Table 1.
Baseline patient characteristics of the propensity-matched systolic and diastolic heart failure patients, by treatment group
| N (%) or mean (±SD) | Left ventricular ejection fraction | |||||
|---|---|---|---|---|---|---|
| ≤45% (N=916)
|
>45% (N=916)
|
|||||
| Placebo (N=450) | Digoxin (N=466) | P Value | Placebo (N=460) | Digoxin (N=456) | P Value | |
| Age (years) | 67 (10) | 67 (11) | 0.561 | 67 (10) | 66 (11) | 0.607 |
| Left ventricular ejection fraction (%) | 32 (8) | 31 (8) | 0.390 | 55 (8) | 55 (8) | 0.744 |
| Serum creatinine (mg/dL) | 1.3 (0.4) | 1.3 (0.4) | 0.859 | 1.27 (0.39) | 1.24 (0.39) | 0.367 |
| Estimated glomerular filtration rate (ml/min per 1.73 m2) | 62 (20) | 61.5 (19) | 0.580 | 61.4 (20) | 63.4 (21) | 0.138 |
| Duration of heart failure (months) | 28 (32) | 25 (30) | 0.156 | 28 (37) | 25 (30) | 0.107 |
| Age ≥65 years | 292 (65%) | 287 (62%) | 0.300 | 293 (64%) | 280 (61%) | 0.474 |
| Female | 161 (36%) | 154 (33%) | 0.384 | 173 (38%) | 174 (38%) | 0.864 |
| Nonwhite | 74 (16%) | 63 (14%) | 0.215 | 59 (13%) | 66 (15%) | 0.468 |
| Estimated glomerular filtration rate <60 ml/min per 1.73 m2 | 214 (48%) | 238 (51%) | 0.287 | 229 (50%) | 207 (45%) | 0.184 |
| Cardiothoracic ratio >0.5 | 218 (48%) | 240 (52%) | 0.355 | 234 (51%) | 236 (52%) | 0.789 |
| New York Heart Association functional class | ||||||
| I | 82 (18%) | 72 (16%) | 0.225 | 96 (21%) | 84 (18%) | 0.405 |
| II | 276 (61%) | 273 (59%) | 255 (55%) | 273 (60%) | ||
| III | 87 (19%) | 115 (25%) | 101 (22%) | 95 (21%) | ||
| IV | 5 (1%) | 6 (1%) | 8 (2%) | 4 (1%) | ||
| Signs or symptoms of heart failure* | ||||||
| 0 | 3 (1%) | 9 (2%) | 0.413 | 4 (1%) | 3 (1%) | 0.401 |
| 1 | 17 (4%) | 12 (3%) | 10 (2%) | 6 (1%) | ||
| 2 | 38 (8%) | 40 (9%) | 31 (7%) | 33 (7%) | ||
| 3 | 38 (8%) | 42 (9%) | 51 (11%) | 36 (8%) | ||
| ≥4 | 354 (79%) | 363 (78%) | 364 (79%) | 378 (83%) | ||
| Previous myocardial infarction | 231 (51%) | 248 (53%) | 0.568 | 241 (52%) | 241 (53%) | 0.889 |
| Current angina pectoris | 126 (28%) | 140 (30%) | 0.496 | 131 (29%) | 140 (31%) | 0.461 |
| Diabetes mellitus | 142 (32%) | 135 (29%) | 0.394 | 133 (29%) | 125 (27%) | 0.614 |
| Hypertension | 254 (56%) | 284 (61%) | 0.167 | 252 (55%) | 273 (60%) | 0.120 |
| Previous digoxin use | 162 (36%) | 163 (35%) | 0.747 | 175 (38%) | 160 (35%) | 0.353 |
| Primary cause of heart failure | ||||||
| Ischemic | 265 (59%) | 283 (61%) | 0.876 | 272 (59%) | 274 (60%) | 0.932 |
| Non-ischemic | 185 (41%) | 183 (39%) | 188 (41%) | 182 (40%) | ||
| Hypertensive | 98 (22%) | 86 (19%) | 86 (19%) | 91 (20%) | ||
| Idiopathic | 48 (11%) | 51 (11%) | 53 (12%) | 51 (11%) | ||
| Concomitant medications | ||||||
| Non-potassium sparing diuretics | 357 (79%) | 355 (76%) | 0.252 | 357 (78%) | 340 (75%) | 0.280 |
| Potassium sparing diuretics | 39 (9%) | 34 (7%) | 0.444 | 39 (9%) | 34 (8%) | 0.568 |
| Angiotensin-converting enzyme inhibitors | 402 (89%) | 401 (86%) | 0.131 | 403 (88%) | 397 (87%) | 0.803 |
| Nitrates | 195 (43%) | 196 (42%) | 0.697 | 182 (40%) | 188 (41%) | 0.608 |
| Daily dose of study medication (mg) | ||||||
| 0.125 | 82 (18%) | 97 (21%) | 0.695 | 103 (23%) | 99 (22%) | 0.277 |
| 0.250 | 310 (69%) | 311 (67%) | 315 (69%) | 303 (67%) | ||
| 0.375 | 51 (11%) | 51 (11%) | 34 (7%) | 50 (11%) | ||
| 0.500 | 6 (1%) | 4 (1%) | 5 (1%) | 3 (1%) | ||
*
The clinical signs or symptoms studied included râles, elevated jugular venous pressure, peripheral edema, dyspnea at rest or on exertion, orthopnea, limitation of activity, S3 gallop, and radiological evidence of pulmonary congestion.