Impact of left atrial stiffness measurement as a pre-procedural predictor of an extensive left atrial low-voltage area

Abstract Background The presence of a left atrial (LA) low-voltage area (LVA) after pulmonary vein isolation for atrial fibrillation (AF) is a strong predictor of recurrence and LVAs are often an additional ablation target. However, predicting the presence of an LVA before the procedure remains challenging. Purpose To assess the LA stiffness index as a preprocedural predictor of an extensive LVA. Methods We prospectively evaluated 74 patients who underwent catheter ablation for AF and high-density bipolar LA voltage mapping during sinus rhythm or high right atrial pacing. "LVA" was defined as an area with bipolar electrograms (<0.5 mV), while "extensive LVA" was defined as the presence of an LVA that covered more than 15% of the LA surface. Echocardiographic measurements, including the LA volume index (LAVi), E/e' ratio, LA reservoir strain (LASr), and LA stiffness index, calculated as the ratio of E/eʹ to LASr, were performed prior to catheter ablation in all patients. Results Overall, 17 patients (23.0%) had an extensive LVA. Patients with extensive LVAs were older (73 ± 7 vs. 66 ± 8 years; P=0.003), predominantly female (59% vs. 23%; P=0.01), and more frequently showed persistent AF (59% vs. 30%; P=0.04) in comparison to patients without extensive LVAs. According to a receiver operating characteristic curve analysis, the LA stiffness index was more accurate than the LAVi or LASr for predicting extensive LVAs (Figure), allowing using a cutoff value ≥0.6 with 73% sensitivity and 91% specificity. A multivariate logistic regression analysis revealed that the LA stiffness index was an independent predictor of an extensive LVA (odds ratio [OR], 44.11; 95% CI 3.83–507.47, P=0.002). Conclusion The LA stiffness index was a robust predictor of the extent of LVAs in AF patients and thus could be useful for the preprocedural selection of candidates for catheter ablation and to determine the most effective ablation strategies.