Candidacy For Transcatheter Edge-to-edge Mitral Valve Repair Despite Low Cardiac Index A Single Center Experience

Abstract

<h3>Introduction</h3> Transcatheter edge to edge repair (TEER) of the mitral valve with the MitraClip system has been shown to improve outcomes in patients with moderate to severe mitral regurgitation (MR). There is a lack of outcome data regarding the impact of MitraClip in recipients who have low cardiac index (CI), defined as those with a CI < 2.0 L/min/m2. The aim of this study was to compare pre-procedural clinical variables and post-procedural outcomes in patients with low and normal CI pre-intervention who underwent TEER of the mitral valve. <h3>Methods</h3> A retrospective analysis was performed utilizing our institutional database of TEER patients which included 181 adults with 3+ or greater MR from 2014-2020. Patients without right heart catheterization (RHC) prior to TEER were excluded. Cardiac output was measured using the indirect Fick method. Analysis was performed with T-test and Fisher's exact test. <h3>Results</h3> 105 patients had a pre TEER RHC, of which 35 patients had low cardiac index (group 1) and 70 patients who had normal cardiac index (group 2). Group 1 had a higher incidence of diabetes mellitus although was similar to group 2 in incidence of prior myocardial infarction (Table 1). Left ventricular ejection fraction was not significantly different between the groups. Both pulmonary capillary wedge pressure and mean pulmonary artery pressures were significantly elevated in group 1 as compared to group 2. The two groups did not have statistically different ICU durations or length of stay (Table 2). Symptom burden difference from baseline as measured by the KCCQ 12 was similar at 30 days. The percentage of patients with moderate MR or better at 30 days was similar between groups. Death on index post procedural hospitalization and in follow up was not statistically different. <h3>Conclusion</h3> A cohort of patients with low cardiac index that underwent TEER of the mitral valve did not demonstrate worse short or intermediate-term outcomes when compared to those with a normal cardiac index pre-procedure. This study may suggest a role for mitral valve TEER in carefully selected patients with cardiogenic shock or on inotropic therapy, who are not optimal candidates for other advanced heart failure therapies. Additional prospective data is required to support these findings.