Abstract
Background Enhanced inflammation may lead to exercise intolerance in heart failure with preserved ejection fraction. The aim of the current study was to determine whether IL (interleukin)-1 blockade with anakinra improved cardiorespiratory fitness in heart failure with preserved ejection fraction. Methods and Results Thirty-one patients with heart failure with preserved ejection fraction and CRP (C-reactive protein) >2 mg/L were randomized to anakinra (100 mg subcutaneously daily, N=21) or placebo (N=10) for 12 weeks. We measured peak oxygen consumption (Vo(2)), ventilatory efficiency (V(E)/Vco(2) slope), and high-sensitivity CRP and NT-proBNP (N-terminal pro-B-type natriuretic peptide) at 4, 12, and 24 weeks. Twenty-eight patients completed ≥2 visits, 18 women (64%), 27 (96%) obese. There were no differences in peak Vo(2) or V(E)/Vco(2) slope between groups at baseline. Peak Vo(2) was not changed after 12 weeks of anakinra (from 13.6 [11.8-18.0] to 14.2 [11.2-18.5] mL·kg(-1)·min(-1), P=0.89), or placebo (14.9 [11.7-17.2] to 15.0 [13.8-16.9] mL·kg(-1)·min(-1), P=0.40), without significant between-group differences in changes at 12 weeks (-0.4 [95% CI, -2.2 to +1.4], P=0.64). V(E)/Vco(2) slope was also unchanged with anakinra (from 28.3 [27.2-33.0] to 30.5 [26.3-32.8], P=0.97) or placebo (from 31.6 [27.3-36.9] to 31.2 [27.8-33.4], P=0.78), without significant between-group differences in changes at 12 weeks (+1.2 [95% CI, -1.8 to +4.3], P=0.97). Within the anakinra-treated patients, high-sensitivity CRP and NT-proBNP levels were lower at 4 weeks compared with baseline ( P=0.026 and P=0.022 versus placebo [between-group analysis], respectively). Conclusions Treatment with anakinra for 12 weeks failed to improve peak Vo(2) and V(E)/Vco(2) slope in a group of obese heart failure with preserved ejection fraction patients. The favorable trends in high-sensitivity CRP and NT-proBNP with anakinra deserve exploration in future studies. Clinical Trial Registration URL: https://www.clinicaltrials.gov . Unique identifier: NCT02173548.