Preprocedural transthoracic echocardiography for predicting outcomes of transcatheter edge-to-edge repair for chronic primary mitral regurgitation

Introduction and objectives

Limited data exist on the prognostic usefulness of transthoracic echocardiography preceding MitraClip for chronic primary mitral regurgitation (MR). We evaluated the predictive ability of transthoracic echocardiography in this setting.

Methods

A total of 410 patients (median age, 83 years, 60.7% males) were included in the study. The primary outcome was the 1-year composite of all-cause mortality or heart failure hospitalization. Secondary endpoints encompassed individual elements of the primary outcome, the persistence of significant functional impairment or above-moderate MR at 1 year, and above-mild MR at 1-month.

Results

The only parameter associated with the risk of the primary outcome was a ventricular end systolic diameter index of ≥ 2.1 cm/m², corresponding to the cohort's 4th quartile (HR, 2.44; 95%CI, 1.09-4.68; P = .022). Concurrently, higher left atrial volume index (LAVi) and a mid-diastolic medial-lateral mitral annular diameter (MAD) equal to or above the cohort's median of 32.2 mm were linked to a higher probability of death and heart failure hospitalization, respectively. LAVi of ≥ 60 mL/m², above-mild mitral annular calcification, and above-moderate tricuspid regurgitation conferred higher odds of functional class III-IV or above-moderate MR persistence. All variables except LAVi and MAD, as well as indexed mid-diastolic medial-lateral MAD of ≥ 20.2 mm/m² and mitral effective regurgitant orifice area of ≥ 0.40 cm², were associated with greater-than-mild MR at 1 month.

Conclusions

Preprocedural increased indexed left heart dimensions, mainly left ventricular end-systolic diameter index, MAD, mitral annular calcification, mitral effective regurgitant orifice area, and tricuspid regurgitation mark a less favorable course post-MitraClip for chronic primary MR.