Impact of sex on short term in-hospital outcomes with transcatheter edge-to-edge mitral valve repair

Abstract

Background and aim of the study

Transcatheter edge-to-edge mitral valve repair with the mitraclip device for treatment of severe mitral regurgitation has been shown to be an effective treatment. However, the impact of sex on in-hospital outcomes has not been studied on a large scale with “real-world” patients. The aim of this study was to assess for disparities of sex in patients treated with mitraclip.

Materials and methods

Data from the National Inpatient Sample (NIS) (2012 through 2014) using the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) procedure code 35.97 for transcatheter mitral valve repair was analyzed for this study. SAS 9.4 (SAS institute, Cary, NC) was used for univariate and multivariate analysis. Multivariate analysis was used to adjust for various confounders.

Results

A total of 521 patients were identified that were treated with MitraClip, with 57.97% males (n = 302) and 42.03% females (n = 219). There was no significant difference in the primary outcome, in-hospital mortality between two sex [2.6% vs. 3.6%, p = 0.43, Odds Ratio 1.62 (95% Confidence Interval, 0.50–5.28)]. After performing multivariate analysis, no difference in any secondary outcomes existed. Additionally, length of stay and median hospitalization cost was similar regardless of sex.

Conclusions

Analysis of this large database of patients undergoing treatment with MitraClip suggests that MitraClip in females is not associated with increased in-hospital mortality, morbidity, length of stay or cost. A prospective registry with excluded patients from the clinical trials needed to be fully access if sex disparities in patients being treated with MitraClip exist.

Introduction

Mitral valve regurgitation (MR) is a common valvular condition, present in adults affecting > 2 million people in the United States [1], [2], [3]. Patients with mild-moderate MR are followed with close surveillance while severe MR often requires repair or replacement [4]. Traditionally, surgical valve repair or replacement has been the standard of care. More recently, percutaneous valve repair with MitraClip® has become an alternative treatment option. To date, surgery has been shown to have more favorable outcomes as compared to a percutaneous approach [5]. An increasing number of patients however are not surgical candidates. The Euro Heart Survey showed that half of the patients eligible for surgery by the ACC guidelines did not have surgery due to high risk for peri-operative complications [6]. The mortality risk with surgery in high risk patients can be as high as 25% [7], [8]. Those patients who are at high-risk for surgery may benefit from treatment with a percutaneous approach.

Surgical literature suggested sex disparities in patients undergoing surgery for mitral valve disease [9]. Women are less likely to be referred for surgery than men and present later in the disease process [9], [10]. At the time of surgery, females have more advanced disease and often present with greater comorbidities than their male counterparts [11]. Females have worse short and long-term post-operative survival compared with males [12]. MitraClip (Abbott Vascular, Santa Clara, CA) has emerged as a novel treatment option for MR. MitraClip is the only percutaneous technology currently approved by the US Food and Drug Administration for mitral valve repair.

There is limited data assessing for sex disparities with in-hospital outcomes, length of stay and cost in patients undergoing treatment with MitraClip in the United States. To date, these studies have had small patient populations and most studies were conducted in Europe [13], [14], [15], [16]. We sought to compare outcomes by sex in patients undergoing MitraClip from a large, US database.