Introduction
The prevalence of valvular heart disease (VHD) is estimated to be 2.5% in developed nations and increases with age, occurring in 14.0% and 12.6% of males and females over the age of 75, respectively [1,2]. Mitral valve disease (MVD) is the most common valvular lesion, with at least moderate mitral regurgitation (MR) occurring in 1.7% of all individuals and 9.3% of those over the age of 75 [2]. The only definitive treatment for MVD is surgical repair or replacement with a mechanical or bioprosthetic valve. Consideration for MV surgical intervention depends on the expected outcomes associated with various preoperative and intraoperative factors and sex is a factor that has been demonstrated to influence these factors [8, 14]. Preoperatively, females are referred later in the disease process with generally higher rates of comorbidities [11-15]. Intraoperatively, there is an increased likelihood of MVR over repair for females compared to males [12, 13, 15] and an increased likelihood of concomitant procedures [13, 14]. Postoperatively, studies have demonstrated inferior outcomes for females as compared to males in MV surgery, with up to a 2.5x increased mortality for females aged 40-59 [11, 12, 18, 19]. While it is well known that the heart remodels after MV surgery, there is little evidence on the impact of sex on cardiac remodeling post MV surgery.
Cardiac remodeling is an integral part of valvular and other cardiac diseases. Changes to hemodynamics, chamber pressure, metabolism, inflammation, and a multitude of other mechanisms can lead to remodeling of the cardiac chambers . In the context of MV disease, cardiac remodeling most often includes left atrial (LA) and left ventricular (LV) dilation as well as an increased LV ejection fraction (LVEF). The consequences of cardiac remodeling include development of arrhythmias and heart failure [20, 21]. It is therefore imperative to understand the factors influencing cardiac remodeling after MV surgery as reversal of pathological remodeling may impact an individual’s recovery and long-term prognosis.
Although higher rates of comorbidities and delayed surgical referral may explain the inequity in MV surgery outcomes between males and females, there have been no factors definitively identified as having a causal effect. The current literature seeking to identify the impact of sex and surgical approach on postoperative cardiac remodeling and outcomes is insufficient. Consequently, identical guidelines are used to treat both sexes while females continue to suffer inferior postoperative outcomes. Current trends in medicine seek to personalize treatments for individual patients. In order to minimize the disease burden and optimize quality of life, treatment in MVD should also be tailored to an individual’s specific presentation. In this propensity-matched retrospective study, we look to identify variations in postoperative cardiac remodeling and outcomes between males and females who have undergone MVR to better inform the clinical decision-making process for patients requiring surgical MVR.