Diagnostic Accuracy of Cardiac Magnetic Resonance Imaging in the Detection and Characterization of Left Atrial Catheter Ablation Lesions: A Multicenter Experience

<jats:p><jats:bold>MRI Detection of Left Atrial Ablation Lesions</jats:bold>. <jats:bold><jats:italic>Introduction:</jats:italic></jats:bold> We tested the hypothesis that cardiovascular magnetic resonance (CMR) imaging can reliably distinguish the presence or absence of left atrial (LA) ablation lesions by blinded analysis of pre‐ and postablation imaging.</jats:p><jats:p><jats:bold> <jats:italic>Methods:</jats:italic> </jats:bold> Consecutive patients at 2 centers undergoing pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation by either wide area circumferential radiofrequency ablation (WACA) or ostial ablation with a cryoballoon underwent CMR late gadolinium enhancement (LGE) imaging pre‐ and 3 months postablation. Imaging was anonymized for blinded analysis of (1) LGE images, and (2) a 3D fusion image with LGE projected onto a segmented LA surface. Scans were categorized using both assessment techniques separately as pre‐ or postablation, and if postablation, whether lesions were in an ostial or WACA distribution.</jats:p><jats:p><jats:bold> <jats:italic>Results:</jats:italic> </jats:bold> LGE imaging was performed in 50 patients (aged 60 ± 10 years, 68% male, 24 underwent WACA and 26 had cryoablation). Sensitivity and specificity for detection of ablation lesions was 60% and 96% on LGE imaging. Sensitivity was higher using 3D fusion imaging (88%; P = 0.003). The proportion in whom lesions were both detected and the distribution correctly assessed as WACA or ostial was higher with 3D fusion imaging compared to LGE imaging (54% vs 28%; P = 0.014). There was no difference in the detection of radiofrequency ablation lesions compared to cryoablation lesions (58% vs 62%; P = 1.000).</jats:p><jats:p><jats:bold> <jats:italic>Conclusion:</jats:italic> </jats:bold> LGE imaging of atrial scar is not yet sufficiently accurate to reliably identify ablation lesions or to determine lesion distribution. <jats:italic>(J Cardiovasc Electrophysiol, Vol. 24, pp. 396‐403, April 2013)</jats:italic></jats:p>