Prolonged atrium electromechanical interval is associated with stroke in patients with atrial fibrillation after catheter ablation

Introduction: Atrial fibrillation (AF) is associated with increased risk of embolic stroke. Catheter ablation of AF provides an effective therapy for patients with symptomatic and drug-refractory AF. The aim of this study was to evaluate whether the atrial electromechanical interval is useful in identifying patients at risk of stroke after successful catheter ablation. Methods and Results: A total of 279 AF patients who received catheter ablation and showed no evidence of recurrences were enrolled. Electromechanical interval (PA-PDI) was determined as the time interval from the initiation of P wave deflection to the peak of mitral inflow A wave on pulse wave Doppler imaging. The PA-PDI interval was measured for each patient after the 3-month blanking period of catheter ablation. The clinical endpoint was the occurrence of ischemic stroke. During the follow-up of 46.5 ± 17.2 months, 6 patients suffered from ischemic strokes. Patients with strokes had higher CHA₂DS₂-VASc scores and longer PA-PDI intervals (138.7 ± 12.4 ms vs 161.2 ± 7.7 ms, P value < 0.001) compared to those without strokes. At a cutoff point of 150 ms identified by ROC curve, the positive and negative predictive values of the PA-PDI interval to predict stroke were 86.7% and 100%, respectively. The PA-PDI interval improved the predictive performance of the CHA ₂DS₂-VASc score, and the area under the ROC curve increased from 0.75 to 0.85. Conclusions: Our results suggest that the PA-PDI interval is a useful tool to identify patients with high risk of stroke after successful catheter ablation of AF.