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.