Introduction:
Previous cardiac MRI studies reported that the baseline diffuse LV fibrosis status should be evaluated before performing catheter ablation (CA) to identify the responders early and triage them with appropriate treatment. However, no study has been conducted to evaluate diffuse LV fibrosis in conjunction with pre-ablation planning cardiac CT.
Objectives:
The purpose of this study was to quantify diffuse left ventricular (LV) fibrosis by the CT-derived extracellular volume fraction (CT-ECV%) in conjunction with cardiac CT performed for CA planning and evaluate its determinants in patients with atrial fibrillation (AF).
Methods:
Prior to AF ablation, 98 patients (50 patients with paroxysmal AF and 48 patients with persistent AF) underwent pre-ablation planning cardiac CT. Additionally, delayed cardiac CT was performed to measure CT-ECV% as an index of diffuse myocardial fibrosis.
Results:
Persistent AF patients more frequently had a history of heart failure. Left atrial (LA) volume index was greater in persistent AF patients compared with paroxysmal AF patients. CT-ECV% of persistent AF patients was significantly higher than that of paroxysmal AF patients (30 ± 5 % vs. 26 ± 5 %, p < 0.001). Univariate and multivariate analysis revealed that only persistent AF was independent associated with CT-ECV%. Furthermore, CT-ECV% in recurrence group after CA for AF was higher than that in non-recurrence group (29 ± 4 % vs. 26 ± 5 %, p = 0.013). Multivariate logistic regression analysis revealed that CT-ECV% was significantly correlated with AF recurrence after CA for AF. Receiver operating characteristic analysis showed that more than 28 % in the CT-ECV% was a significant predictor of AF recurrence (area under the curve 0.692, log-rank test: p < 0.001).
Conclusions:
The quantification of diffuse LV fibrosis by CT-ECV% in conjunction with pre-ablation planning cardiac CT is feasible in AF patients, and persistent AF is independently associated with increasing diffuse LV fibrosis. Furthermore, CT-ECV% was significantly associated with AF recurrence after CA for AF. These findings suggested that it was more important to evaluate cardiac remodeling using CT and intervene early in AF.
Synthetic Extracellular Volume Fraction Derived Using Virtual Unenhanced Attenuation of Blood on Dual-Energy Contrast-Enhanced Cardiac CT in Nonischemic Cardiomyopathy
