Effect of Sacubitril-Valsartan vs Enalapril on Aortic Stiffness in Patients With Heart Failure and Reduced Ejection Fraction

IMPORTANCE: Compared with enalapril, sacubitril-valsartan reduces cardiovascular mortality and heart failure hospitalization in patients with heart failure and reduced ejection fraction (HFrEF). These benefits may be related to effects on hemodynamics and cardiac remodeling. OBJECTIVE: To determine whether treatment of HFrEF with sacubitril-valsartan improves central aortic stiffness and cardiac remodeling compared with enalapril. DESIGN, SETTING, AND PARTICIPANTS: Randomized, double-blind clinical trial of 464 participants with heart failure and ejection fraction of 40% or less enrolled across 85 US sites between August 17, 2016, and June 28, 2018. Follow-up was completed on January 26, 2019. INTERVENTIONS: Randomization (1:1) to sacubitril-valsartan (n = 231; target dosage, 97/103 mg twice daily) vs enalapril (n = 233; target dosage, 10 mg twice daily) for 12 weeks. MAIN OUTCOMES AND MEASURES: The primary outcome was change from baseline to week 12 in aortic characteristic impedance (Zc), a measure of central aortic stiffness. Prespecified secondary outcomes included change from baseline to week 12 in N-terminal pro-B-type natriuretic peptide, ejection fraction, global longitudinal strain, mitral annular relaxation velocity, mitral E/e' ratio, left ventricular end-systolic and end-diastolic volume indexes (LVESVI and LVEDVI), left atrial volume index, and ventricular-vascular coupling ratio. RESULTS: Of 464 validly randomized participants (mean age, 67.3 SD, 9.1 years; 23.5% women), 427 completed the study. At 12 weeks, Zc decreased from 223.8 to 218.9 dyne × s/cm5 in the sacubitril-valsartan group and increased from 213.2 to 214.4 dyne × s/cm5 in the enalapril group (treatment difference, -2.2 95% CI, -17.6 to 13.2 dyne × s/cm5; P = .78). Of 9 prespecified secondary end points, no significant between-group difference in change from baseline was seen in 4, including left ventricular ejection fraction (34%-36% with sacubitril-valsartan vs 33 to 35% with enalapril; treatment difference, 0.6% 95% CI, -0.4% to 1.7%; P = .24). However, greater reductions from baseline were seen with sacubitril-valsartan than with enalapril in all others, including left atrial volume (from 30.4 mL/m2 to 28.2 mL/m2 vs from 29.8 mL/m2 to 30.5 mL/m2; treatment difference, -2.8 mL/m2 95% CI, -4.0 to -1.6 mL/m2; P < .001), LVEDVI (from 75.1 mL/m2 to 70.3 mL/m2 vs from 79.1 mL/m2 to 75.6 mL/m2; treatment difference, -2.0 mL/m2 95% CI, -3.7 to 0.3 mL/m2; P = .02), LVESVI (from 50.8 mL/m2 to 46.3 mL/m2 vs from 54.1 to 50.6 mL/m2; treatment difference, -1.6 mL/m2 95% CI, -3.1 to -0.03 mL/m2; P = .045), and mitral E/e' ratio (from 13.8 to 12.3 vs from 13.4 to 13.8; treatment difference, -1.8 95% CI, -2.8 to -0.8; P = .001). Rates of adverse events including hypotension (1.7% vs 3.9%) were similar in both groups. CONCLUSIONS AND RELEVANCE: Treatment of HFrEF with sacubitril-valsartan, compared with enalapril, did not significantly reduce central aortic stiffness. The study findings may provide insight into mechanisms underlying the effects of sacubitril-valsartan in HFrEF. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02874794.