Comparison of left atrial pressure monitoring with dedicated catheter versus steerable guiding catheter during transcatheter mitral valve repair

Objective: The objective of this study was to determine the accuracy of left atrial pressure (LAP) measurement through the manufacturer provided steerable guiding catheter (SGC) during transcatheter mitral valve repair (TMVR). Background: LAP measurement during TMVR has been shown to be associated with clinical improvement when measured through a dedicated catheter. Methods: Simultaneous LAP was performed in consecutive patients using an independent fluid-filled 4F multipurpose catheter and compared to LAP waveforms measured through the manufacturer-provided MitraClip SGC during TMVR (Abbott, Santa Clara, CA). Results: Mean age of 10 consecutive subjects with primary mitral regurgitation undergoing TMVR was 83 ± 3 years (60% female). Left atrial v wave and mean pressures through the dedicated catheter were 42 ± 7 and 24 ± 3 mmHg vs. 35 ± 7 and 23 ± 3 mmHg through the SGC (P < 0.001 and P = 0.23, respectively). Mean differences in v wave and mean LAP were 8 ± 4 and 1.0 ± 2.4 mmHg (percent difference 19 and 3%), respectively. SGC waveform overdamping was observed in all cases. Conclusions: Left atrial v wave pressure measurement through a dedicated catheter with sideholes during TMVR has superior accuracy compared to the manufacturer provided SGC, which results in waveform overdamping and a significant underestimation of v wave pressure. These data have important implications for clinical practice.