Efficacy and safety of ablation index-guided catheter ablation for atrial fibrillation: an updated meta-analysis.

AIMS: Despite recent advances in catheter ablation for atrial fibrillation (AF), pulmonary vein reconnection (PVR), and AF recurrence remain significantly high. Ablation index (AI) is a new method incorporating contact force, time, and power that should optimize procedural outcomes. We aimed to evaluate the efficacy and safety of AI-guided catheter ablation compared to a non-AI-guided approach. METHODS AND RESULTS: A systematic search was performed on MEDLINE (via PubMED), EMBASE, COCHRANE, and European Society of Cardiology (ESC) databases (from inception to 1 July 2019). We included only studies that compared AI-guided with non-AI-guided catheter ablation of AF. Eleven studies reporting on 2306 patients were identified. Median follow-up period was 12 months. Ablation index-guided ablation had a significant shorter procedural time (141.0 vs. 152.8 min, P = 0.01; I2 = 90%), ablation time (21.8 vs. 32.0 min, P < 0.00001; I2 = 0%), achieved first-pass isolation more frequently [odds ratio (OR) = 0.09, 95%CI 0.04-0.21; 93.4% vs. 62.9%, P < 0.001; I2 = 58%] and was less frequently associated with acute PVR (OR = 0.37, 95%CI 0.18-0.75; 18.0% vs 35.0%; P = 0.006; I2 = 0%). Importantly, atrial arrhythmia relapse post-blanking was significantly lower in AI compared to non-AI catheter ablation (OR = 0.41, 95%CI 0.25-0.66; 11.8% vs. 24.9%, P = 0.0003; I2 = 35%). Finally, there was no difference in complication rate between AI and non-AI ablation, with the number of cardiac tamponade events in the AI group less being numerically lower (OR = 0.69, 95%CI 0.30-1.60, 1.6% vs. 2.5%, P = 0.39; I2 = 0%). CONCLUSIONS: These data suggest that AI-guided catheter ablation is associated with increased efficacy of AF ablation, while preserving a comparable safety profile to non-AI catheter ablation.

Transient atriovenous reconnection induced by adenosine after successful pulmonary vein isolation with the cryothermal energy balloon.

AIMS: Cryothermal energy balloon ablation (CBA), using cryogenic ablative energy, has proven very effective in producing pulmonary vein (PV) isolation in patients with paroxysmal atrial fibrillation (AF). Adenosine testing after PV isolation has demonstrated to be able to unmask incomplete lesion after radiofrequency (RF) ablation. The aim of our study was to assess the rate of transient atriovenous reconnection induced by adenosine after successful PV isolation with the CBA in a group of patients with paroxysmal AF. METHODS AND RESULTS: We prospectively enrolled 39 patients (31 male; age 59 +/- 11 years) elected to circumferential PV isolation with CBA for highly symptomatic paroxysmal AF. A total of 149 PVs were evidenced. Adenosine testing after CBA induced a left atrium-PV reconnection only in 7 (4.6%) of PV. CONCLUSION: Our study showed a low rate of transient PV reconnection after adenosine infusion following successful PV isolation with CBA. However, larger studies will be needed in order to confirm our findings and the prognostic value of adenosine testing after successful PV isolation obtained with CBA.