Results of the SPHERE Per-AF study, investigating the safety and efficacy of Medtronic’s Sphere-9 catheter, have been presented at the Heart Rhythm Society (HRS) annual meeting (16–19 May, Boston, USA), and have demonstrated the safety and efficacy of the system.
The Sphere-9 catheter incorporates pulsed field (PF) and radiofrequency (RF) ablation as well as high density (HD) mapping for the treatment of persistent atrial fibrillation (AF).
The SPHERE Per-AF study, a US Food and Drug Administration (FDA) investigational device exemption (IDE) pivotal trial, compared Sphere-9 to the Thermocool SmartTouch SF radiofrequency ablation catheter with the Carto 3 system (Biosense Webster). Findings were presented as late-breaking clinical data at the HRS 2024 annual meeting and simultaneously published in Nature Medicine.
The Sphere-9 catheter demonstrated a positive safety profile with an excellent primary safety endpoint rate of 1.4% (1% for the control arm). No safety events including pulmonary vein stenosis, oesophageal events or cardiac tamponade were reported. More than 95% of Sphere-9 procedures used a single transeptal puncture compared to 62% in the control arm.
Sphere-9 demonstrated 73.8% freedom from atrial fibrillation (AF) vs. only 65.8% observed in the control arm. Following 100% acute isolation of pulmonary veins and linear lesions, patients treated with the Sphere-9 catheter also observed less recurrence of atrial arrhythmias throughout the 12-month follow up period.
“These are excellent results for the investigational Sphere-9 catheter. The data show Sphere-9 lattice tip technology enables physicians to create a wide circumferential pulmonary vein isolation, which is the cornerstone of any type of AF ablation, and any set of desired ablation lesions, in a safe, effective and efficient manner,” said Elad Anter (Shamir Medical Center, Tel Aviv, Israel). “Persistent AF patients make up 30–50% of the patient population and are often challenging to treat, with the majority of procedures requiring additional lesion sets beyond pulmonary vein isolation. The versatility and ease of use of this mapping and ablation system led to impressive efficiency and treatment outcomes in the trial.”
“As pioneers in cardiac ablation treatment, including cryoablation and PFA, we are thrilled to share these results providing excellent evidence for use of this all-in-one catheter that can be used with no need to pull a second catheter,” said Rebecca Seidel, president, Cardiac Ablations Solutions business, which is part of the Cardiovascular Portfolio at Medtronic.
“The Affera Mapping and Ablation system with Sphere-9 catheter demonstrates a positive safety, efficacy and efficiency profile and can amplify our innovative and trusted portfolio. With these results, we are now one step closer to bringing this technology to the US and beyond.”
In the SPHERE Per-AF prospective, multicentre, randomised clinical trial patients were randomised 1:1 to receive treatment with either the Sphere-9 catheter with the Affera mapping and ablation system or the Thermocool SmartTouch SF radiofrequency ablation catheter with the Carto 3 system.
For the primary analysis, a total of 420 patients were enrolled across 23 sites in the USA, Czech Republic and Israel. All patients in both arms of the trial received pulmonary vein isolation as well as linear lesions based on the patient’s needs.
“We’ve been waiting for one catheter that can be used for every arrhythmia, and these randomised results from centres that routinely use conventional point by point ablation indicate Affera Sphere-9 will be worth the wait with all its innovation and the rapid learning curve of the system,” said Vivek Reddy (Mount Sinai Health System, New York, USA). “These are important, highly anticipated results and groundbreaking news for the electrophysiology community that could change the treatment workflow.”
