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Abstract: Background: In heart failure (HF), digoxin at low serum digoxin concentrations (SDC) reduces all-cause mortality and HF hospitalizations. However, the effects of digoxin on other cause-specific outcomes have not been studied in a propensity-matched cohort. Methods: The Digitalis Investigation Group trial, conducted during 1991–1993, enrolled 7788 ambulatory chronic HF patients. This analysis focuses on 4843 patients: 982 receiving digoxin with low (0.5–0.9 ng/ml) SDC at one month, and 3861 receiving placebo and alive at one month. Propensity scores for low SDC, calculated using a non-parsimonious multivariable logistic regression model, were used to match 982 low-SDC patients with 982 placebo patients. Matched Cox regression analyses were used to determine the effect of digoxin at low SDC on outcomes. Results: All-cause mortality occurred in 315 placebo (rate, 1071/10,000 person-years) and 288 low-SDC digoxin (rate, 871/10,000 person-years) patients, respectively, during 2940 and 3305 years of follow up (hazard ratio {HR}, 0.81, 95% confidence interval {CI}, 0.68–0.98; p =0.028). Cardiovascular hospitalizations occurred in 493 placebo (2359/10,000 person-year) and 471 low-SDC digoxin (1963/10,000 person-year) patients, respectively during 2090 and 2399 years of follow up (HR, 0.82, 95% CI, 0.70–0.95; P =0.010). Low-SDC digoxin to placebo HR (95%CI) for HF mortality and HF hospitalizations were respectively, 0.65 (0.45–0.92; P =0.015) and 0.63 (0.52–0.77; P <0.0001). Low-dose digoxin (≤0.125 mg/day) was the strongest independent predictor of low SDC (adjusted odd ratio, 2.07, 95% CI 1.54–2.80). Conclusions: Digoxin at low SDC significantly reduced mortality and hospitalizations in ambulatory chronic systolic and diastolic HF patients. [Copyright &y& Elsevier]

Presents a study that investigated the association of serum digoxin levels with mortality and hospitalization in patients with congestive heart failure and systolic left ventricular dysfunction. Design; Intervention; Outcome measures; Results; Commentary.

Post hoc analyses of the Digitalis Investigation Group (DIG) trial indicate that digoxin at low (0.5 to 0.9 ng/ml) serum digoxin concentration (SDC) reduces mortality, which is eliminated at higher (≥1 ng/ml) SDC, and that low-dose digoxin (≤0.125 mg/day) predicts low SDC. In the DIG trial, patients with ambulatory chronic systolic and diastolic heart failure (HF) (n = 7,788) in normal sinus rhythm receiving angiotensin-converting enzyme inhibitors and diuretics were randomized to receive placebo (n = 3,899) or digoxin (n = 3,889). The median dose of digoxin (0.25 mg/day) and the target SDC (0.8 to 2.5 ng/ml) were higher than what are currently recommended, which in part may explain the lack of long-term mortality benefit of digoxin in the DIG trial. To test this hypothesis, we examined the effect of digoxin on short-term outcomes; 1-year all-cause mortality occurred in 392 and 448 patients respectively in the digoxin and placebo groups (hazard ratio for digoxin 0.87, 95% confidence interval [CI] 0.76 to 0.995, p = 0.043). Respective hazard ratios for cardiovascular and HF deaths were 0.87 (95% CI 0.76 to 1.01, p = 0.072) and 0.66 (95% CI 0.52 to 0.85, p = 0.001). All-cause hospitalization occurred in 1,411 and 1,529 patients receiving digoxin and placebo respectively (hazard ratio 0.89, 95% CI 0.83 to 0.96, p = 0.002). Respective hazard ratios for cardiovascular and HF hospitalizations were 0.82 (95% CI 0.75 to 0.89, p <0.0001) and 0.59 (95% CI 0.52 to 0.66, p <0.0001). In conclusion, digoxin reduced 1-year mortality and hospitalization in patients with chronic HF receiving angiotensin-converting enzyme inhibitors and diuretics. Randomized clinical trials are needed to determine the effect of low-dose digoxin in contemporary patients with chronic HF. [Copyright &y& Elsevier]

Aims No studies have examined the effect of mineralocorticoid receptor antagonist therapy on new-onset diabetes. In addition, though the combination of diabetes and chronic heart failure (CHF) carries a poor prognosis, few studies have examined predictors of new-onset diabetes in those with CHF. Methods and results In patients with symptomatically mild CHF who participated in the placebo-controlled Eplerenone in Mild Patients Hospitalization and Survival Study in Heart Failure, we examined the effect of the aldosterone antagonist, eplerenone, on physician-diagnosed diabetes using univariate Cox proportional hazard analysis. To identify predictors of new-onset diabetes (measures of glycaemia were not available), data from trial arms were combined and multivariate Cox proportional hazard analyses and receiver operating characteristic curve analyses were conducted. At baseline, the mean age of 1846 initially non-diabetic patients was 69 years and mean left ventricular ejection fraction was 26%. Over 21 months, 69 (3.7%) developed diabetes (33 on eplerenone, 36 on placebo). Eplerenone had no effect on new-onset diabetes [hazard ratio (HR) 0.94, 95% confidence interval (CI) 0.59–1.52] and no effect on the composite of new-onset diabetes or mortality (HR 0.80, 95% CI 0.64–1.01). Independent predictors of new-onset diabetes included digoxin therapy, higher serum alanine aminotransferase, longer duration of heart failure, current or previous smoker, higher waist circumference, lower age, and higher systolic blood pressure with a combined c-statistic of 0.74. Conclusions Eplerenone had no effect on new-onset diabetes in patients with CHF, but further large-scale studies are required to address this question comprehensively. Commonly recorded parameters provided useful information for predicting new-onset diabetes. [ABSTRACT FROM AUTHOR]