Prevalence and multiple predictors of left atrial low voltage in paroxysmal and non-paroxysmal atrial fibrillation patients undergoing ablation: a systematic review and meta-analysis

Background and Aims In the left atrium (LA), low voltage areas (LVAs) detected at electroanatomic mapping in patients with atrial fibrillation (AF) are considered expression of atrial cardiomyopathy (AtCM). This meta-analysis aims at assessing the prevalence and predictors of LVAs in a larger AF population undergoing catheter ablation. Methods Studies comparing patients undergoing LA ablation with vs. those without LVAs were included. Meta-analyses were conducted to estimate the prevalence and odds ratios (ORs) for LVAs. Results Twenty-two studies with 5,278 patients were included. LVAs were present both in paroxysmal (28%) and non-paroxysmal (41%) patients. The strongest predictors of LVA presence were: age>65 years (OR 3.41), CHA2DS2-VASc score (OR 3.29), non-paroxysmal AF (OR 3.19), NT-proBNP>365 pg/ml (OR 2.47), female sex (OR 2.40), E/e' ratio (OR 2.31), eGFR<60 ml/min/m2 (OR 2.28), and LA volume indexed>34 ml/m2 (OR 1.98). Comorbidities were also predictors but with lower ORs. In subgroup analysis, female sex (OR 3.90) was a predictor only in non-paroxysmal, while LA diameter (OR 2.51) and body mass index (BMI; OR 1.85) positively correlated only in paroxysmal AF. Meta-regression analysis showed that non-paroxysmal AF and age were independently and significantly associated with a greater reduction in BMI in patients with compared to those without LVAs. Conclusions LVAs can be present in both paroxysmal and non-paroxysmal AF, and can be predicted by multiple clinical, echocardiographic and biomarker variables. The impact of female sex, LA diameter, and BMI on LVA presence varies according to the type of AF.