Extracellular volume fraction measured by computed tomography predicts improvement in cardiac function after catheter ablation for atrial fibrillation
Y Yamada, M Konishi, S Kato, J Hosoda, Y Taguchi, K Fukui, Y Kine, Y Kimura, K Tsutsumi, H Kondo, S Kodama, S Ishii, A Horigome, K HibiAbstract
Background
Heart failure (HF) is one of the important events in patients with atrial fibrillation (AF). However, the prognostic and diagnostic significance of computed tomography (CT)-derived left ventricular extracellular volume fraction (ECV), which reflects diffuse left ventricular fibrosis, remains unclear.
Purpose
To evaluate whether ECV is associated with surrogate markers of HF (B-type natriuretic peptide (BNP), left atrial volume index, and tissue Doppler-derived E/e’ ratio) and whether it predicts post-ablation improvement in left ventricular ejection fraction (LVEF) in patients with AF.
Methods
We conducted a cohort study, including 423 consecutive patients (median age: 73 years; 70% male; 53% with paroxysmal AF; mean LVEF: 59 ± 11%) scheduled for catheter ablation. Left ventricular ECV was measured using routine contrast-enhanced CT.
Results
The mean ECV was 29.1 ± 5.9%, and baseline BNP levels were 90.7 [40.1–174.4] pg/mL. High ECV, defined as > 35%, was observed in 15% of patients. ECV was significantly associated with log-transformed BNP, left atrial volume index, and E/e’ ratio (r = 0.463, p < 0.001; r = 0.324, p < 0.001; and r = 0.255, p < 0.001, respectively; Figure). Multivariable logistic regression analysis revealed that ECV was independently associated with BNP > 100 pg/mL after adjustment for age, sex, AF phenotype, and LVEF (odds ratio = 1.14, 95% CI: 1.09–1.20 per 1% increase in ECV, p < 0.001). Furthermore, in a subgroup of 32 patients with non-ischemic dilated cardiomyopathy (LVEF < 50%), LVEF improved from 37.4 ± 7.6% to 55.8 ± 11.9% at 6 months after ablation (ΔLVEF: 18.4 ± 11.7%). A significant inverse correlation was observed between ECV and ΔLVEF (r = -0.561, p < 0.001; Figure).
Conclusions
CT-derived left ventricular ECV was feasible to measure, correlated with established markers of heart failure, and predicted improvement in LVEF after catheter ablation.Figure