Table 1.
Baseline characteristics according to discharge heart rate groups.
| Characteristics | <65 bpm (n = 215) | 65–85 bpm (n = 1256) | ≥86 bpm (n = 289) | Statistics | P value |
| Demographic factors | |||||
| Age (years) | 70 (62, 76) | 69 (61, 77) | 67 (57, 75) | 9.588 | 0.008 |
| Female | 79 (36.7) | 535 (42.6) | 109 (37.7) | 4.233 | 0.122 |
| Current smoking | 43 (20.0) | 260 (20.7) | 74 (25.6) | 3.599 | 0.161 |
| Medical history | |||||
| Implantation of pacemaker | 22 (10.2) | 67 (5.3) | 4 (1.4) | 19.327 | <0.001 |
| Coronary artery disease | 117 (54.4) | 652 (51.9) | 143 (49.5) | 1.212 | 0.544 |
| Myocardial infarction | 39 (18.1) | 153 (12.2) | 35 (12.1) | 6.029 | 0.050 |
| Non-ischemic cardiomyopathy | 52 (24.1) | 229 (18.2) | 62 (21.5) | 4.892 | 0.082 |
| Stroke | 52 (24.2) | 313 (24.9) | 54 (18.7) | 5.000 | 0.080 |
| Hypertension | 127 (59.1) | 716 (57.0) | 127 (43.9) | 17.733 | <0.001 |
| LDL-C election | 18 (8.4) | 152 (12.1) | 33 (11.4) | 2.699 | 0.270 |
| Diabetes mellitus | 70 (32.6) | 351 (27.9) | 77 (26.6) | 2.339 | 0.303 |
| Reduced renal function | 78 (36.2) | 333 (26.5) | 67 (23.1) | 11.295 | 0.004 |
| Valvular heart disease | 55 (25.6) | 316 (25.2) | 69 (23.9) | 0.278 | 0.882 |
| COPD | 43 (20.0) | 254 (20.2) | 48 (16.6) | 1.942 | 0.373 |
| LVEF (%) | 47.0 (36.0, 57.0) | 49.0 (38.7, 59.0) | 46.0 (35.0, 56.0) | 9.967 | 0.007 |
| <50% | 118 (54.9) | 651 (51.8) | 165 (57.1) | 4.393 | 0.230 |
| Electrocardiographic results | |||||
| QRS duration (ms) | 108 (94, 124) | 99 (90, 114) | 99 (88, 114) | 17.900 | <0.001 |
| Left bundle branch block | 14 (6.5) | 58 (4.6) | 9 (3.1) | 3.247 | 0.198 |
| Right bundle branch block | 23 (10.7) | 131 (10.4) | 33 (11.4) | 0.252 | 0.886 |
| Atrioventricular block (II–III) | 17 (7.9) | 19 (1.5) | 3 (1.0) | 36.919 | <0.001 |
| Atrial tachycardia | 22 (10.2) | 58 (4.6) | 5 (1.7) | 19.848 | <0.001 |
| Ventricular tachycardia | 27 (12.6) | 105 (8.4) | 14 (4.8) | 9.633 | 0.008 |
| Laboratory tests | |||||
| Serum sodium (mmol/L) | 139.3 (137.0, 142.0) | 139.7 (137.0, 142.0) | 139.1 (137.0, 142.0) | 0.941 | 0.643 |
| Serum potassium (mmol/L) | 4.2 (3.9, 4.6) | 4.1 (3.8, 4.5) | 4.1 (3.8, 4.5) | 5.421 | 0.067 |
| Troponin T (ng/L) | 23.1 (15.0, 42.8) | 18.3 (11.6, 30.4) | 19.6 (11.8, 38.5) | 20.983 | <0.001 |
| Creatinine (μmol/L) | 99.0 (83.0, 119.3) | 92.2 (77.7, 107.7) | 94.2 (79.6, 107.6) | 15.122 | <0.001 |
| NT-proBNP (pg/mL) | 1809.0 (738.0, 3354.0) | 1399.0 (693.1, 3008.0) | 1850.0 (826.2, 3552.0) | 8.893 | 0.012 |
| NYHA classifications (III–IV) | 180 (83.7) | 985 (78.4) | 244 (84.4) | 5.528 | 0.061 |
| SBP at discharge (mmHg) | 120 (108, 130) | 120 (110, 130) | 120 (110, 130) | 5.439 | 0.063 |
| DBP at discharge (mmHg) | 70 (60, 75) | 70 (67, 80) | 72 (67, 80) | 32.231 | <0.001 |
| Heart rhythm at discharge (AF) | 135 (62.8) | 961 (76.5) | 249 (86.2) | 46.269 | <0.001 |
| Rhythm control in hospital | |||||
| Antiarrhythmic agents∗ | 45 (21.0) | 110 (8.8) | 18 (6.0) | 35.406 | <0.001 |
| Radiofrequency ablation for AF | 2 (1.0) | 6 (1.0) | 3 (1.0) | 1.562 | 0.460 |
| Persistent/permanent (vs. paroxysmal) AF | 123 (57.2) | 895 (71.3) | 219 (75.8) | 44.687 | <0.001 |
| Medications at discharge | |||||
| Beta-blockers | 104 (48.4) | 765 (60.9) | 171 (59.2) | 11.903 | 0.003 |
| ACEI/ARB | 106 (49.3) | 642 (51.1) | 113 (39.1) | 13.585 | 0.001 |
| Aldosterone antagonists | 132 (61.4) | 806 (64.2) | 190 (65.7) | 1.023 | 0.599 |
| Diuretic | 150 (69.8) | 878 (69.9) | 205 (70.9) | 0.135 | 0.938 |
| Digoxin | 60 (28.0) | 392 (31.2) | 124 (42.9) | 17.282 | <0.001 |
| Antiarrhythmic agents∗ | 25 (12.0) | 44 (4.0) | 10 (4.0) | 29.187 | <0.001 |
| Length of stay in hospital | 11 (8, 14) | 10 (7, 13) | 9 (7, 12) | 16.648 | <0.001 |
Data are median (IQR) or n (%). The differences of quantitative indexes or categorical variables between the three groups were analyzed using Kruskal-Wallis test or χ2 test. ∗Antiarrhythmic agents including amiodarone, sotalol, and propafenone. ACEI: Angiotensin-converting enzyme inhibitor; AF: Atrial fibrillation; ARB: Angiotensin receptor blocker; Bpm: Beats per minute; COPD: Chronic obstructive pulmonary disease; DBP: Diastolic blood pressure; IQR: Interquartile range; LDL-C: Low-density lipoprotein cholesterol; LVEF: Left ventricular ejection fraction; NT-proBNP: N-terminal pro-brain natriuretic peptide; NYHA: New York Heart Association; SBP: Systolic blood pressure.