Clinical value of assessment of left atrial late gadolinium enhancement in patients undergoing ablation of atrial fibrillation.

BACKGROUND: Left atrial (LA) fibrosis begets atrial fibrillation (AF). Cardiovascular magnetic resonance (CMR) using the late gadolinium enhancement (LGE) technique might visualize the LA fibrosis and thus help to choose an appropriate strategy for treatment of AF. In this regard, we investigated whether the extent of preablation LA LGE would predict AF recurrence after ablation in a non-selected patient population. METHODS: CMR was performed in 95 patients before radiofrequency ablation of AF. An interpretable scan was available in 73 patients (age, 59 ± 8 years; men, 71%; persistent/paroxysmal AF, 55/45%). The extent of LA LGE was quantified by three established thresholding techniques. In addition, CMR was used to quantify LA volume and reservoir function. The patients were followed for AF recurrence for 1.3 ± 0.8 years. RESULTS: The arrhythmia recurred in 29 (40%) of the patients. The extent of LA LGE did not differ between paroxysmal and persistent AF and it did not predict the AF recurrence. Moreover, the extent of LA LGE did not correlate with LA volume, reservoir function and bipolar voltage. CONCLUSIONS: Our data indicate a limited value of a routine assessment of LA LGE before ablation of AF. Further experimental and clinical researches should be done before applying the method to a wide clinical practice.

A novel biomarker-based approach for the detection of asymptomatic brain injury during catheter ablation of atrial fibrillation.

BACKGROUND: Diffusion-weighted magnetic resonance imaging (DW-MRI) is a widely used method for studying of asymptomatic brain injury during catheter ablation of atrial fibrillation (AF). However, this technique lacks sensitivity for subtle or diffuse brain lesions. We investigated whether detection of the ablation-related brain injury can improve by assessment of a biomarker of brain damage-protein S100B. METHODS AND RESULTS: DW-MRI and assessment of S100B were performed in 58 patients undergoing radiofrequency catheter ablation of paroxysmal or persistent AF 1 day before and after the procedure. We observed no symptomatic neurological complications. S100B levels increased after ablation above the upper reference limit of 105 ng/L in 3 patients. One of them developed a new ischemic lesion on the DW-MRI. No acute lesions emerged on DW-MRI in the patients with normal postablation S100B levels. CONCLUSION: Serial assessment of serum protein S100B may improve detection of asymptomatic acute brain injury in patients undergoing radiofrequency catheter ablation of AF. In our study, the incidence of these events was 1.7% when evaluated only by DW-MRI, but the incidence increased to 5% after employing the more sensitive biomarker-based approach.