Impact of electrophysiological and pharmacological noninducibility following pulmonary vein isolation in patients with paroxysmal and persistent atrial fibrillation

Ablation Therapy for Persistent Atrial Fibrillation

Atrial Fibrillation (AF) is the most common form of electrical disturbance of the heart and contributes to significant patient morbidity and mortality. With a better understanding of the mechanisms of atrial fibrillation and improvements in mapping and ablation technologies, ablation has become a preferred therapy for patients with symptomatic AF. Pulmonary Vein Isolation (PVI) is the cornerstone for AF ablation therapy, but particularly in patients with AF occurring for longer than 7 days (persistent AF), identifying clinically significant nonpulmonary vein targets and achieving durability of ablation lesions remains an important challenge.

A novel and simple scoring system for assessing the indication for catheter ablation in patients with atrial fibrillation: The HEAL-AF Score

INTRODUCTION

A scoring system to determine indications for catheter ablation (CA) in atrial fibrillation (AF) is desired.

METHODS AND RESULTS

Among 2898 consecutive patients with AF, CA was performed in 938 (32.4%). A new HEAL-AF score has been developed by six variables, all of which were independently associated with CA by multivariate analysis and for each 1 point was assigned: heart failure ≥ NYHA II, elderly patients (age ≥75 years), asymptomatic AF, long-standing persistent AF, atrial dilation (left atrial diameter ≥ 50 mm), and female sex. Low HEAL-AF score was associated with high incidence of CA performance (52.0% for 0, 36.5% for 1, 15.1% for 2, and 5.6% for ≥ 3) and the predictive capability of this score by AUC of ROC curve was 0.720 (95% CI 0.701-0.739, P < .001). The rates of freedom from AF/AT recurrence were 73.2% in HEAL-AF score 0, 71.0% in 1, 60.0% in 2, and 50.0% in ≥ 3 (log-rank test, P = .004). HEAL-AF score 2 and ≥ 3 were significantly associated with recurrence of atrial tachyarrhythmia as compared with HEAL-AF 0 (HR 1.755, P = .002, and HR 2.211, P = .007, respectively).

CONCLUSIONS

A new HEAL-AF score was associated with patient indication for and the recurrence of atrial tachyarrhythmia after CA in patients with AF. Prescription of CA should be considered carefully in AF patients with HEAL-AF score of 2 and ≥ 3.

Is Atrial Fibrillation Noninducibility by Burst Pacing After Catheter Ablation Associated With Reduced Clinical Recurrence?: A Systematic Review and Meta-Analysis

Background

To date, there is no cumulative evidence supporting the association of atrial fibrillation (AF) noninducibility after ablation and freedom from AF. We performed a systematic review and meta‐analysis to determine whether AF noninducibility by burst pacing after catheter ablation is associated with reduced AF recurrence.

Methods and Results

We searched PubMed, Embase, Web of Science, and Cochrane Library databases through July 2019 to identify studies that evaluated AF noninducibility versus inducibility by burst pacing after catheter ablation for freedom from AF. A fixed effects model was used to estimate relative risk (RR) with 95% CIs. Twelve prospective cohort studies with AF noninducibility (n=1612) and inducibility (n=1160) were included. Compared with AF inducibility, AF noninducibility by burst pacing after ablation was associated with a reduced risk of AF recurrence (RR, 0.68; 95% CI, 0.60–0.77). Subgroup analysis showed that different AF types (paroxysmal AF and nonparoxysmal AF), different follow‐up times (≤6, 6–12, and >12 months), and different degrees of burst pacing (mild, moderate, severe) had no significant impact on the RRs. However, different cut‐off times for AF inducibility had a significant impact on the RR (P_interaction=0.009), and only the cut‐off time of 1 minute showed a significant correlation (RR, 0.54; 95% CI, 0.45–0.66).

Conclusions

AF noninducibility by burst pacing after catheter ablation is associated with reduced clinical recurrence of AF. Induction protocols with a different cut‐off time for AF inducibility have a significant impact on the correlation, and the AF ≥1 minute for AF inducibility is recommended.

Role of inducibility and its dynamic change in the outcome of catheter ablation of atrial fibrillation: a single center prospective study

BACKGROUND

The role of atrial arrhythmia inducibility as an endpoint of catheter ablation of atrial fibrillation (AF) has been a controversial subject in many studies. Our goal is to evaluate the significance of inducibility, the impact of multiple sites or protocols of stimulation or the change in inducibility status in a prospective study including patients with AF undergoing first catheter ablation.

METHODS

We studied 170 consecutive patients with AF (62.9% paroxysmal) undergoing catheter ablation. All patients underwent two separate stimulation protocols before and after the ablation from the coronary sinus ostium and the left atrial appendage: burst pacing at 300, 250, 200 milliseconds (or until refractoriness) for 10 seconds and ramp decrementing from 300 to 200 milliseconds in increments of 10 milliseconds every three beats for 10 seconds. Inducibility was defined as any sustained AF or organized atrial tachycardia (AT) lasting >30 seconds.

RESULTS

We had AF/AT inducibility in 55 patients at baseline compared to 36 following ablation. After a mean of 41, 3 months follow-up, 115 patients were free of AF. Inducibility before or after the ablation or change in inducibility status did not influence AF recurrence. There were no significant differences regarding paroxysmal or persistent patients with AF.

CONCLUSIONS

Non-inducibility of atrial arrhythmia or change in inducibility status following pulmonary vein (PV) isolation and substrate modification are not associated with long-term freedom from recurrent arrhythmia. Therefore, the use of induction of an endpoint in AF ablation is limited.