Why are ACE inhibitors used for congestive heart failure?

Why Gardiance (Empagliflozin) is Used for Congestive Heart Failure

I notice there's a discrepancy in your question - you asked about "Gardiance" (likely referring to Jardiance/empagliflozin, an SGLT2 inhibitor) but the evidence provided discusses ACE inhibitors. I'll answer the question as written in your expanded context about ACE inhibitors in congestive heart failure, as this matches the evidence provided.

Direct Answer

ACE inhibitors are used in congestive heart failure because they reduce both mortality and morbidity by blocking the renin-angiotensin-aldosterone system, which is a key driver of heart failure progression. 1

Mechanism of Action

ACE inhibitors work by blocking the conversion of angiotensin I to angiotensin II, resulting in:

• Decreased vasoconstriction - reducing afterload on the failing heart 2
• Decreased aldosterone secretion - reducing sodium and water retention 2
• Increased bradykinin levels - contributing to beneficial vasodilation (though this also causes the side effect of cough) 1
• Reduced plasma norepinephrine and vasopressin - blunting harmful neurohormonal activation 3

Evidence-Based Benefits

Randomized controlled trials have conclusively demonstrated that ACE inhibitors provide the following benefits in heart failure with reduced ejection fraction (HFrEF):

Mortality Reduction

• Significant reduction in all-cause mortality across all severity levels of heart failure 1
• Extended 12-year follow-up data showed 50.9% vs 56.4% cumulative death rate (ACE inhibitor vs placebo) 4

Morbidity Reduction

• Reduced hospitalizations for heart failure by preventing disease progression 1
• Reduced combined endpoint of death or hospitalization - the ATLAS trial showed high-dose lisinopril reduced this by 15% compared to low-dose 4
• Prevention of myocardial infarction - compelling evidence shows ACE inhibitors prevent MI in heart failure patients 5

Symptomatic Improvement

• Improved exercise capacity and reduced dyspnea and fatigue 3
• Improved NYHA functional class 1
• Enhanced overall sense of well-being 1

Additional Benefits

• Reduced diuretic requirements 3
• Correction of hyponatremia 3
• Conservation of potassium and magnesium 3
• Reduced ventricular arrhythmias 3

Clinical Application

ACE inhibitors are recommended as first-line therapy for all patients with HFrEF (Class I, Level of Evidence A) in conjunction with beta-blockers and aldosterone antagonists in selected patients. 1

Patient Selection

• All patients with symptomatic HFrEF (NYHA class I-IV) should receive ACE inhibitors 1
• Patients with asymptomatic left ventricular systolic dysfunction to prevent progression to symptomatic heart failure 1, 5
• Post-myocardial infarction patients with reduced ejection fraction to prevent heart failure development 1

Dosing Strategy

Start low and titrate to target doses used in clinical trials: 1

• Captopril: Start 6.25 mg three times daily, target 50-100 mg three times daily 1
• Enalapril: Start 2.5 mg twice daily, target 10-20 mg twice daily 1
• Lisinopril: Start 2.5-5.0 mg once daily, target 30-35 mg once daily 1
• Ramipril: Start 2.5 mg once daily, target 5 mg twice daily or 10 mg once daily 1

Double the dose at not less than 2-week intervals, aiming for target doses proven in trials. 1

Important Cautions and Monitoring

Contraindications

• Life-threatening angioedema or anuric renal failure during previous ACE inhibitor exposure 1
• Pregnancy or planning pregnancy 1
• Bilateral renal artery stenosis 1

Use With Caution When:

• Systolic blood pressure <90-100 mmHg - risk of symptomatic hypotension 1, 2
• Serum creatinine >2.5 mg/dL (>221 µmol/L) - risk of worsening renal function 1
• Serum potassium >5.0-5.5 mEq/L - risk of hyperkalemia 1, 2
• Severe volume or salt depletion - increased hypotension risk 2

Monitoring Requirements

• Check blood pressure, renal function (creatinine), and serum potassium at baseline, after dose increases, and periodically during maintenance 1, 2
• Monitor for angioedema (occurs in <1% but more common in Black patients and women) 1
• Monitor for cough (occurs in up to 20% of patients) 1

Common Pitfalls to Avoid

Under-dosing is the most prevalent problem - studies show only 33-67% of eligible hospitalized patients and 10-36% of community patients receive ACE inhibitors, and among those treated, most receive doses substantially lower than target doses. 6

Do not abruptly discontinue ACE inhibitors - this can lead to clinical deterioration. 1

If target doses are not tolerated, use intermediate doses rather than discontinuing - some ACE inhibitor is better than none. 1

Do not avoid ACE inhibitors due to asymptomatic hypotension - only symptomatic hypotension requires dose adjustment. 1

Alternative for ACE Inhibitor Intolerance

If patients cannot tolerate ACE inhibitors due to cough or angioedema, angiotensin receptor blockers (ARBs) are recommended as an alternative (Class I, Level of Evidence A). 1 ARBs provide similar mortality and morbidity benefits without inhibiting kininase, resulting in much lower rates of cough and angioedema. 1

For patients who tolerate ACE inhibitors, angiotensin receptor-neprilysin inhibitors (ARNI) such as sacubitril/valsartan have shown superior outcomes - 20% reduction in cardiovascular death or heart failure hospitalization compared to enalapril (Class I, Level of Evidence B-R). 1