Sex Differences in the Pathophysiology, Diagnosis, and Management of Aortic Stenosis

Recent updates on asymptomatic and symptomatic aortic valve stenosis its diagnosis, pathogenesis, management and future perspectives

Aortic stenosis (AS) is very common in mid-aged and elderly patients, and it has been reported to have a negative impact on both short and long-term survival with a high mortality rate. The current study identified methods of diagnosis, incidence, and causes of AS, pathogenesis, intervention and management and future perspectives of Asymptomatic and Symptomatic Aortic stenosis. A systematic literature search was conducted using PubMed, Scopus and CINAHL, using the Mesh terms and key words "Aortic stenosis", "diagnostic criteria", "pathogenesis", "incidence and causes of AS" and" intervention and management strategies". Studies were retained for review after meeting strict inclusion criteria that included studies evaluating Asymptomatic and Symptomatic AS. Studies were excluded if duplicate publication, overlap of patients, subgroup studies of a main study, lack of data on AS severity, case reports and letters to editors. Forty-five articles were selected for inclusion. Incidence of AS across the studies ranged from 3 % to 7 %. Many factors have been associated with incidence and increased risk of AS, highest incidence of AS was described after aortic valve calcification, rheumatic heart disease, degenerative aortic valve disease, bicuspid aortic valve and other factors. AS is common and can be predicted by aortic root calcification volume, rheumatic heart disease, degenerative aortic valve disease, bicuspid aortic valve. Intervention and management for AS patients is a complex decision that takes into consideration multiple factors. On the other hand, there is not enough progress in preventive pharmacotherapy to slow the progression of AS.

Sex-Related Outcomes of Transcatheter Aortic Valve Implantation With Self-Expanding or Balloon-Expandable Valves: Insights from the OPERA-TAVI Registry

Evidence regarding gender-related differences in response to transcatheter aortic valve implantation according to the valve type is lacking. This study aimed to evaluate the impact of gender on the treatment effect of Evolut PRO/PRO+ (PRO) or SAPIEN 3 Ultra (ULTRA) devices on clinical outcomes. The Comparative Analysis of Evolut PRO vs SAPIEN 3 Ultra Valves for Transfemoral Transcatheter Aortic Valve Implantation (OPERA-TAVI) is a multicenter, multinational registry including patients who underwent the latest-iteration PRO or ULTRA implantation. Overall, 1,174 of 1,897 patients were matched based on valve type and compared according to gender, whereas 470 men and 630 women were matched and compared according to valve type. The 30-day and 1-year outcomes were evaluated. In the PRO and ULTRA groups, men had a higher co-morbidity burden, whereas women had smaller aortic root. The 30-day (device success [DS], early safety outcome, permanent pacemaker implantation, patient-prosthesis mismatch, paravalvular regurgitation, bleedings, vascular complications, and all-cause death) and 1-year outcomes (all-cause death, stroke, and heart failure hospitalization) did not differ according to gender in both valve groups. However, the male gender decreased the likelihood of 30-day DS with ULTRA versus PRO (p for interaction = 0.047). A higher risk of 30-day permanent pacemaker implantation and 1-year stroke and a lower risk of patient-prosthesis mismatch was observed in PRO versus ULTRA, regardless of gender. In conclusion, gender did not modify the treatment effect of PRO versus ULTRA on clinical outcomes, except for 30-day DS, which was decreased in men (vs women) who received ULTRA (vs PRO).

Mineralocorticoid Receptors in Vascular Smooth Muscle: Blood Pressure and Beyond

After half a century of evidence suggesting the existence of mineralocorticoid receptors (MR) in the vasculature, the advent of technology to specifically knockout the MR from smooth muscle cells (SMCs) in mice has elucidated contributions of SMC-MR to cardiovascular function and disease, independent of the kidney. This review summarizes the latest understanding of the molecular mechanisms by which SMC-MR contributes to (1) regulation of vasomotor function and blood pressure to contribute to systemic and pulmonary hypertension; (2) vascular remodeling in response to hypertension, vascular injury, obesity, and aging, and the impact on vascular calcification; and (3) cardiovascular pathologies including aortic aneurysm, heart valve dysfunction, and heart failure. Data are reviewed from in vitro studies using SMCs and in vivo findings from SMC-specific MR-knockout mice that implicate target genes and signaling pathways downstream of SMC-MR. By regulating expression of the L-type calcium channel subunit Cav1.2 and angiotensin II type-1 receptor, SMC-MR contributes to myogenic tone and vasoconstriction, thereby contributing to systemic blood pressure. MR activation also promotes SMC proliferation, migration, production and degradation of extracellular matrix, and osteogenic differentiation by regulating target genes including connective tissue growth factor, osteopontin, bone morphogenetic protein 2, galectin-3, and matrix metallopeptidase-2. By these mechanisms, SMC-MR promotes disease progression in models of aging-associated vascular stiffness, vascular calcification, mitral and aortic valve disease, pulmonary hypertension, and heart failure. While rarely tested, when sexes were compared, the mechanisms of SMC-MR-mediated disease were sexually dimorphic. These advances support targeting SMC-MR-mediated mechanisms to prevent and treat diverse cardiovascular disorders.

Functional aortic valve area differs significantly between sexes: A phase-contrast cardiac MRI study in patients with severe aortic stenosis

Background

Aortic stenosis (AS) is one of the most prevalent valvular heart-diseases in Europe. Currently, diagnosis and classification are not sex-sensitive; however, due to a distinctly different natural history of AS, further investigations of sex-differences in AS-patients are needed. Thus, this study aimed to detect sex-differences in severe AS, especially concerning flow-patterns, via phase-contrast cardiac magnetic resonance imaging (PC-CMR).

Methods

Forty-four severe AS-patients (20 women, 45 % vs. 24 men, 55 %) with a median age of 72 years underwent transthoracic echocardiography (TTE), cardiac catheterization (CC) and CMR. Aortic valve area (AVA) and stroke volume (SV) were determined in all modalities, with CMR yielding geometrical AVA via cine-planimetry and functional AVA via PC-CMR, the latter being also used to examine flow-properties.

Results

Geometrical AVA showed no sex-differences (0.91 cm2, IQR: 0.61-1.14 vs. 0.94 cm2, IQR: 0.77-1.22, p = 0.322). However, functional AVA differed significantly between sexes in all three modalities (TTE: p = 0.044; CC/PC-CMR: p < 0.001). In men, no significant intermethodical biases in functional AVA-measurements between modalities were found (p = 0.278); yet, in women the particular measurements differed significantly (p < 0.001). Momentary flowrate showed sex-differences depending on momentary opening-degree (at 50 %, 75 % and 90 % of peak-AVA, all p < 0.001), with men showing higher flowrates with increasing opening-area. In women, flowrate did not differ between 75 % and 90 % of peak-AVA (p = 0.191).

Conclusions

In severe AS-patients, functional AVA showed marked sex-differences in all modalities, whilst geometrical AVA did not differ. Inter-methodical biases were negligible in men, but not in women. Lastly, significant sex-differences in flow-patterns fit in with the different pathogenesis of AS.

Unique Aspects of Women's Valvular Heart Diseases: Impact for Diagnosis and Treatment

Valvular heart diseases (VHDs) are a major cause of cardiovascular morbidity and mortality worldwide. As degenerative and functional mechanisms represent the main etiologies in high-income countries are degenerative and functional, while in low income countries etiologie is mostly rheumatic. Although therapeutic options have evolved considerably in recent years, women are consistently diagnosed at later stages of their disease, are delayed in receiving surgical referrals, and exhibit worse postoperative outcomes, compared to men. This difference is a result of the historical underrepresentation of women in studies from which current guidelines were developed. However, in recent years, important research, including more female patients, has been conducted and has highlighted substantial sex-specific differences in the etiology, diagnosis, and treatment of VHDs. Systematic consideration of these sex-specific differences in VHD patients is crucial for providing equitable healthcare and optimizing clinical outcomes in both female and male patients. Hence, this review aims to explore implications of sex-specific particularities for diagnosis, treatment options, and outcomes in women with VHDs.

The Canadian Women's Heart Health Alliance ATLAS on the Epidemiology, Diagnosis, and Management of Cardiovascular Disease in Women - Chapter 8: Knowledge Gaps and Status of Existing Research Programs in Canada

Despite significant progress in medical research and public health efforts, gaps in knowledge of women's heart health remain across epidemiology, presentation, management, outcomes, education, research, and publications. Historically, heart disease was viewed primarily as a condition in men and male individuals, leading to limited understanding of the unique risks and symptoms that women experience. These knowledge gaps are particularly problematic because globally heart disease is the leading cause of death for women. Until recently, sex and gender have not been addressed in cardiovascular research, including in preclinical and clinical research. Recruitment was often limited to male participants and individuals identifying as men, and data analysis according to sex or gender was not conducted, leading to a lack of data on how treatments and interventions might affect female patients and individuals who identify as women differently. This lack of data has led to suboptimal treatment and limitations in our understanding of the underlying mechanisms of heart disease in women, and is directly related to limited awareness and knowledge gaps in professional training and public education. Women are often unaware of their risk factors for heart disease or symptoms they might experience, leading to delays in diagnosis and treatments. Additionally, health care providers might not receive adequate training to diagnose and treat heart disease in women, leading to misdiagnosis or undertreatment. Addressing these knowledge gaps requires a multipronged approach, including education and policy change, built on evidence-based research. In this chapter we review the current state of existing cardiovascular research in Canada with a specific focus on women.

Sex, Gender, and Women's Heart Health: How Women's Heart Programs Address the Knowledge Gap

This article aims to bridge existing knowledge gaps that impact clinical cardiovascular care and outcomes for women in Canada. The authors discuss various aspects of women's heart health, emphasizing the efficacy of multidisciplinary care in promoting women's well-being. The article also identifies the impact of national women's heart health campaigns and the value of peer support in improving outcomes. The article addresses the particular risks that women face, such as pregnancy-related complications and hormone replacement therapy, all of which are associated with cardiovascular events, and highlights the differences in ischemic symptoms between men and women. Despite improvements in acute event outcomes, challenges persist in accessing timely ambulatory care, particularly for women. Canada has responded to these challenges by introducing Women Heart Programs, which offer tailored programs, support groups, and specialized testing. However, these programs remain few in number and are found only in urban settings. Overall, this review identifies sex and gender factors related to women's heart health, underscoring the importance of specialized programs and multidisciplinary care in improving women's cardiovascular health.

Sex-Related Differences in Postoperative Outcomes After Transcatheter Aortic Valve Replacement: A Systematic Review and Meta-Analysis

Aortic stenosis is the most common valvular disease of the heart and is increasing in prevalence. Previous literature has found inferior outcomes for females undergoing surgical aortic valve replacement, while recent investigations have found equivalent or superior outcomes for females undergoing transcatheter aortic valve replacement (TAVR). PubMed and Medline were systematically searched for articles published from January 1, 2010, to April 30, 2021, for retrospective and prospective studies comparing outcomes between males and females undergoing TAVR. One thousand one hundred eighty titles and abstracts were screened, and 28 were included in this review. Risk of bias was assessed using questions derived from the ROBINS-I tool and previous literature. The data were compiled and analyzed using the RevMan 5.4 software. The results of this review confirm the previously published literature and have found rates of acute kidney injury ( P = 0.05) and postoperative pacemaker insertion ( P < 0.00001) favoring females and in-hospital mortality ( P = 0.04), stroke ( P < 0.00001), bleeding complications ( P < 0.00001), and vascular complications ( P < 0.00001) favoring males. The previously published literature has demonstrated consistently inferior outcomes for females undergoing heart valve surgery when compared to males. However, contemporary literature investigating sex differences after TAVR has found comparable outcomes for females. While the postoperative outcomes after surgical aortic valve replacement and TAVR are well established, the causal factors are still unidentified. Future studies utilizing matching based on preoperative characteristics and follow-up including collection of postoperative ventricular remodeling and prosthetic valve performance data will aid in elucidating the causal factors impacting outcomes for males and females after TAVR.

Analysis of Prevalence and Clinical Features of Aortic Stenosis in Patients with and without Bicuspid Aortic Valve Using Machine Learning Methods

Aortic stenosis (AS) is the most commonly diagnosed valvular heart disease, and its prevalence increases with the aging of the general population. However, AS is often diagnosed at a severe stage, necessitating surgical treatment, due to its long asymptomatic period. The objective of this study was to analyze the frequency of AS in a population of cardiovascular patients using echocardiography (ECHO) and to identify clinical factors and features associated with these patient groups. We utilized machine learning methods to analyze 84,851 echocardiograms performed between 2010 and 2018 at the National Medical Research Center named after V.A. Almazov. The primary indications for ECHO were coronary artery disease (CAD) and hypertension (HP), accounting for 33.5% and 14.2% of the cases, respectively. The frequency of AS was found to be 13.26% among the patients (n = 11,252). Within our study, 1544 patients had a bicuspid aortic valve (BAV), while 83,316 patients had a tricuspid aortic valve (TAV). BAV patients were observed to be younger compared to TAV patients. AS was more prevalent in the BAV group (59%) compared to the TAV group (12%), with a p-value of <0.0001. By employing a machine learning algorithm, we randomly identified significant features present in AS patients, including age, hypertension (HP), aortic regurgitation (AR), ascending aortic dilatation (AscAD), and BAV. These findings could serve as additional indications for earlier observation and more frequent ECHO in specific patient groups for the earlier detection of developing AS.

Aortic Valvular Stenosis and Heart Failure: Advances in Diagnostic, Management, and Intervention

Up to 30% of patients with aortic stenosis (AS) present with heart failure (HF) symptoms with either reduced or preserved left ventricular ejection fraction. Many of these patients present with a low-flow state, reduced aortic-valve-area (≤1.0 cm²) with low aortic-mean-gradient and aortic-peak-velocity (<40 mm Hg and <4.0 m/s). Thus, determination of true severity is essential for correct management, and multi-imaging evaluation must be performed. Medical treatment of HF is imperative and should be optimized concurrently with the determination of AS-severity. Finally, AS should be treated according to guidelines, keeping in mind that HF and low-flow increase interventions risks.

Cellular-scale sex differences in extracellular matrix remodeling by valvular interstitial cells

Males acquire calcific aortic valve disease (CAVD) twice as often as females, yet stenotic valves from females display significantly higher levels of fibrosis compared to males with similar extent of disease. Fibrosis occurs as an imbalance between the production and degradation of the extracellular matrix (ECM), specifically type I collagen. This work characterizes ECM production and remodeling by male and female valvular interstitial cells (VICs) to better understand the fibrocalcific divergence between sexes evident in CAVD. Male and female VICs were assessed for gene and protein expression of myofibroblastic markers, ECM components, matrix metalloproteinases (MMPs), and tissue inhibitors of MMPs (TIMPs) via qRT-PCR and western blot. Overall metabolic activity was also measured. Activity assays for collagenase and gelatinase were performed to examine degradation behavior. Male VICs produced greater levels of myofibroblastic markers while female VICs showed greater metabolic activity and collagen production. In general, females displayed a greater level of MMP expression and production than males, but no sex differences were observed in TIMP production. Male VICs also displayed a greater level of collagenase and gelatinase activity than female VICs. This work displays sex differences in ECM remodeling by VICs that could be related to the sexual dimorphism in ECM structure seen in clinical CAVD.

Does sex impact outcomes after mitral valve surgery? A systematic review and meta-analysis

Background and objective:

The published literature investigating the impact of sex on outcomes after mitral valve (MV) surgery has demonstrated inferior outcomes for females over males. However, the true relationship between sex and outcomes after MV surgery continues to be poorly understood.

Materials:

PubMed, Medline, and Embase were systematically searched for articles published from 1 January 2005 to 1 August 2021. This systematic review included retrospective and prospective studies investigating the relationship between sex and outcomes after MV surgery. In all, 2068 articles were initially screened and 12 studies were included in this review.

Results:

Few studies were adequately powered or structured to investigate this topic. Few studies propensity matched patients or isolated for surgical approach. In individual studies, females experienced increased rates of short-term and long-term mortality and increased 1-year mortality in the pooled data. Males experienced increased rates of required pacemaker insertion. The remaining rates of morbidity and mortality did not differ significantly between males and females.

Conclusions:

This review identified increased rates of 1-year mortality in the pooled data for females, while males had increased rates of pacemaker insertion. Despite this, the absence of propensity matching and isolating for surgical approach has introduced confounding variables that impair the ability of the included studies to interpret the results found in the current literature. Studies isolating for surgical approach, propensity matching patients, and examining outcomes with long-term follow-up are required to elucidate the true nature of this relationship.

Angiogenic Secretion Profile of Valvular Interstitial Cells Varies With Cellular Sex and Phenotype

Angiogenesis is a hallmark of fibrocalcific aortic valve disease (CAVD). An imbalance of pro- and anti-angiogenic factors is thought to play a role in driving this disease process, and valvular interstitial cells (VICs) may act as a significant source of these factors. CAVD is also known to exhibit sexual dimorphism in its presentation, and previous work suggested that VICs may exhibit cellular-scale sex differences in the context of angiogenesis. The current study sought to investigate the production of angiogenesis-related factors by male and female VICs possessing quiescent (qVIC) or activated (aVIC) phenotypes. Production of several pro-angiogenic growth factors was elevated in porcine aVICs relative to qVICs, with sex differences found in both the total amounts secreted and their distribution across media vs. lysate. Porcine valvular endothelial cells (VECs) were also sex-separated in culture and found to behave similarly with respect to metabolic activity, viability, and tubulogenesis, but male VECs exhibited higher proliferation rates than female VECs. VECs responded to sex-matched media conditioned by VICs with increased tubulogenesis, but decreased proliferation, particularly upon treatment with aVIC-derived media. It is likely that this attenuation of proliferation resulted from a combination of decreased basic fibroblast growth factor and increased thrombospondin-2 (TSP2) secreted by aVICs. Overall, this study indicates that VICs regulate angiogenic VEC behavior via an array of paracrine molecules, whose secretion and sequestration are affected by both VIC phenotype and sex. Moreover, strong sex differences in TSP2 secretion by VICs may have implications for understanding sexual dimorphism in valve fibrosis, as TSP2 is also a powerful regulator of fibrosis.

Validation of aortic valve calcium quantification thresholds measured by computed tomography in Asian patients with calcific aortic stenosis

AIMS

Sex-specific thresholds of aortic valve calcification (AVC) have been proposed and validated in Caucasians. Thus, we aimed to validate their accuracy in Asians.

METHODS AND RESULTS

Patients with calcific aortic stenosis (AS) from seven international centres were included. Exclusion criteria were ≥moderate aortic/mitral regurgitation and bicuspid valve. Optimal AVC and AVC-density sex-specific thresholds for severe AS were obtained in concordant grading and normal flow patients (CG/NF). We included 1263 patients [728 (57%) Asians, 573 (45%) women, 837 (66%) with CG/NF]. Mean gradient was 48 (26-64) mmHg and peak aortic velocity 4.5 (3.4-5.1) m/s. Optimal AVC thresholds were: 2145 Agatston Units (AU) in men and 1301 AU in women for Asians; and 1885 AU in men and 1129 AU in women for Caucasians. Overall, accuracy (% correctly classified) was high and comparable either using optimal or guidelines' thresholds (2000 AU in men, 1200 AU in women). However, accuracy was lower in Asian women vs. Caucasian women (76-78% vs. 94-95%; P < 0.001). Accuracy of AVC-density (476 AU/cm2 in men and 292 AU/cm2 in women) was comparable to absolute AVC in Caucasians (91% vs. 91%, respectively, P = 0.74), but higher than absolute AVC in Asians (87% vs. 81%, P < 0.001). There was no interaction between AVC/AVC-density and ethnicity (all P > 0.41) with regards to AS haemodynamic severity.

CONCLUSION

AVC thresholds defining severe AS are comparable in Asian and Caucasian populations, and similar to those proposed in the guidelines. However, accuracy of AVC to identify severe AS in Asians (especially women) is sub-optimal. Therefore, the use of AVC-density is preferable in Asians.

Sex and Race Differences in the Pathophysiology, Diagnosis, Treatment, and Outcomes of Valvular Heart Diseases

Valvular heart diseases have long been considered to be similar in men and women and across races/ethnicities. Recently, studies have demonstrated major differences between sexes. Unfortunately, studies on valvular heart diseases, as on other cardiovascular diseases, are mostly performed in Caucasian men or in cohorts with a vast majority of Caucasian men. Therefore, our knowledge on valvular diseases in women and non-Caucasians remains limited. Nevertheless, aortic stenosis has been shown to be almost as prevalent in women as in men, and less prevalent in African Americans. Men appear to have a more calcified aortic valve lesion, and women tend to have a more fibrosed one. Primary mitral regurgitation is more frequent in women who have more rheumatic and Barlow etiologies, whereas men have more fibroelastic deficiency and posterior leaflet prolapse/flail. Left ventricular remodelling due to valvular heart diseases is sex related in terms of geometry and probably also in composition of the tissue. Outcomes seem to be worse in women after surgical interventions and better than or equivalent to men after transcatheter ones. Regarding other valvular heart diseases, very few studies are available: Aortic regurgitation is more frequent in men, isolated tricuspid regurgitation more frequent in women. Rheumatic valve diseases are more frequent in women and are mostly represented by mitral and aortic stenoses. Many other sex/gender- and race/ethnic-specific studies are still needed in epidemiology, pathophysiology, presentation, management, and outcomes. This review aims to report the available data on sex differences and race specificities in valvular heart diseases, with a primary focus on aortic stenosis and mitral regurgitation.

Excess Mortality and Undertreatment of Women With Severe Aortic Stenosis

Background

Although women represent half of the population burden of aortic stenosis (AS), little is known whether sex affects the presentation, management, and outcome of patients with AS.

Methods and Results

In a cohort of 2429 patients with severe AS (49.5% women) we aimed to evaluate 5‐year excess mortality and performance of aortic valve replacement (AVR) stratified by sex. At presentation, women were older (P<0.001), with less comorbidities (P=0.030) and more often symptomatic (P=0.007) than men. Women had smaller aortic valve area (P<0.001) than men but similar mean transaortic pressure gradient (P=0.18). The 5‐year survival was lower compared with expected survival, especially for women (62±2% versus 71% for women and 69±1% versus 71% for men). Despite longer life expectancy in women than men, women had lower 5‐year survival than men (66±2% [expected‐75%] versus 68±2% [expected‐70%], P<0.001) after matching for age. Overall, 5‐year AVR incidence was 79±2% for men versus 70±2% for women (P<0.001) with male sex being independently associated with more frequent early AVR performance (odds ratio, 1.49; 1.18–1.97). After age matching, women remained more often symptomatic (P=0.004) but also displayed lower AVR use (64.4% versus 69.1%; P=0.018).

Conclusions

Women with severe AS are diagnosed at later ages and have more symptoms than men. Despite prevalent symptoms, AVR is less often performed in women and 5‐year excess mortality is noted in women versus men, even after age matching. These imbalances should be addressed to ensure that both sexes receive equivalent care for severe AS.