Angiotensin Receptor Neprilysin Inhibition in Heart Failure With Preserved Ejection Fraction: Rationale and Design of the PARAGON-HF Trial

Objectives The PARAGON-HF (Prospective Comparison of ARNI with ARB Global Outcomes in HF With Preserved Ejection Fraction) trial is designed to determine the efficacy and safety of the angiotensin receptor neprilysin inhibitor sacubitril/valsartan compared with valsartan in patients with chronic heart failure and preserved ejection fraction (HFpEF). Background HFpEF is highly prevalent, associated with substantial morbidity and mortality, and in need of effective therapies that improve outcomes. The angiotensin receptor neprilysin inhibitor (ARNI) sacubitril/valsartan, which has been shown to benefit patients with heart failure (HF) and reduced ejection fraction, demonstrated favorable physiologic effects in a phase II HFpEF trial. Methods The PARAGON-HF trial is a randomized, double-blind, parallel group, active-controlled, event-driven trial comparing the long-term efficacy and safety of valsartan and sacubitril/valsartan in patients with chronic HFpEF (left ventricular ejection fraction ≥45%), New York Heart Association functional class II to IV symptoms, elevated natriuretic peptides, and evidence of structural heart disease. Before randomization, all patients entered sequential single-blind run-in periods to ensure tolerability of both drugs at half the target doses (i.e., valsartan titrated to 80 mg bid followed by sacubitril/valsartan 49/51 mg [100 mg] bid). The primary outcome is the composite of cardiovascular death and total (first and recurrent) HF hospitalizations. Conclusions PARAGON-HF will determine whether sacubitril/valsartan is superior to angiotensin receptor blockade alone in patients with chronic symptomatic HFpEF.