Table 1.
Baseline characteristics.
| Variables | Non-anemia | Mild anemia | M-to-S anemia | P-value |
|---|---|---|---|---|
| Overall n, % | 2,206 (52.0) | 1,106 (26.1) | 932 (22%) | - |
| Socio-demographic | ||||
| Age, year, mean (SD) | 70 (12.1) | 74 (11.2) | 75 (12.0) | <0.001 |
| Female sex, n (%) | 1,052 (47.7) | 438 (39.6) | 602 (64.6) | <0.001 |
| Low education, n (%)a | 1,473 (76.0) | 756 (79.2) | 645 (78.8) | 0.095 |
| Low income, n (%)b | 1,252 (66.7) | 647 (69.4) | 533 (67.3) | 0.354 |
| no/low insurance, n (%)c | 1,652 (76.1) | 859 (78.6) | 699 (76.0) | 0.240 |
| Tertiary-level hospital, n (%) | 537 (24.3) | 229 (20.7) | 192 (20.6) | 0.016 |
| Current smoking, n (%) | 208 (9.5) | 95 (8.6) | 41 (4.4) | <0.001 |
| Current drinking, n (%) | 121 (5.5) | 40 (3.6) | 13 (1.4) | <0.001 |
| Clinical features | ||||
| Hemoglobin, g/L, mean (SD) | 139 (12.7) | 118 (5.6) | 93 (17.1) | <0.001 |
| BMI, kg/m2, mean (SD) | 23.7 (3.9) | 23.0 (3.6) | 22.5 (5.4) | <0.001 |
| SBP, mmHg, mean (SD) | 135 (24.4) | 134 (25.6) | 136 (26.3) | 0.160 |
| Heart rate, mean (SD) | 90 (22.9) | 88 (22.7) | 85 (22.0) | <0.001 |
| LVEF, mean (SD) | 49.2 (14.7) | 49.0 (13.4) | 50.1 (12.5) | 0.337 |
| NYHA class IV, n (%) | 992 (45.0) | 532 (48.1) | 497 (53.3) | <0.001 |
| BNP, pg/mL, median (IQR)d | 836 (26,53,175) | 1,093 (44,53,277) | 1,484 (54,84,566) | <0.001 |
| NT-proBNP, pg/mL, median (IQR)e | 2,225 (70,85,960) | 3,683 (12,708,561) | 4,639 (1,85,011,486) | <0.001 |
| eGFR <60mL/min/1.73m2, n (%)f | 477 (22.9) | 309 (29.7) | 403 (46.3) | <0.001 |
| Serum sodium, mean (SD) | 139.4 (4.4) | 138.7 (4.8) | 138.1 (5.4) | <0.001 |
| Serum potassium, mean (SD) | 4.2 (0.6) | 4.1 (0.6) | 4.2 (0.8) | 0.008 |
| LDL-C, mmol/L, mean (SD) | 2.29 (1.80, 2.93) | 2.06 (1.61, 2.64) | 2.00 (1.48, 2.60) | <0.001 |
| Medical history | ||||
| Hypertension, n (%) | 1,036 (47.0) | 503 (45.5) | 486 (52.1) | 0.026 |
| Diabetes, n (%) | 395 (18.0) | 211 (19.2) | 239 (25.7) | <0.001 |
| Coronary artery disease, n (%) | 611 (27.9) | 369 (33.4) | 269 (29.0) | 0.005 |
| COPD, n (%) | 218 (9.9) | 111 (10.1) | 62 (6.7) | 0.009 |
| Atrial fibrillation, n (%) | 597 (27.1) | 298 (27.1) | 220 (23.7) | 0.112 |
| Cerebrovascular disease, n (%) | 311 (14.1) | 174 (15.8) | 145 (15.6) | 0.355 |
| valvular heart disease | 530 (24.2) | 263 (24.0) | 217 (23.4) | 0.882 |
| Congenital heart disease, n (%) | 29 (1.3) | 11 (1.0) | 11 (1.2) | 0.871 |
| Treatment at discharge | ||||
| Renin-angiotensin system inhibitors, n (%) | 1,018 (46.7) | 483 (44.0) | 374 (40.9) | 0.010 |
| β-blockers, n (%) | 1,164 (53.2) | 594 (53.9) | 407 (44.4) | <0.001 |
| MRA, n (%) | 1,564 (71.4) | 820 (74.4) | 648 (70.7) | 0.116 |
| Diuretics, n (%) | 1,304 (59.8) | 668 (60.7) | 539 (59.2) | 0.781 |
| Digoxin, n (%) | 520 (23.8) | 232 (21.0) | 163 (17.8) | 0.001 |
| Statin, n (%) | 1,511 (69.1) | 759 (68.8) | 597 (65.3) | 0.103 |
M-to-S anemia, moderate-to-severe anemia; Non-anemia (hemoglobin ≥ 120 g/L in women or ≥130 g/L in men); mild anemia (110 ≤hemoglobin <130 g/L in men or 110 ≤hemoglobin < 120 g/L in women); moderate-to-severe anemia (hemoglobin < 110 g/L). SD, standard deviation; IQR, interquartile range; SBP, Systolic blood pressure; BMI, body mass index; LVEF, left ventricular ejection fraction; NYHA, New York Heart Association; BNP, brain natriuretic peptide; NT-proBNP, N-terminal pro-B-type natriuretic peptide; eGFR, estimated glomerular filtration rate; LDL-C, low-density lipoprotein cholesterol; COPD, chronic obstructive pulmonary disease; MRA, mineralocorticoid receptor antagonists.
Elementary school or below was defined as low education;
Income < 30 k RMB per year was defined as low income;
New rural cooperative medical scheme was defined as low-coverage insurance;
On-admission NT-proBNP levels were available in 2,360 patients.
On-admission BNP levels were available in 1,103 patients.
eGFR was calculated with the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation.