The Effects of IL-1 Blockade on Inotrope Sensitivity in Patients With Heart Failure (AID-HEART)

Overview

End-stage heart failure (HF) is a progressive illness with a mortality rate similar to most advanced cancers.Roughly 5% of patients with HF have end-stage disease that is refractory to medical therapy (stage D heart failure). When patients reach this point in their disease, the only treatments known to prolong life are cardiac transplantation or left ventricular assist devices. In patients who do not qualify for these options, or elect a palliative approach, inotropes are frequently used to improve hemodynamics through an increase in cardiac output and reduction in filling pressures. While inotropes provide profound symptomatic relief, these benefits are accompanied by significant risks of progressive adverse cardiac remodeling, arrhythmias, and sudden death. There is, therefore, an urgent need to develop strategies to reduce the dose or duration of inotrope use in the management of patients with stage D of HF.

Heart failure (HF) represents a leading cause of morbidity and mortality worldwide. Despite improvements in treatments and widespread efforts to implement guideline directed medical therapies, a growing population of patients with end-stage HF has limited treatment options to improve their quality and quantity of life. When patients reach this point in their disease, the only treatments known to prolong life are cardiac transplantation or left ventricular assist devices. In patients who do not qualify for these options, intravenous (IV) drugs that directly stimulate increased cardiac output ("inotropes") are frequently used to offer symptomatic relief. Inotropes exert their pharmacologic effects through direct activation of the beta-adrenergic receptors in the heart that increase heart rate and contractility. Unfortunately, however, the relief of symptoms from inotropes is accompanied by dose-dependent increased risks of progressive adverse cardiac remodeling, arrhythmias, and sudden death. There is therefore an urgent need to develop treatments that minimize the dosing requirements for inotropes or improve responsiveness to these agents. Inflammation has been recognized as a major pathophysiological contributor to HF. Interleukin (IL)-1 is a potent apical inflammatory cytokine that is abundant in HF patients and correlates with disease severity. Preclinical data have shown that IL-1 is sufficient to induce cardiac dysfunction, desensitize beta-adrenergic receptors (impaired responsiveness to inotropes), and reduce exercise capacity. Among the observed effects of IL-1 in these models of HF, the impaired responsiveness to inotropes showed the greatest signal-to-noise ratio, suggesting a large potential effect size for IL-1 blockade to translated to human subjects. In a 12-week pilot clinical trial in stable HF patients not receiving IV inotropes, daily administration of an IL-1 antagonist (anakinra) improved exercise capacity. However, IL-1 blockade has not yet been evaluated in patients with more advanced HF requiring inotrope therapy.