Comparison of efficacy of phased multipolar versus traditional radiofrequency ablation: A prospective, multicenter study (CAPCOST).

BACKGROUND: Multipolar phased pulmonary vein ablation catheter (PVAC), specifically its second-generation (PVAC-Gold), has been associated with reduced procedural time for atrial fibrillation (AF) ablation compared to traditional catheters. We performed this study to compare the efficacy of PVAC with point-by-point radiofrequency (RF) ablation. METHODS: This is a multicenter-cohort study (2012-2017), involving patients with symptomatic, paroxysmal AF refractory to at least one antiarrhythmic medication. Overall, 230 patients were enrolled to (A) PVAC and (B) control groups. Subanalyses were done for ablations performed with PVAC-Gold, and for ablations performed without left atrial (LA) ablation in addition to pulmonary vein isolation. Electrocardiogram and 48-h Holter monitoring were used to assess patients at 3, 6, 9, and 12 months postablation. Recurrence was defined as any atrial arrhythmia >30 s excluding an initial 3-month blanking period. RESULTS: Freedom from any atrial arrhythmia at 12 months postablation was 35.70% and 52.80% in groups A and B, respectively (P = .01). Freedom from atrial arrhythmia was not significantly different when limiting the PVAC cohort to PVAC-Gold and excluding patients with additional LA ablation (A: 44.30%; B: 44.30%, P = .80). Procedural and ablation time was significantly lower in group A than B. Multivariate regression model showed female gender (odds ratio [OR] = 2.90) and recurrence during blanking period (OR = 6.60) as significant predictors of recurrence. CONCLUSION: This study suggests that PVAC may achieve less freedom from AF than point-by-point RF; however, efficacy is similar when comparing PVAC-Gold and point-by-point stand-alone PV isolation. PVAC is associated with significantly reduced procedural times for AF ablation.

Predictors of cerebral microembolization during phased radiofrequency ablation of atrial fibrillation: role of the ongoing rhythm and the site of energy delivery.

BACKGROUND: Pulmonary vein isolation with phased radiofrequency current and use of a pulmonary vein ablation catheter (PVAC) has recently been associated with a high incidence of clinically silent brain infarcts on diffusion-weighted magnetic resonance imaging, and a high microembolic signal (MES) count detected by transcranial Doppler. We investigated the potential effects of the ongoing rhythm and the target vein during energy delivery (ED) on MES generation during PVAC ablations. METHODS AND RESULTS: A total of 735 EDs during 48 PVAC ablations were analyzed. MES counts were recorded for each ED and time-stamped for correlation with the ongoing rhythm and the target vein for each ED. Significantly higher MES counts were observed during ablations of the left-sided as compared with the right-sided pulmonary veins (P = 0.0003). Similarly, higher MES counts were detected during EDs in atrial fibrillation as compared with sinus rhythm when the temperature was >56°C (P < 0.0001). The ongoing rhythm had no effect on the number of MESs at lower temperatures during ablation. CONCLUSIONS: Both the ongoing rhythm during ED and the site of ablation influence microembolus generation during PVAC ablation procedures.

Direct results of a prospective randomized study comparing ablation with the nMARQ catheter and the PVAC catheter used with and without a 3D system (MAPER 3D Study).

INTRODUCTION: Our aim was to compare in a prospective randomized study the safety, direct results and periprocedural data of ablation using an nMARQ catheter, a PVAC catheter used with the EnSite system, or a PVAC catheter only under fluoroscopy control. MATERIAL AND METHODS: One hundred two patients (70 male, 57 ±11 years) with atrial fibrillation (AF) were prospectively randomized to: group 1 - ablation performed with an nMARQ catheter and the CARTO 3 system; group 2 - a PVAC catheter used with the EnSite system; group 3 - ablation with a PVAC catheter without a 3D system. RESULTS: Complete isolation of 400/402 pulmonary veins (PV) (99.5%). Linear ablation was performed in 23 patients in group 1 (small distance between lines isolating PV), in 3 patients in group 2, in 1 patient in group 3. The superior vena cava was isolated in 1 patient, 9 patients, and 9 patients respectively. Duration of fluoroscopy and dose area product were significantly smaller in group 1 (6.5 ±2.9 min/808.8 ±393.9 cGy/cm2 vs. 13.6 ±5.6 min/1662.6 ±677.8 cGy/cm2 and 18.8 ±7.6 min/2327.9 ±975.5 cGy/cm2; p < 0.001). Procedure duration was shorter in group 1 (82.9 ±18.8 min vs. 101.2 ±19.6 min, p < 0.001 and 99.8 ±20.8 min, NS). Contrast injection was necessary in 2 patients in group 1, in 8 patients in group 2 and in all patients in group 3. Because nMARQ is a thermocool catheter, the volume of fluid injection was significantly greater (2348.5 ±543.5 ml vs. 1077.9 ±280.5 ml and 1076.5 ±375.6 ml, p < 0.001). There were no periprocedural deaths. We observed no cardiac tamponade, neurological complications and no atrioesophageal fistula during follow-up. CONCLUSIONS: The lowest radiological exposure was observed during ablation performed with an nMARQ catheter. 3D systems reduced fluoroscopy duration and the necessity of contrast injection. The nMARQ catheter requires injection of a large volume of fluid.

Predictors of cerebral microembolization during phased radiofrequency ablation of atrial fibrillation: analysis of biophysical parameters from the ablation generator.

BACKGROUND: Pulmonary vein isolation with phased radiofrequency current and use of a pulmonary vein ablation catheter (PVAC) has recently been associated with a high incidence of clinically silent brain infarcts on diffusion-weighted magnetic resonance imaging and a high microembolic signal (MES) count detected by transcranial Doppler. OBJECTIVE: The purpose of this study was to investigate the potential correlation between different biophysical parameters of energy delivery (ED) and MES generation during PVAC ablation. METHODS: MES counts during consecutive PVAC ablations were recorded for each ED and time stamped for correlation with temperature, power, and impedance data from the GENius 14.4 generator. Additionally, catheter-tissue contact was characterized by the template deviation score, calculated by comparing the temperature curve with an ideal template representing good contact, and by the respiratory contact failure score, to quantify temperature variations indicative of intermittent contact due to respiration. RESULTS: A total of 834 EDs during 48 PVAC ablations were analyzed. A significant increase in MES count was associated with a lower average temperature, a temperature integral over 62°C, a higher average power, the total energy delivered, higher respiration and template deviation scores (P <.0001), and simultaneous ED to the most proximal and distal poles of the PVAC (P <.0001). CONCLUSION: MES generation during ablation is related to different indicators of poor electrode-tissue contact, the total power delivered, and the interaction between the most distal and the most proximal electrodes.