EAST-AFNET 4 Trial: Early Rhythm Control vs Usual Care in Atrial Fibrillation (East AF) [Classics Series]

1. The EAST-AFNET 4 trial (East AF) demonstrated that early rhythm control therapy—including antiarrhythmic drugs or catheter ablation—was associated with a significant reduction in the composite outcome of cardiovascular death, stroke, and hospitalization for worsening heart failure or acute coronary syndrome compared to usual care in patients with newly diagnosed atrial fibrillation (AF).

Original Date of Publication: August 2020

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Study Rundown:
Management of atrial fibrillation traditionally emphasizes rate control, with rhythm control reserved for symptom relief. However, whether early rhythm control improves long-term outcomes has been debated. The EAST-AFNET 4 trial, a multicenter, randomized, open-label study, evaluated whether initiating rhythm control within one year of AF diagnosis improves clinical outcomes compared to usual care.

Over 2,700 patients with recent-onset AF and cardiovascular conditions were randomized to receive either early rhythm control (antiarrhythmic therapy or ablation) or usual care (initial rate control, rhythm control only if symptoms persisted).

At 5 years, early rhythm control significantly reduced the primary composite endpoint (cardiovascular death, stroke, hospitalization for heart failure, or acute coronary syndrome) compared to usual care. Rates of stroke and hospitalization were lower, with no significant excess of adverse events.

This study supports the benefit of an early, proactive rhythm control strategy in atrial fibrillation to prevent major cardiovascular events, challenging prior approaches that prioritized rate control until symptoms demanded otherwise.

Click to read the study in NEJM

In-Depth [randomized controlled trial]:

The EAST-AFNET 4 trial was a multicenter, randomized study conducted across 135 European centers, enrolling 2,789 patients who had been diagnosed with atrial fibrillation within the prior year. All patients had at least one additional cardiovascular risk factor, such as hypertension, diabetes, heart failure, prior stroke or TIA, or structural heart disease. The mean age was approximately 70 years, nearly half were women, and the median CHA₂DS₂-VASc score was 3.4.

Patients were randomized to two treatment strategies. In the early rhythm control group, therapy with antiarrhythmic drugs (class Ic or III agents, including flecainide, amiodarone, dronedarone, and sotalol) or catheter ablation was initiated promptly with the goal of maintaining sinus rhythm. In the usual care group, patients were managed primarily with rate control, and rhythm control was introduced only if symptoms persisted or worsened.

Over a median follow-up of just over five years, early rhythm control significantly reduced the primary composite endpoint of cardiovascular death, stroke, hospitalization for worsening heart failure, or hospitalization for acute coronary syndrome compared to usual care. Importantly, the reduction in adverse outcomes was observed early in follow-up and remained consistent throughout the trial. Rates of cardiovascular death, stroke, and hospitalization for heart failure were all lower in the early rhythm control group, while hospitalization for acute coronary syndrome was similar between groups. Quality of life did not differ significantly at two years, suggesting that the main benefit of early rhythm control lies in reducing hard cardiovascular outcomes rather than symptom improvement alone. Safety outcomes were comparable, with serious adverse events occurring in about 17% of patients in each arm.

Trial Results Table

Key Takeaways:

The EAST-AFNET 4 trial demonstrates that initiating rhythm control within the first year of atrial fibrillation diagnosis reduces cardiovascular complications compared to usual care. The results challenge the traditional paradigm of reserving rhythm control for symptom relief and instead support its role as a disease-modifying strategy. For patients with newly diagnosed atrial fibrillation and cardiovascular comorbidities, early rhythm control using antiarrhythmic drugs or catheter ablation is both effective and safe.

These findings stand in contrast to earlier trials such as the AFFIRM trial, which found no mortality benefit of rhythm control when initiated later in the disease course. Together, these studies suggest that timing is crucial: early initiation of rhythm control may alter the long-term outcomes of atrial fibrillation in ways that delayed intervention does not.

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