Catheter Ablation Compared to Amiodarone Drug Therapy in Heart Failure Patients with A-Fib

Background: I previously reported on the ground-breaking CASTLE-AF study published in 2018 which compared treatment with conventional antiarrhythmic drugs (both rate and rhythm control) versus treatment with catheter ablation. I recently came across another, similar study. While the 2016 AATAC study pre-dates the CASTLE-AF study, it also contributes to our understanding of treatment choices for heart failure patients with A-Fib.

Treating Patients with Both Heart Failure and A-Fib

Heart failure is very common in patients with A-Fib (estimated at 42%). These are very sick patients. For people with advanced heart failure, nearly 90% die within one year.

In patients with both conditions, a cardiologist’s first treatment is most often drug therapy with an antiarrhythmic drug. But is this an effective strategy? Is this really in the patient’s best interest? A 2016 study says NO!

AATAC stands for: Ablation vs Amiodarone for Treatment of Atrial Fibrillation in Patients With Congestive Heart Failure and an Implanted ICD/CRTD

AATAC: Catheter Ablation vs. Amiodarone Antiarrhythmic Drug Therapy

In the powerful AATAC multicenter worldwide randomized trial, catheter ablation was compared to drug treatment with amiodarone (the most effective but also the most toxic of the antiarrhythmic drugs).

The 203 enrolled patients had persistent A-Fib and heart failure with an Ejection Fraction of less than 40%. Patients also all had either a dual-chamber implantable cardioverter defibrillator or cardiac resynchronization therapy defibrillator.

All patients in the AATAC study were given optimal medical therapy for congestive heart failure such as ACE inhibitors, etc.

Patients were randomized to receive either a catheter ablation or drug treatment with amiodarone.

Note: The AATAC study should be read in conjunction with the more significant CASTLE-AF study which found similar results.

Group 1: Catheter Ablation

The first group received a catheter ablation of the pulmonary veins (PVI) along with roof lines and extensive ablations on the left atrial posterior wall; if non-PV potentials were found, the superior vena cava was isolated. At their discretion, EPs could ablate complex fractionated electrograms and non-PV triggers.

A ‘re-do procedure’ could be performed during the 3-month blanking period.

Group 2: Amiodarone (AMIO) Drug Treatment

The Amiodarone (AMIO) group was given 400 mg twice a day for 2 weeks followed by 400 mg each day for the next 2 weeks, then they were given a maintenance dose of AMIO 200 mg/day for the balance of the 24 month study period.

Study Follow-up and Results

All patients were followed for a minimum of 24 months. Recurrence was measured by the implantable devices with device interrogation at 3, 6, 12, and 24 months follow-up. Key findings at the end of the trial period include:

• Recurrence: 70% of patients in the ablation group were recurrence and A-Fib free (after an average of 1.4 procedures) vs. only 34% of the Amiodarone (AMIO) group.

• PVI with/without posterior wall isolation: Higher success was reported in patients undergoing PVI with posterior wall isolation compared to PVI alone (79% vs. 8%).

• Amiodarone therapy was found to be significantly more likely to fail.

• Cardioversion: During the 3-month blanking period 51% of the Amiodarone (AMIO) group needed cardioversion vs. 3% of the ablation group.

• The unplanned hospitalization rate was 31% in the ablation group vs. 57% in the AMIO group. This is a 45% relative risk reduction of hospitalization.

• A significantly lower mortality was observed in the ablation group: 8% vs. AMIO 18%.

Summary: Catheter Ablation Superior to Amiodarone Drug Therapy

Heart failure and A-Fib are common cardiac conditions that often coexist.

The AATAC study, the first randomized study of heart failure patients with persistent A-Fib, found that catheter ablation is superior to amiodarone drug therapy in achieving freedom from A-Fib long-term.

In addition, treatment with catheter ablation improved mortality in these patients, increased exercise capacity and Quality of Life (QofL) along with reduced unplanned hospitalizations.

Acknowledging My Bias

I admit to being biased against amiodarone drug therapy due to personal experience and from what others have shared. (For example, see Karen Muccino’s A-Fib story.) I am horrified that anyone would be put on such a high initial dosage of amiodarone as in this study. I would never participate in such a study. But obviously all doctors don’t share my concerns.

If a less potent (and less dangerous) antiarrhythmic drug had been used, it’s probable the study results would have been even more favorable for the ablation group.

What This Means to A-Fib Patients

These patients were in persistent A-Fib along with heart failure. These are some of the most difficult patients to make A-Fib free.

The EPs and A-Fib centers in this study were some of the best in the world. That there was a 70% success rate and no recurrences after 2 years is a testimony to the advanced mapping and ablation skills of these EPs. It’s remarkable how far catheter ablation strategies have improved over the years.

On the downside, not all EPs are equal. The single procedure success rate varied greatly from 29% to 61%. (See Huge Growth in Number of EPs Doing Catheter Ablations, But All EPs Are Not Equal.)

Catheter Ablation Group: Improved Ejection Fractions

Among the 203 enrolled patients, it’s not surprising that there were 26 deaths during this study. These were very sick patients with congestive heart failure and Ejection Fraction below 40%. (An EF below 50% indicates a weakened heart muscle that is no longer pumping efficiently; an EF in the normal range is 50% to 75%.)

The good news is that for many in the catheter ablation group, their ejection fraction was significantly improved and they were no longer in heart failure.

Catheter Ablation Outperforms Antiarrhythmic Drugs

We now have 2 studies which demonstrate that compared to antiarrhythmic drug therapy, catheter ablation lowers death rate among A-Fib patients (with heart failure), improves QofL and lets patients live longer and healthier lives. Other major benefits of ablation include reduced unplanned hospitalizations and increased exercise capacity.

Take-Away for A-Fib Patients

I think we can draw conclusions from the AATAC and the CASTLE AF studies that also apply to A-Fib patients (not in heart failure).

Rather than a life on antiarrhythmic drug therapy, the AATAC and CASTLE AF studies encourage A-Fib patients to seek a catheter ablation (including a second “re-do ablation”, if necessary.)

Bottom-line: Hard research data shows that a catheter ablation is the better choice over drug therapy. An ablation can rid you of your A-Fib symptoms, make you feel better, and let you live a healthier and longer life.

Don’t just live with A-Fib. Seek your cure.