# Moderate Ischemic Mitral Regurgitation with Ejection Fraction <40% Undergoing Concomitant Mitral Valve Repair during Revascularization: A Single-Center Observational Study

## TL;DR

This study found that patients with moderate ischemic mitral regurgitation and low heart function had similar surgical and midterm outcomes to those with better heart function, though they required more prolonged ventilation.

## Contribution

The study provides new insights into the surgical outcomes of patients with moderate ischemic mitral regurgitation and depressed left ventricular function.

## Key findings

- Patients with EF <40% had similar surgical mortality to those with EF ≥40%.
- EF <40% was independently associated with prolonged ventilation.
- Midterm survival was not significantly different between the two groups.

## Abstract

Numerous studies have examined the
therapeutic effects of mitral valve repair during revascularization on moderate
ischemic mitral regurgitation (IMR), as well as the incremental benefit of
subvalvular repair alongside an annuloplasty ring. However, the impact of
depressed left ventricular (LV) function on the surgical outcome of patients with
moderate IMR has been rarely investigated. The aims of this single-center,
retrospective, observational study were firstly to evaluate short- and
medium-term outcomes in this patient group after undergoing mitral valve repair
during revascularization, and secondly to assess the impact of depressed LV
function on surgical outcomes.

A total of 272 eligible patients
who had moderate IMR and underwent concomitant mitral valve repair and
revascularization from January 2010 to December 2017 were included in the study.
These patients were categorized into different groups based on their ejection
fraction (EF) levels: an EF <40% group (n = 90) and an EF ≥40% group
(n = 182). The median time course of follow-up was 42 months and the shortest
follow-up time was 30 months. This study compared in-hospital outcomes (major
postoperative morbidity and surgical mortality) as well as midterm outcomes
(moderate or more mitral regurgitation, all-cause mortality, and reoperation) of
the two groups before and after propensity score (PS) matching (1:1).

No significant difference was observed in surgical mortality
between groups (8.9% vs. 3.3%, p = 0.076). More patients in
the EF <40% group developed low cardiac output (8.9% vs. 2.7%,
p = 0.034) and prolonged ventilation (13.3% vs. 5.5%,
p = 0.026) compared to the EF ≥40% group. Propensity score (PS)
matching successfully established 82 patient pairs in a 1:1 ratio. No
significance was discovered between the matched cohorts in terms of major
postoperative morbidity and surgical mortality, except for prolonged ventilation.
Conditional mixed-effects logistic regression analysis revealed that EF <40%
had an independent impact on prolonged ventilation (odds ratio (OR) = 2.814, 95%
CI 1.321–6.151, p = 0.031), but was not an independent risk factor for
surgical mortality (OR = 2.967, 95% CI 0.712–7.245, p = 0.138) or
other major postoperative morbidity. Furthermore, the two groups showed similar
cumulative survival before (log-rank p = 0.278) and after (stratified
log-rank p = 0.832) PS matching. Cox regression analysis
suggested that EF <40% was not related to mortality compared with EF
≥40% (PS-adjusted hazard ratio (HR) = 1.151, 95% CI 0.763–1.952,
p = 0.281).

Patients with moderate IMR and EF
<40% shared similar midterm outcomes and surgical mortality to patients with
moderate IMR and EF ≥40%, but received prolonged ventilation more often.
Depressed LV function may be not associated with surgical or midterm mortality.