From the Guidelines
Diltiazem should not be used to control heart rate in patients with atrial fibrillation and congestive heart failure because it has negative inotropic effects that can worsen heart failure. According to the most recent guidelines, specifically the 2024 ESC guidelines for the management of atrial fibrillation 1, beta-blockers and/or digoxin are recommended for rate control in patients with atrial fibrillation and left ventricular ejection fraction (LVEF) ≤40%. Diltiazem, a non-dihydropyridine calcium channel blocker, decreases cardiac contractility, which can further reduce the heart's pumping ability in patients whose cardiac function is already compromised.
In patients with atrial fibrillation and congestive heart failure, the primary goal is to control the heart rate and reduce symptoms while minimizing the risk of worsening heart failure. Beta-blockers like metoprolol (starting at 12.5-25 mg twice daily) or bisoprolol (starting at 1.25-2.5 mg daily) are preferred for rate control, as they can be safely uptitrated while monitoring for signs of worsening heart failure. Digoxin (0.125-0.25 mg daily) may also be considered as an adjunct therapy, particularly in patients with persistent symptoms despite beta-blocker therapy.
When initiating rate control therapy in heart failure patients, it's essential to start with low doses, monitor closely for signs of decompensation (increased shortness of breath, edema, or fatigue), and gradually increase the dose as tolerated. The negative inotropic effect of diltiazem can precipitate acute decompensated heart failure in these vulnerable patients, potentially leading to hospitalization or worsening prognosis, as highlighted in earlier guidelines 1. Therefore, diltiazem is not recommended for rate control in patients with atrial fibrillation and congestive heart failure.
From the Research
Reasons to Avoid Diltiazem in Controlling Heart Rate
- Diltiazem has negative inotropic effects, which can worsen heart failure in patients with reduced ejection fraction 2, 3, 4.
- Studies have shown that patients with heart failure and reduced ejection fraction who received diltiazem had a higher incidence of worsening heart failure symptoms compared to those who received metoprolol 2, 3.
- The use of diltiazem in patients with atrial fibrillation and heart failure may lead to increased oxygen requirements, initiation of inotropic support, and other adverse effects 2, 3.
Alternative Treatment Options
- Beta-blockers, such as metoprolol, are often recommended for rate control in patients with atrial fibrillation and heart failure, as they can improve survival and reduce symptoms 5, 4.
- Digoxin may be used in combination with beta-blockers to achieve satisfactory rate control, especially in patients with hypotension or contraindications to beta-blocker treatment 4.
- The Atrial Fibrillation and Congestive Heart Failure (AF-CHF) trial suggests that a rate-control strategy may be a primary approach for patients with atrial fibrillation and heart failure, as it eliminates the need for repeated cardioversion and reduces rates of hospitalization 6.
Considerations for Treatment
- The choice of treatment for atrial fibrillation in patients with heart failure should be individualized, taking into account the patient's underlying condition, symptoms, and other factors 5, 4.
- Further studies are needed to evaluate the safety and efficacy of diltiazem in patients with atrial fibrillation and heart failure 5.