CHF with Atrial Fibrillation — LVEF 30% (HFrEF)

1. Classification & Hemodynamic Impact

• Loss of atrial kick → reduced LV filling
• Rapid, irregular ventricular rate → functional worsening / tachycardia-mediated cardiomyopathy
• Increased risk of thromboembolism and stroke

2. Guideline-Directed Medical Therapy (GDMT) for HFrEF — The "Four Pillars"

A. ACEi / ARB / ARNI

• ARNI (sacubitril/valsartan) preferred over ACEi — PARADIGM-HF showed 20% reduction in CV death/HF hospitalization vs. enalapril
• ACEi (enalapril, lisinopril, ramipril) as alternative if ARNI not tolerated
• ARB (valsartan, candesartan) if ACEi intolerant (cough)
• Avoid ACEi + ARNI combination (36-hour washout required when switching)

B. Beta-Blocker (particularly important with AF)

• Three agents with proven mortality benefit: carvedilol, metoprolol succinate, bisoprolol
• In HFrEF + AF: beta-blockers are preferred for rate control over digoxin (digoxin lacks rate-limiting effects during activity)
• AF-CHF trial substudy: beta-blocker use → significantly lower mortality in HFrEF + AF
• Combination of digoxin + beta-blocker is more effective for resting rate control than either alone

C. Mineralocorticoid Receptor Antagonist (MRA)

• Spironolactone or eplerenone — reduce mortality ~30% in NYHA class III–IV HFrEF
• Requires monitoring: serum K⁺ and creatinine (risk of hyperkalemia, especially with ACEi/ARB)

D. SGLT2 Inhibitor

• Dapagliflozin (DAPA-HF) and empagliflozin (EMPEROR-Reduced) — both reduce CV death or HF hospitalization in HFrEF (LVEF ≤40%), regardless of diabetes status
• LVEF improvement demonstrated in trials

3. Rate vs. Rhythm Control in HFrEF + AF

Key Trial: AF-CHF

• Enrolled chronic HFrEF (EF <35%) patients with AF
• Rate control was NOT inferior to rhythm control for CV mortality (HR 1.06, 95% CI 0.86–1.30, P = 0.59)
• Secondary endpoints (all-cause death, stroke, worsening HF) — no difference
• Conclusion: routine rhythm control strategy is NOT superior for mortality in HFrEF + AF

Rate Control Targets

• Resting ventricular rate: 60–80 bpm at rest (some accept up to 100–110 bpm — RACE II showed lenient rate control was non-inferior to strict)
• Preferred agents: Beta-blockers (carvedilol, metoprolol succinate)
• Digoxin: adjunct — effective at rest, add to beta-blocker for better control
• ⚠️ Non-dihydropyridine CCBs (diltiazem, verapamil) — avoid in HFrEF due to negative inotropy

Rhythm Control — When to Consider

• Reversible secondary cause of AF (thyrotoxicosis, post-cardiac surgery, acute illness)
• Hemodynamic instability (DC cardioversion)
• Symptoms refractory to rate control
• Tachycardia-mediated cardiomyopathy suspected
• Amiodarone is the safest antiarrhythmic in HFrEF for pharmacologic cardioversion (low negative inotropy), but has long-term toxicity (thyroid, pulmonary, hepatic)
• Most other antiarrhythmics (flecainide, propafenone) are contraindicated in HFrEF — negative inotropic + proarrhythmic

4. Catheter Ablation for AF in HFrEF

• Tachycardia-mediated cardiomyopathy suspected (LVEF may recover post-ablation)
• Symptoms persist despite adequate rate control
• NYHA II–IV with symptomatic paroxysmal or persistent AF

5. Anticoagulation (Mandatory)

• LVEF 30% + AF = HIGH thromboembolic risk — CHA₂DS₂-VASc score will be ≥1 from AF alone in context of HF
• DOACs are first-line: apixaban and rivaroxaban are preferred over warfarin (better safety profile)
• Warfarin: if DOAC contraindicated (e.g., significant renal failure, mechanical valve), target INR 2.0–3.0
• WARCEF trial: warfarin is NOT indicated over aspirin for HFrEF in sinus rhythm — but this patient has AF, so anticoagulation IS indicated
• Do NOT rely on aspirin alone for stroke prevention in AF

6. Device Therapy

ICD

• Class I indication: LVEF ≤35%, NYHA class II–III, on GDMT, with >1 year good functional survival expected
• LVEF 30% meets threshold — ICD should be evaluated after at least 3 months of optimal GDMT (LVEF may improve)

CRT / CRT-D

• Consider if: LVEF ≤35%, NYHA II–IV, LBBB with QRS ≥150 ms on GDMT
• With AF: CRT benefit is reduced compared to sinus rhythm; AV node ablation may be needed to optimize biventricular pacing
• CRT-D preferred over CRT-P if ICD criteria also met

7. Other Considerations

Summary Algorithm

HFrEF (LVEF 30%) + AF
        │
        ├── START: GDMT (ARNI/ACEi + β-blocker + MRA + SGLT2i)
        │
        ├── RATE CONTROL: β-blocker ± digoxin (target 60–100 bpm)
        │   ⚠️ Avoid diltiazem/verapamil
        │
        ├── ANTICOAGULATION: DOAC (apixaban/rivaroxaban)
        │
        ├── RHYTHM CONTROL if symptomatic / tachycardia-CMP suspected:
        │   → Amiodarone (pharmacologic) OR
        │   → Catheter ablation (preferred — CASTLE-AF evidence)
        │
        └── DEVICES (after 3–6 months of GDMT):
            → ICD if LVEF ≤35%, NYHA II–III
            → CRT-D if LBBB + QRS ≥150 ms