“Cryoconvergent” hybrid ablation for atrial fibrillation may significantly reduce risk for recurrent AF and AF burden in patients with persistent AF or long-standing persistent AF, researchers reported.
“The hybrid convergent procedure combines minimally invasive epicardial radiofrequency (RF) ablation of the left atrial posterior wall and pulmonary vein (PV) antrum with endocardial PV isolation, and has shown favorable results in achieving sinus rhythm with and without anti-arrhythmic drugs, including in long-standing persistent AF and with longer follow-up,” Kevin Makati, MD, FACC, FHRS, of the electrophysiology lab at St. Joseph’s Hospital of the BayCare Health System in Tampa, Florida, and colleagues wrote. “Most convergent studies used RF as the endocardial and epicardial energy; one previous report investigated endocardial cryothermy. We report safety and efficacy of the convergent procedure using endocardial cryothermy.”
For this retrospective analysis of the TRAC-AF registry, published in Circulation: Arrhythmia and Electrophysiology, researchers included 226 patients who underwent hybrid ablation procedures (mean age, 65 years; 70% men). The primary safety outcome was overall rate of periprocedural complication and the primary effectiveness outcome was freedom from AF or atrial flutter. Individuals underwent convergent procedures with endocardial cryothermy PV isolation (Arctic Front Advance, Medtronic) from November 2011 to May 2018. Recurrence was defined as incidence of more than 30 seconds of AF, atrial flutter or atrial tachycardia on continuous loop monitoring, device interrogation and/or in-office ECG.
Recurrence of AF
Of this cohort, 201 had available 3-, 6-, 12- and 24-month follow-up data.
Overall, 6% of patients experienced periprocedural complications, which included three cases of bleeding and transient/acute renal failure, one pericardial effusion, two phrenic nerve injuries, two vascular complications and one volume overload requiring intubation.
Researchers observed that 75% of patients who were taking previously ineffective anti-arrhythmic drugs were free from AF, atrial flutter and atrial tachycardia after cryoconvergent hybrid ablation.
At the last follow-up, 77% of patients were no longer taking anti-arrhythmic drugs and 69% were free from AF, atrial flutter and atrial tachycardia. Fifty-five percent of the overall cohort was free from arrhythmia and off any anti-arrhythmic drugs.
Moreover, 85% of patients with persistent AF (mean follow-up, 14.7 months) and 70% with long-standing persistent AF (mean follow-up, 16.8 months) were free from AF, atrial flutter and atrial tachycardia.
AF burden reduction
Implantable loop recorders or existing pacemakers were used for continuous loop monitoring of AF burden in 53% of patients, and the remainder had ECGs.
Investigators observed reductions in AF burden within 3 to 12 months of cryoconvergent hybrid ablation for patients with all AF (98.9% reduction), persistent AF (99.3% reduction) and long-standing persistent AF (98.5% reduction). At 12 to 24 months, burden reduction was 91.5% for all AF, 89.3% for persistent AF and 92.5% for long-standing persistent AF.
“Results indicate the ‘CryoConvergent’ procedure provides a promising solution for persistent AF and long-standing persistent AF treatment, evidenced by relatively low AF recurrence rates and marked AF burden reduction after treatment even in long-standing persistent AF.”