Poor Agreement Between Intraoperative Transesophageal Echocardiography and Postoperative Transthoracic Echocardiography for Transmitral Mean Pressure Gradient After Mitral Valve Repair

OBJECTIVES To assess the agreement between intraoperative post-repair transmitral mean pressure gradient (TMPG) on transesophageal echocardiography (TEE) and postoperative TMPG on transthoracic echocardiography (TTE) after mitral valve repair, as well as the agreement between preoperative TTE TMPG and intraoperative post-repair TMPG on TEE. DESIGN A retrospective observational study. SETTING A single tertiary academic medical center. PARTICIPANTS Adult patients undergoing mitral valve repair. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS A total of 395 patients were included, with 206 in the final analysis; the median age was 64 years (interquartile range, 55-70 years), and 64% of patients were male. The average body mass index was 26.9 ± 4.7. Posterior mitral valve pathology was present in 196 patients, while 68 had anterior mitral valve pathology and 58 had both anterior and posterior valve pathology. The intraclass correlation coefficient (ICC) between the post-repair intraoperative mean gradient and the postoperative mean gradient was 0.25 (p = 0.02). The ICC between the preoperative mean pressure gradient and the post-repair pressure gradient was 0.79 (p < 0.001). Spearman correlation analysis between intraoperative post-repair TMPG and postoperative TMPG showed a correlation of 0.15 (95% confidence interval [CI], 0.02 to 0.28; p = 0.03). Bland-Altman analysis of post-repair and postoperative TMPGs showed a mean difference of -0.19 (95% CI, -0.38 to 0.00), with upper and lower limits of agreement of 2.5 (95% CI, 2.2 to 2.9) and -2.9 (95% CI, -3.2 to -2.6), respectively. Spearman correlation analysis between the preoperative mean TMPG and the intraoperative pre-repair mean TMPG showed a correlation coefficient of 0.62 (95% CI, 0.43 to 0.75; p < 0.001). Bland-Altman analysis of preoperative and pre-repair TMPGs revealed a mean difference of 0.46 (95% CI, 0.23 to 0.68), with upper and lower limits of agreement of -1.32 (95% CI, -1.7 to -0.9) and 2.24 (95% CI, 1.8 to 2.6), respectively. CONCLUSIONS This study demonstrates that intraoperative post-repair TMPG has poor agreement with immediate postoperative TMPG while showing moderate agreement between preoperative and post-repair gradients. These findings challenge the reliance on intraoperative TMPG cutoffs and highlight the importance of postoperative echocardiographic follow-up.