Table 1.
Baseline characteristics of heart failure (HF) patients with prior digoxin use (n=2471)
| N (%) or mean (±SD) | Digoxin discontinued, on placebo (N=1674) |
Digoxin continued at SDC 0.5–0.9 (N=457) |
Digoxin continued at SDC ≥1.0 (N=340) |
Overall P |
|---|---|---|---|---|
| Age, years | 64 (±11) | 62 (±11) | 65 (±10) | 0.002 |
| Women | 409 (24%) | 98 (21%) | 104 (31%) | 0.011 |
| Non-whites | 266 (16%) | 63 (14%) | 35 (10%) | 0.024 |
| BMI, kg/sq.m | 27 (±5) | 27(±5) | 26 (±5) | 0.058 |
| Heart rate, beats per minute | 79 (±12) | 77 (±12) | 76 (±13) | <0.0001 |
| HF duration, months | 36 (±39) | 37 (±42) | 41 (±40) | 0.074 |
| NYHA class III-IV | 541 (32%) | 137 (30%) | 114 (34%) | 0.523 |
| Ischemic etiology | 1119 (67%) | 314 (69%) | 245 (74%) | 0.158 |
| Ejection fraction, % | 31 (±12) | 31 (±12) | 31 (±11) | 0.963 |
| Ejection fraction >45% | 179 (11%) | 39 (9%) | 30 (9%) | 0.287 |
| Hypertension | 750 (45%) | 198 (43%) | 145 (43%) | 0.698 |
| Diabetes | 447 (27%) | 142 (31%) | 104 (31%) | 0.097 |
| Chronic kidney disease | 775 (46%) | 165 (36%) | 168 (55%) | <0.0001 |
| ACE inhibitor use | 1581 (94%) | 438 (96%) | 323 (95%) | 0.483 |
| Diuretic use | 1397 (84%) | 369 (81%) | 299 (88%) | 0.0251 |
| Dose of study medication | 0.24 (±0.1) | 0.24 (±0.1) | 0.24 (±0.1) | 0.119 |
| Pulmonary congestion | 220 (13%) | 58 (13%) | 70 (21%) | 0.001 |
| Cardiothoracic ratio >0.5 | 1013 (61%) | 273 (60%) | 223 (66%) | 0.176 |
| Serum creatinine, mg/dL | 1.3 (±0.4) | 1.2 (±0.3) | 1.4 (±0.4) | <0.0001 |
| eGFR, ml/min/1.73 sq.m | 64 (±29) | 69 (±21) | 58 (±18) | <0.0001 |
| Serum potassium, mEq/L | 4.3 (±0.5) | 4.3 (±0.5) | 4.3 (±0.4) | 0.478 |
ACE=angiotensin-converting enzyme; BMI=body mass index; CKD=chronic kidney disease, defined as estimated baseline glomerular filtration rate (GFR) <60 ml/1.73 m2 body surface area; eGFR=estimate glomerular filtration rate; NYHA=New York Heart Association; SDC=serum digoxin concentration