Sex Differences in Epidemiology, Morphology, Mechanisms, and Treatment of Mitral Valve Regurgitation

Impact of biological sex on valvular heart disease, interventions, and outcomes

Valvular heart disease (VHD) is common, affecting >14% of individuals aged >75, and is associated with morbidity, including heart failure and arrhythmia, and risk of early mortality. Increasingly, important sex differences are being found between males and females with VHD. These sex differences can involve the epidemiology, pathophysiology, presentation, diagnosis, and outcomes of the disease. Females are often disadvantaged, and female sex has been shown to be associated with delayed diagnosis and inferior outcomes in various forms of VHD. In addition, the unique pathophysiologic state of pregnancy is associated with increased risk for maternal and fetal morbidity and mortality in many forms of VHD. Therefore, understanding and recognizing these sex differences, and familiarity with the attendant risks of pregnancy and management of pregnant females with VHD, is of great importance for any primary care or cardiovascular medicine practitioner caring for the female patient. This review will outline sex differences in aortic, mitral, pulmonic, and tricuspid VHD, with particular focus on differences in pathophysiology, clinical presentation, and outcomes. In addition, the pathophysiology and management implications of pregnancy will be discussed.

Longitudinal Outcomes Following Mitral Valve Repair for Infective Endocarditis

Mitral valve repair is the ideal approach in managing mitral valve infective endocarditis for patients requiring surgery. However, viable repair is influenced by the extent of valve destruction and there can be technical challenges in reconstruction following debridement. Overall, data describing long-term outcomes following mitral repair of infective endocarditis are scarce. We, therefore, assessed the late outcomes of 101 consecutive patients who underwent mitral valve repair for IE at the University of Ottawa Heart Institute from 2001 to 2021. The 5- and 10-year survival rate was 80.8 ± 4.7% and 61.2 ± 9.2%, respectively. Among these 101 patients, 7 ultimately required mitral valve reoperation at a median of 5 years after their initial operation. These patients were of a mean age of 35.9 ± 7.3 years (range 22-44 years) at the time of their initial operation. The 5- and 10-year freedom from mitral valve reoperation was 93.6 ± 3.4% and 87.7 ± 5.2%, respectively. Overall, mitral valve repair can be an effective method for treating infective endocarditis with a favourable freedom from reoperation and mortality over the long term.

Overcoming the Disparity in Mitral Valve Repair: A Sex-Based Analysis of Long-Term Outcomes

BACKGROUND

Sex disparities remain pervasive across most cardiovascular diseases and continue to demonstrate notably worse early and late outcomes for women, especially after surgical repair. This study aims to investigate outcomes of mitral valve (MV) repair by sex and identify opportunities for improvement.

METHODS

A single center retrospective analysis of consecutive patients undergoing MV repair from May 2008 to February 2023 was conducted. In-hospital and long-term outcomes, including survival and symptomatic disease recurrence were examined by sex. Adjusted outcome analysis was performed using inverse-probability treatment weighting.

RESULTS

In total, 490 patients underwent MV repair (median age, 65 years; interquartile range [IQR], 57-73 years; sternotomy n = 128 [26%], minimally invasive n = 362 [74%]), including 343 male and 147 female patients. Median follow-up time was 5.4 years (IQR, 3.1-8.4 years). inverse-probability treatment weighting-adjusted 30-day outcomes for female vs male, including death (1.4% vs 0.6%, P = .59) and major adverse cardiovascular events (8.2% vs 7.6%, P = .81), were not significantly different. Survival for female vs male after mitral valve repair was 94.9% vs 98.0% at 2 years, 91.4% vs 97.8% at 4 years, and 87.2% vs 88.7% at 8 years (hazard ratio, 0.52; IQR, 0.19-1.44). Both unadjusted and inverse-probability treatment weighting-adjusted Cox-regression hazard ratios for survival and freedom from symptomatic disease recurrence demonstrated no significant difference between sexes at long-term follow-up.

CONCLUSIONS

These contemporary results are encouraging and suggest that a critical "bridging of the gap" between sexes is possible with comprehensive efforts including earlier detection and awareness and improved surgical techniques, though other factors may be important to explore further.

Technical and Clinical Outcomes After Transcatheter Edge-to-Edge Repair of Mitral Regurgitation in Male and Female Patients: Is Equality Achieved?

BACKGROUND

Currently, no clear impact of sex on short- and long-term survival following transcatheter edge-to-edge mitral valve repair (TEER) is evident, although no data are available on postprocedural life expectancy. Our aim was to assess sex-specific differences in outcomes of patients with mitral regurgitation (MR) treated by TEER.

METHODS AND RESULTS

Short-term and 5-year outcomes in men and women undergoing TEER between 2011 and 2018 who were included in the large, multicenter, real-world MitraSwiss registry were analyzed. Outcomes were compared stratified by sex and according to MR cause (primary versus secondary). The impact of TEER on postprocedural life expectancy was estimated by relative survival analysis. Among 1142 patients aged 60 to 89 years, 39.8% were women. They were older, with fewer cardiovascular risk factors and lower functional capacity compared with men. Thirty-day mortality was higher in men than in women (3.3% versus 1.1%; odds ratio, 3.16 [95% CI, 1.16-10.7]; P=0.020). Five-year survival was comparable in both sexes (adjusted hazard ratio for 5-year mortality in men, 1.14 [95% CI, 0.90-1.44], P=0.275). Both men and women with either primary or secondary MR showed similar clinical efficacy over time. TEER provided high relative survival estimates among all groups, and fully restored predicted life expectancy in women with primary MR (5-year relative survival estimate, 97.4% [95% CI, 85.5-107.0]).

CONCLUSIONS

TEER is not associated with increased short-term mortality in women, whereas 5-year outcomes are comparable between sexes. Moreover, TEER completely restored normal life expectancy in women with primary MR. A residual excess mortality persists in secondary MR, independently of sex.

Disparities in Mitral Valve Disease Associated with Heart Failure

Heart failure (HF) affects millions of people around the world and is a prevalent health issue in the United States. In many cases, HF has an intricate connection with mitral valvular disease (MVD), which can alter a patient's disease course. Factors such as gender, race, ethnicity, and social determinants of health impact the prevalence, etiology, and treatment of MVD associated with HF. This literature review examines the connection between MVD and HF among adult patients, considering MVD as both a cause and an outcome of HF. This article also identifies the differences in epidemiology and treatment of MVD associated with HF across different gender, ethnicity, race, and socioeconomic groups. This is in an effort to not only identify currently overlooked disparities but to highlight potential ways to improve them. MVD was analyzed based on its hemodynamic subtypes, mitral regurgitation (MR) and mitral stenosis (MS), as these subtypes encompass different etiologies of MVD. The purpose of this article was to identify broad disparities in MVD in association with HF in the adult population. The results of this study found stark differences between prevalence, treatment, and disease outcomes across groups. Women and Black patients were identified as high-risk for under-utilization and prescription delay of treatment options. Women were often treated at more advanced stages of MVD, while treatment was often delayed in Black patient populations. Factors such as these impact treatment outcomes. Conversely, men and White patients were identified as lower-risk groups for treatment inadequacies and poor HF and MVD related outcomes. Socioeconomic status (SES) was also found to play a role, with low SES being a risk factor for developing rheumatic heart disease. Low SES groups are also more likely to develop HF, which predisposes to secondary MR. Despite general knowledge of these disparities, few studies analyze HF and MVD for specific groups. This literature review is thus necessary to identify current inequities in care and underscore potential solutions to raise awareness for further research efforts and funding. This analysis identifies MVD treatment guidelines and contributing social determinants of health as areas that must be addressed to minimize HF and MVD disparities.

Considerations & challenges of mitral valve repair in females: diagnosis, pathology, and intervention

PURPOSE OF REVIEW

Disparities in mitral valve (MV) repair outcomes exist between men and women. This review highlights sex-specific differences in MV disease aetiology, diagnosis, as well as timing and type of intervention.

RECENT FINDINGS

Females present with more complicated disease: anterior or bileaflet prolapse, leaflet dysplasia/thickening, mitral annular calcification, and mixed mitral lesions. The absence of indexed echocardiographic mitral regurgitation (MR) severity parameters contributes to delayed intervention in women, resulting in more severe symptom burden at time of surgery. The sequelae of chronic MR also necessitate concomitant procedures (e.g. tricuspid repair, arrhythmia surgery) at the time of mitral surgery. Complex MV pathology, greater patient acuity, and more complicated procedures collectively pose challenges to successful MV repair and postoperative recovery. As a consequence, women receive disproportionately more MV replacement than men. In-hospital mortality after MV repair is also greater in women than men. Long-term outcomes of MV repair are comparable after risk-adjustment for preoperative status; however, women experience a greater incidence of postoperative heart failure.

SUMMARY

To address the inequity in MV repair outcomes between sexes, indexed diagnostic measurements, diligent surveillance of asymptomatic MR, increased recruitment of women in large clinical trials, and mandatory reporting of sex-based subgroup analyses are recommended.

Identification and Analysis of Sex-Biased MicroRNAs in Human Diseases

It is well known that significant differences exist between males and females in both physiology and disease. Thus, it is important to identify and analyze sex-biased miRNAs. However, previous studies investigating sex differences in miRNA expression have predominantly focused on healthy individuals or restricted their analysis to a single disease. Therefore, it is necessary to comprehensively identify and analyze the sex-biased miRNAs in diseases. For this purpose, in this study, we first identified the miRNAs showing sex-biased expression between males and females in diseases based on a number of miRNA expression datasets. Then, we performed a bioinformatics analysis for these sex-biased miRNAs. Notably, our findings revealed that women exhibit a greater number of conserved miRNAs that are highly expressed compared to men, and these miRNAs are implicated in a broader spectrum of diseases. Additionally, we explored the enriched transcription factors, functions, and diseases associated with these sex-biased miRNAs using the miRNA set enrichment analysis tool TAM 2.0. The insights gained from this study could carry implications for endeavors such as precision medicine and possibly pave the way for more targeted and tailored approaches to disease management.