Arrhythmia-induced versus arrhythmia-superimposed cardiomyopathy: outcome in patients with atrial fibrillation and heart failure undergoing cryoballoon pulmonary vein isolation
Authors: Yogarajah J , Hutter J , Kahle P , Berkowitsch A , Tomic M , Hain A , Sperzel J , Sossalla S , Kuniss M , Neumann T 
Published: May 2024

Abstract

Introduction
The outcome in patients with arrhythmia-induced cardiomyopathy (AIC) compared with that in patients with arrhythmia-mediated/superimposed cardiomyopathy (AMC) undergoing cryoballoon pulmonary vein isolation (cryo-PVI) is also poorly defined.

Methods
In this retrospective observational study, we analysed patients with AF and reduced left ventricular ejection fraction (LVEF &lt; 50%) who underwent cryoballoon ablation between 2014 and 2020. Patients with LVSD were divided into AIC and AMC. AIC was diagnosed ex juvantibus during first year after ablation at 3- and 12-month follow-up when LVEF recovered to &gt; 50% and by more than 10% after ablation and a different aetiology for reduced LVEF was excluded. AMC was diagnosed when structural heart disease was responsible for LVSD and AF had likely exacerbated pre-existing LVSD. For identification of independent predictors of LVEF non-improvement after ablation, univariate and multivariate logistic regression analyses were performed. LVEF non-improvement was defined when LVEF neither increased by more than 10% nor increased over absolute 50% at 12-month follow-up. The first documented &gt; 30-s atrial arrhythmia recurrence after a 3-month blanking period during the one-year follow-up was compared by Kaplan-Meier analysis.

Results
Out of 1293 consecutive patients who underwent cryoballoon ablation, 113 AF patients with reduced LVEF (&lt;50%) were identified. After 1-year follow-up these patients were divided into AIC (N= 77) and AMC (N = 36) groups. The prevalence of persistent AF was comparable in both groups (85.7% vs. 77.8 %, p = 0.435). LVEF, left atrial (LA) enlargement, and left ventricular end diastolic diameter (LVEDD) were similar between the groups. After one year, the median LVEF improved significantly in the AIC group from 42% (IQR: 35-45%) to 60% (IQR: 58-63%; p &lt; 0.0001) and in the AMC group from 42% (IQR: 33-45%) to 47.5% (IQR= 43-53%; p=0.015). At follow-up LVEF was significantly higher in the AIC than in the AMC cohort (p &lt; 0,001). After univariate and multivariate analysis, the following parameters were associated with non-LVEF improvement: LVEDD (OR = 1.12, p = 0.012) and atrial arrhythmia recurrence (OR = 5.87, p = 0.031; Figure 1). In the AIC group LA area decreased from 25.6 cm2 (IQR: 22.4-29.5 cm2) to 21.8 cm2 (IQR: 18.3-25.2 cm2; p = 0.012). In AMC patients LA enlargement did not change with respect to baseline.
Kaplan-Meier curves demonstrated no difference in recurrence-free survival rate between the groups during the 12-month follow-up (75.3% vs. 75%, log-rank P = 0.89; Figure 2).

Conclusions
LVEDD and arrhythmia recurrence were identified as predictors of non-LVEF improvement after cryo-PVI. The LVEF increased in both groups after ablation, but in AIC group more than in AMC group. In the AIC group LA atrial area decreased compared to the AMC group. Atrial arrhythmia recurrence rates were comparable between AIC and AMC groups after 12 months.Figure 1Figure 2