What we know and do not know about sex and cardiac disease

Interactions of ST-elevation myocardial infarction, age, and sex and the risk of major adverse cardiovascular events among Chinese adults: a secondary analysis of a single-centre prospective cohort

OBJECTIVES

This study aimed to evaluate the interactions of ST-elevation myocardial infarction (STEMI), ageing and sex with respect to the incidence of major adverse cardiovascular events (MACE) among Chinese adults.

DESIGN

Secondary analysis of a single-centre prospective cohort.

SETTING

Patients who were admitted to cardiology clinics of the Affiliated Hospital of Jiangsu University due to acute myocardial infarction (MI) from June 2017 to November 2019 were eligible for inclusion in the study. This research only examined in-hospital cases.

PARTICIPANTS

Patients aged <18 years or confirmed dead within 24 hours from admission were excluded. A total of 843 adults were included in the analysis.

PRIMARY AND SECONDARY OUTCOME MEASURES

MACE was defined as any occurrence of cardiovascular mortality, MI recurrence, cardiogenic shock or heart failure. The relative excess risk due to interaction (RERI), attributable proportion (AP) and the synergy index were computed to quantify the interactions. Men without STEMI and adults without STEMI aged <60 years were the reference groups when examining the risk of MACE.

RESULTS

The female participants with STEMI showed a statistically higher risk of MACE compared with the male participants without STEMI (relative risk (RR): 2.713, CI: 1.350 to 5.426, p=0.005). A 3.327 times higher risk of MACE was detected in the older adults with STEMI (aged ≥60 years) compared with the adults without STEMI aged <60 years (RR: 3.327, CI: 1.414 to 8.955, p=0.01). Older female patients also had an increased risk of MACE (RR: 3.033, CI: 1.432 to 6.777, p=0.005). A positive additive interaction was detected between STEMI and age (RERI: 1.917, CI: 0.196 to 3.637; AP: 0.576, CI: 0.174 to 0.979). STEMI and sex also indicated an additive interaction (AP: 0.459, CI: 0.018 to 0.899).

CONCLUSION

In this Chinese population with MI, the risk of MACE was increased by about 2.7 times in women with STEMI compared with men without STEMI. MACE incidence increased by about 3.3 times in older patients with STEMI compared with younger patients without STEMI. STEMI and age, and STEMI and sex, may have a positive additive interaction.

Sex-Steroid Signaling in Lung Diseases and Inflammation

Sex/gender difference exists in the physiology of multiple organs. Recent epidemiological reports suggest the influence of sex-steroids in modulating a wide variety of disease conditions. Sex-based discrepancies have been reported in pulmonary physiology and various chronic inflammatory responses associated with lung diseases like asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis, and rare lung diseases. Notably, emerging clinical evidence suggests that several respiratory diseases affect women to a greater degree, with increased severity and prevalence than men. Although sex-specific differences in various lung diseases are evident, such differences are inherent to sex-steroids, which are major biological variables in men and women who play a central role to control these differences. The focus of this chapter is to comprehend the sex-steroid biology in inflammatory lung diseases and to understand the mechanistic role of sex-steroids signaling in regulating these diseases. Exploring the roles of sex-steroid signaling in the regulation of lung diseases and inflammation is crucial for the development of novel and effective therapy. Overall, we will illustrate the importance of differential sex-steroid signaling in lung diseases and their possible clinical implications for the development of complementary and alternative medicine to treat lung diseases.

Trimetazidine therapy for diabetic mouse hearts subjected to ex vivo acute heart failure

Acute heart failure (AHF) is the most common primary diagnosis for hospitalized heart diseases in Africa. As increased fatty acid β-oxidation (FAO) during heart failure triggers detrimental effects on the myocardium, we hypothesized that trimetazidine (TMZ) (partial FAO inhibitor) offers cardioprotection under normal and obese-related diabetic conditions. Hearts were isolated from 12-14-week-old obese male and female diabetic (db/db) mice versus lean non-diabetic littermates (db/+) controls. The Langendorff retrograde isolated heart perfusion system was employed to establish an ex vivo AHF model: a) Stabilization phase-Krebs Henseleit buffer (10 mM glucose) at 100 mmHg (25 min); b) Critical Acute Heart Failure (CAHF) phase-(1.2 mM palmitic acid, 2.5 mM glucose) at 20 mmHg (25 min); and c) Recovery Acute Heart Failure phase (RAHF)-(1.2 mM palmitic acid, 10 mM glucose) at 100 mmHg (25 min). Treated groups received 5 μM TMZ in the perfusate during either the CAHF or RAHF stage for the full duration of each respective phase. Both lean and obese males benefited from TMZ treatment administered during the RAHF phase. Sex differences were observed only in lean groups where the phases of the estrous cycle influenced therapy; only the lean follicular female group responded to TMZ treatment during the CAHF phase. Lean luteal females rather displayed an inherent cardioprotection (without treatments) that was lost with obesity. However, TMZ treatment initiated during RAHF was beneficial for obese luteal females. TMZ treatment triggered significant recovery for male and obese female hearts when administered during RAHF. There were no differences between lean and obese male hearts, while lean females displayed a functional recovery advantage over lean males. Thus TMZ emerges as a worthy therapeutic target to consider for AHF treatment in normal and obese-diabetic individuals (for both sexes), but only when administered during the recovery phase and not during the very acute stages.

Sex steroid signaling: implications for lung diseases

There is increasing recognition that sex hormones (estrogen, progesterone, and testosterone) have biological and pathophysiological actions in peripheral, non-reproductive organs, including the lung. Clinically, sex differences in the incidence, morbidity and mortality of lung diseases such as asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis, lung cancer and pulmonary hypertension have been noted, although intrinsic sex differences vs. the roles of sex steroids are still not well-understood. Accordingly, it becomes important to ask the following questions: 1) Which sex steroids are involved? 2) How do they affect different components of the lung under normal circumstances? 3) How does sex steroid signaling change in or contribute to lung disease, and in this regard, are sex steroids detrimental or beneficial? As our understanding of sex steroid signaling in the lung improves, it is important to consider whether such information can be used to develop new therapeutic strategies to target lung diseases, perhaps in both sexes or in a sex-specific manner. In this review, we focus on the basics of sex steroid signaling, and the current state of knowledge regarding how they influence structure and function of specific lung components across the life span and in the context of some important lung diseases. We then summarize the potential for sex steroids as useful biomarkers and therapeutic targets in these lung diseases as a basis for future translational research in the area of gender and individualized medicine.

Gender aspects in clinical presentation and prognostication of chronic heart failure according to NT-proBNP and the Heart Failure Survival Score

AIMS

We performed a prospective multi-center study to assess gender-specific differences in the predictive value of the measured level of NT-proBNP and the calculated Heart Failure Survival Score (HFSS).

METHODS

Baseline characteristics and follow-up data up to 5 years from 2,019 men and 530 women diagnosed with chronic heart failure (CHF) due to ischemic heart disease or dilated cardiomyopathy were prospectively compared. Death from any cause constituted the endpoint of the study. NT-proBNP was measured and HFSS calculated according to standard methods. Survival of men and women according to level of NT-proBNP and HFSS was analyzed in logistic regression models.

RESULTS

Median NT-proBNP level in men was 1,394 ng/l (IQR 516-3,406 ng/l) and 1,168 ng/l (IQR 444-2,830 ng/l) in women (p = n.s.). Median HFSS value was 8.4 (IQR 7.7-9.1) and 8.5 (8.0-9.1) in men and women, respectively. NT-proBNP levels and HFSS score correlated well with survival rates in both genders (p for interaction = 0.22 for NT-proBNP and 0.93 for HFSS). The all-cause death rates were similar in men and women.

CONCLUSION

Despite a number of gender-specific differences in CHF and the general predominance of men measured levels of NT-proBNP and HFSS score can be utilized for risk stratification with similar informative value in men and women.

Effects of gender, ejection fraction and weight on cardiac force development in patients undergoing cardiac surgery--an experimental examination

Background

It has long been recognized that differences exist between men and women in the impact of risc factors, symptoms, development and outcome of special diseases like the cardiovascular disease. Gender determines the cardiac baseline parameters like the number of cardiac myocyte, size and demand and may suggest differences in myofilament function among genders, which might be pronounced under pathological conditions. Does gender impact and maybe impair the contractile apparatus? Are the differences more prominent when other factors like weight, age, ejection fraction are added?

Therefore we performed a study on 36 patients (21 male, 15 female) undergoing aortic valve replacement (AVR) or aortocoronary bypass operation (CABG) to examine the influence of gender, ejection fraction, surgical procedure and body mass index (BMI) on cardiac force development.

Methods

Tissue was obtained from the right auricle and was stored in a special solution to prevent any stretching of the fibers. We used the skinned muscle fiber model and single muscle stripes, which were mounted on the “muscle machine” and exposed to a gradual increase of calcium concentration calculated by an attached computer program.

Results

1.) In general female fibers show more force than male fibers: 3.9 mN vs. 2.0 mN (p = 0.03) 2.) Female fibers undergoing AVR achieved more force than those undergoing CABG operation: 5.7 mN vs. 2.8 mN (p = 0.02) as well as male fibers with AVR showed more force values compared to those undergoing CABG: 2.0 mN vs. 0.5 mN (p = 0.01). 3.) Male and female fibers of patients with EF > 55% developed significantly more force than from those with less ejection fraction than 30%: p = 0.002 for the male fibers (1.6 vs. 2.8 mN) and p = 0.04 for the female fibers (5.7 vs. 2.8 mN). 4.) Patients with a BMI between 18 till 25 develop significant more force than those with a BMI > 30: Females 5.1 vs. 2.6 mN; p 0.03, Males 3.8 vs. 0.8 mN; p 0.04).

Conclusion

Our data suggest that female patients undergoing AVR or CABG develop significantly more force than male fibers. Additionally we could image the clinical impression of negative impact of overweight and obesity as well as low ejection fraction on cardiac function on level of the myofilaments and observed a reduced force capacity, which is more prominent in male fibers.

Sex differences and sex steroids in lung health and disease

Sex differences in the biology of different organ systems and the influence of sex hormones in modulating health and disease are increasingly relevant in clinical and research areas. Although work has focused on sex differences and sex hormones in cardiovascular, musculoskeletal, and neuronal systems, there is now increasing clinical evidence for sex differences in incidence, morbidity, and mortality of lung diseases including allergic diseases (such as asthma), chronic obstructive pulmonary disease, pulmonary fibrosis, lung cancer, as well as pulmonary hypertension. Whether such differences are inherent and/or whether sex steroids play a role in modulating these differences is currently under investigation. The purpose of this review is to define sex differences in lung structure/function under normal and specific disease states, with exploration of whether and how sex hormone signaling mechanisms may explain these clinical observations. Focusing on adult age groups, the review addresses the following: 1) inherent sex differences in lung anatomy and physiology; 2) the importance of certain time points in life such as puberty, pregnancy, menopause, and aging; 3) expression and signaling of sex steroid receptors under normal vs. disease states; 4) potential interplay between different sex steroids; 5) the question of whether sex steroids are beneficial or detrimental to the lung; and 6) the potential use of sex steroid signaling as biomarkers and therapeutic avenues in lung diseases. The importance of focusing on sex differences and sex steroids in the lung lies in the increasing incidence of lung diseases in women and the need to address lung diseases across the life span.

Exercise training does not improve cardiac function in compensated or decompensated left ventricular hypertrophy induced by aortic stenosis

There is ample evidence that regular exercise exerts beneficial effects on left ventricular (LV) hypertrophy, remodeling and dysfunction produced by ischemic heart disease or systemic hypertension. In contrast, the effects of exercise on pathological LV hypertrophy and dysfunction produced by LV outflow obstruction have not been studied to date. Consequently, we evaluated the effects of 8 weeks of voluntary wheel running in mice (which mitigates post-infarct LV dysfunction) on LV hypertrophy and dysfunction produced by mild (mTAC) and severe (sTAC) transverse aortic constriction. mTAC produced ~40% LV hypertrophy and increased myocardial expression of hypertrophy marker genes but did not affect LV function, SERCA2a protein levels, apoptosis or capillary density. Exercise had no effect on global LV hypertrophy and function in mTAC but increased interstitial collagen, and ANP expression. sTAC produced ~80% LV hypertrophy and further increased ANP expression and interstitial fibrosis and, in contrast with mTAC, also produced LV dilation, systolic as well as diastolic dysfunction, pulmonary congestion, apoptosis and capillary rarefaction and decreased SERCA2a and ryanodine receptor (RyR) protein levels. LV diastolic dysfunction was likely aggravated by elevated passive isometric force and Ca(2+)-sensitivity of myofilaments. Exercise training failed to mitigate the sTAC-induced LV hypertrophy and capillary rarefaction or the decreases in SERCA2a and RyR. Exercise attenuated the sTAC-induced increase in passive isometric force but did not affect myofilament Ca(2+)-sensitivity and tended to aggravate interstitial fibrosis. In conclusion, exercise had no effect on LV function in compensated and decompensated cardiac hypertrophy produced by LV outflow obstruction, suggesting that the effect of exercise on pathologic LV hypertrophy and dysfunction depends critically on the underlying cause.