Background and Aims

Intraprocedural assessment of residual mitral regurgitation (MR) is crucial for the success of transcatheter edge-to-edge mitral valve repair (M-TEER), yet challenging in the case of ambiguous echocardiographic findings. Monitoring left atrial (LA) pressure can complement the evaluation of residual MR after device placement. This study aimed to determine the prognostic impact of intraprocedural changes in LA pressure on the clinical outcome following M-TEER.
Methods

We enrolled 299 patients undergoing M-TEER for primary or secondary MR in a prospective observational study. During the procedure, LA mean (LAmP) and LA v wave pressure (LAvP) were recorded before and after device implantation. The primary endpoint was death or hospitalization for heart failure during a 2-year follow-up.
Results

Mean age of the study population was 76.6 ± 8.2 years. Secondary mitral regurgitation was identified in 62.9% of the patients. Reduction to MR grade I or II was achieved in 95.3% of cases. During M-TEER, LAvP decreased from 30.5 ± 15.0 to 23.2 ± 10.4 mmHg (P < .001) after device implantation, accompanied by a modest reduction of LAmP from 16.6 ± 6.3 to 15.3 ± 5.9 mmHg (P = .006). LAvP post M-TEER was a strong predictor of death or hospitalization for heart failure in both univariate and multivariate analysis, independent of echocardiographic MR severity (hazard ratio per 10 mmHg 1.37 [1.15–1.63], P < .001 and 1.29 [1.06–1.57], P = .012). Residual LAvP below 25 mmHg was strongly associated with a favourable outcome irrespective of residual echocardiographic MR grade, including patients with residual MR grade I and II.
Conclusion

High residual LAvP predicts death or hospitalization for heart failure after M-TEER. LAvP after device implantation provides incremental prognostic information beyond echocardiographic MR grading and may therefore assist intraprocedural decision-making during M-TEER.