Kicking the tyres of a heart failure trial: physician response to the approval of sacubitril/valsartan in the USA

Angiotensin receptor-neprilysin inhibition has been shown to be superior to target doses of an ACE inhibitor in reducing the risk of cardiovascular death and clinical disease progression in patients with chronic heart failure and a reduced EF. Nevertheless, although sacubitril/valsartan has been available in the USA for a year, uptake of the drug by practitioners has been slow, in part because of misconceptions about the pivotal trial that demonstrated its efficacy in heart failure (PARADIGM-HF). This review addresses questions that have been raised in the USA about the design of the trial as well as the patients who were studied, the replicability and applicability of the results, and the safety of neprilysin inhibition. The totality of evidence indicates that the PARADIGM-HF trial used an appropriate comparator; enrolled patients typical of those seen in the community with mild to moderate symptoms; yielded highly persuasive and replicable results; and demonstrated benefits that are applicable to patients taking subtarget doses of ACE inhibitors and ARBs. Regulatory review in the USA concluded that the established advantages of sacubitril/valsartan on cardiovascular death and disease progression outweighed hypothetical uncertainties about the long-term effects of neprilysin inhibition in patients who might not have survived without the drug. Accordingly, both the new US and European Society of Cardiology heart failure guidelines recommend sacubitril/valsartan as the preferred approach to inhibiting the renin-angiotensin system in patients with chronic heart failure who are currently receiving an ACE inhibitor or ARB.