Left atrial remodeling and voltage-guided ablation outcome in persistent atrial fibrillation patients over 75 years of age

Abstract

Background: The prevalence of atrial fibrillation (AF) increases with age. The improvement in ablation techniques has widened the indications, particularly in elderly patients. Data on LA remodeling and low-voltage zone (LVZ) extent in this subgroup are scarce.

Objective: We assessed the left atrial (LA) bipolar voltage, LVZ extent, and efficacy of voltage-guided ablation in a cohort of patients with persistent AF according to age.

Methods: Three hundred fifty-three patients with persistent AF undergoing a first voltage-guided ablation procedure were enrolled and divided into 2 groups: those <75 years of age (n=286) and those ≥75 years of age (n=67). LA voltage maps were obtained in sinus rhythm. LVZ was defined as <0.5 mV. A propensity score-matching analysis was used to assess the impact of age on LA remodeling.

Results: The LA bipolar voltage was lower (P<.01) in elderly patients. LVZs were found in 67% of elderly patients and 30% of younger patients (P<.01), especially in mild (P<.01) and moderate (P<.01) LVZs. After propensity score matching, these differences were no longer noticeable. Pulmonary vein isolation alone was performed in 33% of elderly patients and 70% of patients <75 years of age (P<.01). Female sex (P<.001), age ≥ 75 years (P=.042), estimated glomerular filtration rate (P=.009), and LA volume index (P<.001) were predictive of LVZ presence. After 36 months of follow-up, the AF-free survival rate after a single procedure was similar between the 2 groups.

Conclusion: Patients >75 years of age with persistent AF display increased LA substrate remodeling than do younger patients. LA scar did not seem to negatively affect the results of substrate-guided ablation, and the complication rate was low.

Keywords: Atrial fibrillation; Atrial remodeling; Catheter ablation; Elderly patients; Low-voltage zones; Voltage map; Voltage-guided ablation.

Figure 1

Flowchart of the study. Of the 574 patients admitted for initial radiofrequency ablation of persistent AF between November 2017 and February 2023, 353 (62%) met the inclusion criteria. One hundred thirty-three patients (23%) had no LA voltage mapping in sinus rhythm, and 88 (15%) were excluded from the analysis because of structural heart disease. AF = atrial fibrillation; CA = cardiac amyloidosis; DCM = dilated cardiomyopathy; HCM = hypertrophic cardiomyopathy; ICM = ischemic cardiomyopathy; LA = left atrial; VHD = valvular heart disease.

Figure 2

Pie charts showing the number of regional LVZs according to age. Patients <75 years of age had significantly fewer LVZs than did those >75 years of age (199 [70%] vs 22 [33%]; P < .01). We observed that 3 atrial regions with LVZ were significantly higher in patients >75 years of age (14 [21%] vs 13 [4.6%]; P < .01). In addition, 4 atrial regions with LVZ were more present at the limit of significance in patients >75 years of age (3 [4.5%] vs 2 [0.7%]; P = .05). LVZ = low-voltage zone.

Figure 3

Kaplan-Meier survival curves showing the cumulative AF/AT recurrence-free survival rates according to age after a single procedure. AA = atrial arrhythmia; AF = atrial fibrillation; AT = atrial tachycardia.