Effect of saline administration on left atrial pressure during transcatheter mitral valve repair

Objectives: To measure the intraprocedural change in left atrial pressure (LAP) with saline administration during transcatheter mitral valve repair (TMVR). Background: TMVR with MitraClip offers an alternative to surgery in select patients. During this procedure, large volumes of fluid are routinely administered with anesthesia and to facilitate transcatheter valve repair. LAP, a measure used to guide repair, may thereby change as a result of volume expansion, suggesting a need for continuous intracardiac pressure monitoring. Methods: Consecutive patients with severe mitral regurgitation underwent TMVR with MitraClip and continuous LAP monitoring through a dedicated sampling catheter. Specific LAP values were acquired immediately after transseptal access; before first clip deployment; and after deployment of the last clip. Results: 151 patients (age 80 ± 8 years, 64% male) underwent TMVR with MitraClip and continuous LAP monitoring. Mean LAP and v-wave pressure increased significantly from baseline to pre-MitraClip deployment (P < 0.0001) and decreased significantly from deployment to procedure end (P < 0.0001). Linear regression of v-wave pressure change (from procedure start to clip deployment) relative to volume administration yielded a significantly nonzero slope (0.28 mmHg/min, P < 0.0001, r = 0.30). Conclusion: Fluid administration during TMVR leads to time-dependent increases in LAP. Such intraprocedural change underscores the need for targeted, if not continuous, LAP measurement during TMVR to optimize MitraClip placement and mitral regurgitation reduction.