Digoxin Benefit Varies by Risk of Heart Failure Hospitalization: Applying the Tufts MC HF Risk Model.
Am J Med. 2017 Dec 25;:
Authors: Upshaw JN, van Klaveren D, Konstam MA, Kent DM
BACKGROUND: Digoxin has been shown to reduce heart failure hospitalizations with a neutral effect on mortality. It is unknown whether there is heterogeneity of treatment effect for digitalis therapy according to predicted risk of heart failure hospitalization.
METHODS AND RESULTS: We conducted a post hoc analysis of the Digitalis Investigator Group (DIG) studies, randomized controlled trials of digoxin versus placebo in participants with heart failure and left ventricular ejection fraction less than or equal to 45% (main DIG study, n=6800) or >45% (ancillary DIG study, n=988). Using a previously derived multistate model to risk stratify DIG study participants, we determined the differential treatment effect on hospitalization and mortality outcomes. There was a 13% absolute reduction in the risk of any heart failure hospitalizations (39% versus 52%; odds ratio [OR] = 0.58 (0.47 -0.71) in the digoxin versus placebo arms in the highest risk quartile compared to a 3% absolute risk reduction for any heart failure hospitalization (17% versus 20%; odds ratio [OR] = 0.84 (0.66- 1.08) in the lowest risk quartile. There were 12 fewer total all-cause hospitalizations per 100 person-years in the highest risk quartile compared with an increase of 8 hospitalizations per 100 person-years in the lowest risk quartile. There was neutral effect of digoxin on mortality in all risk quartiles and no interaction between baseline risk and the effect of digoxin on mortality (p=0.94).
CONCLUSIONS: Participants in the DIG study at higher risk of hospitalization as identified by a multistate model were considerably more likely to benefit from digoxin therapy to reduce heart failure hospitalization.
PMID: 29284111 [PubMed - as supplied by publisher]