Abstract

CO-RRRELATION OF SERUM DIGOXIN CONCENTRATION AND ITS OUTCOME IN HEART FAILURE

Premshanker Singh*, Ritu Karoli, Nikhil Gupta, Shobhit Shakya and PK Singh

ABSTRACT

We aimed to assess variations in serum digoxin concentration (SDC) and their association with mortality and hospitalization in patients with heart failure. This study was conducted from Apr 2017 to Apr 2020 at Tertiary care hospital (Dr RML Institute of Medical Sciences, Lucknow, India) with the main analysis restricted to men with a left ventricular ejection fraction of 45% or less (n = 3780). Patients randomly assigned to receive digoxin were divided into 3 groups based on SDC at 1 month (0.5-0.8 ng/mL, n = 572; 0.9-1.1 ng/mL, n = 322; and ≥1.2 ng/mL, n = 277) and compared with patients randomly assigned to receive placebo (n = 2610). All-cause mortality at a mean follow-up of 36 months. SDCs were associated with increased crude all-cause mortality rates (0.5-0.8 ng/mL, 29.9%; 0.9-1.1 ng/mL, 38.8%; and ≥1.2 ng/mL, 48.0%; P = .006 for trend). Patients with SDCs of 0.5 to 0.8 ng/mL had a 6.3% (95% confidence interval [CI], 2.1%-10.5%) lower mortality rate compared with patients receiving placebo. Digoxin was not associated with a reduction in mortality among patients with SDCs of 0.9 to 1.1 ng/mL (2.6% increase; 95% CI, − 3.0% to 8.3%), whereas patients with SDCs of 1.2 ng/mL and higher had an 11.8% (95% CI, 5.7%-18.0%) higher absolute mortality rate than patients receiving placebo. The association between SDC and mortality persisted after multivariable adjustment (SDC 0.5-0.8 ng/mL hazard ratio [HR] 0.80, 95% CI, 0.68-0.94; SDC 0.9-1.1 ng/mL HR 0.89, 95% CI, 0.74-1.08; SDC ≥1.2 ng/mL HR 1.16, 95% CI, 0.96-1.39; and HR of 1.00 [referent] for placebo). Our findings demonstrate that higher SDCs were associated with increased mortality and suggest that the effectiveness of digoxin therapy in men with heart failure and a left ventricular ejection fraction of 45% or less may be optimized in the SDC range of 0.5 to 0.8 ng/mL. This study found the efficacy of digoxin therapy for patients with heart failure, found that digoxin therapy had no effect on mortality but modestly reduced hospitalizations due to worsening heart failure.

Keywords: .