Contact force sensing catheters “safe and effective” in persistent AF ablation

Moussa Mansour

Contact force (CF) sensing catheters have been shown to be safe and effective in persistent atrial fibrillation (AF) ablation, according to the findings of the PRECEPT study, which have been presented online during a late-breaking clinical trial session at the Hearth Rhythm 2020 Science Session. The findings were presented by the study’s lead author, Moussa Mansour (Massachusetts General Hospital, Boston, USA). The findings of the study were published simultaneously in the Journal of the American College of Cardiology (JACC): Electrophysiology.

During his presentation, Mansour noted that while the safety and effectiveness of catheter ablation of paroxysmal AF has been long established, there are limited data on outcomes in patients with persistent, and no ablation catheter is currently approved by the FDA for persistent AF ablation. The PRECEOT study sought to evaluate the safety and effectiveness of catheter ablation of persistent AF using a CF sensing radiofrequency catheter (Thermocool Smarttouch SF, Biosense Webster).

The study was a prospective, multicentre, non-randomised trial, taking place at 27 sites in the USA and Canada, involving patients who had documented symptomatic persistent AF, defined as continuous AF sustained beyond seven days but less than one year, and nonresponse or intolerant to at least one antiarrhythmic drug (AAD) (Class I or III). The trial’s primary safety endpoint was the  incidence of primary adverse events occurring within seven days of the initial and repeat ablation procedures, and the primary effectiveness endpoint was freedom from documented recurrence of AF, atrial flutter (AFL) or atrial tachycardia (AT) episodes of 30 seconds or longer and freedom from an additional five failure modes at 15 months, which included: acute procedural failure, use of non-study catheter, repeat procedures, use of new/higher dose AAD or surgical ablation.

A total of 381 patients were enrolled in the study between 27 July 2016, and 6 February 2018, of which 348 had the investigational catheter inserted and comprised the safety population. All participants in the safety population underwent RF ablation. Four participants had missing three months data for safety assessment and thus were removed from the primary safety endpoint analysis. The effectiveness population comprised 333 participants after exclusion of 14 participants who did not meet inclusion criteria and one participant who was ablated with a non-study catheter.

According to the results presented by Mansour, the Kaplan-Meier estimate of primary effectiveness at 15 months stood at 61.7% [95% CI: 56.2-67.2%] of patients reporting freedom from recurrences of AF, AT or AFL, acute procedural failure, use of non-study catheter, repeat procedures, use of new/higher dose AAD or surgical ablation. This meant that the study’s performance goal 40.0% for primary effectiveness was met. Clinical success, defined as freedom from documented symptomatic AF, AT or AFL recurrence, was reported in 80.4% of patients, Mansour stated.

On the safety outcomes, Mansour and colleagues note that overall, 14 primary adverse events were reported for 13 participants. The primary adverse event rate was 3.8% and one-sided exact 97.5% upper confidence bound was 6.4%, significantly less than the specified performance goal of 16.0%.

In conclusion, Mansour and colleagues wrote: “The PRECEPT study demonstrated the clinical safety and effectiveness of PsAF ablation using CF-sensing technologies with protocol-defined effectiveness of 62% and clinical success of 80%. The PAE [primary adverse event] rate was within the acceptable and expected range and similar to that for paroxysmal AF ablation. Comparison of with other multicentre studies suggests individualised ablation approach base on patient’s clinical presentation may optimize treatment outcome.”


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