Background
The acute efficacy of the cavotricuspid isthmus (CTI) ablation using the pentaspline catheter and pulsed-electric field (PEF) energy has not been systematically evaluated.
Aims
To assess the acute efficacy and haemolysis associated with CTI ablation using two available configurations of the catheter.
Methods
A tolal of 178 patients (age 65±10 years, males 66%) undergoing CTI PEF ablation in conjunction with AF ablation were randomized to the ablation using basket configuration (n=95) or the flower configuration (n=83) of the pentaspline catheter. The CTI ablation was guided by intracardiac echocardiography. Venous blood samples to assess haemolytic biomarkers were collected before and after the CTI ablation.
Results
The groups were broadly comparable in baseline characteristics. The flower group demonstrated superior procedural efficiency, with fewer applications required to achieve a CTI block (3.4 ± 3.1 vs 8.0 ± 4.1, P <0.001), a shorter time to block (96 ± 289 vs 177 ± 192 s, P <0.001), and fewer total applications (10.1 ± 3.4 vs 13.3 ± 5.1, P <0.001). Acute reconduction occurred in 20% of cases overall but was significantly lower in the flower group (6% vs 32%, P <0.001; hazard ratio: 0.26, 95% confidence interval: 0.08–0.92). Haemolysis was notably lower in the flower group, with significantly less post-procedural free haemoglobin (154 ± 112 vs 210 ± 115 mg/L, P <0.001). One case of transient ST elevations occurred in the flower group without clinical consequence.
Conclusion
PEF ablation of the CTI using the flower configuration of the pentaspline catheter proved to be more effective in achieving acute CTI block and safer in terms of haemolysis when compared to the basket configuration. This is likely due to the larger footprint and improved tissue contact of all electrodes, minimizing the leakage of PEF energy into the blood pool.