Which medication should be stopped in a 72-year-old male with atrial fibrillation, heart failure with reduced ejection fraction (HFrEF), type 2 diabetes mellitus, and hypertension, currently taking amiodarone, diltiazem, sacubitril/valsartan, metformin, apixaban, and furosemide, with normal blood pressure and heart rate, to minimize the risk of hospital readmission?

Diltiazem Should Be Discontinued

Diltiazem must be stopped immediately in this patient with HFrEF (EF 35%) due to its negative inotropic effects and association with increased risk of worsening heart failure and hospital readmission. 1, 2

Rationale for Stopping Diltiazem

Contraindication in HFrEF

• Non-dihydropyridine calcium channel blockers (diltiazem and verapamil) are contraindicated in heart failure with reduced ejection fraction due to their negative inotropic properties and increased likelihood of worsening HF symptoms 1
• The 2016 AHA Scientific Statement explicitly states these agents "should be avoided" in patients with HFrEF 1
• Recent evidence demonstrates that diltiazem use in HFrEF patients presenting with atrial fibrillation is associated with a significantly higher rate of worsening heart failure (17% vs 4.8% in preserved EF patients, p=0.005) 3

Redundant Rate Control

• This patient's heart rate is already well-controlled at 65 bpm with amiodarone, making diltiazem unnecessary for rate control 1
• Amiodarone alone provides adequate rate control in HF patients with atrial fibrillation 1
• The combination of amiodarone and diltiazem creates excessive bradycardia risk and redundant negative chronotropic effects 1

Guideline-Directed Alternatives

• For rate control in atrial fibrillation with HFrEF, beta-blockers are the preferred agents, not calcium channel blockers 1
• If additional rate control is needed beyond amiodarone, digoxin would be safer than diltiazem in this HFrEF patient 1

Why Other Medications Should Continue

Amiodarone

• Appropriate for rhythm and rate control in atrial fibrillation with HFrEF due to minimal myocardial depression and low proarrhythmic potential 1, 4
• Can be safely used in patients with heart failure, unlike diltiazem 1

Sacubitril/Valsartan

• Foundational therapy for HFrEF that reduces HF-related hospitalizations and cardiovascular mortality 1, 5
• The 2019 ESC guidelines recommend sacubitril/valsartan in HFrEF patients with diabetes to reduce cardiovascular events 1
• Current dose (24/26 mg twice daily) is appropriate as a starting dose and can be uptitrated 5

Metformin

• Safe and appropriate in HFrEF patients with eGFR >30 mL/min/1.73 m² 1
• Should be considered as baseline therapy for type 2 diabetes in patients with heart failure 1
• No association with increased hospital readmission risk 1

Clinical Action Plan

Immediate Steps

• Discontinue diltiazem immediately to reduce risk of worsening heart failure 1, 2
• Monitor heart rate and blood pressure after discontinuation 1
• Assess for signs of fluid overload or worsening HF symptoms 2

Monitoring Parameters

• Heart rate should remain controlled with amiodarone alone given current rate of 65 bpm 1
• If heart rate increases above 100 bpm after stopping diltiazem, consider adding a beta-blocker (carvedilol, metoprolol succinate, or bisoprolol) rather than restarting diltiazem 1, 2
• Monitor for amiodarone-related bradycardia, which may require dose adjustment 1

Common Pitfalls to Avoid

• Do not restart diltiazem even if heart rate increases, as beta-blockers are the appropriate choice for additional rate control in HFrEF 1
• Avoid assuming that current hemodynamic stability justifies continuing diltiazem—the negative inotropic effects increase long-term risk regardless of current presentation 3
• Do not discontinue sacubitril/valsartan, as it is essential guideline-directed medical therapy for HFrEF that reduces mortality and hospitalizations 1, 5