Can you use diltiazem (dilt) drip for atrial fibrillation (a fib) with reduced ejection fraction (EF) of 20% and heart failure?

From the Guidelines

Diltiazem drip is not recommended for atrial fibrillation in patients with severely reduced ejection fraction (EF 20%) and heart failure due to its negative inotropic effects, which can worsen heart failure symptoms. The most recent and highest quality study, the 2024 ESC guidelines for the management of atrial fibrillation 1, recommends beta-blockers and/or digoxin for rate control in patients with AF and LVEF ≤40%. This is because calcium channel blockers like diltiazem can decrease myocardial contractility, which is already significantly compromised in patients with an EF of 20%, creating a high risk of precipitating cardiogenic shock or acute decompensated heart failure.

Some key points to consider in this scenario include:

• The negative inotropic effects of diltiazem can further depress cardiac function in patients with severely reduced EF 1
• Beta-blockers, such as metoprolol or carvedilol, are preferred for rate control in this situation, starting at low doses and titrating carefully while monitoring for signs of worsening heart failure 1
• Digoxin may be considered for acute management as it provides rate control without significant negative inotropic effects 1
• Amiodarone is another alternative for both rate and rhythm control in this population 1
• Close hemodynamic monitoring is essential when using any rate control agent in severe heart failure, including blood pressure, heart rate, oxygen saturation, and clinical signs of worsening heart failure 1

From the FDA Drug Label

The use of diltiazem hydrochloride injection or diltiazem hydrochloride for injection should be undertaken with caution when the patient is compromised hemodynamically or is taking other drugs that decrease any or all of the following: peripheral resistance, myocardial filling, myocardial contractility, or electrical impulse propagation in the myocardium In a limited number of studies of patients with compromised myocardium (severe congestive heart failure, acute myocardial infarction, hypertrophic cardiomyopathy), administration of intravenous diltiazem produced no significant effect on contractility, left ventricular end diastolic pressure, or pulmonary capillary wedge pressure However, in rare instances, worsening of congestive heart failure has been reported in patients with preexisting impaired ventricular function

Caution is advised when using diltiazem drip for atrial fibrillation (a fib) with reduced ejection fraction (EF) of 20% and heart failure, as the patient is compromised hemodynamically. The drug label does not provide direct evidence to support the use of diltiazem in this specific scenario, but it does suggest that diltiazem can be used with caution in patients with compromised myocardium. However, the risk of worsening congestive heart failure cannot be ruled out. 2 2

From the Research

Diltiazem Drip for Atrial Fibrillation with Reduced Ejection Fraction

• The use of diltiazem drip for atrial fibrillation (AF) with rapid ventricular response (RVR) and heart failure with reduced ejection fraction (HFrEF) is a topic of interest, with studies examining its safety and efficacy 3, 4, 5, 6.
• A study published in 2024 found that diltiazem is an effective rate control agent for AF RVR, but its negative inotropic effects may increase the risk for worsening heart failure in patients with a reduced ejection fraction (EF) 3.
• Another study from 2022 compared the incidence of adverse effects in HFrEF patients treated with IV diltiazem or metoprolol, and found that while there was no difference in total adverse events, the diltiazem group had a higher incidence of worsening heart failure symptoms 4.
• A 2018 study evaluated outcomes in patients with low ejection fraction treated with diltiazem, and found that there was a significantly higher frequency of acute kidney injury in patients with low EF compared to those with normal EF 5.
• A retrospective cohort study from 2019 examined the effects of metoprolol versus diltiazem in the acute management of AF with RVR in patients with HFrEF, and found that IVP diltiazem achieved similar rate control with no increase in adverse events compared to IVP metoprolol 6.
• In terms of administration route, a 2018 study compared oral immediate-release and IV continuous infusion diltiazem after an initial IV loading dose, and found that oral immediate-release diltiazem was associated with a lower rate of treatment failure at four hours 7.

Considerations for Diltiazem Use in HFrEF

• The negative inotropic effects of diltiazem may increase the risk for worsening heart failure in patients with a reduced ejection fraction (EF) 3, 4.
• Patients with HFrEF may be at higher risk for adverse effects such as worsening heart failure symptoms and acute kidney injury when treated with diltiazem 4, 5.
• The choice of administration route may influence the disposition of the patient from the ED, with oral immediate-release diltiazem potentially being associated with a lower rate of treatment failure compared to IV continuous infusion 7.

Specific Consideration for EF of 20%

• While the studies do not specifically address an EF of 20%, they do suggest that patients with reduced EF (< 50%) may be at higher risk for adverse effects when treated with diltiazem 3, 4, 5.
• The decision to use diltiazem in a patient with an EF of 20% should be made on a case-by-case basis, taking into account the individual patient's risk factors and medical history 3, 4, 5, 6.