Effect of Sacubitril/Valsartan vs Standard Medical Therapies on Plasma NT-proBNP Concentration and Submaximal Exercise Capacity in Patients With Heart Failure and Preserved Ejection Fraction The PARALLAX Randomized Clinical Trial

This trial tested the efficacy of sacubitril/valsartan vs standard care in reducing NT-proBNP levels and improving exercise capacity and quality of life in patients with chronic heart failure. Importance There is limited evidence on the benefits of sacubitril/valsartan vs broader renin angiotensin system inhibitor background therapy on surrogate outcome markers, 6-minute walk distance, and quality of life in patients with heart failure and mildly reduced or preserved left ventricular ejection fraction (LVEF >40%). Objective To evaluate the effect of sacubitril/valsartan on N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, 6-minute walk distance, and quality of life vs background medication-based individualized comparators in patients with chronic heart failure and LVEF of more than 40%. Design, Setting, and Participants A 24-week, randomized, double-blind, parallel group clinical trial (August 2017-October 2019). Of 4632 patients screened at 396 centers in 32 countries, 2572 patients with heart failure, LVEF of more than 40%, elevated NT-proBNP levels, structural heart disease, and reduced quality of life were enrolled (last follow-up, October 28, 2019). Interventions Patients were randomized 1:1 either to sacubitril/valsartan (n = 1286) or to background medication-based individualized comparator (n = 1286), ie, enalapril, valsartan, or placebo stratified by prior use of a renin angiotensin system inhibitor. Main Outcomes and Measures Primary end points were change from baseline in plasma NT-proBNP level at week 12 and in the 6-minute walk distance at week 24. Secondary end points were change from baseline in quality of life measures and New York Heart Association (NYHA) class at 24 weeks. Results Among 2572 randomized patients (mean age, 72.6 years [SD, 8.5 years]; 1301 women [50.7%]), 2240 (87.1%) completed the trial. At baseline, the median NT-proBNP levels were 786 pg/mL in the sacubitril/valsartan group and 760 pg/mL in the comparator group. After 12 weeks, patients in the sacubitril/valsartan group (adjusted geometric mean ratio to baseline, 0.82 pg/mL) had a significantly greater reduction in NT-proBNP levels than did those in the comparator group (adjusted geometric mean ratio to baseline, 0.98 pg/mL) with an adjusted geometric mean ratio of 0.84 (95% CI, 0.80 to 0.88; P < .001). At week 24, there was no significant between-group difference in median change from baseline in the 6-minute walk distance with an increase of 9.7 m vs 12.2 m (adjusted mean difference, -2.5 m; 95% CI, -8.5 to 3.5; P = .42). There was no significant between-group difference in the mean change in the Kansas City Cardiomyopathy Questionnaire clinical summary score (12.3 vs 11.8; mean difference, 0.52; 95% CI, -0.93 to 1.97) or improvement in NYHA class (23.6% vs 24.0% of patients; adjusted odds ratio, 0.98; 95% CI, 0.81 to 1.18). The most frequent adverse events in the sacubitril/valsartan group vs the comparator group were hypotension (14.1% vs 5.5%), albuminuria (12.3% vs 7.6%), and hyperkalemia (11.6% vs 10.9%). Conclusions and Relevance Among patients with heart failure and left ventricular ejection factor of higher than 40%, sacubitril/valsartan treatment compared with standard renin angiotensin system inhibitor treatment or placebo resulted in a significantly greater decrease in plasma N-terminal pro-brain natriuretic peptide levels at 12 weeks but did not significantly improve 6-minute walk distance at 24 weeks. Further research is warranted to evaluate potential clinical benefits of sacubitril/valsartan in these patients. Question What is the effect of sacubitril/valsartan compared with standard medical therapy on plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration and submaximal exercise capacity in patients with heart failure and preserved ejection fraction? Findings This randomized clinical trial included 2572 participants with heart failure and left ventricular ejection fraction higher than 40%. Treatment with sacubitril/valsartan vs standard treatment with enalapril, valsartan, or placebo resulted in a statistically significant reduction in plasma NT-proBNP levels at 12 weeks (adjusted geometric mean ratio, 0.84) but did not significantly change the 6-minute walk distance at 24 weeks (9.7 m vs 12.2 m). Meaning Compared with standard medical therapies, sacubitril/valsartan resulted in a significantly greater decrease in plasma N-terminal pro-brain natriuretic peptide at 12 weeks but did not improve submaximal exercise capacity at 24 weeks.

Automated summary

The study demonstrated that compared with standard medical therapies, treatment with sacubitril/valsartan led to a significant reduction in plasma N-terminal pro-brain natriuretic peptide levels at 12 weeks but did not result in a significant improvement in 6-minute walk distance at 24 weeks for patients with heart failure and LVEF higher than 40%.