STOP-AF FIRST and Cryo-FIRST Cryoballoon Ablation Trial results were presented at ESC
Catheter Ablation was Safe and Effective as First-Line Treatment for Symptomatic Paroxysmal Atrial Fibrillation (Afib)
September 4, 2020
- Summary: STOP-AF FIRST and Cryo-FIRST Trial results presented at the 2020 European Society of Cardiology Congress
- Reading time: 3–5 minutes
STOP-AF First Trial
At the 2020 European Society of Cardiology Congress, a late-breaking science session featured the results of the STOP-AF First Trial. The trial’s principal Investigator, Dr. Oussama Wazni of the Cleveland Clinic, presented the results. (You may remember him as a recent faculty member from our afib patient conference.)
Afib progresses, starting early, and can lead to cardiovascular issues and decreased quality of life. It is believed that earlier intervention may prevent this progression. But, there are few randomized controlled trials of catheter ablation as a first line treatment for those with symptomatic paroxysmal afib. The few trials to date used radiofrequency ablation.
The STOP-AF First Trial is FDA-regulated (U.S. only). It evaluated the safety and effectiveness of cryoballoon catheter ablation as a first-line treatment for those with recurrent symptomatic paroxysmal atrial fibrillation (afib that comes and goes) in a drug-naïve population (those who have not received antiarrhythmic drugs for their afib). In this randomized trial, patients received either pulmonary vein isolation (PVI) with a cryoballoon catheter (uses freezing to treat afib) or antiarrhythmic drugs.
Of the 203 patients, 104 received pulmonary vein isolation with the Arctic Front Advance Cryoballoon, and 99 received antiarrhythmic drugs. The drugs used were: flecainide 66%, dronedarone 13%, sotalol 11%, propafenone 8%, amiodarone 1%, and diltiazen 1% (one patient stayed on this rate control drug after being unable to tolerate an antiarrhythmic drug).
After 12 months, 75% of those in the cryoballoon ablation group, but only 45% of those in the antiarrhythmic drug group, were free from afib, atrial flutter, and atrial tachyarrhythmias. There were two safety events (1.9%) in the ablation group.
The Cryo-FIRST Trial took place in Europe, Australia, and Latin America. It was similar to STOP AF First in that it evaluated those with symptomatic paroxysmal afib who were drug-naïve (no prior antiarrhythmic drugs). Patients were randomized to receive a cryoballoon ablation as a first-line treatment or antiarrhythmic drugs.
The trial required complete pulmonary vein isolation in all patients receiving a cryoballoon ablation, and re-ablation was allowed during or after the 3-month blanking period. There were 20 crossovers (9%), with 19 of those going from antiarrhythmic drugs to cryoballoon ablation and one going from ablation to medication. The medications given were: flecainide 60%, propafenone 32%, dronedarone 2%, and sotalol 6%.
This study showed similar results to STOP-AF First, with 82.2% of the patients having cryoballoon ablation and 67.6% of those on antiarrhythmic drugs being free of afib and other atrial arrhythmias at twelve months. These numbers were slightly higher than STOP-AF First, but this was a younger population (median age of 53).
The electrophysiologists in the study were highly-skilled, and there was no difference in safety between the two groups. There were no serious adverse events (such as stroke, death, phrenic nerve injury, atrial esophageal fistula, or pericardial tamponade).
The Quality of Life results, as measured with the AFEQT tool, showed a significant improvement for those in the catheter ablation group compared to those in the antiarrhythmic drug group. At 12 months, 86.5% of the cryoballoon ablation group were symptom-free as compared to 70.4% of the antiarrhythmic drug group.
These trials continue to show that catheter ablation as a first-line treatment is safe and effective, with superior results to antiarrhythmic drugs.
To learn more about these trials, see:
- STOP-AF First: Cryoballoon Catheter Ablation in an Antiarrhythmic Drug Naive Paroxysmal Atrial Fibrillation
- Catheter Cryoablation Versus Antiarrhythmic Drug as First-Line Therapy of Paroxysmal Atrial Fibrillation (Cryo-FIRST)
- Medtronic Press Release: Medtronic Cryoablation Superior to Drug Therapy for Symptomatic Paroxysmal Atrial Fibrillation