Description
The measure of left atrial pressure (LAP) is an ideal marker for the clinical efficacy of transcatheter mitral valve intervention. Currently, only the invasive measurement of LAP (i-LAP) is available and no echocardiographic methods are reliable in the setting of transcatheter mitral valve intervention. This study sought to validate a new echocardiographic method for the estimation of LAP (e-LAP) by comparing it with i-LAP. During percutaneous edge-to-edge procedure with MitraClip, the i-LAP was routinely monitored. Across the iatrogenic interatrial septum defect, the flow was sampled with continuous-wave Doppler echocardiography for deriving the mean pressure gradient between the left atrium and the right atrium, and the central venous pressure was added to obtain the e-LAP. The correlation between the measures derived from these 2 methods was explored. A total of 34 consecutive patients were included. Intraclass correlation coefficient between e-LAP and i-LAP was high (intraclass correlation coefficient [95% confidence interval] 0.809 [0.625 to 0.902], R Pearson 0.6, p <0.001); a bias of -1.3 mm Hg for e-LAP versus i-LAP was found (p = 0.32). The median follow-up was 108 days (interquartile range 40 to 264). No death occurred and 6 patients were rehospitalized for heart failure. Postimplant e-LAP was correlated with rehospitalization at follow-up (hazard ratio 1.46, 95% confidence interval 1.022 to 2.1, p = 0.038). A cut-off value of 9.5 mm Hg for the e-LAP was identified as predictor of rehospitalization for heart failure. The evaluation of e-LAP has optimal reliability compared with i-LAP; a value more than 9.5 mm Hg was found to be related to higher risk of events at short follow-up.