Evaluation of Expanded Mitral Regurgitation Grading in Patients Undergoing Transcatheter Edge-to-Edge Repair

An expanded tricuspid regurgitation scale has been shown to be incrementally useful in understanding the response to transcatheter therapies. A similar approach to mitral regurgitation (MR) has not been evaluated. The purpose of this study was to investigate how an expanded MR grading system that includes categories of massive and torrential would regrade patients undergoing transcatheter edge-to-edge repair (TEER) for MR and evaluate procedural outcomes.

We retrospectively identified 142 consecutive patients with severe MR who underwent TEER. Transesophageal echocardiography was used to assess the quantitative severity of MR and reclassify regurgitation into severe, massive, and torrential grades. Similarly, residual MR was assessed postprocedurally.

In the expanded scale, 59% of patients were regraded as severe, 23% as massive, and 18% as torrential, with respective median effective regurgitant orifice area (cm²) of 0.45 [0.39, 0.50], 0.68 [0.65, 0.75], and 0.95 [0.85, 1.20]. Ninety-three percent of the entire cohort and 93% of severe, 94% of massive, and 96% of torrential patients, achieved moderate or less MR post-TEER (p = 0.850) with corresponding improvements in New York Heart Association Functional Classification and 12-item Kansas City Cardiomyopathy Questionnaire scores.

An expanded grading system demonstrated that patients with massive and torrential MR still achieve adequate procedural success with reduction in regurgitation and improvement in health status. Further evaluation of how an expanded MR grading scale may be useful is warranted.