Sex Differences in the Coronary System

Coronary Artery Bypass Graft Failure in Women: Incidence and Clinical Implications

BACKGROUND

Women have worse outcomes after coronary artery bypass surgery (CABG) than men.

OBJECTIVES

This study aimed to determine the incidence of CABG graft failure in women, its association with cardiac events, and whether it contributes to sex-related differences in outcomes.

METHODS

A pooled analysis of individual patient data from randomized clinical trials with systematic imaging follow-up was performed. Multivariable logistic regression models were used to assess the association of graft failure with myocardial infarction and repeat revascularization between CABG and imaging (primary outcome) and death after imaging (secondary outcome). Mediation analysis was performed to evaluate the effect of graft failure on the association between female sex and risk of death.

RESULTS

Seven randomized clinical trials (N = 4,413, 777 women) were included. At a median imaging follow-up of 1.03 years, graft failure was significantly more frequent among women than men (37.3% vs 32.9% at the patient-level and 20.5% vs 15.8% at the graft level; P = 0.02 and P < 0.001, respectively). In women, graft failure was associated with an increased risk of myocardial infarction and repeat revascularization (OR: 3.94; 95% CI: 1.79-8.67) and death (OR: 3.18; 95% CI: 1.73-5.85). Female sex was independently associated with the risk of death (direct effect, HR: 1.84; 95% CI: 1.35-2.50) but the association was not mediated by graft failure (indirect effect, HR: 1.04; 95% CI: 0.86-1.26).

CONCLUSIONS

Graft failure is more frequent in women and is associated with adverse cardiac events. The excess mortality risk associated with female sex among CABG patients is not mediated by graft failure.

Vasodilator reactive oxygen species ameliorate perturbed myocardial oxygen delivery in exercising swine with multiple comorbidities

Multiple common cardiovascular comorbidities produce coronary microvascular dysfunction. We previously observed in swine that a combination of diabetes mellitus (DM), high fat diet (HFD) and chronic kidney disease (CKD) induced systemic inflammation, increased oxidative stress and produced coronary endothelial dysfunction, altering control of coronary microvascular tone via loss of NO bioavailability, which was associated with an increase in circulating endothelin (ET). In the present study, we tested the hypotheses that (1) ROS scavenging and (2) ETA+B-receptor blockade improve myocardial oxygen delivery in the same female swine model. Healthy female swine on normal pig chow served as controls (Normal). Five months after induction of DM (streptozotocin, 3 × 50 mg kg-1 i.v.), hypercholesterolemia (HFD) and CKD (renal embolization), swine were chronically instrumented and studied at rest and during exercise. Sustained hyperglycemia, hypercholesterolemia and renal dysfunction were accompanied by systemic inflammation and oxidative stress. In vivo ROS scavenging (TEMPOL + MPG) reduced myocardial oxygen delivery in DM + HFD + CKD swine, suggestive of a vasodilator influence of endogenous ROS, while it had no effect in Normal swine. In vitro wire myography revealed a vasodilator role for hydrogen peroxide (H2O2) in isolated small coronary artery segments from DM + HFD + CKD, but not Normal swine. Increased catalase activity and ceramide production in left ventricular myocardial tissue of DM + HFD + CKD swine further suggest that increased H2O2 acts as vasodilator ROS in the coronary microvasculature. Despite elevated ET-1 plasma levels in DM + HFD + CKD swine, ETA+B blockade did not affect myocardial oxygen delivery in Normal or DM + HFD + CKD swine. In conclusion, loss of NO bioavailability due to 5 months exposure to multiple comorbidities is partially compensated by increased H2O2-mediated coronary vasodilation.

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.

Statin use and incident type 2 diabetes mellitus in women after menopause

Menopause is associated with adverse cardiometabolic changes which increase the risk of new-onset type 2 diabetes (T2DM) and cardiovascular disease (CVD). Statins are widely used for primary and secondary CVD prevention, given their beneficial effects on the lipid profile and the vessel wall. On the other hand, statins increase the risk of T2DM. This association has been evaluated mainly in mixed-gender studies, without gender-specific evaluation. This narrative review evaluates the use of statins and the related risk of new-onset T2DM among postmenopausal women. Studies that incorporated a gender-specific analysis report a higher risk of new-onset T2DM in women than in men on treatment with statins. Fewer studies evaluated female-only samples; these confirm the observed association between statin use and new-onset T2DM. Factors influencing the association between statin use and T2DM include the type and dose of statin and the baseline metabolic status. Women may benefit from stratification of their metabolic risk before initiating a statin for CVD prevention.

Contemporary socioeconomic-based disparities in cardiac surgery: Are we closing the disparities gap?

OBJECTIVE

Female sex and lower income residence location are associated with worse health care outcomes. In this study we analyzed the national, contemporary status of socioeconomic disparities in cardiac surgery.

METHODS

Adult patients within the Nationwide Readmissions Database who underwent coronary artery bypass grafting (CABG), surgical aortic valve replacement (SAVR), mitral valve (MV) replacement, MV repair, or ascending aorta surgery from 2016 to 2018 were included. Sex and median household income quartile (MHIQ) were compared within each surgery group. Primary outcome was 30-day mortality. Multivariable analysis was adjusted for patient characteristics and hospital-level factors.

RESULTS

A weighted total of 358,762 patients were included. Fewer women underwent CABG (22.3%), SAVR (32.2%), MV repair (37.5%), and ascending aorta surgery (29.7%). In adjusted analysis, female sex was independently associated with higher 30-day mortality rates after CABG (adjusted odds ratio [aOR], 1.6), SAVR (aOR, 1.4), MV repair (aOR, 1.8), and ascending aorta surgery (aOR, 1.2; all P < .03). The lowest MHIQ was independently associated with higher 30-day mortality rates after CABG (aOR, 1.4), SAVR (aOR, 1.5), MV replacement (aOR, 1.3), and ascending aorta surgery (aOR, 1.8; all P < .004) compared with the highest quartile. Women were less likely to receive care at urban and academic hospitals for CABG compared with men. Patients of lower MHIQ received less care at urban and academic institutions for all surgeries.

CONCLUSIONS

Despite advances in the techniques and safety, women and patients of lower socioeconomic status continue to have worse outcomes after cardiac surgery. These persistent disparities warrant the need for root cause analysis.

Sex differences of sequential changes in coronary blood flow and microvascular function in patients with suspected angina

AIMS

This study evaluated the sex differences of sequential changes in coronary blood flows and microvascular function in patients with suspected angina but with no obstructed coronary arteries.

METHODS

A total of 202 consecutive patients who experienced chest pain but had no significant coronary artery stenosis and who underwent adenosine stress echocardiography were included in the study. Coronary blood flow (CBF) velocities were measured at 1, 2, and 3 min after adenosine infusion.

RESULTS

The mean age was 61 years, and 138 (68%) were women. Approximately 40% of patients had coronary microvascular dysfunction (CMD, coronary flow velocity reserve < 2.3), with women exhibiting higher CMD prevalence. The left ventricular (LV) mass index was similar between men and women, while women exhibited higher baseline rate pressure products (RPP). At baseline, coronary blood flow velocities were similar between the sexes. However, CBF velocities in women gradually increased during the examination; and in men, the increase was abrupt and steep during the early stages of examination (p = 0.015 for interaction between time and sex), even with similar RPP in stress. Coronary flow velocity reserve was steadily lower in women compared to men (1 min, 2.09 ± 0.86 vs 2.44 ± 0.87; 2 min, 2.39 ± 0.72 vs 2.63 ± 0.85; 3 min, 2.45 ± 0.70 vs 2.68 ± 0.73).

CONCLUSIONS

In patients with suspected angina but with no obstructed coronary arteries, CMD was especially prevalent among women. Women exhibited higher oxygen consumption, while exhibiting slower and gradual increases in CBF velocities. Conversely, men exhibited faster and steeper increases in CBF velocities even with similar RPP in stress.

Sex differences in diagnostic modalities of atherosclerosis in the macrocirculation

Asymptomatic atherosclerosis begins early in life and may progress in a sex-specific manner to become the major cause of cardiovascular morbidity and death. As diagnostic tools to evaluate atherosclerosis in the macrocirculation, we discuss imaging methods (in terms of computed tomography, positron emission tomography, intravascular ultrasound, magnetic resonance imaging, and optical coherence tomography), along with derived scores (Agatston, Gensini, Leaman, Syntax), and also hemodynamic indices of vascular stiffness (including flow-mediated dilation, shear stress, pulse pressure, augmentation index, arterial distensibility), assessment of plaque properties (composition, erosion, rupture), stenosis measures such as fractional flow reserve. Moreover, biomarkers including matrix metalloproteinases, vascular endothelial growth factors and miRNAs, as well as the impact of machine learning support, are described. Special attention is given to age-related aspects and sex-specific characteristics, along with clinical implications. Knowledge gaps are identified and directions for future research formulated.

Sex differences in coronary artery bypass graft surgery outcomes: a narrative review

Background and Objective

Coronary artery bypass grafting (CABG) is the most commonly performed cardiac surgery globally and in the United States, however, women have worse outcomes than men. We aim to examine the possible drivers of this sex difference in CABG outcomes.

Methods

A narrative review using a current search of the most recent literature on this topic.

Key Content and Findings

The sex difference in outcomes after CABG has persisted despite advances in the field, with women having well-described worse operative mortality and morbidity than men. Several explanatory mechanisms have been proposed for these differences. These include, but are not limited to, preoperative factors such as the natural history of coronary artery disease in women, older age, and higher prevalence of comorbidities at the time of presentation for CABG surgery. Intraoperative factors have also been proposed to play a role, including the smaller coronary artery size and greater coronary artery reactivity in women, the degree of intraoperative hemodilution anemia, the type of grafting, and the completeness of revascularization. However, no definitive etiology has been identified to date.

Conclusions

The sex difference in outcomes after CABG remains present, and despite numerous proposed etiopathologies, the main driver remains unclear. Further research is needed to identify, and address, the root cause of this difference, and greater participation of women in cardiovascular and cardiac surgery trials is crucial.

The Role of Imaging in Preventive Cardiology in Women

PURPOSE OF REVIEW

The prevalence of CVD in women is increasing and is due to the increased prevalence of CV risk factors. Traditional CV risk assessment tools for prevention have failed to accurately determine CVD risk in women. CAC has shown to more precisely determine CV risk and is a better predictor of CV outcomes. Coronary CTA provides an opportunity to determine the presence of CAD and initiate prevention in women presenting with angina. Identifying women with INOCA due to CMD with use of cPET or cMRI with MBFR is vital in managing these patients. This review article outlines the role of imaging in preventive cardiology for women and will include the latest evidence supporting the use of these imaging tests for this purpose.

RECENT FINDINGS

CV mortality is higher in women who have more extensive CAC burden. Women have a greater prevalence of INOCA which is associated with higher MACE. INOCA is due to CMD in most cases which is associated with traditional CVD risk factors. Over half of these women are untreated or undertreated. Recent study showed that stratified medical therapy, tailored to the specific INOCA endotype, is feasible and improves angina in women. Coronary CTA is useful in the setting of women presenting with acute chest pain to identify CAD and initiate preventive therapy. CAC confers greater relative risk for CV mortality in women versus (vs.) men. cMRI or cPET is useful to assess MBFR to diagnose CMD and is another useful imaging tool in women for CV prevention.

Sex-Dependent Mechanisms of Cell Death Modalities in Cardiovascular Disease

Despite currently available therapies, cardiovascular diseases (CVD) are among the leading causes of death globally. Biological sex is a critical determinant of the occurrence, progression and overall outcome of CVD. However, the underlying mechanisms are incompletely understood. A hallmark of CVD is cell death. Based on the inability of the human heart to regenerate, loss of functional cardiac tissue can lead to irreversible detrimental effects. Here, we summarize current knowledge on how biological sex affects cell death-related mechanisms in CVD. Initially, we discuss apoptosis and necrosis, but we specifically focus on the relatively newly recognized programmed necrosis-like processes: pyroptosis and necroptosis. We also discuss the role of 17β-estradiol (E2) in these processes, particularly in terms of inhibiting pyroptotic and necroptotic signaling. We put forward that a better understanding of the effects of biological sex and E2 might lead to the identification of novel targets with therapeutic potential.

Female gender and mortality in ST-segment-elevation myocardial infarction treated with primary PCI

AIMS

To investigate gender difference in mortality among patients with ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous angioplasty (PPCI).

METHODS

We analyzed data from the prospective registries of two hub PPCI centres over a 10-year period to assess the role of female gender as an independent predictor of both all-cause and cardiac death at 30 days and 1 year. To account for all confounding variables, a propensity score (PS)-adjusted multivariable Cox regression model and a PS-matched comparison between the male and female were used.

RESULTS

Among 4370 consecutive STEMI patients treated with PPCI at participating centres, 1188 (27.2%) were women. The survival rate at 30 days and 1 year were significantly lower in women (Log-rank P-value < 0.001). At PS-adjusted multivariable Cox regression analysis, female gender was independently associated with an increased risk of 30-day all-cause death [hazard ratio (HR) = 2.09; 95% confidence interval (CI): 1.45-3.01, P < 0.001], 30-day cardiac death (HR = 2.03;95% CI:1.41-2.93, P < 0.001), 1-year all-cause death (HR = 1.45; 95% CI:1.16-1.82, P < 0.001) and 1-year cardiac death (HR = 1.51; 95% CI:1.15-1.97, P < 0.001). For the study outcome, we found a significant interaction of gender with the multivessel disease in females who were at increased risk of mortality in comparison with men in absence of multivessel disease. After the PS matching procedure, a subset of 2074 patients were identified. Women still had a lower survival rate and survival free from cardiac death rate both at 30-day and at 1-year follow-up.

CONCLUSION

As compared with men, women with STEMI treated with PPCI have higher risk of both all-cause death and cardiac mortality at 30-day and 1-year follow-up.

Cardiovascular Imaging for Ischemic Heart Disease in Women: Time for a Paradigm Shift

Heart disease is the leading cause of death among men and women. Women have a unique phenotype of ischemic heart disease with less calcified lesions, more nonobstructive plaques, and a higher prevalence of microvascular disease compared with men, which may explain in part why current risk models to detect obstructive coronary artery disease (CAD) may not work as well in women. This paper summarizes the sex differences in the functional and anatomical assessment of CAD in women presenting with stable chest pain and provides an approach for using multimodality imaging for the evaluation of suspected ischemic heart disease in women in accordance to the recently published American Heart Association/American College of Cardiology guidelines for the evaluation and diagnosis of chest pain. A paradigm shift in the approach to imaging ischemic heart disease women is needed including updated risk models, a more profound understanding of CAD in women where nonobstructive disease is more prevalent, and algorithms focused on the evaluation of ischemia with nonobstructive CAD and myocardial infarction with nonobstructive CAD.

Nuclear Cardiology in Women and Underrepresented Minority Populations

PURPOSE OF REVIEW

To outline sex-specific features of coronary artery disease (CAD) that should be considered in the assessment of women, including those from ethnic minority populations with suspected stable ischemic heart disease (IHD). Second, to determine the latest nuclear imaging tools available to assess microvascular CAD.

RECENT FINDINGS

Latest studies indicate that women are more likely to have ischemia with no obstructive coronary arteries (INOCA) and paradoxically have worse outcomes. Therefore, the evaluation of women with suspected IHD should include assessing microvascular and epicardial coronary circulation. The prevalence of CAD is increasing in younger women due to the increased cardiovascular disease (CVD) risk burden. CAD is often underrecognized in these patients. There is increasing recognition that INOCA is not benign and should be accurately diagnosed and managed. Nuclear imaging assesses the full spectrum of CAD from microvascular CAD to multivessel obstructive epicardial CAD. Further research on myocardial blood flow (MBF) assessment with PET MPI is needed.

Coronary Arterial Function and Disease in Women With No Obstructive Coronary Arteries

Ischemic heart disease (IHD) is the leading cause of mortality in women. While traditional cardiovascular risk factors play an important role in the development of IHD in women, women may experience sex-specific IHD risk factors and pathophysiology, and thus female-specific risk stratification is needed for IHD prevention, diagnosis, and treatment. Emerging data from the past 2 decades have significantly improved the understanding of IHD in women, including mechanisms of ischemia with no obstructive coronary arteries and myocardial infarction with no obstructive coronary arteries. Despite this progress, sex differences in IHD outcomes persist, particularly in young women. This review highlights the contemporary understanding of coronary arterial function and disease in women with no obstructive coronary arteries, including coronary anatomy and physiology, mechanisms of ischemia with no obstructive coronary arteries and myocardial infarction with no obstructive coronary arteries, noninvasive and invasive diagnostic strategies, and management of IHD.

Sex Differences in the Association Between Midlife Cardiovascular Conditions or Risk Factors With Midlife Cognitive Decline

BACKGROUND AND OBJECTIVES

The prevalence of midlife cardiovascular conditions and risk factors is higher in men than women. Associations between midlife cardiovascular conditions or risk factors and midlife cognitive decline have been reported, but few studies have assessed sex differences in these associations.

METHODS

We included 1,857 participants enrolled in the population-based Mayo Clinic Study of Aging who were 50 to 69 years of age at baseline. Participants were evaluated every 15 months by a coordinator, including neurologic evaluation and neuropsychological testing. The neuropsychological testing used 9 tests to calculate global cognitive and domain-specific (memory, language, executive function, and visuospatial skills) z scores. Nurse abstractors reviewed participant medical records to determine the presence of cardiovascular conditions (coronary heart disease, arrhythmias, congestive heart failure) and risk factors (hypertension, diabetes, dyslipidemia, obesity, ever smoking). Linear mixed-effect models evaluated the association between baseline cardiovascular conditions or risk factors and global and domain-specific cognitive decline. Multivariable models adjusted for demographics, APOE genotype, depression, and other medical conditions. Interactions between sex and each cardiovascular condition or risk factor were examined, and results were stratified by sex.

RESULTS

Overall, 1,465 (78.9%) participants had at least 1 cardiovascular condition or risk factor; the proportion of men was higher than women (767 [83.4%] vs 698 [74.5%], p < 0.0001). Cross-sectionally, coronary heart disease and ever smoking were associated with a lower visuospatial z score in multivariable models. Longitudinally, several cardiovascular conditions and risk factors were associated with declines in global and domain-specific z scores but not visuospatial z scores. Most cardiovascular conditions were more strongly associated with cognition among women: coronary heart disease and other cardiovascular conditions were associated with global cognitive decline only in women (all p < 0.05). In addition, diabetes, dyslipidemia, and coronary heart disease were associated with language z score decline only in women (all p < 0.05). However, congestive heart failure was associated with language z score decline only in men (all p < 0.05).

DISCUSSION

Midlife cardiovascular conditions and risk factors are associated with midlife cognitive decline. Moreover, specific cardiovascular conditions and risk factors have stronger associations with cognitive decline in midlife for women than men despite the higher prevalence of those conditions in men.

Underrepresentation of women in cardiovascular trials- it is time to shatter this glass ceiling

Cardiovascular disease (CVD) is the leading cause of death in women, with underrepresented minority (URM) women experiencing the highest mortality rate. For decades, there has been an underrepresentation of women in CVD trials. Although more recent studies have increased the number of women enrolled in these trials, systematic reviews have demonstrated that this enrollment is still low. The National Institute of Health along with other agencies have boosted their efforts to increase enrollment of women and URM populations in CVD trials. Despite these efforts, there still remains a gap. This paper reviews the magnitude, implications and causes of the underrepresentation of women in CVD trials. A proposed multifaceted approach to solving this issue is also outlined in this commentary. Hopefully, implementation of these proposed solutions may facilitate the increase of women, including URM women, enrolled in CVD trials. It is anticipated that this will improve CVD outcomes in these patients.

Gender differences, inequalities and biases in the management of Acute Coronary Syndrome

OBJECTIVE

The approach to Acute Coronary Syndrome from a gender perspective is relatively recent. Research is extensive at epidemiological and clinical levels. However, available evidence, besides neglecting the social dimensions of the disease, has made women invisible. The objective of this review was to analyze the inequalities and gender biases in Acute Coronary Syndrome, from the beginning of the disease process to the final resolution.

METHODS

An exhaustive review of the literature of the entire health care process, from risk factors to rehabilitation and recovery, was carried out. The search for articles on gender, gender inequalities, or gender bias was conducted in indexed journals of social and health sciences. Also, a specific search was performed for each stage of the process, such as risk factors, prehospital phase, diagnosis, treatment, and rehabilitation.

RESULTS

Results showed the presence of gender biases throughout the entire health care process in Acute Coronary Syndrome. It is shown gender inequalities in the access to medical care, including a poor recognition among women themselves as well as among health professionals; longer prehospital delays; inadequate diagnoses and treatments; or less assistance to cardiac rehabilitation programmes. These biases occurred at the different levels of the health services involved. Finally, this review included recommendations proposed or arising from the revised papers.

CONCLUSIONS

Reducing gender biases in Acute Coronary Syndrome implies developing strategies to raise awareness among women, improve training of professionals serving at the different levels of health services, reduce delays, develop health management measures, and promote a research agenda.

Pulmonary valve tissue engineering strategies in large animal models

In the last 25 years, numerous tissue engineered heart valve (TEHV) strategies have been studied in large animal models. To evaluate, qualify and summarize all available publications, we conducted a systematic review and meta-analysis. We identified 80 reports that studied TEHVs of synthetic or natural scaffolds in pulmonary position (n = 693 animals). We identified substantial heterogeneity in study designs, methods and outcomes. Most importantly, the quality assessment showed poor reporting in randomization and blinding strategies. Meta-analysis showed no differences in mortality and rate of valve regurgitation between different scaffolds or strategies. However, it revealed a higher transvalvular pressure gradient in synthetic scaffolds (11.6 mmHg; 95% CI, [7.31-15.89]) compared to natural scaffolds (4,67 mmHg; 95% CI, [3,94-5.39]; p = 0.003). These results should be interpreted with caution due to lack of a standardized control group, substantial study heterogeneity, and relatively low number of comparable studies in subgroup analyses. Based on this review, the most adequate scaffold model is still undefined. This review endorses that, to move the TEHV field forward and enable reliable comparisons, it is essential to define standardized methods and ways of reporting. This would greatly enhance the value of individual large animal studies.

Lipidomic Analysis to Assess Oxidative Stress in Acute Coronary Syndrome and Acute Stroke Patients

Alterations in lipid metabolism mediated by oxidative stress play a key role in the process of atherosclerosis and superimposed thrombosis; these can lead to acute coronary syndrome (ACS) and acute ischemic stroke (AIS). Multiple studies have shown that the formation of atheromatous lesions is initiated by oxidation of low-density lipoproteins incorporated into the intima of the vessel wall. Here, we studied lipids in plasma samples from three cohorts: 61 patients with ACS (group A), 49 patients with AIS (group D), and 82 controls (group K). Untargeted lipidomics based on high-performance liquid chromatography coupled to mass spectrometry (UHPLC-HRMS) was employed to obtain comprehensive information on whether relationships exist between these patient categories based on lipid patterns. In addition, malondialdehyde (MDA) as a standard marker of oxidative stress was monitored. The most characteristic lipids in group K were fatty acyls of hydroxyfatty acids (FAHFAs). As expected, MDA concentrations were the lowest in group K. Our findings can better explain ongoing pathologies, both acute and chronic, with the potential for future diagnosis and treatment.

Impact of Age and Sex on Subclinical Coronary Atherosclerosis in a Healthy Asian Population

Background

The influence of age and sex on clinical atherosclerotic cardiovascular disease is well reported, but literature remains sparse on whether these extend to the disease in its preclinical stage.

Objectives

The purpose of this study was to report the prevalence, risk factors, and impact of age and sex on the burden of subclinical coronary atherosclerosis in a healthy Asian population.

Methods

Healthy subjects age 30 to 69 years, with no history of cardiovascular disease or diabetes were recruited from the general population. Subclinical coronary atherosclerosis was quantified via the coronary artery calcium score (CAC) with CAC of 0 indicating absence of calcified plaque, 1 to 10 minimal plaque, 11 to 100 mild plaque, and >100 moderate to severe plaque.

Results

A total of 663 individuals (mean age 49.4 ± 9.2 years; 44.8% men) were included. The prevalence of any CAC was 29.3%, with 9% having CAC >100. The prevalence was significantly higher in men than women (43.1% vs 18.0%; P < 0.001). Multivariable analysis revealed significant associations of increasing age, male sex, higher blood pressure, increased glucose levels, and higher low-density lipoprotein cholesterol levels with the presence of any CAC. Low-density lipoprotein cholesterol was more significantly associated with CAC in women compared with men (P_interaction = 0.022).

Conclusions

The prevalence of preclinical atherosclerosis increased with age, and was higher in men, with sex-specific differences in associated risk factors. These results will better inform individualized future risk management strategies to prevent the development and progression of coronary artery disease within healthy individuals.

Sex-differences in circulating biomarkers during acute myocardial infarction: An analysis from the SWEDEHEART registry

BACKGROUND

Sex-differences in the pathobiology of myocardial infarction are well established but incompletely understood. Improved knowledge on this topic may help clinicians to improve management of men and women with myocardial infarction.

METHODS

In this registry-based cohort study (SWEDEHEART), we analyzed 175 circulating biomarkers reflecting various pathobiological axes in 856 men and 243 women admitted to Swedish coronary care units because of myocardial infarction. Two multimarker panels were applied (Proximity Extension Assay [Olink Bioscience], Multiple Reaction Monitoring mass spectrometry). Lasso analysis (penalized logistic regression), multiple testing-corrected Mann-Whitney tests and Cox regressions were used to assess sex-differences in the concentrations of these biomarkers and their implications on all-cause mortality and major adverse events (median follow-up up to 6.6 years).

RESULTS

Biomarkers provided a very high discrimination between both sexes, when considered simultaneously (c-statistics 0.972). Compared to women, men had higher concentrations of six biomarkers with the most pronounced differences seen for those reflecting atherogenesis, myocardial necrosis and metabolism. Women had higher concentrations of 14 biomarkers with the most pronounced differences seen for those reflecting activation of the renin-angiotensin-aldosterone axis, inflammation and for adipokines. There were no major variations between sexes in the associations of these biomarkers with outcome.

CONCLUSIONS

Severable sex-differences exist in the expression of biomarkers in patients with myocardial infarction. While these differences had no impact on outcome, our data suggest the presence of various sex-related pathways involved in the development of coronary atherosclerosis, the progression to plaque rupture and acute myocardial damage, with a greater heterogeneity in women.

Sex differences in heart failure hospitalisation risk following acute myocardial infarction

OBJECTIVE

We evaluated the sex differences in 6-month heart failure (HF) hospitalisation risk in acute myocardial infarction (AMI) survivors.

METHODS

For this retrospective cohort analysis, adult survivors of an AMI between January and June 2014 were identified from the US Nationwide Readmissions Database. The primary outcome was a HF hospitalisation within 6 months. Secondary outcomes were fatal HF hospitalisation and the composite of index in-hospital HF or 6-month HF hospitalisation.

RESULTS

Of 237 549 AMI survivors, females (37.9%) were older (70±14 years vs 65±13 years; p<0.001), had a higher prevalence of cardiac comorbidities and a lower revascularisation rate compared with males. The primary outcome occurred in 12 934 patients (5.4%), at a 49% higher rate in females (6.8% vs 4.6% in males, p<0.001), which was attenuated to a 19% higher risk after multivariable adjustment. Findings were consistent across subgroups of age, AMI type and major risk factors. In the propensity-matched time-to-event analysis, female sex was associated with a 13% higher risk for 6-month HF readmission (6.4% vs 5.8% in males; HR 1.13, 95% CI 1.05 to 1.21, p<0.001), and the increased risk was evident early on after the AMI. Fatal HF rate was similar between groups (4.7% vs 4.6%, p=0.936), but females had a higher rate of the composite HF outcome (36.2% vs 27.5%, p<0.001).

CONCLUSION

In a large all-comers AMI survivors' cohort, females had a higher HF hospitalisation risk that persisted after adjustment for baseline risk differences. This was consistent across several clinically relevant subgroups and was evident early on after the AMI.

Sex-Based Differences in Coronary and Structural Percutaneous Interventions

In the current state of interventional cardiology, the ability to offer advanced therapies to patients who historically were not surgical candidates has grown exponentially in the last few decades. As therapies have expanded in complex coronary and structural interventions, the nuances of treating certain populations have emerged. In particular, the role of sex-based anatomic and outcome differences has been increasingly recognized. As guidelines for cardiovascular prevention and treatment for certain conditions may vary by sex, therapeutic interventions in the structural and percutaneous coronary areas may also vary. In this review, we aim to discuss these differences, the current literature available on these topics, and areas of focus for the future.

Sex-Specific Influence of the SCARB1 Rs5888 SNP on the Serum Lipid Response to Atorvastatin in Patients with Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention

Background

Epidemiological studies have shown that there are sex differences in blood lipid levels and lipid responses to statins. Previous studies have shown that the rs5888 single nucleotide polymorphism (SNP) in the scavenger receptor class B type 1 (SCARB1) gene is associated with serum lipid levels in a sex-specific manner. The present study was undertaken to detect the sex-specific influence of the SCARB1 rs5888 SNP on the serum lipid response to atorvastatin in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI).

Methods

A total of 158 unrelated ACS patients (108 males, 50 females) were enrolled, and all patients received atorvastatin 20 mg/daily after PCI. Genotyping of the rs5888 SNP was performed by polymerase chain reaction and direct sequencing. Serum lipid profiles were determined before treatment and after an average follow-up time of one year.

Results

The baseline serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and apolipoprotein (Apo)AI levels were higher in females than in males (P<0.05). After treatment with atorvastatin, serum TC, LDL-C, and ApoB were decreased, and ApoAI was increased (P<0.05). The effects of atorvastatin on serum lipid levels were different between males and females, and females had greater decreases in TC, LDL-C and ApoB levels than males (P<0.05). The genotypic frequencies of the rs5888 SNP were not different between males and females. The atorvastatin response was not associated with the rs5888 SNP in males (P > 0.05). Nonetheless, in female individuals carrying the rs5888 T-allele, we observed a greater reduction in TC, LDL-C, and ApoB levels after the use of 20 mg/day atorvastatin (P<0.05).

Conclusion

This study indicates that the SCARB1 rs5888 T-allele was associated with a greater reduction in serum TC, LDL-C, and ApoB after atorvastatin treatment in female patients with ACS undergoing PCI.

Coronary microvascular dysfunction in stable ischaemic heart disease (non-obstructive coronary artery disease and obstructive coronary artery disease)

Diffuse and focal epicardial coronary disease and coronary microvascular abnormalities may exist side-by-side. Identifying the contributions of each of these three players in the coronary circulation is a difficult task. Yet identifying coronary microvascular dysfunction (CMD) as an additional player in patients with coronary artery disease (CAD) may provide explanations of why symptoms may persist frequently following and why global coronary flow reserve may be more prognostically important than fractional flow reserve measured in a single vessel before percutaneous coronary intervention. This review focuses on the challenges of identifying the presence of CMD in the context of diffuse non-obstructive CAD and obstructive CAD. Furthermore, it is going to discuss the pathophysiology in this complex situation, examine the clinical context in which the interaction of the three components of disease takes place and finally look at non-invasive diagnostic methods relevant for addressing this question.

Rationale and Design of the Future Optimal Research and Care Evaluation in Patients with Acute Coronary Syndrome (FORCE-ACS) Registry: Towards "Personalized Medicine" in Daily Clinical Practice

Diagnostic and treatment strategies for acute coronary syndrome have improved dramatically over the past few decades, but mortality and recurrent myocardial infarction rates remain high. An aging population with increasing co-morbidities heralds new clinical challenges. Therefore, in order to evaluate and improve current treatment strategies, detailed information on clinical presentation, treatment and follow-up in real-world patients is needed. The Future Optimal Research and Care Evaluation in patients with Acute Coronary Syndrome (FORCE-ACS) registry (ClinicalTrials.gov Identifier: NCT03823547) is a multi-center, prospective real-world registry of patients admitted with (suspected) acute coronary syndrome. Both non-interventional and interventional cardiac centers in different regions of the Netherlands are currently participating. Patients are treated according to local protocols, enabling the evaluation of different diagnostic and treatment strategies used in daily practice. Data collection is performed using electronic medical records and quality-of-life questionnaires, which are sent 1, 12, 24 and 36 months after initial admission. Major end points are all-cause mortality, myocardial infarction, stent thrombosis, stroke, revascularization and all bleeding requiring medical attention. Invasive therapy, antithrombotic therapy including patient-tailored strategies, such as the use of risk scores, pharmacogenetic guided antiplatelet therapy and patient reported outcome measures are monitored. The FORCE-ACS registry provides insight into numerous aspects of the (quality of) care for acute coronary syndrome patients.

Sex-Specific Interpretation of Coronary Flow Reserve and Fractional Flow Reserve Metrics, Including Their Companions

BACKGROUND

Impairment of coronary flow is usually evaluated by considering the ratio of two measurements. Fractional flow reserve (FFR) estimates impact on an epicardial artery by taking mean post-stenotic pressure divided by mean aortic pressure, both obtained during adenosine induced hyperemia. Coronary flow reserve (CFR) compares hyperemic flow or velocity with the baseline situation, also as a ratio. As severity of underlying pathology may differ for men and women, we investigate the impact of these differences on relevant metrics.

METHODS

As sex associated differences may cancel out in a ratio, this weakness of a ratio can be compensated by analyzing the intrinsic companion (C) and consider polar coordinates. Thus, besides the familiar ratio based metrics, we also analyze FFRC and CFRC. Outcomes of in silico studies are employed to extrapolate actual patient data and predict consequences. For FFR 129 patients (38 women) were invasively studied using pressure wires. CFR was measured noninvasively for the left anterior descending coronary artery by recording ultrasound based Doppler velocity in 114 individuals (28 women).

RESULTS

The FFR can be identified as an indicator of the pressure gradient over the stenosis (R=-0.90), while FFRC differs for men compared to women (P=0.04) and correlates (R=0.93) with post-stenotic driving pressure. CFR shows a difference for men versus women (P=0.04) and is best associated with hyperemic flow (R=0.64), whereas CFRC relates to hyperemia recruited velocity (R=0.97). Simulation studies show that FFR may differ for both sexes when considering elderly.

CONCLUSIONS

Analysis of ratios require inclusion of the companion, and sex-specific differences deserve attention.

Sex-specific cardiac remodeling in early and advanced stages of hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most frequent genetic cardiac disease with a prevalence of 1:500 to 1:200. While most patients show obstructive HCM and a relatively stable clinical phenotype (stage II), a small group of patients progresses to end-stage HCM (stage IV) within a relatively brief period. Previous research has shown sex-differences in stage II HCM with more diastolic dysfunction in female than in male patients. Moreover, female patients more often show progression to heart failure. Here we investigated if differences in functional and structural properties of the heart may underlie sex-differences in disease progression from stage II to stage IV HCM. Cardiac tissue from stage II and IV patients was obtained during myectomy (n = 54) and heart transplantation (n = 10), respectively. Isometric force was measured in membrane-permeabilized cardiomyocytes to define active and passive myofilament force development. Titin isoform composition was assessed using gel electrophoresis, and the amount of fibrosis and capillary density were determined with histology. In accordance with disease stage-dependent adverse cardiac remodeling end-stage patients showed a thinner interventricular septal wall and larger left ventricular and atrial diameters compared to stage II patients. Cardiomyocyte contractile properties and fibrosis were comparable between stage II and IV, while capillary density was significantly lower in stage IV compared to stage II. Women showed more adverse cellular remodeling compared to men at stage II, evident from more compliant titin, more fibrosis and lower capillary density. However, the disease stage-dependent reduction in capillary density was largest in men. In conclusion, the more severe cellular remodeling in female compared to male stage II patients suggests a more advanced disease stage at the time of myectomy in women. Changes in cardiomyocyte contractile properties do not explain the progression of stage II to stage IV, while reduced capillary density may underlie disease progression to end-stage heart failure.

Ratiology and a Complementary Class of Metrics for Cardiovascular Investigations

Cardiovascular investigations often involve ratio-based metrics or differences: ejection fraction, arterial pressure augmentation index, coronary fractional flow reserve, pulse pressure. Focusing on a single number (ratio or difference) implies that information is lost. The lost companions constitute a well-defined but thus far unrecognized class, having additive value, a physical dimension, and often a physiological meaning. Physiologists should play a prominent role in exploring these complementary avenues and also define alternatives.

Fractional Flow Reserve Evaluated as Metric of Coronary Stenosis - A Mathematical Model Study

Introduction: Coronary arterial stenosis may impair myocardial perfusion with myocardial ischemia and associated morbidity and mortality as result. The myocardial fractional flow reserve (FFR) is clinically used as a stenosis-specific index. Aim: This study aims to identify the relation between the FFR and the degree of coronary arterial stenosis using a simple mathematical model of the coronary circulation. Methods: A mathematical model of the coronary circulation, including an arterial stenosis of variable degree, was developed. The relation between the FFR and the degree of stenosis (defined as the fractional cross sectional area narrowing) was investigated, including the influence of the aortic and venous pressures and the capillary resistance. An additional study concerning 22 patients with coronary artery disease permits comparison of clinical data and in silico findings. Results: The FFR shows an S-shaped relationship with the stenosis index. We found a marked influence of venous and aortic pressure and capillary resistance. The FFR is accompanied by a clinically relevant co-metric (FFR C ), defined by the Pythagorean sum of the two pressures in the definition formula for FFR. In the patient group the FFR C is strongly related to the post-stenotic pressure (R = 0.91). The FFR C requires establishment of a validated cut-off point using future trials. Conclusion: The S-shaped dependence of FFR on the severity of the stenosis makes the FFR a measure of the ordinal scale. The marked influences of the aortic and venous pressures and the capillary resistance on the FFR will be interpreted as significant variations in intra- and inter-individual clinical findings. These fluctuations are partly connected to the neglect of considering the FFR C . At otherwise identical conditions the FFR as measured at baseline differs from the value obtained during hyperemic conditions. This expected observation requires further investigation, as the current hyperemia based evaluation fails to take advantage of available baseline data.

Allostatic load in the association of depressive symptoms with incident coronary heart disease: The Jackson Heart Study

African Americans are at heightened risk for coronary heart disease (CHD), with biologic pathways poorly understood. We examined the role of allostatic load (AL) in the association of depressive symptoms with incident CHD among 2,670 African American men and women in the prospective Jackson Heart Study. Depressive symptoms were quantified using the Center for Epidemiologic Studies Depression Scale (CES-D). Incident CHD was ascertained by self-report, death certificate survey, and adjudicated medical record surveillance. Baseline AL was quantified using biologic parameters of metabolic, cardiovascular, immune, and neuroendocrine subsystems and as a combined meta-factor. Sequential models adjusted for demographic, socioeconomic, and behavioral covariates, stratified to examine differences by sex. Greater depressive symptomatology was associated with greater metabolic, cardiovascular, and immune AL (p-values≤0.036) and AL meta-factor z-scores (p = 0.007), with findings driven by observations among females. Each 1-point increase in baseline depressive symptomatology, and 1-SD increase in metabolic AL, neuroendocrine AL, and AL meta-factor z-scores was associated with 3.3%, 88%, 39%, and 130% increases in CHD risk, respectively (p-values <0.001). Neuroendocrine AL and AL meta-factor scores predicted incident CHD among males but not females in stratified analyses. Metabolic AL partially mediated the association of depressive symptoms with incident CHD (5.79% mediation, p = 0.044), a finding present among females (p = 0.016) but not males (p = 0.840). Among African American adults, we present novel findings of an association between depressive symptomatology and incident CHD, partially mediated by metabolic AL. These findings appear to be unique to females, an important consideration in the design of targeted interventions for CHD prevention.

Improved Outcome of Cardiogenic Shock Triggered by Takotsubo Syndrome Compared With Myocardial Infarction

BACKGROUND

Cardiogenic shock (CS) is a severe complication of myocardial infarction (MI) or of takotsubo syndrome (TTS). For both diseases, CS is related to a worse long-term outcome. The outcome of CS has not been studied in a direct comparison of patients with MI and patients with TTS.

METHODS

Mortality and cardiovascular complications were compared in patients presenting with CS based on MI or TTS between 2003 and 2017 during a follow-up of 5 years. A total of 138 patients with TTS and 532 patients with MI were included. Of these, 66 patients with MI and 25 patients with TTS developed CS (12% vs 18%, P = 0.08).

RESULTS

Patients with MI and CS had more often malignant arrhythmias (74% vs 28%, P < 0.01), and need for resuscitation (80% vs 24%, P < 0.01) or death (71% vs 24%, P < 0.01) than patients with TTS and CS during the first 30 days. Although the overall rate of death remained higher in MI than in TTS (75.8% vs 52%, log rank, P < 0.01), deaths occurred in TTS constantly throughout the follow-up time, but not in MI. The incidence of heart failure increased in MI but not in TTS (31.8% vs 4%, P < 0.01) during follow-up.

CONCLUSIONS

Patients with MI and CS have a worse prognosis than patients with TTS and CS. This is driven by cardiovascular events or death during the first 30 days after the index event. However, patients with TTS and CS show high mortality as well, especially during long-term follow-up.

Coronary Microvascular Disease Pathogenic Mechanisms and Therapeutic Options: JACC State-of-the-Art Review

Coronary microvascular disease (CMD) refers to the subset of disorders affecting the structure and function of the coronary microcirculation, is prevalent in patients across a broad spectrum of cardiovascular risk factors, and is associated with an increased risk of adverse events. Contemporary evidence supports that most patients with CMD also have macrovessel atherosclerosis, which has important implications for their prognosis and management. In this state-of-the-art review, the authors summarize the pathophysiology of CMD, provide an update of diagnostic testing strategies, and classify CMD into phenotypes according to severity and coexistence with atherosclerosis. They examine emerging data highlighting the significance of CMD in specific populations, including obesity and insulin resistance, myocardial injury and heart failure with preserved ejection fraction, and nonobstructive and obstructive coronary artery disease. Finally, they discuss the role of CMD as a potential target for novel interventions beyond conventional approaches, representing a new frontier in cardiovascular disease reduction.

Sex- and Age-Related Reference Values in Cardiology, with Annotations and Guidelines for Interpretation

The definition of "abnormal" in clinical sciences is often based on so-called reference values which point to a range that experts by some sort of consensus consider as normal when looking at biological variables. Such a level is commonly calculated by taking (twice) the standard deviation from the mean, or considering certain percentiles. The suspicion or even confirmation of a disease is then established by demonstrating that the value measured exceeds the upper or lower reference value. As is often the case, the measurement accuracy may depend on the conditions and specific method employed to collect and analyze data. This implies that, for example, data assessed by 2D echocardiography possibly differ from those obtained by MRI and therefore require modality-specific reference values. In this review we summarize reference values for the electrocardiogram, cardiac compartmental volumes, and arterial vessel size in males and females for various age groups. These values may further depend on other variables such as body size, physical training status, and ethnicity. Additional variables relevant for cardiology such as those referring to the microcirculation and biomarkers are only mentioned with reference to the pertinent literature. In general, the sex- and age-specific differences observed are often remarkable and warrant consideration in clinical practice and basic biomedical sciences.