Table 1.
Baseline Characteristics of the Study Population by Dyspnea Severity at Admission
| Characteristic | Dyspnea Severity | p Value | ||
|---|---|---|---|---|
| Moderate Activity (n = 4022) |
Minimal Activity (n = 19,619) |
At Rest (n = 24,975) |
||
| Age (years) | 79.6 (73.9–85.0) | 79.7 (73.9–85.1) | 80.1 (74.2–85.8) | < 0.001 |
| Men | 1864 (46.3%) | 8840 (45.1%) | 10,636 (42.6%) | < 0.001 |
| Race | < 0.001 | |||
| Black | 517 (12.9%) | 2,055 (10.5%) | 2745 (11.0%) | |
| White | 3304 (82.1%) | 16,181 (82.5%) | 20,430 (81.8%) | |
| Other/unknown | 201 (5.0%) | 1383 (7.0%) | 1800 (7.2%) | |
| Medical history | ||||
| Anemia | 2082 (51.8%) | 10,826 (55.2%) | 13,315 (53.3%) | < 0.001 |
| Atrial fibrillation | 1367 (34.0%) | 7264 (37.0%) | 8650 (34.6%) | < 0.001 |
| Coronary artery disease | 2375 (59.1%) | 12,059 (61.5%) | 15,217 (60.9%) | 0.02 |
| Chronic renal insufficiency | 949 (23.6%) | 5623 (28.7%) | 7095 (28.4%) | < 0.001 |
| Chronic obstructive pulmonary disease | 1128 (28.0%) | 6095 (31.1%) | 7965 (31.9%) | < 0.001 |
| Diabetes mellitus | 1522 (37.8%) | 8057 (41.1%) | 10,326 (41.3%) | 0.001 |
| Heart failure admission in prior 6 months | 487 (12.1%) | 2760 (14.1%) | 3706 (14.8%) | < 0.001 |
| Hyperlipidemia | 1511 (37.6%) | 7770 (39.6%) | 9216 (36.9%) | < 0.001 |
| Hypertension | 2982 (74.1%) | 14,777 (75.3%) | 18,786 (75.2%) | 0.28 |
| Myocardial infarction | 1168 (29.0%) | 6220 (31.7%) | 7977 (31.9%) | 0.001 |
| Peripheral vascular disease | 743 (18.5%) | 3804 (19.4%) | 4960 (19.9%) | 0.09 |
| Stroke or transient ischemic attack | 680 (16.9%) | 3582 (18.3%) | 4923 (19.7%) | < 0.001 |
| Smoker | < 0.001 | |||
| Never | 1832 (45.5%) | 8251 (42.1%) | 10,950 (43.8%) | |
| Former | 1551 (38.6%) | 7627 (38.9%) | 9286 (37.2%) | |
| Current | 307 (7.6%) | 1448 (7.4%) | 1909 (7.6%) | |
| Missing | 332 (8.3%) | 2293 (11.7%) | 2830 (11.3%) | |
| Devices | ||||
| Cardiac resynchronization therapy | 72 (1.8%) | 365 (1.9%) | 377 (1.5%) | 0.01 |
| Implantable cardioverter-defibrillator | 208 (5.2%) | 1143 (5.8%) | 1326 (5.3%) | 0.04 |
| Pacemaker | 738 (18.3%) | 3899 (19.9%) | 4613 (18.5%) | < 0.001 |
| Initial evaluation | ||||
| Ejection fraction | < 0.001 | |||
| ≥ 40% | 2007 (49.9%) | 9438 (48.1%) | 11,320 (45.3%) | |
| < 40% | 1417 (35.2%) | 7298 (37.2%) | 9318 (37.3%) | |
| Missing | 598 (14.9%) | 2883 (14.7%) | 4337 (17.4%) | |
| Fatigue | 1240 (30.8%) | 7475 (38.1%) | 8758 (35.1%) | < 0.001 |
| Pulmonary edema | 3385 (84.2%) | 17,224 (87.8%) | 22,931 (91.8%) | < 0.001 |
| Rales | 2632 (65.4%) | 13,805 (70.4%) | 19,266 (77.1%) | < 0.001 |
| Initial vital signs | ||||
| BNP level (pg/mL) | 739 (397–1307) | 839 (437–1440) | 924 (470–1540) | < 0.001 |
| Missing | 1705 (42.4%) | 8406 (42.8%) | 10,485 (42.0%) | |
| Pulse (bpm) | 82.0 (70.0–96.0) | 82.0 (70.0–98.0) | 86.0 (73.0–103) | < 0.001 |
| Systolic blood pressure (mm Hg) | 143 (124–165) | 142 (122–163) | 145 (124–168) | < 0.001 |
| Initial laboratory test results | ||||
| eGFR (mL/min/1.73 m2) | 51.2 (36.0–67.3) | 48.2 (33.7–63.7) | 47.7 (33.3–63.6) | < 0.001 |
| Hemoglobin (g/dL) | 12.2 (10.9–13.5) | 12.1 (10.7–13.4) | 12.1 (10.8–13.5) | < 0.001 |
| Serum creatinine (mg/dL) | 1.3 (1.0–1.7) | 1.3 (1.0–1.8) | 1.3 (1.0–1.8) | < 0.001 |
| Serum sodium (mEq/L) | 139 (136–141) | 139 (136–141) | 139 (136–141) | 0.04 |
| Medication at discharge† | ||||
| ACE inhibitor or ARB | 2511 (63.8%) | 12,080 (63.6%) | 14,430 (61.3%) | < 0.001 |
| Aspirin | 1972 (50.1%) | 9222 (48.5%) | 11,297 (48.0%) | 0.05 |
| β-Blocker | 2329 (59.2%) | 11,476 (60.4%) | 14,057 (59.8%) | 0.26 |
| Clopidogrel | 510 (13.0%) | 2660 (14.0%) | 3366 (14.3%) | 0.08 |
| Diuretic | 2959 (75.2%) | 14,887 (78.3%) | 17,404 (74.0%) | < 0.001 |
| Lipid-lowering agent | 1482 (37.7%) | 6979 (36.7%) | 8233 (35.0%) | < 0.001 |
| Warfarin | 1126 (28.6%) | 5671 (29.8%) | 6286 (26.7%) | < 0.001 |
| Index hospitalization year | < 0.001 | |||
| 2001 | 86 (2.1%) | 549 (2.8%) | 743 (3.0%) | |
| 2002 | 1141 (28.4%) | 5605 (28.6%) | 7561 (30.3%) | |
| 2003 | 1353 (33.6%) | 6607 (33.7%) | 7914 (31.7%) | |
| 2004 | 980 (24.4%) | 5055 (25.8%) | 5917 (23.7%) | |
| 2005 | 420 (10.4%) | 1646 (8.4%) | 2597 (10.4%) | |
| 2006 | 42 (1.0%) | 157 (0.8%) | 243 (1.0%) | |
Definitions: Anemia, hypertension, and hyperlipidemia were based on documentation of these clinical diagnoses in the medical history.
Abbreviations: ACE, angiotensin-converting enzyme; ARB, angiotensin II receptor blocker; BNP, B-type natriuretic peptide; eGFR, estimated glomerular filtration rate.
*
Within the previous 6 months.
†
Data are presented only for patients discharged alive, including 3933 patients with dyspnea with moderate activity, 19,006 patients with dyspnea with minimal activity, and 23,524 patients with dyspnea at rest.