The impact of baseline transmitral diastolic mean gradient on left atrial pressure reduction in patients undergoing transcatheter mitral valve edge-to-edge repair

Background: Elevated transmitral gradient post transcatheter mitral valve edge-to-edge repair (TEER) has been associated with worse outcomes. Whether an elevated baseline transmitral diastolic mean gradient (MG) ≥5 mmHg is associated with hemodynamic outcomes after TEER is unknown. Methods: A total of 164 consecutive patients undergoing TEER at Mayo Clinic between June 2014 and May 2018 were analyzed in this retrospective study. Baseline demographics, as well as clinical, echocardiographic, and procedural data were obtained. Data on direct left atrial pressure (LAP) before and after TEER were recorded. Logistic regression models were constructed to evaluate the association between preprocedure transmitral diastolic mean gradient (pre-MG) and (1) improvement in LAP following TEER, (2) postprocedure transmitral diastolic mean gradient (post-MG). A decrease in LAP post TEER was considered an improvement in hemodynamic response. Pre-MG was categorized as: ≥5 and <5 mmHg. Results: Median age of the cohort was 81.5 years (Q1: 76.3, Q3: 87) and 34% were female. At baseline, median transmitral diastolic MG was 4 mmHg (Q1: 3, Q3: 5) and median LAP was 19 mmHg (Q1:16, Q3: 23.5). In a multivariable model, adjusted for age and sex, patients with pre-MG ≥ 5 mmHg were less likely to see an improvement in LAP post TEER (adjusted odds ratio [aOR]: 0.22, 95% confidence interval [CI]: 0.09, 0.55; p = 0.001) and more likely to have elevated post-MG (aOR; 7.08, 95% CI: 2.93, 17.13; p < 0.001). Conclusion: Higher pre-MG (≥5 mmHg) was associated with a lower reduction in LAP and higher residual transmitral gradient following TEER suggesting other potential contributors to increased LAP besides mitral regurgitation as a cause of elevated baseline MG.