Finding the Unknown: Decrease in Left Atrial Appendage Velocity as a Surrogate Marker of Successful MitraClip Implantation in Patients With and Without Atrial Fibrillation
Jain T, Wang D, Gorgis S, Lemor A, Villablanca P, Isley M, Lee J, Zweig B, Parikh S, Frisoli TM, Eng M, Nemeh H, O'Neill W. Finding the Unknown: Decrease in Left Atrial Appendage Velocity as a Surrogate Marker of Successful MitraClip Implantation in Patients With and Without Atrial Fibrillation. JACC Cardiovasc Interv 2019; 12(4):S58.
JACC Cardiovasc Interv
Background: Percutaneous mitral valve repair with mitral clip is an established treatment for patients with severe mitral regurgitation who are prohibitive or high-risk for surgery. Transesophageal echocardiogram (TEE) plays an integral role in the planning of a successful procedure. Left atrial appendage (LAA) velocity is a marker of LAA function with low velocity associated with elevated risk of stroke. However, there are no data about the impact of MitraClip procedure on the LAA function and velocity. We sought to assess the utility of post mitral clip implantation LAA velocity as assessed by intra-procedural TEE in patients with and without atrial fibrillation (AF). Methods: We evaluated a total of 71 patients with severe mitral regurgitation (MR) who were poor surgical candidates for mitral valve surgery and thus underwent mitral clip procedure between July 2015 to October 2017 after patients with missing data were excluded. Baseline demographics and intra-procedure TEE data were obtained, and patients were followed for 30-day clinical outcomes. MR severity was graded as (1=mild, 2=moderate, 3=moderate-severe, 4=severe). Results: Among the 71 patients, 64% were females, and the mean age at the time of procedure was 77.6 years. The mean Society of Thoracic Surgeons mortality risk score was 9.8%. 40 (56%) patients had pre-existing AF with mean CHA2DS2-VASc score of 5.6. There was a significant decrease in post-procedure LAA velocity in the overall cohort (38.9 ± 17.3 vs 27.4 ± 12.4 cm/sec, p = 0.001) as well as in patients with and without AF. Post-procedure LAA velocity was lower in patients with AF compared to patients without AF (23.2 ± 11.4 vs 33.4 ± 11.5 cm/sec, p = 0.001). All patients had pre-existing grade 4 MR which was reduced to grade 1 in 57/71 (80%) and grade 2 in 9/71 (12.6%) patients after the procedure. 30-day mortality was 9.8% (7/71) out of which 6 were in-hospital deaths. 56/71 (78.8%) patients were discharged home, and 9/71 (12.6%) were discharged to nursing home facility. At 30-day follow-up, 1 patient with AF had a stroke compared to none in non-AF patients (p = 1). Conclusion: Successful reduction of mitral regurgitation in MitraClip procedures was associated with a significant decrease in post-procedure LAA velocity both in AF and non-AF patients, which in turn was not associated with an increased risk of stroke. In the setting of mitral regurgitation, post-procedure LAA velocity may serve as a surrogate marker of successful transcatheter mitral interventions.