Table 1.
Baseline patient characteristics by treatment group
| Variables | Placebo (N=3899) | Digoxin (N=3889) |
|---|---|---|
| Age (years), mean (±SD) | 64.0 (±10.8) | 63.9 (±11.0) |
| Ejection fraction (%), mean (±SD) | 31.9 (±12.6) | 32.0 (±12.5) |
| Serum creatinine (mg/dL), mean (±SD) | 1.28 (±0.37) | 1.28 (±0.37) |
| Estimated glomerular filtration rate (ml/min/1.73 sq. meter), mean (±SD) | 63.4 (±24.5) | 63.6 (±20.1) |
| Median duration of heart failure (months) | 17 | 17 |
| Age ≥ 65 years | 52.1 % | 51.5 % |
| Women | 24.7 % | 24.7 % |
| Non-whites | 14.6 % | 14.3 % |
| Estimated glomerular filtration rate <60 ml/min/1.73 sq. meter | 45.7 % | 44.9 % |
| Ejection fraction ≥ 0.45 | 12.7 % | 12.7 % |
| Cardiothoracic ratio >0.55 | 33.4 % | 33.6 % |
| New York Heart Association functional class | ||
| I | 14.0 % | 14.4 % |
| II | 54.8 % | 49.6 % |
| III | 29.3 % | 29.4 % |
| IV | 1.9 % | 2.1 % |
| Number of signs or symptoms of heart failure† | ||
| <4 | 19.0 % | 19.0 % |
| ≥4 | 81.0 % | 80.5 % |
| Medical history | ||
| Previous myocardial infarction | 63.2 % | 62.8 % |
| Current angina pectoris | 26.8 % | 27.5 % |
| Diabetes mellitus | 28.8 % | 28.2 % |
| Hypertension | 47.2 % | 47.1 % |
| Previous digoxin use | 43.6 % | 42.8 % |
| Primary cause of heart failure | ||
| Ischemic | 68.7 % | 69.0 % |
| Non-ischemic | 31.3 % | 31.0 % |
| Hypertensive | 10.6 % | 10.0 % |
| Idiopathic | 13.7 % | 14.8 % |
| Others‡ | 7.0 % | 6.2 % |
| Concomitant medications | ||
| Non-potassium-sparing diuretics | 78.3 % | 77.8 % |
| Potassium-sparing diuretics | 8.2 % | 7.1 % |
| Angiotensin-converting enzyme inhibitors | 93.7 % | 93.1 % |
| Nitrates | 42.9 % | 41.9 % |
| Other vasodilators§ | 1.5 % | 1.0 % |
| Daily dose of study medication (mg) | ||
| 0.125 | 18.4 % | 18.5 % |
| 0.250 | 69.8 % | 70.1 % |
| 0.375 | 10.8 % | 10.3 % |
| 0.500 | 1.0 % | 1.0 % |
†
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 radiologic evidence of pulmonary congestion.
‡
This category included valvular and alcohol-related causes of heart failure.
§
These drugs included clonidine hydrochloride, doxazosin mesylate, flosequinan, labetalol hydrochloride, minoxidil, prazosin hydrochloride, and terazosin hydrochloride