Lower versus standard amiodarone dose to keep normal heart rhythm after electrical cardioversion

Multicenter Randomized Clinical Trial To Evaluate Two Different Amiodarone Regimens To Maintain Sinus Rhythm After Electrical Cardioversion In Persistent Atrial Fibrillation

This study will test whether 100 mg/day of amiodarone can keep normal heart rhythm as well as 200 mg/day for people with persistent atrial fibrillation after electrical cardioversion while causing fewer side effects.

Quick facts

• Phase: PHASE4
• Study type: Interventional
• Enrollment: 312 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: Fundació Institut de Recerca de l'Hospital de la Santa Creu i Sant Pau (other)
• Locations: 1 site (Barcelona)
• Trial ID: NCT07273994 on ClinicalTrials.gov

What this trial studies

Adults with persistent atrial fibrillation who undergo elective electrical cardioversion will be treated with either 200 mg/day or 100 mg/day of amiodarone and followed for 12 months. The trial compares maintenance of sinus rhythm at 12 months and records adverse events during follow-up. Researchers will measure amiodarone plasma levels and analyze genetic polymorphisms to see how genetics relate to drug levels, effectiveness, and toxicity. Regular clinical visits and laboratory testing will monitor rhythm status and safety.

Who should consider this trial

Good fit: Adults (≥18 years) with documented persistent atrial fibrillation (≥7 days) who are electively referred for electrical cardioversion, able to consent, and without excluded cardiac, thyroid, or liver conditions are ideal candidates.

Not a fit: Patients requiring urgent cardioversion, those with post‑operative AF, recent myocardial infarction, NYHA class IV heart failure, LVEF <45%, significant valve disease, active thyroid or severe liver disease, or who cannot commit to follow-up are unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, patients might keep sinus rhythm with a lower risk of long-term amiodarone toxicity by using the reduced dose.

How similar studies have performed: Amiodarone is established as effective for maintaining sinus rhythm, but direct randomized comparisons of 100 mg versus 200 mg with accompanying pharmacogenetic and plasma‑level data over 12 months are limited.

Eligibility criteria

Inclusion Criteria

1. Patients aged ≥ 18 years
2. Documented persistent atrial fibrillation (≥ 7 days in duration)
3. Electively referred for Electrical Cardioversion
4. Signed informed consent.

Exclusion Criteria

1. Urgent electrical cardioversion
2. Atrial fibrillation post-cardiac surgery
3. Previous myocardial infarction
4. New York Heart Association (NYHA) Class IV heart failure
5. Left ventricular ejection fraction (LVEF) \<45%
6. Significant left ventricular hypertrophy (wall thickness ≥ 15mm)
7. Hyperthyroidism or hypothyroidism
8. Known hepatobiliary disease (acute hepatitis, cirrhosis...) or ALT/AST \> 3 x upper limit of normal (ULN)
9. Allergy, intolerance, or known hypersensitivity to study medications
10. Women of childbearing potential unwilling to use contraceptive measures and breastfeeding women.
11. Participation in another clinical trial involving investigational drugs
12. Life expectancy less than 12 months
13. Rheumatic mitral stenosis of any degree or severe mitral or aortic valve dysfunction.
14. Patients with contraindications to amiodarone, such as uncontrolled thyroid dysfunction, severe sinus bradycardia, second- or third-degree AV block without a pacemaker, and a history of amiodarone-induced pulmonary toxicity.
15. Patients in whom chronic amiodarone treatment previously failed to maintain sinus rhythm
16. Patients with abnormal baseline QTc (\>450 ms in males and \>470 in females) or abnormal ECG that precludes QTc assessment
17. Patients requiring concomitant medications that have a higher risk of QTc prolongation.
18. Patient do not have a smart mobile phone or do not know how to use it adequately.

Where this trial is running

Barcelona

• Hospital de la Santa Creu i Sant Pau — Barcelona, Spain (RECRUITING)

Study contacts

• Study coordinator: Jose M Guerra, MD, PhD

Conditions: Persistent Atrial Fibrillation, Atrial fibrillation, Electrical cardioversion, Amiodarone, Pharmacogenetics, Adverse effects