Operator learning curve with a novel balloon-based PFA catheter

Abstract Background Utilizing a novel medical technology may present early challenges in familiarization and workflow before future benefits of greater efficacy, safety, or efficiency are realized. Data on the results of PFA in protocol-driven cohorts and initial real-world cases have been well-covered; however, learning curve results from a multicenter experience with a novel PFA catheter have not been well reported. Purpose Determine how procedural effectiveness, safety, and efficiency in the Volt-AF IDE study were impacted over the course of the operator learning curve in this sub-analysis. Methods The VOLT-AF IDE study is a prospective, single-arm global IDE study designed to demonstrate that the Volt PFA System is safe and effective for the treatment of PAF and PsAF (AF sustained >7 days and <1 year). Per protocol, ablation was PVI only. Included in this sub-analysis were cases by physicians who enrolled >10 subjects without prior experience with the Volt catheter, split by operator into Early Procedures (EaP, Cases 1-5), Mid-Term Procedures (MP, Cases 6-10), and Late Procedures (LP, Cases 11 and later), then grouped for multicenter analysis. The roll-in procedure contributed to the operators’ EaP. Chi-square test was used to compare data across the groups. Results There were 140 cases in this sub-analysis; 59.3% PAF (n=21 EaP, n=25 MP, n=37 LP) and 40.7% PsAF (n=9 EaP, n=5 MP, n=43 LP). Acute effectiveness and safety were unchanged across the learning curve, with acute success achieved in 100% (21/21), 100% (25/25), and 97.3% (36/37) of patients with PAF (EaP, MP, and LP groups, respectively) and in 100% of patients with persistent AF for all 3 groups (p=1.0 for both indications). A primary safety event occurred in 0% for all 3 groups for patients with PAF and in 0% (0/9), 0% (0/5), and 7.0% (3/43) of patients with PsAF (EaP, MP, and LP groups, respectively, p=1.0 for both indications). The number of PFA applications did increase significantly across the learning curve (Figure 1), from 17.0±3.8 applications in the EaP group to 19.0±3.2 in the LP group (p=0.004). Procedure time and LA dwell time both decreased significantly across the learning curve (Figure 2), with a decrease in procedure time from 104.7±20.5 min in the EaP group to 91.9±18.2 min in the LP group (p=0.0024), and a decrease in LA dwell time from 47.6±17.6 min in the EaP group to 39.8±13.7 min in the LP group (p=0.0203). There was a downward trend in fluoroscopy time across the learning curve (p=0.0705). Conclusion AF ablation using a novel balloon-based PFA catheter has a high degree of acute success and safety regardless of the stage within an operator’s learning curve, demonstrating a low barrier to technology adoption. Procedural efficiency and the number of PFA applications increased across the learning curve with this novel technology. Further analysis of the factors contributing to the difference in number of applications is warranted.