Hybrid ablation, a procedure which involves “attacking” the atrial substrate from the epicardium and endocardium, has been shown to result in significantly higher freedom from arrhythmia compared to conventional catheter ablation, in persistent and long-standing persistent atrial fibrillation (AF)—late-breaking data presented at the digital AF Symposium (29–31 January, virtual) indicate.
This was the conclusion drawn by Bart Maesen (Maastricht University, Maastricht, The Netherlands), presenting one-year data from the HARTCAP-AF trial—a pilot trial comparing the safety and efficacy of catheter ablation versus hybrid ablation, consisting of thoracoscopic epicardial surgery combined with endocardial catheter ablation (performed one-stage), in preventing the recurrence of atrial fibrillation (AF) in symptomatic, drug refractory patients with persistent or longstanding persistent atrial fibrillation.
HARTCAP-AF trial investigators hypothesised that hybrid AF ablation would be more effective than repeated transvenous endocardial catheter ablation in patients with persistent and long-standing persistent atrial fibrillation, without increasing the number of associated major adverse events, Maesen told the AF Symposium audience.
In the trial, patients who had non paroxysmal AF without prior ablation were included and were randomised 1:1 between receiving the hybrid treatment or catheter ablation. In the hybrid group, bilateral pulmonary vein isolation and a box lesion was performed using bipolar radiofrequency. The left atrial appendage was clipped, and endocardial validation and touch-up ablation was performed where needed, Maesen explained. In the catheter group, bilateral pulmonary vein isolation and a box lesion was performed using up-to-the-standard contact force radiofrequency, he added.
“In patients with right atrial dilatation, right atrial flutter, or patients developing a flutter during the procedure, a cavo-tricuspid isthmus line was made. Other ablation was left to the discretion of the operating electrophysiologist. A repeat catheter ablation, within six months was permitted but only in the catheter ablation group,” Maesen noted.
The primary endpoint of the trial was freedom from any atrial tachyarrhythmia lasting longer than five minutes without the use of antiarrhythmic drugs at the 12 month follow-up point, monitored using a seven day Holter monitor. In total, 41 patients were randomised. 19 patients to the hybrid group and 22 patients to the catheter group.
Most of the patient characteristics were comparable between the two groups, Maesen explained, although there was a tendency to more obstructive sleep apnoea, longer pre-intervention AF duration, and higher left atrial volume in the hybrid group. In all patients, the ablation was performed per-protocol. In the hybrid group, there were eight patients that needed endocardial touch-up ablation, he added, detailing that five of these were at the superior or inferior connecting lines, two patients at the right superior pulmonary vein, and one patient at the carina. CTI line was performed in 14 patients, mitral isthmus line in one patient. In the catheter group, CTI ablation was performed in 10 patients and there was no repeat catheter ablation in the first six months.
The primary endpoint, arrhythmia-free survival at 12 month without the use of antiarrhythmic drugs was met in 83% of patients in the hybrid, and 45% in the catheter group, Maesen revealed, noting that this difference was significant.
He added: “When allowing AADs there was one patient in the catheter group more that remained in sinus rhythm. So, the arrhythmia-free survival at 12 months, allowing AAD, remained the same in the hybrid group, and was 50% in the catheter group. Also this difference was significant.”
He added that no deaths, strokes, or pacemaker implantations, and no conversions to sternotomy were observed. Complications in the catheter ablation group included one femoral bleed requiring surgery, and one AV fistula, and one pericardial effusion in the hybrid group.
“Furthermore, we observed one pericarditis in the hybrid group in the first 30 days. Quality of life assessment at the 12 month follow-up point showed no significant difference in any of the five scoring parameters between both groups.”
In conclusion, Maesen said: “In patients with non-paroxysmal AF, hybrid AF ablation resulted in a significantly higher freedom of atrial arrhythmias compared to the conventional catheter ablation, without increasing the number of associated major adverse events.”
HARTCAP-AF was the second of two studies presented during the AF Symposium late-breaking trial session to support a hybrid approach to long-standing persistent AF. Earlier, findings of a sub-analysis of the CONVERGE clinical trial, presented by David DeLurgio (Emory St Joseph’s Hospital, Atlanta, USA), showed that the hybrid Convergent procedure yields superior outcomes to catheter ablation in these patients.