Association of left atrium voltage amplitude and distribution with the risk of atrial fibrillation recurrence and evolution after pulmonary vein isolation: An ultrahigh-density mapping study.

INTRODUCTION: Ultrahigh-density-voltage mapping (uHDV M) is a new tool that can add new insights into the pathophysiology of atrial fibrillation (AF). The aim of this study was to evaluate the performance of uHDV M in predicting postablation AF recurrence (AFR). METHODS AND RESULTS: We included 98 consecutive patients undergoing pulmonary vein isolation for AF (40.8% persistent) using an uHDV M system and followed for 1 year. The left atrium (LA) mean voltage (Vm ) and the Vslope (slope of the voltage histogram calculated by linear interpolation, with the relative frequency on the vertical axis and the bipolar potential on the horizontal axis) were calculated from 12 567 ± 5486 points per map. Patients with AFR (N = 29) had lower Vm and higher Vslope as compared with patients without AFR (N = 69). Receiver operating characteristic curves identified Vm as the strongest predictor of AFR, with a higher incidence of AFR in patients with Vm 0.758 mV (57.6%) or lower than patients with Vm higher than 0.758 mV (15.4%; P < .0001). Among patients with Vm  higher than 0.758 mV, patients with Vslope 0.637 or higher exhibited higher (P = .043) AFR incidence (31.3%) than patients with Vslope lower than 0.637 (10.2%). This classification showed incremental predictive value over relevant covariables. Vm values were lower and Vslope values were higher in patients that progressed from paroxysmal to persistent AF. Patients with Vslope 0.637 or higher had a 14.2% incidence of postablation atypical atrial flutter, whereas patients with Vslope lower than 0.637 did not present this outcome. CONCLUSIONS: The risk of AFR, atrial flutter, and progression from paroxysmal to persistent AF can be detected by quantitative analysis of LA uHDV M identifying diverse patterns of atrial substrate alterations.

Economic evaluation of an ultra-high density mapping system compared to non-ultra-high density mapping systems for radiofrequency catheter ablation procedures in patients with atrial fibrillation.

PURPOSE: Advanced non-fluoroscopic mapping systems for radiofrequency ablation (RFA) have shown to be an effective treatment of atrial fibrillation. This study analyzes the resource usage and subsequent costs associated with the implementation of an ultra-high density mapping system (UHDMS) compared to non-ultra-high density mapping systems (NUHDMS). METHODS: This retrospective observational study included 120 patients (18 years or older) with paroxysmal or persistent atrial fibrillation who underwent RFA for de novo pulmonary vein isolation guided either by an UHDMS (n=63) or NUHDMS (n=57) for their index procedure. We compared patient characteristics, short- and long-term procedural outcomes, resource usage, and clinical outcomes followed up to 16 months between the two treatment groups. The cost analysis was conducted from the perspective of a single center in Spain (Clinica Universidad de Navarra). RESULTS: Neither baseline patient characteristics nor complication rate differed between groups. Repeat RFAs following recurrent arrhythmia at 16 months was lower in the UHDMS patient group than in the NUHDMS group (6 vs. 14, respectively; P=0.027). The average total cost per patient was €1,600 lower in the UHDMS group, compared to the NUHDMS group (€11,061 and €12,661, respectively; P=0.03). CONCLUSION: In patients treated with an NUHDMS, 25% had a repeat ablation for recurrent arrhythmia, whereas only 9% of patients treated with a UHDMS had one (61% relative risk reduction), resulting in an average cost saving per patient of €1,600.