Is it Time for Sex-Specific Guidelines for Cardiovascular Disease?

Hearts apart: sex differences in cardiac remodeling in health and disease

Biological sex is an important modifier of physiology and influences pathobiology in many diseases. While heart disease is the number one cause of death worldwide in both men and women, sex differences exist at the organ and cellular scales, affecting clinical presentation, diagnosis, and treatment. In this Review, we highlight baseline sex differences in cardiac structure, function, and cellular signaling and discuss the contribution of sex hormones and chromosomes to these characteristics. The heart is a remarkably plastic organ and rapidly responds to physiological and pathological cues by modifying form and function. The nature and extent of cardiac remodeling in response to these stimuli are often dependent on biological sex. We discuss organ- and molecular-level sex differences in adaptive physiological remodeling and pathological cardiac remodeling from pressure and volume overload, ischemia, and genetic heart disease. Finally, we offer a perspective on key future directions for research into cardiac sex differences.

Addressing the Global Burden of Cardiovascular Disease in Women: JACC State-of-the-Art Review

Cardiovascular diseases (CVDs) are responsible for approximately 35% of all deaths in women. In 2019, the global age-standardized CVD prevalence and mortality of women were 6,403 per 100,000 and 204 per 100,000, respectively. Although the age- and population-adjusted prevalence has decreased globally, opposite trends are evident in regions of socioeconomic deprivation. Cardiovascular health and outcomes are influenced by regional socioeconomic, environmental, and community factors, in addition to health care system and individual factors. Cardiovascular care in women is commonly plagued by delayed diagnoses, undertreatment, and knowledge gaps, particularly in women-specific or women-predominant conditions. In this paper, we describe the global epidemiology of CVD and highlight multilevel determinants of cardiometabolic health. We review knowledge and health care gaps that serve as barriers to improving CVD outcomes in women. Finally, we present national, community, health care system, and research strategies to comprehensively address cardiometabolic risk and improve outcomes in women.

Differences in coronary angiographic findings and outcomes between men and postmenopausal women with stable chest pain

BACKGROUND

Despite the significant increase in cardiovascular events in women after menopause, studies comparing postmenopausal women and men are scarce.

METHODS

We analyzed data from a nationwide, multicenter, prospective registry and enrolled 2412 patients with stable chest pain who underwent elective coronary angiography. Binary coronary artery disease (b-CAD) was defined as the ≥50% stenosis of epicardial coronary arteries, including the left main coronary artery.

RESULTS

Compared with the men, postmenopausal women were older (66.6 ± 8.5 vs. 59.5 ± 11.4 years) and had higher high-density lipoprotein cholesterol levels (49.0 ± 12.8 vs. 43.6 ± 11.6 mg/dl, P  < 0.01). The prevalence of diabetes did not differ significantly ( P  = 0.40), and smoking was more common in men than in postmenopausal women ( P  ≤ 0.01). At enrollment, b-CAD and revascularization were more common in men than in postmenopausal women (50.3% vs. 41.0% and 14.4% vs. 9.7%, respectively; both P  < 0.01). However, multivariate analyses revealed that revascularization [odds ratio (OR): 0.72; 95% confidence interval (CI): 0.49-1.08] was not significantly related to sex and a similar result was found in age propensity-matched population (OR: 0.80; 95% CI: 0.52-1.24). During the follow-up period, the secondary composite cardiovascular outcomes were lower in postmenopausal women than in men (OR: 0.55; 95% CI: 0.31-0.98), also consistent with the result using the age propensity-mated population (OR: 0.33; 95% CI: 0.13-0.85).

CONCLUSION

Postmenopausal women experienced coronary revascularization comparable to those in men at enrollment, despite the average age of postmenopausal women was 7 years older than that of men.Postmenopausal women exhibit better clinical outcomes than those of men if optimal treatment is provided.

Sex-based differences in the phenotypic expression and prognosis of idiopathic non-ischaemic cardiomyopathy: a cardiovascular magnetic resonance study

AIMS

We sought to characterize sex-related differences in cardiovascular magnetic resonance-based cardiovascular phenotypes and prognosis in patients with idiopathic non-ischaemic cardiomyopathy (NICM).

METHODS AND RESULTS

Patients with NICM enrolled in the Cardiovascular Imaging Registry of Calgary (CIROC) between 2015 and 2021 were identified. Z-score values for chamber volumes and function were calculated as standard deviation from mean values of 157 sex-matched healthy volunteers, ensuring reported differences were independent of known sex-dependencies. Patients were followed for the composite outcome of all-cause mortality, heart failure admission, or ventricular arrhythmia. A total of 747 patients were studied, 531 (71%) males. By Z-score values, females showed significantly higher left ventricular (LV) ejection fraction (EF; median difference 1 SD) and right ventricular (RV) EF (difference 0.6 SD) with greater LV mass (difference 2.1 SD; P < 0.01 for all) vs. males despite similar chamber volumes. Females had a significantly lower prevalence of mid-wall striae (MWS) fibrosis (22% vs. 34%; P < 0.001). Over a median follow-up of 4.7 years, 173 patients (23%) developed the composite outcome, with equal distribution in males and females. LV EF and MWS were significant independent predictors of the outcome (respective HR [95% CI] 0.97 [0.95-0.99] and 1.6 [1.2-2.3]; P = 0.003 and 0.005). There was no association of sex with the outcome.

CONCLUSION

In a large contemporary cohort, NICM was uniquely expressed in females vs. males. Despite similar chamber dilation, females demonstrated greater concentric remodelling, lower reductions in bi-ventricular function, and a lower burden of replacement fibrosis. Overall, their prognosis remained similar to male patients with NICM.

Effect of Mavacamten in Women Compared With Men With Obstructive Hypertrophic Cardiomyopathy: Insights From EXPLORER-HCM

BACKGROUND

Compared with men, women with hypertrophic cardiomyopathy (HCM) have a higher incidence of heart failure and worse outcomes. We investigated baseline clinical and echocardiographic characteristics and response to mavacamten among women compared with men in the EXPLORER-HCM study (Clinical Study to Evaluate Mavacamten [MYK-461] in Adults With Symptomatic Obstructive Hypertrophic Cardiomyopathy).

METHODS

A prespecified post hoc analysis of sex from the blinded, randomized EXPLORER-HCM trial of mavacamten versus placebo in symptomatic patients with obstructive HCM was performed. Baseline characteristics were compared with t tests for continuous variables (expressed as mean values) and χ2 tests for categorical variables. Prespecified primary, secondary, and exploratory end points and echocardiographic measurements from baseline to end of treatment (week 30) were analyzed with ANCOVA for continuous end points and a generalized linear model with binomial distribution for binary end points, with adjustment for each outcome's baseline value, New York Heart Association class, β-blocker use, and ergometer type.

RESULTS

At baseline, women (n=102) were older (62 years versus 56 years; P<0.0001), had lower peak oxygen consumption (16.7 mL·kg-1·min-1 versus 21.3 mL·kg-1·min-1; P<0.0001), were more likely to be assigned New York Heart Association class III (42% versus 17%; P<0.0001), had worse health status (Kansas City Cardiomyopathy Questionnaire-Clinical Summary Score 64 versus 75; P<0.0001), and had higher baseline plasma NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels (1704 ng/L versus 990 ng/L; P=0.004) than men (n=149). After 30 weeks of mavacamten treatment, similar improvements were observed in women and men in the primary composite end point (percentage difference on mavacamten versus placebo, 22% versus 19%, respectively; P=0.759) and in the secondary end points of change in postexercise left ventricular outflow tract gradient (-42.4 mm Hg versus -33.6 mm Hg; P=0.348), change in peak oxygen consumption (1.2 mL·kg-1·min-1 versus 1.6 mL·kg-1·min-1; P=0.633), and percentage achieving ≥1 New York Heart Association class improvement (41% versus 28%; P=0.254). However, women had greater improvement in health status (Kansas City Cardiomyopathy Questionnaire-Clinical Summary Score 14.8 versus 6.1; P=0.026) and in the exploratory end point of NT-proBNP levels (-1322 ng/L versus -649 ng/L; P=0.0008).

CONCLUSIONS

Although at baseline women with symptomatic obstructive HCM enrolled in EXPLORER-HCM were older and had worse heart failure and health status than men, treatment with mavacamten resulted in similar improvements in the primary and most secondary EXPLORER-HCM end points and greater improvements in health status and NT-proBNP.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03470545.

The Canadian Women's Heart Health Alliance ATLAS on the Epidemiology, Diagnosis, and Management of Cardiovascular Disease in Women - Chapter 7: Sex, Gender, and the Social Determinants of Health

Women vs men have major differences in terms of risk-factor profiles, social and environmental factors, clinical presentation, diagnosis, and treatment of cardiovascular disease. Women are more likely than men to experience health issues that are complex and multifactorial, often relating to disparities in access to care, risk-factor prevalence, sex-based biological differences, gender-related factors, and sociocultural factors. Furthermore, awareness of the intersectional nature and relationship of sociocultural determinants of health, including sex and gender factors, that influence access to care and health outcomes for women with cardiovascular disease remains elusive. This review summarizes literature that reports on under-recognized sex- and gender-related risk factors that intersect with psychosocial, economic, and cultural factors in the diagnosis, treatment, and outcomes of women's cardiovascular health.

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.

Polycystic Ovary Syndrome Fuels Cardiovascular Inflammation and Aggravates Ischemic Cardiac Injury

BACKGROUND

Reducing cardiovascular disease burden among women remains challenging. Epidemiologic studies have indicated that polycystic ovary syndrome (PCOS), the most common endocrine disease in women of reproductive age, is associated with an increased prevalence and extent of coronary artery disease. However, the mechanism through which PCOS affects cardiac health in women remains unclear.

METHODS

Prenatal anti-Müllerian hormone treatment or peripubertal letrozole infusion was used to establish mouse models of PCOS. RNA sequencing was performed to determine global transcriptomic changes in the hearts of PCOS mice. Flow cytometry and immunofluorescence staining were performed to detect myocardial macrophage accumulation in multiple PCOS models. Parabiosis models, cell-tracking experiments, and in vivo gene silencing approaches were used to explore the mechanisms underlying increased macrophage infiltration in PCOS mouse hearts. Permanent coronary ligation was performed to establish myocardial infarction (MI). Histologic analysis and small-animal imaging modalities (eg, magnetic resonance imaging and echocardiography) were performed to evaluate the effects of PCOS on injury after MI. Women with PCOS and control participants (n=200) were recruited to confirm findings observed in animal models.

RESULTS

Transcriptomic profiling and immunostaining revealed that hearts from PCOS mice were characterized by increased macrophage accumulation. Parabiosis studies revealed that monocyte-derived macrophages were significantly increased in the hearts of PCOS mice because of enhanced circulating Ly6C+ monocyte supply. Compared with control mice, PCOS mice showed a significant increase in splenic Ly6C+ monocyte output, associated with elevated hematopoietic progenitors in the spleen and sympathetic tone. Plasma norepinephrine (a sympathetic neurotransmitter) levels and spleen size were consistently increased in women with PCOS when compared with those in control participants, and norepinephrine levels were significantly correlated with circulating CD14++CD16- monocyte counts. Compared with animals without PCOS, PCOS animals showed significantly exacerbated atherosclerotic plaque development and post-MI cardiac remodeling. Conditional Vcam1 silencing in PCOS mice significantly suppressed cardiac inflammation and improved cardiac injury after MI.

CONCLUSIONS

Our data documented previously unrecognized mechanisms through which PCOS could affect cardiovascular health in women. PCOS may promote myocardial macrophage accumulation and post-MI cardiac remodeling because of augmented splenic myelopoiesis.

Sex-specific trajectories of molecular cardiometabolic traits from childhood to young adulthood

BACKGROUND

The changes which typically occur in molecular causal risk factors and predictive biomarkers for cardiometabolic diseases across early life are not well characterised.

METHODS

We quantified sex-specific trajectories of 148 metabolic trait concentrations including various lipoprotein subclasses from age 7 years to 25 years. Data were from 7065 to 7626 offspring (11 702 to14 797 repeated measures) of the Avon Longitudinal Study of Parents and Children birth cohort study. Outcomes were quantified using nuclear magnetic resonance spectroscopy at 7, 15, 18 and 25 years. Sex-specific trajectories of each trait were modelled using linear spline multilevel models.

RESULTS

Females had higher very-low-density lipoprotein (VLDL) particle concentrations at 7 years. VLDL particle concentrations decreased from 7 years to 25 years with larger decreases in females, leading to lower VLDL particle concentrations at 25 years in females. For example, females had a 0.25 SD (95% CI 0.20 to 0.31) higher small VLDL particle concentration at 7 years; mean levels decreased by 0.06 SDs (95% CI -0.01 to 0.13) in males and 0.85 SDs (95% CI 0.79 to 0.90) in females from 7 years to 25 years, leading to 0.42 SDs (95% CI 0.35 to 0.48) lower small VLDL particle concentrations in females at 25 years. Females had lower high-density lipoprotein (HDL) particle concentrations at 7 years. HDL particle concentrations increased from 7 years to 25 years with larger increases among females leading to higher HDL particle concentrations in females at 25 years.

CONCLUSION

Childhood and adolescence are important periods for the emergence of sex differences in atherogenic lipids and predictive biomarkers for cardiometabolic disease, mostly to the detriment of males.

Influence of poor sleep on cardiovascular disease-free life expectancy: a multi-resource-based population cohort study

BACKGROUND

The complexity of sleep hinders the formulation of sleep guidelines. Recent studies suggest that different unhealthy sleep characteristics jointly increase the risks for cardiovascular disease (CVD). This study aimed to estimate the differences in CVD-free life expectancy between people with different sleep profiles.

METHODS

We included 308,683 middle-aged adults from the UK Biobank among whom 140,181 had primary care data linkage. We used an established composite sleep score comprising self-reported chronotype, duration, insomnia complaints, snoring, and daytime sleepiness to derive three sleep categories: poor, intermediate, and healthy. We also identified three clinical sleep disorders captured by primary care and inpatient records within 2 years before enrollment in the cohort: insomnia, sleep-related breathing disorders, and other sleep disorders. We estimated sex-specific CVD-free life expectancy with three-state Markov models conditioning on survival at age 40 across different sleep profiles and clinical disorders.

RESULTS

We observed a gradual loss in CVD-free life expectancy toward poor sleep such as, compared with healthy sleepers, poor sleepers lost 1.80 [95% CI 0.96-2.75] and 2.31 [1.46-3.29] CVD-free years in females and males, respectively, while intermediate sleepers lost 0.48 [0.41-0.55] and 0.55 [0.49-0.61] years. Among men, those with clinical insomnia or sleep-related breathing disorders lost CVD-free life by 3.84 [0.61-8.59] or 6.73 [5.31-8.48] years, respectively. Among women, sleep-related breathing disorders or other sleep disorders were associated with 7.32 [5.33-10.34] or 1.43 [0.20-3.29] years lost, respectively.

CONCLUSIONS

Both self-reported and doctor-diagnosed poor sleep are negatively associated with CVD-free life, especially pronounced in participants with sleep-related breathing disorders.

Optimization of Drug Therapy for Heart Failure With Reduced Ejection Fraction Based on Gender

PURPOSE OF REVIEW

Over the last decades, several classes of drugs have been introduced for the treatment of patients with heart failure with reduced ejection fraction (HFrEF). Their use has been supported by randomized controlled trials that have demonstrated improved patient outcomes. However, these trials enrolled a small number of female patients and sometimes have reported gender-related differences regarding the efficacy of the treatments. The aim of this review is to revise the available data about the influence of gender on the optimal treatment and drug dose in patients with HFrEF.

RECENT FINDINGS

Several gender-related differences in terms of pharmacokinetic and pharmacodynamic characteristics of the drugs have been described. These characteristics could be responsible for a different response and tolerability in men and women also when current recommended treatment of HFrEF is considered. Some studies have shown that, in women, lower doses of beta-blockers and inhibitors of renin angiotensin aldosterone system could be equally effective than higher doses in men, whereas sacubitril/valsartan could exert its favorable effect at greater values of left ventricular ejection fraction. Although there is evidence about differences in the response to treatment of HFrEF in men and women, this has not been sufficient for differentiating current recommended therapy. Further studies should better clarify if the treatment of HFrEF should be based also on the patients' gender.

A Systematic Review of Sex-Specific Reporting in Heart Failure Clinical Trials: Trial Flow and Results

Background

Females are historically underenrolled in heart failure (HF) randomized controlled trials (RCTs) relative to disease prevalence. Sex differences in trial flow, including withdrawals and losses to follow up, may further limit the generalizability of results.

Objectives

This study aimed to assess the frequency of sex-specific reporting of trial flow, treatment efficacy, and adverse events in HF RCTs.

Methods

We systematically searched MEDLINE, Embase, and CINAHL for HF RCTs published between 2000 and 2020 in journals with an impact factor ≥10. We assessed whether trial flow, treatment effect, and adverse events were disaggregated by sex. We used multivariable regression to assess associations between trial characteristics and sex subgroup analysis. We analyzed temporal trends in sex-specific reporting.

Results

We included 224 RCTs with 228,801 total participants (28.2% female). No RCT reported sex-disaggregated screening, consent, or withdrawal rates; and 2 (0.9%) reported sex-disaggregated losses to follow-up. Seventy-five RCTs (33.4%) presented sex subgroup analysis, and 63 (28.3%) reported sex-treatment interaction. No RCT reported sex-specific adverse events. Large trial size (odds ratio: 13.16, 95% CI: 5.67-30.52; P < 0.001) and device/procedure interventions (odds ratio: 5.13, 95% CI: 1.55-16.95; P < 0.007) were independently associated with sex subgroup analysis. Over the study period, there was an increase in sex subgroup analysis (P < 0.001) and testing for sex-treatment interaction (P < 0.001).

Conclusions

HF RCTs rarely reported sex differences in trial flow or adverse events and uncommonly performed sex subgroup analysis. Improved sex-disaggregated reporting could highlight the causes and extent of sex differences in trial participation and facilitate appropriate inferences about treatment effect.

Distinct pathophysiological pathways in women and men with heart failure

AIMS

Clinical differences between women and men have been described in heart failure (HF). However, less is known about the underlying pathophysiological mechanisms. In this study, we compared multiple circulating biomarkers to gain better insights into differential HF pathophysiology between women and men.

METHODS AND RESULTS

In 537 women and 1485 men with HF, we compared differential expression of a panel of 363 biomarkers. Then, we performed a pathway over-representation analysis to identify differential biological pathways in women and men. Findings were validated in an independent HF cohort (575 women, 1123 men). In both cohorts, women were older and had higher left ventricular ejection fraction (LVEF). In the index and validation cohorts respectively, we found 14/363 and 12/363 biomarkers that were relatively up-regulated in women, while 21/363 and 14/363 were up-regulated in men. In both cohorts, the strongest up-regulated biomarkers in women were leptin and fatty acid binding protein-4, compared to matrix metalloproteinase-3 in men. Similar findings were replicated in a subset of patients from both cohorts matched by age and LVEF. Pathway over-representation analysis revealed increased activity of pathways associated with lipid metabolism in women, and neuro-inflammatory response in men (all p &lt; 0.0001).

CONCLUSION

In two independent cohorts of HF patients, biomarkers associated with lipid metabolic pathways were observed in women, while biomarkers associated with neuro-inflammatory response were more active in men. Differences in inflammatory and metabolic pathways may contribute to sex differences in clinical phenotype observed in HF, and provide useful insights towards development of tailored HF therapies.

Sex-Based Differences in Outcomes Following Peripheral Artery Revascularization: Insights From VOYAGER PAD

Background

Despite high female prevalence of peripheral artery disease (PAD), little is known about sex‐based outcomes after lower extremity revascularization (LER) for symptomatic PAD. The effects of rivaroxaban according to sex following LER have not been fully reported.

Methods and Results

In VOYAGER PAD (Vascular Outcomes Study of ASA [acetylsalicylic acid] Along with Rivaroxaban in Endovascular or Surgical Limb Revascularization for Peripheral Artery Disease), low‐dose rivaroxaban versus placebo on a background of aspirin reduced the composite primary efficacy outcome of cardiovascular and limb events in patients with PAD undergoing LER. Unplanned index limb revascularization was prespecified and prospectively ascertained. The primary safety outcome was Thrombolysis in Myocardial Infarction major bleeding. Analyses of outcomes and treatment effects by sex were performed using Cox proportional hazards models. Among 6564 randomly assigned patients followed for a median of 28 months, 1704 (26.0%) were women. Among patients administered placebo, women were at similar risk for the primary efficacy outcome (hazard ratio [HR], 0.90; [95% CI, 0.74–1.09]; P=0.29) as men, while female sex was associated with a trend toward higher risk of unplanned index limb revascularization (HR, 1.18; [95% CI, 1.00–1.40]; P=0.0499). Irrespective of sex, effects of rivaroxaban were consistent for the primary efficacy outcome (P‐interaction=0.22), unplanned index limb revascularization (P‐interaction=0.64), and bleeding (P‐interaction=0.61). Women were more likely than men to discontinue study treatment (HR, 1.13; [95% CI, 1.03–1.25]; P=0.0099).

Conclusions

Among >1700 women with PAD undergoing LER, women and men were at similar risk for the primary outcome, but a trend for greater risk of unplanned index limb revascularization among women was observed. Effects of rivaroxaban were consistent by sex, though women more often discontinued treatment. Better understanding of sex‐based outcomes and treatment adherence following LER is needed.

Registration

URL: http://clinicaltrials.gov; Unique identifier: NCT02504216.

The Impact of Sex and Gender on Stroke

Women face a disproportionate burden of stroke mortality and disability. Biologic sex and sociocultural gender both contribute to differences in stroke risk factors, assessment, treatment, and outcomes. There are substantial differences in the strength of association of stroke risk factors, as well as female-specific risk factors. Moreover, there are differences in presentation, response to treatment, and stroke outcomes in women. This review outlines current knowledge of impact of sex and gender on stroke, as well as delineates research gaps and areas for future inquiry.

Representation of Females in Atrial Fibrillation Clinical Practice Guidelines

BACKGROUND

Atrial fibrillation (AF) is the most common arrhythmia in males and females worldwide, and its prevalence is increasing. Management of AF is guided by evidence-based clinical practice guidelines which provide recommendations based on available evidence. The extent of sex-specific data in the AF literature used to provide guideline recommendations has not been investigated. Therefore, using the 2020 Canadian Cardiovascular Society (CCS) Atrial Fibrillation Management Guidelines as example, the purpose of this study was to review female representation and the reporting of sex-disaggregated data in the studies referenced in AF guidelines.

METHODS

Randomized controlled trials (RCTs), prospective and retrospective cohorts, were screened to calculate the proportion of study participants who were female and to establish whether studies provided sex disaggregated analyses. The participant prevalence ratio (PPR), a quotient of the female participant rate and the prevalence of females in the AF population, was calculated for each study.

RESULTS

A total of 885 studies included in the CCS guidelines were considered. Of those, 467 met the inclusion criteria. Overall, females represented 39.1% of the population in all studies and RCTs had the lowest proportions of females (33.8%, PPR: 0.70). Of studies with sex-disaggregated analyses (n=140 (29.9%)), single centered RCTs, and retrospective cohorts had the lowest and highest rate of sex-specific analyses respectively (11.5% vs 32.5%).

CONCLUSION

The evidence used to derive guideline recommendations may be inadequate for sex-specific recommendations. Until enough data can support female specific guidelines, increased inclusion of females in AF studies, may aid in the precision of recommendations.

Cardiac rehabilitation - The answer for the second chance

In the United States and worldwide, the leading cause of death in females is cardiovascular disease (CVD). However, compared to males, females have overall higher mortality rates, especially within the first few years of having an acute myocardial infarction (AMI). Despite the increased awareness of CVD in females and established benefits of cardiac rehabilitation (CR) programs, there is still delayed initiation of care, under-recognition of atypical presentations of angina in females, under referral of females to CR, and under-representation of females in CVD trials. In this paper, we will investigate the barriers to female participation in CR, explore the fundamental differences in physiology between males and females, and current limitations in CVD trials where females are under-represented. Finally, we aim to provide potential methods to increase enrollment of females in CR and CR related trials.

Protection by inclusion: Increasing enrollment of women in cardiovascular trials

Despite differences in biology that influence disease incidence, drug metabolism, and response to therapies, women remain under-enrolled in cardiovascular clinical trials. Estimates regarding treatment efficacy and safety are derived from male-predominant trial populations, with inadequate balance between sex subgroups for meaningful analysis on sex-specific treatment effects. Treatment strategies for women, particularly women of childbearing years, are derived from trials with predominantly men participants, from lower quality, observational studies, or anecdotal evidence. Guideline recommendations for women who are pregnant or lactating are typically based on opinion as there is little evidence to guide them. In this review, we discuss trial design factors independently associated with the under-enrollment of women, identify possible strategies to increase the enrollment of women in trials, and suggest multi-level actions that could close sex-based research disparities. Recruiting and retaining women trialists, independently associated with increased enrollment of women and Black, Indigenous, and Persons of Color (BIPOC) participants, and diversifying research teams may be effective approaches. Modifying trial design by eliminating default sex-specific exclusion criteria, developing patient-centered consent and participation processes, incorporating pragmatic follow-up schemes, and incorporating sex/gender analysis into trial planning may also increase the enrollment of women participants. Journals and funding bodies should require trials to report participant to prevalence ratios, sex-disaggregated trial flow, and sex-treatment interactions. Healthcare systems can help create research-ready cultures that both enhance patient engagement in trials and expedite end-of-trial knowledge translation.

Sex and survival following pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension: a Scandinavian observational cohort study

Studies have suggested sex-related survival differences in chronic thromboembolic pulmonary hypertension (CTEPH). Whether long-term prognosis differs between men and women following pulmonary endarterectomy for CTEPH remains unclear. We investigated sex-specific survival after pulmonary endarterectomy for CTEPH. We included all patients who underwent pulmonary endarterectomy for CTEPH at two Scandinavian centers and obtained baseline characteristics and vital statuses from patient charts and national health-data registers. Propensity scores and weighting were used to account for baseline differences. Flexible parametric survival models were employed to estimate the association between sex and all-cause mortality and the absolute survival differences. The expected survival in an age-, sex-, and year of surgery matched general population was obtained from the Human Mortality Database, and the relative survival was used to estimate cause-specific mortality. A total of 444 patients were included, comprising 260 (59%) men and 184 (41%) women. Unadjusted 30-day mortality was 4.2% in men versus 9.8% in women (p = 0.020). In weighted analyses, long-term survival did not differ significantly in women compared with men (hazard ratio: 1.36; 95% confidence interval: 0.89–2.06). Relative survival at 15 years conditional on 30-day survival was 94% (79%–107%) in men versus 75% (59%–88%) in women. In patients who underwent pulmonary endarterectomy for CTEPH, early mortality was higher in women compared with men. After adjustment for differences in baseline characteristics, female sex was not associated with long-term survival. However, relative survival analyses suggested that the observed survival in men was close to the expected survival in the matched general population, whereas survival in women deviated notably from the matched general population.

Factors Associated With Racial and Ethnic Diversity Among Heart Failure Trial Participants: A Systematic Bibliometric Review

BACKGROUND

Heart failure has a disproportionate burden on patients who are Black, Indigenous, and people of color (BIPOC), but not much is known about representation of these groups in randomized controlled trials (RCTs). We explored temporal trends in and RCT factors associated with the reporting of race and ethnicity data and the enrollment of BIPOC in heart failure RCTs.

METHODS

We searched MEDLINE, EMBASE, and CINAHL for heart failure RCTs published in journals with an impact factor ≥10 between January 1, 2000 and June 17, 2020. We used the Cochran-Armitage and Jonchkeere-Terpstra tests to examine temporal trends, and multivariable regression to assess the association between trial characteristics and outcomes.

RESULTS

Of 414 RCTs meeting inclusion criteria, only 157 (37.9% [95% CI, 33.2%-2.8%]) reported race and ethnicity data. Among 158 200 participants in these 157 RCTs, 29 512 (18.7% [95% CI, 18.5%-18.9%]) were BIPOC. There was a temporal increase in reporting of race and ethnicity data (29.5% in 2000-2003 to 54.7% in 2016-2020, P<0.001) and in enrollment of BIPOC (14.4% in 2000-2003 to 22.2% in 2016-2020, P=0.038). Trial leadership by a woman was independently associated with twice the odds of reporting race and ethnicity data (odds ratio, 2.0 [95% CI, 1.1-3.8]; P=0.028) and an 8.4% increase (95% CI, 1.9%-15.0%; P=0.013) in BIPOC enrollment.

CONCLUSIONS

A minority of heart failure RCTs reported race and ethnicity data, and among these, BIPOC were under-enrolled relative to disease distribution. Both reporting of race and ethnicity as well as enrollment of BIPOC increased between 2000 and 2020. After multivariable adjustment, trials led by women had greater odds of reporting race and ethnicity and enrolling BIPOC.

REGISTRATION

URL: https://www.crd.york.ac.uk/PROSPERO/; Unique identifier: CRD42021237497.

Heart Failure with Reduced Ejection Fraction-Does Sex Matter?

PURPOSE OF REVIEW

There is an increasing recognition of the importance of sex in susceptibility, clinical presentation, and outcomes for heart failure. This review focusses on heart failure with reduced ejection fraction (HFrEF), unravelling differences in biology, clinical and demographic features and evidence for diagnostic and therapeutic strategies. This is intended to inform clinicians and researchers regarding state-of-the-art evidence relevant to women, as well as areas of unmet need.

RECENT FINDINGS

Females are well recognised to be under-represented in clinical trials, but there have been some improvements in recent years. Data from the last 5 years reaffirms that women presenting with HFrEF women are older and have more comorbidities like hypertension, diabetes and obesity compared with men and are less likely to have ischaemic heart disease. Non-ischaemic aetiologies are more likely to be the cause of HFrEF in women, and women are more often symptomatic. Whilst mortality is less than in their male counterparts, HFrEF is associated with a bigger impact on quality of life in females. The implications of this for improved prevention, treatment and outcomes are discussed. This review reveals distinct sex differences in HFrEF pathophysiology, types of presentation, morbidity and mortality. In light of this, in order for future research and clinical medicine to be able to manage HFrEF adequately, there must be more representation of women in clinical trials as well as collaboration for the development of sex-specific management guidelines. Future research might also elucidate the biochemical foundation of the sex discrepancy in HFrEF.

Temporal Trends and Clinical Trial Characteristics Associated With the Inclusion of Women in Heart Failure Trial Steering Committees: A Systematic Review

BACKGROUND

Trial steering committees (TSCs) steer the conduct of randomized controlled trials (RCTs). We examined the gender composition of TSCs in impactful heart failure RCTs and explored whether trial leadership by a woman was independently associated with the inclusion of women in TSCs.

METHODS

We systematically searched MEDLINE, EMBASE, and CINAHL for heart failure RCTs published in journals with impact factor ≥10 between January 2000 and May 2019. We used the Jonckheere-Terpstra test to assess temporal trends and multivariable logistic regression to explore trial characteristics associated with TSC inclusion of women.

RESULTS

Of 403 RCTs that met inclusion criteria, 127 (31.5%) reported having a TSC but 20 of these (15.7%) did not identify members. Among 107 TSCs that listed members, 56 (52.3%) included women and 6 of these (10.7%) restricted women members to the RCT leaders. Of 1213 TSC members, 11.1% (95% CI, 9.4%-13.0%) were women, with no change in temporal trends (P=0.55). Women had greater odds of TSC inclusion in RCTs led by women (adjusted odds ratio, 2.48 [95% CI, 1.05-8.72], P=0.042); this association was nonsignificant when analysis excluded TSCs that restricted women to the RCT leaders (adjusted odds ratio 1.46 [95% CI, 0.43-4.91], P=0.36).

CONCLUSIONS

Women were included in 52.3% of TSCs and represented 11.1% of TSC members in 107 heart failure RCTs, with no change in trends since 2000. RCTs led by women had higher adjusted odds of including women in TSCs, partly due to the self-inclusion of RCT leaders in TSCs.