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.

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 (Vo₂), ventilatory efficiency (V_E/Vco₂ 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 Vo₂ or V_E/Vco₂ slope between groups at baseline. Peak Vo₂ 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/Vco₂ 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).

Treatment with anakinra for 12 weeks failed to improve peak Vo₂ and V_E/Vco₂ 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.

URL: https://www.clinicaltrials.gov. Unique identifier: NCT02173548.