Background:
Although several transcatheter therapies are available for the treatment of patients with mitral regurgitation (MR), a significant proportion of patients remain ineligible for any mitral valve (MV) intervention. Medical therapy in these patients is associated with poor outcomes.
Aims:
To characterize patients ineligible for MV interventions from a large international registry using an unsupervised phenotypic clustering approach.
Methods: Between 2014 and 2022, the CHOICE-MI registry included 984 patients undergoing screening for transcatheter mitral valve replacement at 33 international sites. For this study, only patients with screening failure resulting in medical therapy alone were included. Patients receiving transcatheter or surgical treatment were excluded (Figure 1). A cluster analysis was performed on baseline clinical and imaging variables, and predictors of all-cause mortality within these clusters were assessed.
Results:
Among 284 patients (77.4±8.82 years, 56.0% female, EuroSCORE II 6.6±5.8%) considered ineligible for any MV intervention, two clinically distinct phenogroups (PG) were identified using unsupervised hierarchical clustering of principal components (Figure 2): (PG1) Elderly women with primary MR, high left ventricular (LV) ejection fraction, and annular calcification; (PG2) Patients with secondary or mixed MR, LV and annular dilation, and high prevalence of comorbidities. There were no differences regarding Kaplan-Meier estimated 1-year all-cause mortality (PG1 vs. PG2, 21.4% vs. 23.4%, p=0.89) and 1-year cardiovascular mortality (10.4% vs. 13.5%, p=0.53). Predictors of mortality were albumin, renal function, extracardiac arteriopathy for PG1, and albumin, coronary artery disease, and prior myocardial infarction for PG2.
Conclusions:
This study identified two major subgroups among patients ineligible for mitral interventions showing profound differences in clinical and anatomical profiles, and predictors of outcome. Identifying these factors may drive technological evolution to address the unmet clinical need for therapeutic options in patients with MR.
