Feasibility and Safety of Ablation using a Dual-Energy, Lattice-Tip, Map-and-Ablate Catheter in Patients with Mechanical Heart Valves.

BACKGROUND: Catheter ablation near mechanical prosthetic valves is associated with a risk of catheter-valve interaction and entrapment. OBJECTIVE: To evaluate the feasibility, safety, and efficacy of atrial ablation using a dual-energy, lattice-tip catheter in patients with mechanical heart valves. METHODS: Consecutive patients undergoing atrial catheter ablation near a mechanical valve using the Sphere-9 catheter were identified at two tertiary centres. Primary safety endpoints included abortion of ablation because of catheter interference and procedural complications. Freedom from atrial tachyarrhythmia during follow-up was assessed as an efficacy endpoint. An in vitro valve interaction testing was additionally performed. RESULTS: Nine patients (median age 59 years; 56% male) were identified. Ablation lines anchored to a mechanical valve were created in six patients, using RFA close to the valve in 5 patients and pulsed-field ablation (PFA) in 1 patient. Interference during ablation leading to abortion of individual applications occurred in three patients, all during RFA, without preventing completion of the intended ablation strategy. No catheter entrapment, valve dysfunction, or procedural adverse events occurred. After a median follow-up of 114 days, all patients were free from recurrent atrial tachyarrhythmias. Bench testing demonstrated no propensity of the lattice-tip catheter to become wedged within a bileaflet mechanical heart valve. CONCLUSION: Atrial ablation using a lattice-tip catheter appears feasible in patients with mechanical heart valves. No catheter entrapment or major complications were observed. However, given the small sample size, these findings should be interpreted as preliminary, and larger studies are needed to better assess safety and clinical outcomes.