From the Guidelines
Flecainide cannot be given in congestive heart failure (CHF) because it has been shown to increase mortality in patients with structural heart disease, including those with CHF.
Key Points
- The CAST trial demonstrated that patients with asymptomatic ventricular arrhythmias post-MI on the class IC antiarrhythmics encainide or flecainide had increased mortality 1.
- Class IC antiarrhythmic agents, including flecainide, are generally avoided in patients with structural heart disease, such as CHF.
- The 2024 ESC guidelines recommend against using flecainide in patients with AF and impaired left ventricular systolic function, which includes those with CHF 1.
- Amiodarone and dofetilide are the only antiarrhythmic agents with neutral effects on mortality in clinical trials of patients with HFrEF, and may be considered as alternatives to flecainide in patients with CHF 1.
Important Considerations
- The use of antiarrhythmic agents in patients with CHF requires careful consideration of the individual patient's risk-benefit calculus and should be done in conjunction with electrophysiology consultation.
- Patients with CHF should be closely monitored for decompensation when using antiarrhythmic agents, and alternative treatments such as catheter ablation may be considered in selected patients.
From the FDA Drug Label
Flecainide acetate has a negative inotropic effect and may cause or worsen CHF, particularly in patients with cardiomyopathy, preexisting severe heart failure (NYHA functional class III or IV) or low ejection fractions (less than 30%). In patients with supraventricular arrhythmias new or worsened CHF developed in 0. 4% (1/225) of patients. In patients with sustained ventricular tachycardia during a mean duration of 7.9 months of flecainide acetate therapy, 6.3% (20/317) developed new CHF. In patients with sustained ventricular tachycardia and a history of CHF, during a mean duration of 5.4 months of flecainide acetate therapy, 25. 7% (78/304) developed worsened CHF.
Flecainide cannot be given in congestive heart failure (CHF) because it has a negative inotropic effect, which means it can worsen CHF, particularly in patients with preexisting severe heart failure or low ejection fractions. The risk of developing new or worsened CHF is significant, ranging from 0.4% to 25.7% in different patient populations 2.
From the Research
Flecainide in Congestive Heart Failure (CHF)
- Flecainide is a class Ic antiarrhythmic agent that has been shown to be effective in treating atrial and ventricular arrhythmias 3.
- However, its use in patients with congestive heart failure (CHF) is limited due to the increased risk of mortality and adverse cardiac events 3, 4.
- The Cardiac Arrhythmia Suppression Trial (CAST) found that flecainide and encainide increased mortality in patients with frequent ventricular ectopics and reduced left ventricular function who had survived an infarction 3.
- Current guidelines recommend that flecainide not be used in patients with heart failure, and its use is generally limited to carefully selected patients with atrial fibrillation and no documented structural heart disease 3.
Pharmacokinetics and Pharmacodynamics
- Flecainide is absorbed promptly and nearly completely after oral administration, with a plasma half-life of approximately 13-20 hours 5.
- The drug is excreted primarily in the urine, with a small portion excreted in the feces 5.
- The rate of flecainide elimination from plasma may be reduced in patients with moderate renal failure and CHF, and dosage adjustments may be necessary in these patients 5, 6.
Clinical Studies
- A study of patients with supraventricular arrhythmias found that flecainide was effective in treating these conditions, but cardiac side effects were more frequent in patients with chronic atrial fibrillation and structural heart disease 4.
- Another study found that flecainide could be safely administered to patients with CHF, but its use was associated with decreased cardiac index and increased pulmonary wedge pressure 6.
- A prospective observational study found that flecainide was safe and effective for cardioversion in patients with persistent atrial fibrillation and elevated cardiovascular risk, but its use was associated with a lower rate of conversion in patients taking ACE inhibitors 7.