Amiodarone Use and Survival in Non-Valvular Atrial Fibrillation: Insights from the China-AF Registry
Atrial fibrillation (AF)—a rapid, irregular heart rhythm—affects over 33 million people globally, increasing risks of stroke, heart failure, and death. For decades, amiodarone—a potent antiarrhythmic drug (AAD) used to restore and maintain the heart’s normal “sinus rhythm”—has been a cornerstone of AF treatment. But past research, including the landmark AFFIRM trial, raised concerns: amiodarone might be linked to higher mortality, intensive care stays, and non-cardiovascular deaths. Now, a real-world study from China’s largest AF registry updates this picture, exploring whether amiodarone still makes sense for patients with non-valvular AF (NVAF)—the most common type, not caused by heart valve problems.
What the Study Did
The research, led by cardiologists from Beijing Tongren Hospital and Beijing Anzhen Hospital (Capital Medical University), uses data from the China Atrial Fibrillation (China-AF) Registry—a prospective, multicenter study of 20,666 AF patients in Beijing (2011–2017). The team focused on 8,161 NVAF patients who had never taken AADs before joining the registry—a key group to avoid “carryover effects” from prior medications.
Participants were split into two groups:
- Amiodarone group: 689 patients prescribed amiodarone at enrollment or during follow-up.
- Non-AAD group: 6,167 patients who stayed off all class I/III AADs (the most common types for rhythm control).
The primary goal was to compare 1-year all-cause mortality (death from any cause). Researchers also tracked how well amiodarone maintained sinus rhythm—the heart’s healthy, regular beat. To ensure accuracy, they used a Cox proportional hazard model (a statistical tool to compare survival rates while accounting for factors like age, comorbidities, and medication use).
Who Was in the Study?
Amiodarone users were very different from those who stayed off AADs:
- Younger: Average age 65.6 vs. 68.6 years.
- Healthier: Fewer cases of chronic heart failure (CHF), prior bleeding, or stroke.
- Less severe AF: More likely to have new-onset or paroxysmal AF (temporary episodes) and less likely to have persistent AF (long-lasting rhythm problems).
- More access to care: Treated in tertiary (top-tier) hospitals more often.
They were also less likely to take oral anticoagulants (OACs)—drugs that prevent stroke—but more likely to have completed high school and drink alcohol (though these factors didn’t affect the main results).
Key Findings
The study’s most important result: amiodarone use was not significantly linked to lower 1-year all-cause mortality compared to a non-AAD strategy.
- Mortality rates: 2.44 deaths per 100 people in the amiodarone group vs. 3.91 in the non-AAD group. But this difference was not “statistically significant”—meaning it could have been due to chance, not the drug itself.
- After adjusting for factors like age, CHF, and OAC use, amiodarone still showed no clear benefit or harm: the adjusted hazard ratio (HR) was 0.79 (95% confidence interval: 0.42–1.49). A HR below 1 suggests lower risk, but the wide interval means the data is too uncertain to draw firm conclusions.
However, amiodarone did help patients stay in sinus rhythm: 55.7% of amiodarone users maintained a normal heartbeat at their last follow-up, vs. just 40.1% of non-AAD patients. This difference was statistically significant—meaning amiodarone effectively restores rhythm, even if it doesn’t impact survival.
Why the Results Matter
The study’s findings contrast with the AFFIRM trial’s concerns—and there are good reasons why:
- Younger patients: Amiodarone users in China-AF were 4 years younger on average (65.6 vs. 69.7 years). Younger patients often benefit more from rhythm control, as their hearts are more resilient to drug side effects.
- Fewer comorbidities: The amiodarone group had lower rates of CHF (18.6% vs. 22.8%) and established coronary artery disease (CAD, 19.0% vs. 27.6%) than AFFIRM participants. Healthier patients may tolerate amiodarone better.
- Less digoxin use: Digoxin—a rate-control drug linked to higher mortality—was used by just 8.9% of amiodarone patients (vs. 32.9% in AFFIRM). This likely reduced unnecessary risks.
What This Means for Patients and Doctors
The study does not say amiodarone is “safe”—only that, in this real-world group of younger, healthier NVAF patients, it didn’t increase (or decrease) 1-year mortality. Key takeaways:
- Rhythm control benefit: Amiodarone still helps maintain sinus rhythm, which improves quality of life for many patients.
- Individualized care: The drug’s risks (e.g., thyroid, lung, or liver toxicity) mean it should be reserved for patients where rhythm control is critical—like those with severe AF symptoms.
- Caution for low-risk patients: A recent study found amiodarone increases mortality in people with no structural heart disease, so it’s best used as a second-line therapy here.
Limitations to Consider
As an observational study (not a randomized trial), the research can’t prove cause and effect—only associations. Other gaps:
- Beijing-centric: The study includes mostly patients from Beijing, so results may not apply to rural or non-Chinese populations.
- No AF burden data: AF “burden” (how much time patients spend in irregular rhythm) is a key predictor of stroke and death—but this wasn’t measured.
- Dose uncertainty: The study didn’t track amiodarone dosage, which affects both effectiveness and safety.
Conclusion
For “real-world” patients with NVAF, this study suggests amiodarone use is not significantly linked to lower 1-year all-cause mortality compared to avoiding AADs. But it does effectively restore sinus rhythm—a critical goal for patients with disabling AF symptoms. As with all drugs, the decision to use amiodarone should be personalized: weighing its rhythm-control benefits against risks like organ toxicity, especially for older or sicker patients.
Study Details
The research was published in the Chinese Medical Journal in 2021 by Xiao-Xia Hou, Liu He, Xin Du, Guo-Hong Wang, Jian-Zeng Dong, and Chang-Sheng Ma (Beijing Tongren Hospital and Beijing Anzhen Hospital). The full study is available at:
doi.org/10.1097/CM9.0000000000001270
The China-AF Registry is funded by China’s National Key Research and Development Program and National Science Foundation.
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