MRI as a Promising Planning Modality Alternative
Dallan et al. describe a unique series utilizing cardiac magnetic resonance imaging (CMR) as a strategy for LAAO procedural planning [8]. The authors should be commended for developing a novel strategy for effective procedural planning in the face of unique circumstances limiting the availability of iodinated contrast and, therefore, the availability of CT. The series is well described, and 100% of patients had successful implantation, demonstrating the technical feasibility of the modality. All patients were discharged the same day following implantation. Notably, there were no immediate procedural complications or adverse events at three months post-implant. The authors appropriately acknowledge the limitations of a small series at a high-volume center with experienced proceduralists. These data suggest that CMR may be an effective alternative to current imaging modalities for LAAO procedural planning with more investigation.
As with any novel series, potential challenges should be anticipated. While CMR has become more available in recent years, many centers worldwide do not have same-day access nor the radiology support required to utilize CMR as a routine, same-day procedural planning modality. CMR is typically considerably more expensive than a CT or TEE, limiting widespread adoption. Further, in 2 cases (20%), LAA size was overestimated, and a smaller device had to be exchanged based on angiography sizing. This is considerably higher than more extensive series utilizing CT [7] and could increase the average number of devices per procedure and cost. While no LAA thrombi were described in this report, and it stands to reason that CMR should be able to evaluate for thrombus effectively, this would need to be further investigated in a more extensive series.