Sex differences in the pathophysiology, treatment, and outcomes in IHD

Ischemic Heart Disease in Women

This review synthesizes the current understanding of ischemic heart disease in women, briefly discussing differences in risk factors, presentation, and treatment. We have underscored the unique clinical phenotype of IHD in women with a higher prevalence of ischemia with non-obstructive coronary arteries. Further research is needed to elucidate the complexities of ischemic heart disease in women, understand the discordance between ischemic burden and clinical symptoms, and optimize treatment strategies.

Cardiorespiratory Fitness Benefits of Long-Term Maintenance-Phase Cardiac Rehabilitation in Males and Females: A Retrospective Cohort Study

Purpose

This study investigated if associations exist between enrolment delay and VO2peak over five years of maintenance-phase cardiac rehabilitation (CR) in males and females.

Method

Data were extracted from the records of participants who had enrolled for ≥ 1 year in CR and completed ≥ 2 cardiopulmonary exercise tests. Mixed model analyses examined VO2peak trajectories for up to five years of enrolment. Interactions between enrolment delay × enrolment duration, baseline age × enrolment duration, and baseline VO2peak × enrolment duration were explored for inclusion in the model.

Results

The charts of 151 males (aged 63.9 ± 9.4 y) and 32 females (aged 65.3 ± 9.0 y) were included in the analyses. The enrolment delay following a cardiovascular event was 1.8 ± 3.0 years for males and 1.3 ± 1.7 years for females. No associations were found between enrolment delay × enrolment duration on VO2peak in males (β[SEj, 0.07[0.05]; 95% CI -0.02, 0.16, p = 0.12) or in females (β[SE], 0.07[0.13j; 95% CI -0.18, 0.33, p = 0.57), but predicted trajectories suggest clinically significantly improvements in VO2 peak (range, 1.3 to 1.6 mL/kg/min).

Conclusions

Early enrolment in CR is recommended and encouraged, but the benefits of long-term CR are possible despite delays.

Association of cardiovascular health at old age with all-cause mortality: a prospective cohort study in China

BACKGROUND

Cardiovascular disease has become the leading cause of death worldwide, but there is a lack of data on whether cardiovascular health (CVH) is associated with elderly mortality in China. We investigated the relationship between the ideal CVH score of Chinese elderly and the all-cause mortality.

METHODS

The Beijing Elderly Comprehensive Health Cohort Study included a total of 4,499 participants aged 60 years and above. The CVH metric was calculated at baseline and had a score ranging from 0 to 12. The relationship of CVH metrics with all-cause mortality was investigated using Cox proportional hazard regression analysis. The robustness of results was tested using subgroup and sensitivity analysis.

RESULTS

The median CVH score among participants was 8.00 (2.00), with only 8.0% scoring 11-12 points. 667 deaths were observed during an average follow-up time of 8.2 years. Participants with a CVH score of 11-12 had a decreased risk of all-cause mortality when compared to those with a CVH score of 0-4(HR = 0.584, 95% CI: 0.373-0.913). Participants had a 7.5% lower risk of all-cause death with each unit higher CVH score (HR = 0.925, 95%CI: 0.885-0.967) with a linearly decreasing trend (P nonlinear = 0.575). The relationships were greater in younger elderly people and stroke patients (P interaction = 0.011 and 0.037. respectively). The consistency of significant trends in sensitivity analysis shows the robustness of association (P trend < 0.001).

CONCLUSIONS

Among the Chinese elderly, there was a linear relationship between improving CVH scores and a lower risk of all-cause mortality. Because of the enormous benefits brought by one point, strategies are essential for improving cardiovascular health attainment.

TRIAL REGISTRATION

This study was registered at China Clinical Trial Registration Center (ChiCTR2100049866).

Association of reproductive factors with cardiovascular disease risk in pre-menopausal women: nationwide population-based cohort study

BACKGROUND

Although the morbidity and mortality of cardiovascular diseases (CVD) are rising in young women, the risk factors of CVD among Korean pre-menopausal women have not been intensively investigated.

AIMS

To determine how age at menarche and other female reproductive factors are associated with the risk of CVD in pre-menopausal women.

METHODS AND RESULTS

A total of 1 088 992 pre-menopausal women who participated in health screening in 2009 were included. The study outcomes were myocardial infarction (MI) and ischaemic stroke. Cox proportional hazards regression analysis was conducted with adjustment of traditional CVD risk factors and reproductive factors.

RESULTS

Mean age was 43.8 ± 5.3 years (98.9%, < 55 years), 3.5% were current smokers, and 1.2% were heavy drinkers. During a mean follow-up of 8.3years [9 032 685.9 person-years (PY)], there were 10 876 CVD events (1.0 per 1000 PY).With later menarche, the risk of CVD increased; ≤12 years [adjusted hazard ratio (HR) 1.04, 95% confidence interval 0.93-1.16], 13 years (reference), 14 years (1.06, 0.98-1.14), 15 years (1.15, 1.07-1.24), 16 years (1.23, 1.14-1.34), and ≥17 years (1.33, 1.24-1.44). Compared with non-users, oral contraceptives (OC) users (≥1 year) had an increased risk of CVD (1.11, 1.01-1.22) (P for trend = 0.007).

CONCLUSIONS

Later menarche than the mean age at menarche (13 years old) and the use of OC (≥1 year) were associated with a higher risk of CVD, after adjusting for traditional cardiovascular risk factors. This study suggests that female reproductive factors could be unique risk factors for CVD in pre-menopausal women.

Current status of nuclear cardiology practice in Latin America and the Caribbean, in the era of multimodality cardiac imaging approach: 2022 update

Cardiovascular diseases (CVDs) are the leading cause of mortality in Latin America and the Caribbean (LAC), with the risk in men being slightly higher than in women. The coronavirus disease 2019 (COVID-19) pandemic caused a significant reduction in the number of cardiac diagnostic procedures globally and in particular in LAC. Nuclear cardiology is available in the region, but there is variability in terms of existing technology, radiopharmaceuticals, and human resources. In the region, there are 2385 single photon emission computed tomography (SPECT) and 315 PET scanners, Argentina and Brazil have the largest number. There is an increasing number of new technologies such as cadmium-zinc-telluride (CZT) cardiac-dedicated gamma cameras, SPECT/computed tomography (CT), and PET/CT. All countries performed myocardial perfusion imaging studies, mainly gated-SPECT; the rest are multi-gated acquisition, mainly for cardiac toxicity; detection of viability; rest gated SPECT in patients with dilated cardiomyopathy, and bone-avid tracer cardiac scintigraphy for transthyretin cardiac amyloidosis diagnosis. Regarding other non-nuclear cardiac imaging modalities, Argentina, Colombia, and Chile have the highest ratio of CT scanners, while Brazil, Argentina, and Chile show the highest ratio of MRI scanners. The development of nuclear cardiology and other advanced imaging modalities is challenged by the high cost of equipment, lack of equipment maintenance and service, insufficient-specific training both for imaging specialists and referring clinicians, and lack of awareness of cardiologists or other referring physicians on the clinical applications of nuclear cardiology. Another important aspect to consider is the necessity of implementing cardiac imaging multimodality training. A joint work of nuclear medicine specialists, radiologists, cardiologists, and clinicians, in general, is mandatory to achieve this goal. National, regional, and international cooperation including support from scientific professional societies such as the American Society of Nuclear Cardiology and Latin American Association of Biology and Nuclear Medicine Societies, cardiological societies, and organizations such as the International Atomic Energy Agency, and Pan American Health Organization, as well as government commitment are key factors in the overall efforts to tackle the burden of cardiovascular diseases in the region.

Association of Number of Live Births With Electrocardiographic and Cardiac Structural Changes

Background Pregnancy is a major life event unique to women and leads to significant hemodynamic, hormonal, and metabolic changes. The purpose of this study was to use the DHS (Dallas Heart Study), a multiethnic population-based cohort study of Dallas county adults, to evaluate the association between number of live births and cardiac magnetic resonance imaging and ECG parameters later in life. Methods and Results Women were included if they had data on self-reported live births and ECG or cardiac magnetic resonance imaging measurements. The 3014 women were stratified by number of live births: 0, 1, 2, 3, 4, and ≥5. Higher number of live births was associated with larger left ventricular (LV) end-diastolic volume (β, 1.31±0.41; P<0.01), LV end-systolic volume (β, 0.83±0.24; P<0.01), and LV mass (β, 1.13±0.49; P=0.02) and lower LV ejection fraction (β, -0.004±0.0014; P<0.01). Increasing parity was associated with longer PR intervals (β, 1.07±0.38; P<0.01). Subgroup analysis by race demonstrated that the association between number of live births and magnetic resonance imaging parameters (LV end-diastolic volume, LV end-systolic volume, and LV ejection fraction) only remained significant in Black women (P value for interaction <0.05). Conclusions Increasing number of live births was associated with electrocardiographic and cardiac structural changes in a multiethnic population. When stratified by race and ethnicity, magnetic resonance imaging structural changes only remained significant in Black participants. Whether these changes are pathologic and increase the risk of heart failure or arrhythmias in multiparous women warrants further investigation.

Age-dependent and sex-dependent differences in mortality from influenza-associated cardiovascular diseases among older adults in Shanghai, China: a population-based study

OBJECTIVES

Influenza epidemics lead to substantial morbidity and mortality among older adults. This study aimed to analyse and assess the age-specific and sex-specific differences in mortality rates for cardiovascular disease (CVD) associated with influenza in older adults.

DESIGN

We obtained weekly data on mortality from CVD in adults≥60 years, categorised into five age groups. We used a quasi-Poisson model and adjusted for long-term and seasonal trends and absolute humidity as confounding factors. The male-to-female ratio (M/F ratio) was an indicator for assessing sex differences.

SETTING

Shanghai, China.

PARTICIPANT

We analysed 440 107 CVD deaths in adults aged ≥60 years, including 44 913 cases positive for influenza and 1 927 487 outpatient visits for influenza-like illness from 2010 to 2019.

MAIN OUTCOME MEASURES

Age-specific and sex-specific excess CVD mortality rates in older adults for various combinations of CVDs and influenza viruses.

RESULTS

Variations were observed in the excess mortality from CVD, ischaemic heart disease (IHD) and stroke depending on the influenza types/subtypes in different age and sex categories. The ≥85 years group had the highest excess mortality rates per 100 000 persons for CVD, IHD and stroke, while influenza A (H3N2) virus accounted for the highest mortality from CVD, IHD and stroke in people aged ≥65 years. Older men had a significantly lower influenza-associated IHD mortality rate than women, with an M/F ratio of 0.77 (p<0.05).

CONCLUSIONS

Excess mortality rates for CVDs associated with influenza increased with age in older adults. The risk for influenza-associated IHD mortality was significantly higher in older women than men. Our findings will help implement targeted health strategies, including the promotion of influenza vaccination and early therapeutic intervention for the older population with CVD, to curb the influenza burden effectively.

Age-Period-Cohort Analysis of Ischemic Heart Disease Morbidity and Mortality in China, 1990-2019

BACKGROUND

The disease burden of ischemic heart disease (IHD) continues to increase. This study aimed to assess the age, period, and cohort effects on the long-term trends of IHD incidence and mortality in China from 1990 to 2019.

METHODS AND RESULTS

The data were obtained from the Global Burden of Disease Study (GBD) 2019, and the age-standardized incidence/mortality rate (ASIR/ASMR) was calculated. The age-period-cohort (APC) model, which is a generalized linear model revealing the correlation of disease rate and attained age, period, and cohort, was applied to estimate the net drift (estimated annual percentage change [EAPC]s), the local drifts (age-specific EAPCs), the age, period, and cohort effects. The analyses elucidated that the ASIR and ASMR of IHD declined after 2013. The net drift of incidence was 0.212% in females, and the net drift of mortality was 0.371% in males. The local drifts of mortality were above 0 in males aged 20-84 years and in females aged 65-84 years. The age effects showed elevated trends during the study period. The period effects declined after 2013. The cohort effects of mortality in males were higher than that in females.

CONCLUSIONS

The decrease of ASIR and ASMR indicated that measures to prevent IHD have been effective in China. However, the cardiovascular health of the elderly and males should be considered in future policy decisions.

Sex-related differences among young adults with heart failure in Sweden

BACKGROUND

Differences between the sexes among the non-elderly with heart failure (HF) have been insufficiently evaluated. This study aims to investigate sex-related differences in early-onset HF.

METHODS

Patients aged 18 to 54 years who were registered from 2003 to 2014 in the Swedish Heart Failure Register were included. Each patient was matched with two controls from the Swedish Total Population Register. Data on comorbidities and outcomes were obtained through the National Patient Register and Cause of Death Register.

RESULTS

We identified 3752 patients and 7425 controls. Of the patients, 971 (25.9%) were women and 2781 (74.1%) were men with a mean (standard deviation) age of 44.9 (8.4) and 46.4 (7.3) years, respectively. Men had more hypertension and ischemic heart disease, whereas women had more congenital heart disease and obesity. During the median follow-up of 4.87 years, 26.5 and 24.7 per 1000 person-years male and female patients died, compared with 3.61 and 2.01 per 1000 person-years male and female controls, respectively. The adjusted hazard ratios for all-cause mortality, compared with controls, were 4.77 (3.78-6.01) in men and 7.84 (4.85-12.7) in women (p for sex difference = 0.11). When HF was diagnosed at 30, 35, 40, and 45 years, women and men lost up to 24.6 and 24.2, 24.4 and 20.9, 20.5 and 18.3, and 20.7 and 16.5 years of life, respectively.

CONCLUSION

Long-term mortality was similar between the sexes. Women lost more years of life than men.

Women Have Lower Mortality Than Men After Attending a Long-Term Medically Supervised Exercise Program

PURPOSE

Medically supervised exercise programs (MSEPs) are equally recommended for men and women with cardiovascular disease (CVD). Aware of the lower CVD mortality in women, we hypothesized that among patients attending a MSEP, women would also have better survival.

METHODS

Data from men and women, who were enrolled in a MSEP between 1994 and 2018, were retrospectively analyzed. Sessions included aerobic, resistance, flexibility and balance exercises, and cardiopulmonary exercise test was performed. Date and underlying cause of death were obtained. Kaplan-Meier methods and Cox proportional hazards regression were used for survival analysis.

RESULTS

A total of 2236 participants (66% men, age range 33-85 yr) attended a median of 52 (18, 172) exercise sessions, and 23% died during 11 (6, 16) yr of follow-up. In both sexes, CVD was the leading cause of death (39%). Overall, women had a more favorable clinical profile and a longer survival compared to men (HR = 0.71: 95% CI, 0.58-0.85; P < .01). When considering those with coronary artery disease and similar clinical profile, although women had a lower percentage of sex- and age-predicted maximal oxygen uptake at baseline than men (58 vs 78%; P < .01), after adjusting for age, women still had a better long-term survival (HR = 0.68: 95% CI, 0.49-0.93; P = .02).

CONCLUSION

Survival after attendance to a long-term MSEP was better among women, despite lower baseline cardiorespiratory fitness. Future studies should address whether men and women would similarly benefit when participating in an MSEP.

Assessment of Atypical Cardiovascular Risk Factors Using Single Photon Emission Computed Tomography in Mexican Women

BACKGROUND

Ischemic heart disease (IHD) is a health care problem in women that increases morbimortality, particularly in developing countries. There is limited information regarding atypical risk factors associated with IHD in Mexican women.

AIM

To explore risk factors in women that could contribute to IHD and myocardial dysfunction using the single photon emission computed tomography (SPECT) myocardial perfusion study (MPS).

METHODS

We designed a cross-sectional study in which we evaluated atypical and typical risk factors using a clinical questionnaire. We performed a SPECT-MPS to evaluate the presence of ischemia/infarction, decreased left ventricular ejection fraction, systolic dyssynchrony and diastolic function by peak filling rate and time to peak filling rate.

RESULTS

172 women were included, 64 with IHD. Adverse events during pregnancy (premature birth and miscarriage), rheumatoid arthritis, gynecological conditions (menopause and age of first menstruation) and low educational level, together with previously known typical risk factors were associated with infarction or ischemia and ventricular dysfunction. Potential associated factors for systolic dyssynchrony were rheumatoid arthritis (OR: 2.90, 95% CI: 0.95-8.66, p = 0.054) and history of premature birth (OR: 0.13, 95% CI: 0.01-0.66, p <0.01). Although those women with arterial hypertension and smoking shown an increased risk for dyssynchrony, these factors were not statistically significant. Low-educational level (OR 2.16, 95% CI 1.1-4.18, p = 0.019) was associated with decreased peak filling rate.

CONCLUSION

The presence of atypical risk factors in women could lead to decreased myocardial function, particularly in women at risk of developing IHD.

Sex disparities in cardiovascular health metrics among rural-dwelling older adults in China: a population-based study

Background

Cardiovascular health (CVH) metrics among Chinese older adults are poorly understood. We investigated sex disparities in CVH metrics and their management among rural-dwelling older adults in China.

Methods

This community-based study included 5026 participants (age ≥ 65 years; 57.2% women) in the baseline survey of a multimodal intervention study in rural China. In March–September 2018, data were collected through face-to-face interviews, clinical examinations, and laboratory tests. We defined six CVH metrics (three behavioral factors—smoking, body mass index, and physical activity; three biological factors—blood pressure, total cholesterol, and blood glucose) following the modified American Heart Association’s recommendations. We performed descriptive analysis separately for men and women.

Results

Of all participants, only 0.8% achieved ideal levels in all six CVH metrics. Men were more likely than women to have ideal levels in all CVH metrics but smoking. Women had higher prevalence of ideal global (9.7% vs. 7.8%) and behavioral (18.3% vs. 9.5%) CVH metrics (p < 0.001), whereas men had higher prevalence of ideal biological CVH metrics (5.4% vs. 3.5%, p < 0.001). The prevalence of ideal global and behavioral CVH metrics increased with age in both women and men (p for trend< 0.001). Women were more likely to be aware of their hypertension and diabetes, and to receive antihypertensive treatment, while men were more likely to achieve the goal of high cholesterol treatment (p < 0.05).

Conclusions

The CVH metrics among older adults living in the rural communities in China are characterized by an extremely low proportion of optimal global CVH metrics and distinct sex differences, alongside poor management of major biological risk factors.

Trial registration

ChiCTR1800017758 (Aug 13, 2018).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02116-x.

Participation of Women in Clinical Trials Supporting FDA Approval of Cardiovascular Drugs

BACKGROUND

Concerns exist that women are underrepresented in trials of cardiovascular medications.

OBJECTIVES

The authors sought to examine women's participation and the reported safety and efficacy by gender for pivotal cardiovascular disease (CVD) trials submitted to the U.S. Food and Drug Administration (FDA) supporting marketing applications.

METHODS

On the basis of publicly available FDA reviews, the authors assessed enrollment of women in trials supporting 36 drug approvals from 2005 to 2015. Prevalence-corrected estimates for the participation of women were calculated as the percentage of women among trial participants divided by the percentage of women in the disease population (participation to prevalence ratio [PPR]), with a range between 0.8 and 1.2 reflecting similar representation of women in the trial and disease population. Sex differences in efficacy and safety were assessed.

RESULTS

The proportion of women enrolled ranged from 22% to 81% (mean 46%). The calculated PPR by disease area was within or above the desirable range for atrial fibrillation (0.8 to 1.1), hypertension (0.9), and pulmonary arterial hypertension (1.4); PPR was <0.8 for heart failure (0.5 to 0.6), coronary artery disease (0.6), and acute coronary syndrome/myocardial infarction (0.6). The authors found little indication of clinically meaningful gender differences in efficacy or safety. Gender differences in efficacy or safety were described in labeling for 4 drugs.

CONCLUSIONS

Women were well represented in trials of drugs for hypertension and atrial fibrillation, and overrepresented for pulmonary arterial hypertension. Representation of women fell below a PPR of 0.8 for trials in heart failure, coronary artery disease, and acute coronary syndrome. Minimal gender differences in drug efficacy and safety profiles were observed.

Sex differences in brain activation patterns with mental stress in patients with coronary artery disease

Background

Stress is an important contributor to myocardial ischemia and the progression of coronary artery disease (CAD), and women are more susceptible than men to these effects. Little is known, however, about the neural basis of these sex differences.

Methods

We investigated sex differences in neural correlates of mental stress in a sample of 53 female and 112 male participants (N = 165) with CAD, with and without mental stress-induced myocardial ischemia (MSI), during exposure to mental arithmetic tasks and public speaking stress tasks using high-resolution positron emission tomography (HR-PET) and radiolabeled water imaging of the brain.

Results

Women compared to men had significantly greater activation with stress in the right frontal (BA 9, 44), right parietal lobe (Area 3, 6, 40), right posterior cingulate gyrus (BA 31), bilateral cerebellum, and left temporal/fusiform gyrus (BA 37) and greater deactivation in bilateral anterior cingulate gyrus (BA 24, 32), bilateral medial frontal gyrus (BA 6, 8, 9, 10), right parahippocampal gyrus, and right middle temporal gyrus (BA 21). Women with MSI (but not those without MSI) showed significantly greater activation than men in the right posterior cingulate gyrus (BA 31) and greater deactivation in several frontal and temporal lobe areas.

Conclusion

Men and women with CAD show differences in responses to stress in brain limbic areas that regulate emotion, and these functional responses differ by MSI status. Our results suggest that the cingulate gyrus may be involved in sex differences in MSI.

Electronic supplementary material

The online version of this article (10.1186/s13293-019-0248-4) contains supplementary material, which is available to authorized users.

N-terminal pro-B-type natriuretic peptide in chronic heart failure: The impact of sex across the ejection fraction spectrum

OBJECTIVE

The aim was to assess sex-specific differences in N-terminal B-type natriuretic peptide (NT-proBNP) regarding concentrations, predictors of high concentrations, and prognostic role, in a large and unselected population with chronic heart failure (HF) with preserved (HFpEF), mid-range (HFmrEF), and reduced ejection fraction (HFrEF).

METHODS AND RESULTS

In 9847 outpatients with HFpEF, HFmrEF, and HFrEF (49 vs. 35 vs. 25% females, respectively) from the Swedish HF Registry, median NT-proBNP concentrations were 1598 ng/L in females vs. 1310 ng/L in males in HFpEF, 1764 vs. 1464 ng/L in HFmrEF, and 2543 vs. 2226 ng/L in HFrEF (p < 0.05 for all). The differences persisted after multiple adjustment. The largest sex-difference in NT-proBNP levels was observed in HFpEF with sinus rhythm, where median concentrations were 1.4 folds higher in females (923 vs. 647 ng/L). Independent predictors of NT-proBNP levels (defined as above the different medians according to sex and HF phenotype) were overall consistent across sexes and EF. NT-proBNP levels were similarly associated with risk of all-cause death/HF hospitalization in both sexes regardless of EF.

CONCLUSION

Concentrations of NT-proBNP were higher in females across the EF spectrum, with larger relative differences in HFpEF with sinus rhythm. However, similar predictors of high levels were observed in both sexes. There were no sex-differences in the prognostic role of NT-proBNP. These findings support the use of NT-proBNP for prognostic purposes in chronic HF, regardless of sex.

Tailored nurse-led cardiac rehabilitation after myocardial infarction results in better risk factor control at one year compared to traditional care: a retrospective observational study

BACKGROUND

Cardiac rehabilitation improves prognosis after an acute myocardial infarction (AMI), however, the optimal method of implementation is unknown. The aim of the study was to evaluate the effect of individually-tailored, nurse-led cardiac rehabilitation on patient outcomes.

METHOD

This single-centre retrospective observational study included 217 patients (62 ± 9 years, 73% men). All patients attended cardiac rehabilitation including at least two follow-up consultations with a nurse. Patients receiving traditional care (n = 105) had a routine cardiologist consultation, while for those receiving tailored care (n = 112) their need for a cardiologist consultation was individually evaluated by the nurses. Regression analysis was used to analyse risk factor control and hospital readmissions at one year.

RESULTS

Patients in the tailored group achieved better control of total cholesterol (- 0.1 vs + 0.4 mmol/L change between baseline (time of index event) and 12-14-month follow-up, (p = 0.01), LDL cholesterol (- 0.1 vs + 0.2 mmol/L, p = 0.02) and systolic blood pressure (- 2.1 vs + 4.3 mmHg, p = 0.01). Active smokers, at baseline, were more often smoke-free at one-year in the tailored group [OR 0.32 (0.1-1.0), p = 0.05]. There was a no significant difference in re-admissions during the first year of follow-up. In the tailored group 60% of the patients had a cardiologist consultation compared to 98% in the traditional group (p < 0.001). The number of nurse visits was the same in both groups, while the number of telephone contacts was 38% higher in the tailored group (p = 0.02).

CONCLUSION

A tailored, nurse-led cardiac rehabilitation programme can improve risk factor management in post-AMI patients.

Sex and Gender Differences Research Design for Basic, Clinical, and Population Studies: Essentials for Investigators

A sex- and gender-informed perspective increases rigor, promotes discovery, and expands the relevance of biomedical research. In the current era of accountability to present data for males and females, thoughtful and deliberate methodology can improve study design and inference in sex and gender differences research. We address issues of motivation, subject selection, sample size, data collection, analysis, and interpretation, considering implications for basic, clinical, and population research. In particular, we focus on methods to test sex/gender differences as effect modification or interaction, and discuss why some inferences from sex-stratified data should be viewed with caution. Without careful methodology, the pursuit of sex difference research, despite a mandate from funding agencies, will result in a literature of contradiction. However, given the historic lack of attention to sex differences, the absence of evidence for sex differences is not necessarily evidence of the absence of sex differences. Thoughtfully conceived and conducted sex and gender differences research is needed to drive scientific and therapeutic discovery for all sexes and genders.

Inferior long-term allograft and patient outcomes among recipients of offspring living donor kidneys

While offspring-to-parent living donor kidney transplantations may represent an ideal donor-recipient combination to optimize long-term transplantation outcomes, the sex-specific long-term success of these transplantations remains unclear. We hypothesize that allograft and recipient survivals in offspring-to-parent living donor kidney transplantation differ between men and women due to donor-specific alloimmunization during pregnancy. We retrospectively analyzed long-term allograft and patient survival among men and women who received an offspring living donor kidney compared with those who received other haplotype-matched living donor kidneys. Based on multivariable Cox proportional hazards modeling of Organ Procurement and Transplantation Network data from 2001 to 2015, we found that both men and women who received offspring living donor kidneys had significantly increased mortality compared with recipients who received nonoffspring living donor kidneys. While male recipients of any living donor kidney had greater risk of mortality and allograft failure than female recipients, there was no significant difference in all-cause allograft failure or mortality in male versus female recipients of offspring living donor kidney transplantations. Our analysis demonstrated no significant interaction between recipient sex and donor offspring status. We conclude that nonoffspring living donors should be considered whenever feasible for both men and women with multiple donor options.

Chronic Variable Stress Induces Sex-Specific Alterations in Social Behavior and Neuropeptide Expression in the Mouse

Chronic exposure to stressors impairs the function of multiple organ systems and has been implicated in increased disease risk. In the rodent, the chronic variable stress (CVS) paradigm has successfully modeled several stress-related illnesses. Despite striking disparities between men and women in the prevalence and etiology of disorders associated with chronic stress, most preclinical research examining chronic stressor exposure has focused on male subjects. One potential mediator of the consequences of CVS is oxytocin (OT), a known regulator of stress neurocircuitry and behavior. To ascertain the sex-specific effects of CVS in the C57BL/6 mouse on OT and the structurally similar neuropeptide arginine vasopressin (AVP), the numbers of immunoreactive and mRNA-containing neurons in the paraventricular nucleus (PVN) and supraoptic nucleus (SON) were determined using immunohistochemistry and in situ hybridization, respectively. In addition, the mice underwent a battery of behavioral tests to determine whether CVS affects social behaviors known to be regulated by OT and AVP. Six weeks of CVS increased sociability in the female mouse and decreased PVN OT immunoreactivity (ir) and AVP mRNA. In the male mice, CVS decreased PVN OT mRNA but had no effect on social behavior, AVP, or OT-ir. CVS also increased the soma volume for PVN OT neurons. In contrast, OT and AVP neurons in the SON were unaffected by CVS treatment. These findings demonstrate clear sex differences in the effects of CVS on neuropeptides in the mouse, suggest a pathway through which CVS alters sociability and stress-coping responses in females and reveals a vulnerability to CVS in the C57BL/6 mouse strain.

Trends in diagnosis-specific work disability before and after ischaemic heart disease: a nationwide population-based cohort study in Sweden

OBJECTIVES

We examined trends of diagnosis-specific work disability before and after ischaemic heart disease (IHD).

DESIGN

Participants were followed 4 years before and 4 years after an IHD event for diagnosis-specific work disability (sickness absence and disability pension).

SETTING AND PARTICIPANTS

A Swedish population-based cohort study using register data on all individuals aged 25-60 years, living in Sweden, and who suffered their first IHD event in 2006-2008 (n=23 971) was conducted.

RESULTS

Before the event, the most common diagnoses of work disability were musculoskeletal disorders (21 annual days for men and 44 for women) and mental disorders (19 men and 31 for women). After multivariable adjustments, we observed a fivefold increase (from 12 to 60 days) in work disability due to diseases of the circulatory system in the first postevent year compared with the last pre-event year among men. Among women, the corresponding increase was fourfold (from 14 to 62 days). By the second postevent year, the number of work disability days decreased significantly compared with the first postevent year among both sexes (to 19 days among men and 23 days among women). Among women, mean days of work disability due to diseases of the circulatory system remained at a higher level than among men during the postevent years. Work disability risk after versus before an IHD event was slightly higher among men (rate ratio (RR) 2.49; 95% CI 2.36 to 2.62) than among women (RR 2.29, 95% CI 2.12 to 2.49). When pre-event long-term work disability was excluded, diseases of the circulatory system were the most prevalent diagnosis for work disability after an IHD event among both men and women.

CONCLUSIONS

An IHD event was strongly associated with an increase in work disability due to diseases of the circulatory system, especially among men and particularly in the first postevent year.

Challenges in Sex- and Gender-Centered Prevention and Management of Cardiovascular Disease: Implications of Genetic, Metabolic, and Environmental Paths

The recognition of cardiovascular disease (CVD) as a "male" privilege has been a commonly held concept. However, emerging data describe another reality. Heterogeneities have been convincingly demonstrated regarding CVD manifestations, risk factor burden, and prognosis between males and females. The aim of the present narrative review was to highlight sex- and gender-related discrepancies in primary and secondary CVD prevention, underscoring plausible underlying mechanisms. Manifestation of CVD in women is characterized by atypical symptoms/signs and inadequately studied pathophysiology features challenging accurate diagnosis and effective treatment. Regarding CVD risk assessment, the burden and effect size of conventional, novel, and female-specific risk factors needs better clarification. Hitherto outcomes are nonconsistent, while most importantly, the interpretation of the attendant metabolic paths remains a challenge; the interactions among genetic, metabolic, and environmental factors are of high complexity regulated by genomic and nongenomic sex hormones effects. To deal with these key points, the National Institutes of Health currently calls upon investigators to provide a sex- and gender-specific reporting in all health research hypotheses. The implementation of high-quality studies addressing these issues is an imperative need to maximize cost-effectiveness in prevention and management strategies.

Coronary Surgery in Women and the Challenges We Face

This review was undertaken to understand the dynamics that have shaped our current treatment of women who undergo coronary artery bypass grafting (CABG) and summarize the current literature on surgical revascularization in women. There has been improved access to CABG over the past several decades. Despite this, compared with men, CABG in women involves fewer grafts and less frequent use of arterial grafts, the latter having improved long-term patency compared with saphenous vein grafts. We attempt to determine whether the adverse clinical profile of women, when referred for CABG is responsible for this finding. Female coronary anatomy and pathophysiology are reviewed and an attempt is made to understand how this might affect decisions of selection and outcome measures post CABG. We review the short-term, long-term, and quality of life outcomes in women. These data are taken from large databases, as well as from more recent publications. Randomized controlled trial data and meta-analytic data are used when available. Differential use of and outcomes of surgical strategies, including off-pump CABG and total arterial revascularization, are contrasted with those in men. This review shows that there continues to be widespread differences in surgical approach to coronary artery disease in female vs male patients. We provide evidence suggestive of the existence of issues specific to women that affect selection for surgical procedures and outcomes in women. More work is required to understand the reason for these differences and how to optimize sex-specific outcomes.

Cardiac Rehabilitation Following Acute Coronary Syndrome in Women

OPINION STATEMENT

Acute coronary syndrome (ACS) is among the leading burdens of disease among women. It is a significant driver of morbidity and chronically undermines their quality of life. Cardiac rehabilitation (CR) is indicated for ACS patients in clinical practice guidelines, including those specifically for women. CR is a multi-component model of care, proven to reduce mortality and morbidity, including in women. However, women are significantly less likely to be referred to CR by providers, and if they are referred, to enroll and adhere to programs. Reasons include lack of physician encouragement, preference not to feel fatigue and pain, transportation barriers, comorbidities and caregiving obligations. Strategies to mitigate this under-use include systematic early inpatient referral, tailoring programs to meet women's needs and preferences (e.g., offering dance, opportunities for social interaction), and offering non-supervised delivery models. Unfortunately, these strategies are not widely available to women. Given the greater longevity seen in women, the critical role CR plays in augmenting quality of life in this population must be recognized and care providers must do more to facilitate referral to and encourage participating in CR programs.

Sex-Based Differences in Cardiometabolic Biomarkers

BACKGROUND

Few data are available comparing cardiovascular disease (CVD) biomarker profiles between women and men in the general population. We analyzed sex-based differences in multiple biomarkers reflecting distinct pathophysiological pathways, accounting for differences between women and men in CVD risk factors, body composition, and cardiac morphology.

METHODS

A cross-sectional analysis was performed using data from the Dallas Heart Study, a multiethnic population-based study. Associations between sex and 30 distinct biomarkers representative of 6 pathophysiological categories were evaluated using multivariable linear regression adjusting for age, race, traditional CVD risk factors, kidney function, insulin resistance, MRI and dual-energy x-ray absorptiometry measures of body composition and fat distribution, and left ventricular mass.

RESULTS

After excluding participants with CVD, the study population included 3439 individuals, mean age 43 years, 56% women, and 52% black. Significant sex-based differences were seen in multiple categories of biomarkers, including lipids, adipokines, and biomarkers of inflammation, endothelial dysfunction, myocyte injury and stress, and kidney function. In fully adjusted models, women had higher levels of high-density lipoprotein cholesterol and high-density lipoprotein particle concentration, leptin, d-dimer, homoarginine, and N-terminal pro B-type natriuretic peptide, and lower levels of low-density lipoprotein cholesterol, adiponectin, lipoprotein-associated phospholipase A2 mass and activity, monocyte chemoattractant protein-1, soluble endothelial cell adhesion molecule, symmetrical dimethylarginine, asymmetrical dimethylarginine, high-sensitivity troponin T, and cystatin C.

CONCLUSIONS

Biomarker profiles differ significantly between women and men in the general population. Sex differences were most apparent for biomarkers of adiposity, endothelial dysfunction, inflammatory cell recruitment, and cardiac stress and injury. Future studies are needed to characterize whether pathophysiological processes delineated by these biomarkers contribute to sex-based differences in the development and complications of CVD.

Young Hispanic Women Experience Higher In-Hospital Mortality Following an Acute Myocardial Infarction

Background

Although mortality rates for acute myocardial infarction (AMI) have declined for men and women, prior studies have reported a sex gap in mortality such that younger women were most likely to die after an AMI.

Methods and Results

We sought to explore the impact of race and ethnicity on the sex gap in AMI patterns of care and mortality for younger women in a contemporary patient cohort. We constructed multivariable hierarchical logistic regression models to examine trends in AMI hospitalizations, procedures, and in-hospital mortality by sex, age (<65 and ≥65 years), and race/ethnicity (white, black, and Hispanic). Analyses were derived from 194 071 patients who were hospitalized for an AMI with available race and ethnicity data from the 2009–2010 National Inpatient Sample. Hospitalization rates, procedures (coronary angiography, percutaneous coronary interventions, and cardiac bypass surgery), and inpatient mortality were analyzed across age, sex, and race/ethnic groups. There was significant variation in hospitalization rates by age and race/ethnicity. All racial/ethnic groups were less likely to undergo invasive procedures compared with white men (P<0.001). After adjustment for comorbidities, younger Hispanic women experienced higher in-hospital mortality compared with younger white men, with an odds ratio of 1.5 (95% CI 1.2 to 1.9), adjusted for age and comorbidities.

Conclusion

We found significant racial and sex disparities in AMI hospitalizations, care patterns, and mortality, with higher in-hospital mortality experienced by younger Hispanic women. Future studies are necessary to explore determinants of these significant racial and sex disparities in outcomes for AMI.