; AMI: acute myocardial infarction; ARB: angiotensin II receptor antagonists; BMI: body mass index; CABG: coronary artery bypass graft; CCB: calcium channel blockers; CCr: creatinine clearance; CK-MB: creatine kinase-MB; COPD: chronic obstructive pulmonary disease; IABP: intra-aortic balloon counterpulsation; IVUS: intravascular ultrasound; LAD: left anterior descending artery; LVEF: left ventricular ejection fraction; PAD: peripheral vascular disease; PCI: percutaneous coronary intervention; SBP: systolic blood pressure; UA: unstable angina.