From the Guidelines
Diltiazem is not necessarily better than metoprolol for patients with atrial fibrillation and heart failure with low ejection fraction, as the choice between these medications depends on various factors including the patient's specific condition and the clinical context. In the management of atrial fibrillation (AF) with heart failure (HF), the primary goals are to prevent thromboembolism and control symptoms. For patients with AF and HF with reduced ejection fraction (HFrEF), the management strategy often involves rate control or rhythm control.
- The 2024 ESC guidelines for the management of atrial fibrillation 1 recommend beta-blockers and/or digoxin for patients with AF and LVEF ≤40% to control heart rate and reduce symptoms.
- However, in certain acute settings, diltiazem may be considered for rate control due to its mechanism of action, which involves blocking calcium channels and slowing conduction through the AV node without the negative inotropic effects associated with beta-blockers like metoprolol.
- It's crucial to note that while diltiazem can provide effective rate control, its use in patients with depressed EF should be cautious due to its potential negative inotropic effect, as highlighted in the 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation 1.
- The choice between diltiazem and metoprolol should be tailored to the individual patient, considering factors such as the severity of heart failure, the presence of any contraindications, and the patient's response to therapy.
- Monitoring of blood pressure, heart rate, and symptoms of worsening heart failure is essential when using either medication, with adjustments made as necessary to optimize the patient's outcome.
From the FDA Drug Label
CLINICAL PHARMACOLOGY The therapeutic benefits achieved with diltiazem hydrochloride are believed to be related to its ability to inhibit the influx of calcium ions during membrane depolarization of cardiac and vascular smooth muscle Studies to date, primarily in patients with good ventricular function, have not revealed evidence of a negative inotropic effect; cardiac output, ejection fraction, and left ventricular end-diastolic pressure have not been affected.
The FDA drug label does not answer the question.
From the Research
Comparison of Diltiazem and Metoprolol in AFib with Heart Failure
- Diltiazem and metoprolol are both used for rate control in atrial fibrillation (AFib) with rapid ventricular response (RVR) in patients with heart failure with reduced ejection fraction (HFrEF) 2, 3, 4.
- Studies have shown that diltiazem and metoprolol have similar efficacy in achieving rate control in AFib with RVR in HFrEF patients 3, 4.
- However, diltiazem may have a higher incidence of worsening heart failure symptoms compared to metoprolol 2.
Safety Outcomes
- The incidence of adverse effects, such as hypotension and bradycardia, was similar between diltiazem and metoprolol in some studies 3, 4.
- However, another study found that diltiazem was associated with a higher incidence of worsening heart failure symptoms, defined as increased oxygen requirements or initiation of inotropic support 2.
- A study published in 2023 found that hypotensive and bradycardic events were zero in both the metoprolol and diltiazem groups 4.
Clinical Guidelines
- The American Heart Association has published a scientific statement on managing AFib in patients with heart failure and reduced ejection fraction, which highlights the importance of rate and rhythm control in these patients 5.
- The statement notes that catheter ablation for AFib in patients with heart failure and reduced ejection fraction has shown superiority in improving survival, quality of life, and ventricular function compared to antiarrhythmic drugs and rate control therapies 5.
Patient Outcomes
- A study published in 2024 found that approximately 30% of patients with reduced ejection fraction who received intravenous diltiazem for AFib with RVR were safely discharged home 6.
- The development of worsening heart failure is multifactorial and may include the use of diltiazem in critically ill patients requiring hospital admission 6.