Sacubitril/Valsartan (ARNI)

Sacubitril/Valsartan is an Angiotensin Receptor–Neprilysin Inhibitor (ARNI).

It combines:

• Sacubitril – neprilysin inhibitor • Valsartan – angiotensin receptor blocker (ARB)

ARNI therapy is preferred over ACE inhibitors or ARBs in HFrEF.

Heart Failure Module


Mechanism of Action

Sacubitril:

• Inhibits neprilysin • Increases natriuretic peptides (ANP, BNP) • Promotes natriuresis • Promotes vasodilation • Reduces remodeling

Valsartan:

• Blocks AT1 receptor • Reduces angiotensin II effects • Decreases aldosterone • Reduces afterload

Net Effects:

• ↓ Afterload • ↓ Preload • ↓ Remodeling • ↓ Mortality • ↓ Hospitalization

ARNI enhances protective pathways while suppressing maladaptive RAAS activation.


Why ARNI > ACE Inhibitor

PARADIGM-HF Trial:

• Reduced cardiovascular death • Reduced HF hospitalization • Superior to enalapril

ARNI is now preferred first-line RAAS therapy in HFrEF.

Alternative if not tolerated:

ACE InhibitorARB


Indications

HFrEF (EF ≤40%) ★

• NYHA Class II–IV • Part of the Four Pillars of GDMT

Heart Failure Module

Not indicated for HFpEF as core therapy.


ACE Inhibitor Washout Requirement

Do NOT start ARNI within 36 hours of ACE inhibitor use.

Reason:

• Increased bradykinin levels • Increased risk of angioedema

Switching from ACE inhibitor requires 36-hour washout.

Switching from ARB does NOT require washout.


Adverse Effects

• Hypotension • Hyperkalemia • Increased creatinine • Angioedema (rare but serious)

Lower cough risk compared to ACE inhibitors.


Monitoring

Monitor:

• Blood pressure • Serum potassium • Renal function

Check labs within 1–2 weeks of initiation or dose increase.


Contraindications

• History of angioedema • Concomitant ACE inhibitor use • Pregnancy • Severe hypotension

Use caution in:

• Advanced renal dysfunction • Hyperkalemia


ARNI vs ACEi vs ARB

ACE Inhibitors: • Block angiotensin II production • Increase bradykinin • Cause cough

ARBs: • Block AT1 receptor • No bradykinin increase

ARNI: • Blocks AT1 receptor • Inhibits neprilysin • Enhances natriuretic peptides • Superior outcomes in HFrEF


Clinical Pearls

✔ First-line RAAS therapy in HFrEF ✔ Superior to ACE inhibitors in reducing mortality ✔ Requires 36-hour ACE inhibitor washout ✔ Part of the Four Pillars of GDMT ✔ Monitor potassium and renal function


Related:

Heart Failure ModuleACE InhibitorsARBsReturn to Cardiovascular Modules