Experience with the "trefoil" method for left common pulmonary vein isolation

Aim. To evaluate the clinical efficacy and safety of antral segmental balloon left common pulmonary vein (LCPV) isolation using the "trefoil" method and to identify clinical and echocardiographic factors associated with the procedure success.

Material and methods. This retrospective-prospective observational study included 98 patients with paroxysmal and/or persistent atrial fibrillation (AF) and verified large-diameter LCPV exceeding the cryoballoon size. All patients underwent antral segmental balloon isolation using the proprietary "trefoil" technique. Isolation effectiveness was assessed clinically and, in the presence of AF recurrence, confirmed by repeat electrophysiological studies. A comparative analysis was conducted between groups with successful and unsuccessful LCPV isolation. Univariate and multivariate logistic regression analyses, as well as ROC analysis, were used to identify predictors.

Results. Effective LCPV isolation was achieved in 85 (86,7%) patients. Comparative analysis revealed no differences between the groups in age, sex, AF type, comorbidities, and left ventricular parameters (p>0,05). Significantly higher values of left atrial (LA) volume and LA anteroposterior diameter (APD) were found in patients without successful LCPV isolation (p<0,001). In a multivariate analysis, LA APD was the only independent predictor of effective LCPV isolation (odds ratio (OR) 0,816; 95% confidence interval: 0,680-0,980; p=0,030). ROC analysis demonstrated high prognostic significance of this indicator (area under the curve (AUC)=0,898).

Conclusion. A segmental balloon LCPV isolation technique ("trefoil") has been presented for the first time and has demonstrated high efficacy and safety. The proposed algorithm allows for expanded application of balloon techniques for various anatomical pulmonary vein variants, including LCPV. The left pulmonary vein (LPV) is an independent anatomical predictor of procedural efficacy and can be used to predict catheter-based treatment outcomes in this patient population.

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