Sacubitril–Valsartan (ARNI)

Details

Sacubitril–valsartan (brand name: Entresto; formerly LCZ696) is an angiotensin receptor–neprilysin inhibitor (ARNI) combining a neprilysin inhibitor prodrug (sacubitril, converted to LBQ657) and an AT1 receptor blocker (valsartan) in a single molecule. Neprilysin inhibition prevents degradation of natriuretic peptides (BNP, ANP, CNP), bradykinin, and adrenomedullin, amplifying their vasodilatory, natriuretic, and antifibrotic effects. Combined AT1R blockade prevents angiotensin II–mediated vasoconstriction and fluid retention. The combination suppresses the renin–angiotensin–aldosterone and sympathetic nervous systems while enhancing the natriuretic peptide system.

Dosing (target): Sacubitril 97 mg / valsartan 103 mg twice daily (titrated from sacubitril 24–26/valsartan 26–51 mg BID). Requires 36-hour washout after ACE inhibitor before initiation (angioedema risk).

Contraindications: ACE inhibitor co-administration; history of angioedema with ACE inhibitor or ARNI; pregnancy.

Key Facts

HFrEF — PARADIGM-HF (Primary Evidence)

• PARADIGM-HF (McMurray et al., 2014, NEJM): n=8,399 ITT (4,187 LCZ696 / 4,212 enalapril); LVEF ≤40% (amended to ≤35% during trial); NYHA II–IV; BNP ≥150 pg/mL; sacubitril–valsartan vs enalapril 10 mg BID; median 27 months; 1,043 centres, 47 countries; stopped early at third interim analysis for overwhelming benefit. (sources/arni-paradigm-hf-nejm-2014, rating: very high)
• Primary composite (CV death + first HF hospitalisation): HR 0.80 (95% CI 0.73–0.87; P<0.001); 21.8% vs 26.5%; NNT = 21. (sources/arni-paradigm-hf-nejm-2014, rating: very high)
• CV death: HR 0.80 (95% CI 0.71–0.89; P<0.001); 13.3% vs 16.5%; NNT = 32. (sources/arni-paradigm-hf-nejm-2014, rating: very high)
• HF hospitalisation: HR 0.79 (95% CI 0.71–0.89; P<0.001); 12.8% vs 15.6%. (sources/arni-paradigm-hf-nejm-2014, rating: very high)
• All-cause death: HR 0.84 (95% CI 0.76–0.93; P<0.001); 17.0% vs 19.8%. (sources/arni-paradigm-hf-nejm-2014, rating: very high)
• KCCQ at 8 months: Between-group difference +1.64 points (P=0.001); +0.95 points (P=0.004) excluding imputed deaths — statistically significant but below the ~5-point MCID. (sources/arni-paradigm-hf-nejm-2014, rating: very high)
• Safety advantages over enalapril: Less cough; less creatinine ≥2.5 mg/dL; less potassium >6.0 mmol/L; fewer renal impairment discontinuations (0.7% vs 1.4%, P=0.002); angioedema not significantly different (19 vs 10, P=0.13); more symptomatic hypotension but rare discontinuation for it. (sources/arni-paradigm-hf-nejm-2014, rating: very high)
• Consistent benefit across all 18 prespecified subgroups. LCZ696 also lowered SBP by 3.2 mmHg more than enalapril, though BP as a time-dependent covariate did not explain the incremental outcome benefit. (sources/arni-paradigm-hf-nejm-2014, rating: very high)
• This established sacubitril–valsartan as a pillar of HFrEF therapy — Class I, Level A/B across all major guidelines.

HFrEF — Guideline Recommendation

• AHA 2022: COR 1 in symptomatic HFrEF (LVEF ≤40%) to reduce CV death and HF hospitalisation; replaces ACE-I/ARB.
• ESC 2021/2023: Class I, Level B in HFrEF tolerating ACE inhibitor/ARB; switch to ARNI to further reduce risk.
• AHA 2022 also supports use in HFmrEF (COR 2b) and HFpEF at lower LVEF (COR 2b, based on PARAGON-HF subgroup).

HFpEF — PARAGON-HF (Key Evidence)

• PARAGON-HF (Solomon et al., 2019, NEJM): n=4,796, LVEF ≥45%, NYHA II–IV, elevated natriuretic peptides, structural heart disease; sacubitril–valsartan vs valsartan (active comparator); median 35 months. (sources/arni-paragon-hf-nejm-2019, rating: very high)
• Primary outcome (total HF hospitalisations + CV death): RR 0.87 (95% CI 0.75–1.01; P=0.06) — did not meet significance.
• HF hospitalisations: RR 0.85 (95% CI 0.72–1.00) — borderline.
• CV death: HR 0.95 (95% CI 0.79–1.16) — no difference.
• Secondary signals (exploratory after primary not met):
  • NYHA class improvement at 8 months: 15.0% vs 12.6% (OR 1.45, 95% CI 1.13–1.86)
  • Worsening renal function: 1.4% vs 2.7% (HR 0.50, 95% CI 0.33–0.77) — significant renal protection
  • KCCQ score: +1.0 point improvement (95% CI 0.0–2.1) — modest
• Subgroup signals: Possible benefit in LVEF 45–57% (lower EF boundary, overlapping HFmrEF) and in women — hypothesis-generating only. (sources/arni-paragon-hf-nejm-2019, rating: very high)
• Safety: Higher hypotension and angioedema; lower hyperkalemia and elevated creatinine vs valsartan.

HFpEF — Guideline Recommendation

• AHA 2022: ARNi COR 2b, LOE B-R — "particularly in those with lower LVEF" (PARAGON-HF subgroup signal). Not a routine recommendation.
• ESC 2023: Not specifically recommended for HFpEF; SGLT2 inhibitors received Class I, Level A.
• ESC 2021: Listed as having no convincing evidence in HFpEF.
• The PARAGON-HF result provided sufficient signal to shift guideline language toward COR 2b in selected patients (lower EF, women) but did not meet the bar for a strong recommendation.

COPD+HFpEF — Dual Cardiac and Pulmonary Mechanisms (Mechanistic)

• In the COPD+HFpEF comorbid population, sacubitril/valsartan (ARNI) may offer dual benefit through cardiac and pulmonary mechanisms — no dedicated RCT exists; evidence is mechanistic and from PARAGON-HF subgroup data. (sources/copd-hfpef-eschf-2025, rating: high)
• Sacubitril (neprilysin inhibitor) — pulmonary effects:
  • Prevents degradation of natriuretic peptides (BNP, ANP) → ↑bioavailability → vasodilation + ↓pulmonary artery smooth muscle cell proliferation — potentially beneficial for COPD-related pulmonary vascular changes. (sources/copd-hfpef-eschf-2025, rating: high)
  • Induces bronchodilation by stimulating acetylcholine release from bronchial epithelial cells — direct airway benefit in COPD. (sources/copd-hfpef-eschf-2025, rating: high)
• Valsartan+sacubitril combined — anti-remodelling: Valsartan suppresses myocardial remodelling (guanine nucleotide-binding protein family inhibition); sacubitril prevents myocardial cell death (PTEN inhibition); additive effect → ↓LV extracellular matrix remodelling. (sources/copd-hfpef-eschf-2025, rating: high)
• These mechanisms support ARNI as a candidate for further clinical trial investigation specifically in the COPD+HFpEF population. (sources/copd-hfpef-eschf-2025, rating: high)

Contradictions / Open Questions

• PARADIGM-HF stopped early: Terminated at the third planned interim analysis. Trials stopped early for benefit systematically overestimate the true effect size; the true HR may be closer to 0.85–0.88 than the reported 0.80. (sources/arni-paradigm-hf-nejm-2014, rating: very high)
• KCCQ improvement below MCID: The 1.64-point between-group KCCQ difference is statistically significant but below the ~5-point minimal clinically important difference, raising the question of whether the symptomatic benefit is clinically perceptible to individual patients. (sources/arni-paradigm-hf-nejm-2014, rating: very high)
• GDMT gap — SGLT2i not included: PARADIGM-HF background therapy (2009–2014) did not include SGLT2i. It is unknown whether LCZ696 provides additive mortality benefit on top of quadruple GDMT (ARNI + beta-blocker + MRA + SGLT2i). Observational and subgroup data suggest benefit persists, but no dedicated RCT has tested this.
• Primary endpoint P=0.06 — negative or near-positive? PARAGON-HF is considered "negative" by pre-specified alpha of 0.048, but the effect size (RR 0.87) and secondary signals raise the question of whether a different trial design (vs placebo, higher power, different EF threshold) would have reached significance. (sources/arni-paragon-hf-nejm-2019, rating: very high)
• Active comparator bias: Valsartan itself has a modest benefit signal in HFpEF (CHARM-Preserved), which may have attenuated the difference between arms — the trial may underestimate true ARNI benefit vs placebo. (sources/arni-paragon-hf-nejm-2019, rating: very high)
• Run-in exclusion: Sequential double run-in (enalapril then LCZ696) excluded ~12% of patients with adverse events (cough, hypotension, hyperkalemia, renal dysfunction), enriching the randomized population for tolerators of both drugs — reduces external validity and likely inflates observed tolerability vs unselected real-world patients. (sources/arni-paradigm-hf-nejm-2014, rating: very high)
• EF boundary problem: PARAGON-HF enrolled LVEF ≥45%; the subgroup signal at LVEF 45–57% overlaps with HFmrEF, blurring whether ARNI benefits HFpEF proper or only the low-EF boundary. Subsequent DELIVER trial (dapagliflozin) showed SGLT2i benefit across the full LVEF spectrum, potentially relegating ARNI to a specific HFpEF niche.
• ATTR amyloidosis: At higher EF (>57%), ATTR amyloid cardiomyopathy may account for reduced ARNI responsiveness — a confounding population not systematically excluded.

Connections

• Related to entities/HFpEF — primary evidence source; COR 2b basis
• Related to entities/Heart-Failure — approved pillar therapy in HFrEF; investigational in HFpEF
• Related to concepts/Pulmonary-Hypertension-Classification — HFmrEF EF boundary relevant to PARAGON-HF subgroup
• Related to sources/HF-AHA-2022 — COR 2b recommendation context
• Related to sources/HF-ESC-2021 — failed to reduce morbidity/mortality in HFpEF (pre-PARAGON-HF)

Sources

• sources/arni-paradigm-hf-nejm-2014 — PARADIGM-HF RCT (HFrEF; primary evidence for Class I recommendation)
• sources/arni-paragon-hf-nejm-2019 — PARAGON-HF RCT (HFpEF; basis for COR 2b; primary endpoint negative P=0.06)
• sources/copd-hfpef-eschf-2025 — Meta-analysis; ARNI dual cardiac+pulmonary mechanisms in COPD+HFpEF