Multicentre randomised trial comparing contact force with electrical coupling index in atrial flutter ablation (VERISMART trial)

Abstract

Introduction Electrical coupling index (ECI) and contact force (CF) have been developed to aid lesion formation during catheter ablation. ECI measures tissue impedance and capacitance whilst CF measures direct contact. The aim was to determine whether the presence of catheter / tissue interaction information, such as ECI and CF, reduce time to achieve bidirectional cavotricuspid isthmus block during atrial flutter (AFL) ablation. Methods Patients with paroxysmal or persistent AFL were randomised to CF visible (range 5-40g), CF not visible, ECI visible (change of 12%) or ECI not visible. Follow-up occurred at 3 and 6 months and included a 7 day ECG recording. The primary endpoint was time to bidirectional cavotricuspid isthmus block. Results 114 patients were randomised, 16 were excluded. Time to bidirectional block was significantly shorter when ECI was visible (median 30.0 mins (IQR 31) to median 10.5mins (IQR 12) p 0.023) versus ECI not visible. There was a trend towards a shorter time to bidirectional block when CF was visible. Higher force was applied when CF was visible (median 9.03g (IQR 7.4) vs. 11.3g (5.5) p 0.017). There was no difference in the acute recurrence of conduction between groups. The complication rate was 2%, AFL recurrence was 1.1% and at 6 month follow-up, 12% had atrial fibrillation. Conclusion The use of tissue contact information during AFL ablation was associated with reduced time taken to achieve bidirectional block when ECI was visible. Contact force data improved contact when visible with a trend towards a reduction in the procedural endpoint. ClinicalTrials.gov trial identifier: NCT02490033 .

Recurrent atrial arrhythmia in a randomized controlled trial comparing contact force guided and contact force blinded ablation for typical atrial flutter

“…In the setting of performing CF-guided CTIA, majority of studies conducted have been observational by design (6)(7)(8) and mainly focused on acute procedural parameters. Two RCT's found no difference in acute procedural parameters comparing CF-guided and CF-blinded CTIA (9,10). In our recent RCT, we found no difference regarding rate of cavo-tricuspid isthmus re-conduction at three months between CF-guided and CF-blinded CTIA (10).…”

Safety and chronic lesion characterization of pulsed field ablation in a Porcine model

“…Safe and effective dosing of thermal energy has a small but ever present risk of severe complications which has not abated despite new technologies for monitoring contact force and lesion index 3,34–38 . This study examined excessive deliveries on the same bands of tissue in the RAA and RSPV that produced no injuries to local adjacent endocardial tissue, pulmonary tissues, adjacent nerves, nor esophageal tissue.…”

Gaps in Patient Reported Outcome Measures in Randomised Clinical Trials of Cardiac Catheter Ablation: A Systematic Review

“…Organisations such as the UK's National Institute for Health and Care Excellence (NICE) routinely use EQ-5D and SF-36 11 to assess HRQL, employing them in comparative effectiveness research and costeffectiveness analyses (CEAs). Accurate cost, clinical outcome, and HRQL data are all required as inputs for economic models used in CEAs.…”

“…Individual RCT scores are provided in the supplementary material. Table 4 splits the studies into high (6)(7)(8)(9)(10)(11), medium (3)(4)(5) and low ranges (1-2) of adherence to CONSORT PRO standards. For RCTs that were in the top tertile, there was increased use of validated PROMs that could be subsequently used in CEAs, as well as a longer follow-up time.…”

“…For explanatory trials, only four studies were deemed to have outcomes which meant PROMs were not relevant [Figure 2]. 8,[10][11][12] The flowchart outlines the logic of this and the definition of an outcome important to patient is as follows:…”