Abstract

BACKGROUND: In the main Digitalis Investigation Group (DIG) trial, digoxin reduced the risk of 30-day all-cause hospitalization in older systolic heart failure patients. However, this effect has not been studied in older diastolic heart failure patients. METHODS: In the ancillary DIG trial, of the 988 patients with chronic heart failure and preserved (> 45%) ejection fraction, 631 were age ≥ 65 years (mean age 73 years, 45% women, 12% non-whites), of whom 311 received digoxin. RESULTS: All-cause hospitalization 30-day post randomization occurred in 4% of patients in the placebo group and 9% each among those in the digoxin group receiving 0.125 mg and ≥ 0.25 mg a day dosage (P = .026). Hazard ratios (HR) and 95% confidence intervals (CI) for digoxin use overall for 30-day, 3-month, and 12-month all-cause hospitalizations were 2.46 (1.25-4.83), 1.45 (0.96-2.20) and 1.14 (0.89-1.46), respectively. There was one 30-day death in the placebo group. Digoxin-associated HRs (95% CIs) for 30-day hospitalizations due to cardiovascular, heart failure, and unstable angina causes were 2.82 (1.18-6.69), 0.51 (0.09-2.79), and 6.21 (0.75-51.62), respectively. Digoxin had no significant association with 30-day all-cause hospitalization among younger patients (6% vs 7% for placebo; HR 0.80; 95% CI, 0.36-1.79). CONCLUSIONS: In older patients with chronic diastolic heart failure, digoxin increased the risk of 30-day all-cause hospital admission, but not during longer follow-up. Although chance finding due to small sample size is possible, these data suggest that unlike in systolic heart failure, digoxin may not reduce 30-day all-cause hospitalization in older diastolic heart failure patients.