Cardiovascular magnetic resonance imaging for accurate sizing of the left atrium: predictability of pulmonary vein isolation success in patients with atrial fibrillation

Purpose

To prospectively determine the most reproducible approach for left‐atrial size assessment using cardiovascular magnetic resonance (CMR) imaging in patients with atrial fibrillation and its value for prediction of pulmonary vein isolation (PVI) treatment success.

Materials and Methods

Eighty patients underwent CMR imaging prior to PVI; the CMR examination included standard cine sequences, a multislice cine sequence in 4‐chamber orientation with full left‐atrial coverage, and a contrast‐enhanced MR angiography of the left atrium. Left‐atrial size was determined as: diameter, area, volume segmented from angiography, and diastolic/systolic volumes from cine imaging (Simpson's rule). All measurements were carried out by two independent observers and repeated by one observer to assess inter‐ and intrareader variability. Treatment success was defined as persisting sinus rhythm after PVI (follow‐up period 12.6 ± 6.6 months).

Results

All left‐atrial measurements showed substantial intrareader agreement. Interreader agreement was substantial for diastolic/systolic left‐atrial volumes only. Calculated bias was found to be minimal (0.1%–4.9%). Predictability of PVI treatment success was best using cine volumetric measurements (cutoff value for diastolic volume, 112 mL) yielding a sensitivity and specificity of 80% and 70%, respectively.

Conclusion

Left‐atrial volumetry based on cine imaging represented the most reproducible approach to determine left‐atrial size. PVI success was predicted best using cine volumetry. J. Magn. Reson. Imaging 2011;33:455–463. © 2011 Wiley‐Liss, Inc.