What is the optimal management plan for an elderly male patient with new onset A-fib (atrial fibrillation) and HFmrEF (heart failure with mildly reduced ejection fraction)?

Optimal Management of New Onset Atrial Fibrillation with HFmrEF

Your current management plan is excellent and aligns with contemporary guideline-directed medical therapy (GDMT), but requires specific optimization of the beta-blocker choice and consideration of additional rhythm control strategies given the new onset atrial fibrillation in the setting of heart failure. 1

Anticoagulation Strategy

• Continue Eliquis (apixaban) 5 mg twice daily for stroke prevention in atrial fibrillation, which is strongly recommended for all patients with diabetes and AF regardless of other CHA₂DS₂-VASc factors 1
• Anticoagulation must be maintained indefinitely even if sinus rhythm is achieved, as silent recurrence of AF carries high embolic risk 1
• Monitor renal function carefully when prescribing NOACs in elderly patients 1

Heart Failure Medical Therapy Optimization

Core GDMT Components (All Four Pillars)

Your initiation of Entresto, Farxiga, and metoprolol represents appropriate GDMT, but requires careful sequencing and titration: 1, 2

• Entresto (sacubitril/valsartan): Start at 24/26 mg or 49/51 mg twice daily depending on blood pressure tolerance, then up-titrate to target dose of 97/103 mg twice daily 1, 2
• Farxiga (dapagliflozin) 10 mg daily: Continue as initiated - SGLT2 inhibitors reduce HF hospitalizations across the EF spectrum and should be started early 1, 3
• Mineralocorticoid receptor antagonist (MRA): Add spironolactone 12.5-25 mg daily (target 25-50 mg daily) as the fourth pillar of GDMT for HFmrEF 1, 2
• Loop diuretic: Continue for volume management, adjusting dose based on clinical signs of congestion 1

Beta-Blocker Selection Critical Decision

Switch from metoprolol to a more appropriate beta-blocker for dual AF rate control and HF management: 1

• Carvedilol or bisoprolol are preferred over metoprolol tartrate for HFmrEF as they have stronger evidence for mortality reduction 1, 2
• If using metoprolol, metoprolol succinate (extended-release) is required, not metoprolol tartrate - start 25-50 mg daily, target 200 mg daily 1, 2
• Selective β₁ receptor blockers may be preferred due to lesser BP-lowering effects in patients with borderline blood pressure 1
• Target resting heart rate <80-90 bpm at rest and <110-130 bpm during moderate exercise 1

Atrial Fibrillation Management Strategy

Rate vs. Rhythm Control Decision

Both rate control and rhythm control strategies have equivalent outcomes in HF patients with AF, but rhythm control may offer benefits in new onset AF with HFmrEF: 1, 4

• Rate control with beta-blockers is reasonable as first-line given equivalent mortality outcomes in major trials 1
• However, consider rhythm control strategy given this is new onset AF and the patient has HFmrEF - catheter ablation shows improved outcomes especially in early persistent or paroxysmal AF with HFpEF/HFmrEF 4
• If beta-blockers alone are insufficient for rate control, add digoxin rather than amiodarone initially 1
• Avoid Class I antiarrhythmic drugs (flecainide, propafenone) due to cardiodepressant and proarrhythmic effects in structural heart disease 1

Rhythm Control Pharmacotherapy (If Pursued)

• Amiodarone is the safest antiarrhythmic if pharmacologic rhythm control is chosen, though monitor for organ toxicity 1
• Dronedarone may be considered as it reduces cardiovascular events in AF patients with HFmrEF/HFpEF (HR 0.76), though this requires dedicated trial confirmation 5
• Dofetilide is an alternative but requires inpatient initiation due to proarrhythmic risk 1

Structural Heart Disease Management

Moderate-Severe Mitral Regurgitation

Your referral to structural heart cardiology is appropriate and time-sensitive: 1

• The moderate-severe MR may be functional (secondary to LV dilation and dysfunction) or primary 1
• Optimize GDMT first as this may reduce functional MR by improving LV remodeling 1
• Transcatheter edge-to-edge repair (TEER) may be considered if MR remains severe despite optimal medical therapy 1

Fixed Apical Defects on Nuclear Stress

• Fixed defects suggest prior infarction rather than reversible ischemia 1
• Continue high-intensity statin therapy (LDL 74 is at goal for secondary prevention) 1
• Add aspirin 81 mg daily for secondary prevention given ischemic cardiomyopathy, balancing bleeding risk with Eliquis 1

Device Therapy Consideration

Evaluate for cardiac resynchronization therapy (CRT) eligibility: 1

• With LVEF 40-45%, if QRS duration ≥120 ms and NYHA class II-III symptoms persist on optimal medical therapy, CRT with or without ICD is reasonable 1
• For patients with AF and HF requiring frequent ventricular pacing, CRT is reasonable even without wide QRS 1
• If QRS <120 ms, ICD for primary prevention should be considered if LVEF remains ≤35% after 3 months of optimal medical therapy 1

Titration and Monitoring Protocol

4-Week Follow-up Plan

Your planned 4-week reassessment is appropriate with these specific monitoring parameters: 1, 2

• Check BNP, potassium, creatinine, eGFR before visit (already ordered appropriately) 1, 2
• Assess volume status clinically - adjust loop diuretic to achieve euvolemia without overdiuresis 1
• Up-titrate one medication at a time using small increments every 1-2 weeks until target or maximally tolerated doses achieved 1, 2
• Monitor for symptomatic hypotension - transient dizziness is common and usually manageable with patient education rather than dose reduction 1

Medication Titration Sequence

Recommended order for optimization: 1, 2

1. Start MRA (spironolactone) immediately as it doesn't lower BP significantly 1
2. Continue Farxiga as initiated - no titration needed 2
3. Up-titrate beta-blocker to target dose for rate control 1, 2
4. Up-titrate Entresto gradually to target dose 97/103 mg twice daily 1, 2

Critical Pitfalls to Avoid

• Do not use non-dihydropyridine calcium channel blockers (diltiazem, verapamil) for rate control - they depress myocardial function and increase HF risk in reduced EF 1, 6
• Do not abruptly discontinue beta-blockers once started - this causes rebound tachycardia and worsening HF 6
• Avoid excessive diuresis which worsens renal function and may prevent GDMT up-titration 1, 6
• Monitor potassium closely when combining MRA with ACEI/ARB/ARNI - hold MRA if K+ >5.0-5.5 mEq/L 1, 3
• Do not delay GDMT initiation waiting for structural intervention - optimize medical therapy concurrently 1, 2

Long-term Monitoring

• Repeat echocardiogram in 3-6 months after GDMT optimization to reassess LVEF, MR severity, and CRT/ICD eligibility 1
• Screen for recurrent AF with periodic ECG or event monitoring given high recurrence rates (79% prevalence in HFmrEF/HFpEF cohorts) 7
• Annual lipid panel, renal function, and electrolytes on stable GDMT 1