High‐Flow Perfusion of Sheaths for Prevention of Thromboembolic Complications During Complex Catheter Ablation in the Left Atrium

INTRODUCTION: Mechanisms for thromboembolic complications during complex ablation procedures in left atrium (LA) have not been defined. The aim of this study was to determine the effect of the perfusion rate of the transseptal sheath on the incidence of thromboembolic complications during catheter ablation for atrial fibrillation (AF) or LA macroreentrant tachycardia. METHODS AND RESULTS: We analyzed clinical and procedural data from 86 consecutive patients (153 procedures) referred for catheter ablation of AF (74 patients) or LA macroreentrant tachycardia (12 patients). The transseptal sheath was continuously perfused at a low flow rate (3 mL/hour) for the first 32 patients and at a high flow rate (180 mL/hour) for the subsequent 54 patients. Ablation was mainly performed using map-guided isolation of pulmonary veins for AF and three-dimensional electroanatomic mapping for LA macroreentrant tachycardia. Five patients (6% of patients and 3.5% of procedures) developed a cerebral thromboembolic complication, all during procedures using low-flow perfusion. Sheath perfusion rate and total procedure duration were the two variables significantly associated with the occurrence of stroke (P = 0.013 and 0.001, respectively). After adjustment in a multivariable analysis, sheath perfusion rate remained the only risk factor for stroke. The risk was 17 times higher using low-flow than high-flow perfusion (odds ratio 17.26, 95% confidence interval 1.14-260.81, P = 0.04). No other clinical or procedural parameters had any significant effect. CONCLUSION: Sheath perfusion rate is an important determinant of the risk factor for stroke during complex LA ablation procedures. Continuous high-flow perfusion appears to be effective in preventing this complication.