Medical Student University of Ottawa Ottawa, Ontario, Canada
Background: The sex-based prognosis of patients with ischemic mitral regurgitation (MR) undergoing mitral valve surgery remains unclear. In this systematic review, we aim to evaluate rates of all-cause mortality, reoperation, heart failure rehospitalization and MR recurrence in females who undergo mitral valve surgery for chronic ischemic MR, compared to males.
METHODS AND RESULTS: The MEDLINE, EMBASE, Scopus and Cochrane Central Register of Controlled Trials databases were searched on June 10, 2024. All studies reporting sex-based surgical outcomes for ischemic MR were included. Exclusion criteria comprised studies with < 1 year of follow-up, studies involving transcatheter or medical therapies only, and studies with < 10 males or 10 females. The primary endpoint was long-term (≥ 1 year) all-cause mortality. Risk of bias was ascertained with the Newcastle-Ottawa Scale. Meta-analyses with a random-effects model were conducted.
Twenty-five studies were included, with a total of 6,886 patients of which 1,519 (22.1%) were females (Table 1). Twenty-one studies (84%) were retrospective cohort studies, 2 (8%) were randomized controlled trials, 1 (4%) was a case-control study and 1 (4%) was a prospective cohort study. Among the 8 studies reporting a hazard ratio (HR) for the primary outcome, there was no statistically significant difference in long-term all-cause mortality between sexes (Pooled HR, 1.27 [95% CI, 0.92; 1.75], P=0.35; Figure 1). Operative mortality was also similar between sexes (Pooled Odds Ratio, 1.02 [95% CI, 0.66; 1.56], P=0.94), but females had higher rates of MR recurrence (Pooled HR, 1.80 [95% CI, 1.15; 2.82], P= 0.01). According to the Newcastle-Ottawa risk of bias Scale, 13 studies exhibited an overall high quality, 11 had moderate quality and 1 was deemed low quality.
Conclusion: Although females were underrepresented in the ischemic MR literature, there was no sex-based difference in long-term and operative mortality in patients undergoing mitral valve surgery for ischemic MR, but females were at higher risk of recurrent MR at follow-up. However, most included studies did not adjust for baseline characteristic imbalances between sexes. Further high-quality studies are required to elucidate the sex-based prognosis of patients with ischemic MR (Funding sources: None; PROSPERO ID: CRD42024560892).
