Sex-related differences in ventricular remodeling after myocardial infarction

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

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

Neglected cardiometabolic risk factors and subclinical target organ damage in post-menopausal women with normal glucose tolerance

BACKGROUND

Menopausal transition is a crucial step in the women's cardiovascular health, and the risk stratification in apparently health post-menopausal females has been rarely assessed. Heart ultrasonography, unusually performed in such subjects, would be able to detect initial signs of organ damage. We described the cardiovascular risk profile of non-diabetic post-menopausal women, evaluating how easily computed, biochemistry-derived scores were related to ultrasonographic measures of target organ damage.

METHODS

We analyzed the characteristics of a cohort of two-hundred and seventy-three women consecutively referring to a prevention program of Azienda Ospedaliero-Universitaria Pisana (years 2017-2022) who underwent clinical evaluation, complete routine biochemical analyses with proxies of insulin resistance, heart and carotid ultrasonography. The cohort was further divided into four groups according to presence of isolated hypercholesterolemia (HC, 37%), isolated hypertension (HT, 5%), both HC/HT (38%), or none of them.

RESULTS

In HC and HC/HT, LDL cholesterol was sharply above the recommended values (149 [134-171] mg/dL and 141 [123-159] mg/dL, respectively). E/e' ratio and left atrium size were augmented in HT women and further worsened in HT/HC, with an independent effect of hypertension (E/e' ß=0.055, P=0.013, left atrium volume ß=0.059, P=0.003). Presence of carotid plaques was independently linked to hypertension (ß=0.474, P=0.003). In HC and HC/HT, the Triglycerides-Glucose Index, a surrogate of insulin resistance, was higher than in the other classes (P=0.0013), and it was associated with E/A in HC and HT/HC, with a significative interaction (P=0.0004) with hypertension. Past hormone replacement therapy did not influence clinical, biochemical or echocardiographic parameters.

CONCLUSIONS

Postmenopausal women display a high cardiovascular risk burden; a simple clinical and biochemistry screening would be advisable to identify and treat those more at risk. Cardiac ultrasonographic parameters were worse in hypertensive, hypercholesterolemic and insulin-resistant subjects, who may also deserve a deep and early instrumental characterization, especially when these conditions are associated.

Effect of six month's treatment with omega-3 acid ethyl esters on long-term outcomes after acute myocardial infarction: The OMEGA-REMODEL randomized clinical trial

BACKGROUND

Omega-3 polyunsaturated fatty acids (O3-FA) have been shown to reduce inflammation and adverse cardiac remodeling after acute myocardial infarction (AMI). However, the impact of O3-FA on long-term clinical outcomes remains uncertain.

AIMS

To investigate the impact of O3-FA on adverse cardiac events in long-term follow up post AMI in a pilot-study.

METHODS

Consecutive patients with AMI were randomized 1:1 to receive 6 months of O3-FA (4 g/daily) or placebo in the prospective, multicenter OMEGA-REMODEL trial. Primary endpoint was a composite of major adverse cardiovascular events (MACE) encompassing all-cause death, heart failure hospitalizations, recurrent acute coronary syndrome, and late coronary artery bypass graft (CABG).

RESULTS

A total of 358 patients (62.8% male; 48.1 ± 16.1 years) were followed for a median of 6.6 (IQR: 5.0-9.1) years. Among those receiving O3-FA (n = 180), MACE occurred in 65 (36.1%) compared to 62 (34.8%) of 178 assigned to placebo. By intention-to-treat analysis, O3-FA treatment assignment did not reduce MACE (HR = 1.014; 95%CI = 0.716-1.436; p = 0.938), or its individual components. However, patients with a positive response to O3-FA treatment (n = 43), defined as an increase in the red blood cell omega-3 index (O3I) ≥5% after 6 months of treatment, had lower annualized MACE rates compared to those without (2.9% (95%CI = 1.2-5.1) vs 7.1% (95%CI = 5.7-8.9); p = 0.001). This treatment benefit persisted after adjustment for baseline characteristics (HRadjusted = 0.460; 95%CI = 0.218-0.970; p = 0.041).

CONCLUSION

In long-term follow-up of the OMEGA-REMODEL randomized trial, O3-FA did not reduce MACE after AMI by intention to treat principle, however, patients who achieved a ≥ 5% increase of O3I subsequent to treatment had favorable outcomes.

CD73/adenosine axis exerts cardioprotection against hypobaric hypoxia-induced metabolic shift and myocarditis in a sex-dependent manner

BACKGROUND

Clinical and experimental studies have shown that the myocardial inflammatory response during pathological events varies between males and females. However, the cellular and molecular mechanisms of these sex differences remain elusive. CD73/adenosine axis has been linked to anti-inflammatory responses, but its sex-specific cardioprotective role is unclear. The present study aimed to investigate whether the CD73/adenosine axis elicits sex-dependent cardioprotection during metabolic changes and myocarditis induced by hypobaric hypoxia.

METHODS

For 7 days, male and female mice received daily injections of the CD73 inhibitor adenosine 5'- (α, β-methylene) diphosphate (APCP) 10 mg/kg/day while they were kept under normobaric normoxic and hypobaric hypoxic conditions. We evaluated the effects of hypobaric hypoxia on the CD73/adenosine axis, myocardial hypertrophy, and cardiac electrical activity and function. In addition, metabolic homeostasis and immunoregulation were investigated to clarify the sex-dependent cardioprotection of the CD73/adenosine axis.

RESULTS

Hypobaric hypoxia-induced cardiac dysfunction and adverse remodeling were more pronounced in male mice. Also, male mice had hyperactivity of the CD73/adenosine axis, which aggravated myocarditis and metabolic shift compared to female mice. In addition, CD73 inhibition triggered prostatic acid phosphatase ectonucleotidase enzymatic activity to sustain adenosine overproduction in male mice but not in female mice. Moreover, dual inhibition prostatic acid phosphatase and CD73 enzymatic activities in male mice moderated adenosine content, alleviating glycolytic shift and proinflammatory response.

CONCLUSION

The CD73/adenosine axis confers a sex-dependent cardioprotection. In addition, extracellular adenosine production in the hearts of male mice is influenced by prostatic acid phosphatase and tissue nonspecific alkaline phosphatase.

An eNAMPT-neutralizing mAb reduces post-infarct myocardial fibrosis and left ventricular dysfunction

Myocardial infarction (MI) triggers adverse ventricular remodeling (VR), cardiac fibrosis, and subsequent heart failure. Extracellular nicotinamide phosphoribosyltransferase (eNAMPT) is postulated to play a significant role in VR processing via activation of the TLR4 inflammatory pathway. We hypothesized that an eNAMPT specific monoclonal antibody (mAb) could target and neutralize overexpressed eNAMPT post-MI and attenuate chronic cardiac inflammation and fibrosis. We investigated humanized ALT-100 and ALT-300 mAb with high eNAMPT-neutralizing capacity in an infarct rat model to test our hypothesis. ALT-300 was 99mTc-labeled to generate 99mTc-ALT-300 for imaging myocardial eNAMPT expression at 2 hours, 1 week, and 4 weeks post-IRI. The eNAMPT-neutralizing ALT-100 mAb (0.4 mg/kg) or saline was administered intraperitoneally at 1 hour and 24 hours post-reperfusion and twice a week for 4 weeks. Cardiac function changes were determined by echocardiography at 3 days and 4 weeks post-IRI. 99mTc-ALT-300 uptake was initially localized to the ischemic area at risk (IAR) of the left ventricle (LV) and subsequently extended to adjacent non-ischemic areas 2 hours to 4 weeks post-IRI. Radioactive uptake (%ID/g) of 99mTc-ALT-300 in the IAR increased from 1 week to 4 weeks (0.54 ± 0.16 vs. 0.78 ± 0.13, P < 0.01). Rats receiving ALT-100 mAb exhibited significantly improved myocardial histopathology and cardiac function at 4 weeks, with a significant reduction in the collagen volume fraction (%LV) compared to controls (21.5 ± 6.1% vs. 29.5 ± 9.9%, P < 0.05). Neutralization of the eNAMPT/TLR4 inflammatory cascade is a promising therapeutic strategy for MI by reducing chronic inflammation, fibrosis, and preserving cardiac function.

Rapamycin treatment unmasks a sex-specific pattern of scar expansion of the infarcted rat heart: The relationship between mTOR and KATP channel

Inhibition of the mammalian target of rapamycin (mTOR) with the macrolide rapamycin or pharmacological suppression of KATP channel opening translated to scar expansion of the myocardial infarcted (MI) adult female rodent heart. The present study tested the hypotheses that rapamycin-mediated scar expansion was sex-specific and that mTOR signaling directly influenced KATP channel subunit expression/activity. Scar size was significantly larger in post-MI male rats as compared to the previous data reported in post-MI female rats. The reported scar expansion of rapamycin-treated post-MI female rats was not observed following the administration of the macrolide to post-MI male rats. Protein levels of the KATP channel subunits Kir6.2 and SUR2A and phosphorylation of the serine2448 residue of mTOR were similar in the normal heart of adult male and female rats. By contrast, greater tuberin inactivation characterized by the increased phosphorylation of the threonine1462 residue and reduced raptor protein levels were identified in the normal heart of adult female rats. Rapamycin pretreatment of phorbol 12,13-dibutyrate (PDBu)-treated neonatal rat ventricular cardiomyocytes (NNVMs) suppressed hypertrophy, inhibited p70S6K phosphorylation, and attenuated SUR2A protein upregulation. In the presence of low ATP levels, KATP channel activity detected in untreated NNVMs was significantly attenuated in PDBu-induced hypertrophied NNVMs via a rapamycin-independent pathway. Thus, rapamycin administration to post-MI rats unmasked a sex-specific pattern of scar expansion and mTOR signaling in PDBu-induced hypertrophied NNVMs significantly increased SUR2A protein levels. However, the biological advantage associated with SUR2A protein upregulation was partially offset by an mTOR-independent pathway that attenuated KATP channel activity in PDBu-induced hypertrophied NNVMs.

MicroRNA‑378: An important player in cardiovascular diseases (Review)

Cardiovascular disease (CVD) is a common chronic clinical condition and is the main cause of death in humans worldwide. Understanding the genetic and molecular mechanisms involved in the development of CVD is essential to develop effective prevention strategies and therapeutic measures. An increasing number of CVD‑related genetic studies have been conducted, including those on the potential roles of microRNAs (miRs). These studies have demonstrated that miR‑378 is involved in the pathological processes of CVD, including those of myocardial infarction, heart failure and coronary heart disease. Despite the potential importance of miR‑378 CVD, a comprehensive summary of the related literature is lacking. Thus, the present review aimed to summarize the findings of previous studies on the roles and mechanisms of miR‑378 in a variety of CVDs and provide an up‑to date basis for further r research targeting the prevention and treatment of CVDs.

Cardiac magnetic resonance shows increased adverse ventricular remodeling in younger patients after ST-segment elevation myocardial infarction

OBJECTIVES

Young patients account for about half of ST-segment elevation myocardial infarction (STEMI) patients and display a unique risk profile compared with old patients. Whether these differences are related to disparities in ventricular remodeling remains unknown. This study aimed to evaluate age-related differences in ventricular remodeling after primary percutaneous coronary intervention (PPCI) for STEMI.

METHODS

In this observational study, consecutive STEMI patients between October 2019 and March 2021 who underwent serial cardiovascular magnetic resonance at index admission (3 to 7 days) and 3 months after PPCI were enrolled. Adverse remodeling was defined as ≥ 10% enlargement in left ventricular end-diastolic volume index (LVEDVi), while reverse remodeling was defined as a decrease in left ventricular end-systolic volume index (LVESVi) of more than 10%.

RESULTS

A total of 123 patients were included and grouped into young (< 60 years, n = 71) and old (≥ 60 years, n = 52) patients. Despite generally similar baseline structural and infarct characteristics, LVESVi significantly decreased only in old patients during follow-up (p = 0.034). The incidence of adverse remodeling was higher (49.3% vs 30.8%, p = 0.039), while the incidence of reverse remodeling was lower (31.0% vs 53.8%, p = 0.011) in young compared with old patients. Younger age (< 60 years) was associated with a significantly higher risk of adverse remodeling (adjusted OR 3.51, 95% CI 1.41-8.74, p = 0.007) and lower incidence of reverse remodeling (adjusted OR 0.42, 95% CI 0.18-0.97, p = 0.046).

CONCLUSIONS

In STEMI patients undergoing PPCI, young patients are at a higher risk of adverse remodeling and less probably develop reverse remodeling than old patients. Equal or more attention should be paid to young patients with STEMI compared with their older counterparts.

KEY POINTS

• In STEMI patients undergoing PPCI, young patients displayed unfavorable remodeling compared with old patients. • Young patients are at a higher risk of adverse remodeling and less probably develop reverse remodeling than old patients. • Equal or more attention should be paid to young patients compared with their older counterparts.

Collagen matricryptin promotes cardiac function by mediating scar formation

AIMS

A peptide mimetic of a collagen-derived matricryptin (p1159) was shown to reduce left ventricular (LV) dilation and fibrosis after 7 days delivery in a mouse model of myocardial infarction (MI). This suggested p1159 long-term treatment post-MI could have beneficial effects and reduce/prevent adverse LV remodeling. This study aimed to test the potential of p1159 to reduce adverse cardiac remodeling in a chronic MI model and to elucidate p1159 mode-of-action.

MATERIALS AND METHODS

Using a permanent occlusion MI rodent model, animals received p1159 or vehicle solution up to 28 days. We assessed peptide treatment effects on scar composition and structure and on systolic function. To assess peptide effects on scar vascularization, a cohort of mice were injected with Griffonia simplicifolia isolectin-B4. To investigate p1159 mode-of-action, LV fibroblasts from naïve animals were treated with increasing doses of p1159.

KEY FINDINGS

Matricryptin p1159 significantly improved systolic function post-MI (2-fold greater EF compared to controls) by reducing left ventricular dilation and inducing the formation of a compliant and organized infarct scar, which promoted LV contractility and preserved the structural integrity of the heart. Specifically, infarcted scars from p1159-treated animals displayed collagen fibers aligned parallel to the epicardium, to resist circumferential stretching, with reduced levels of cross-linking, and improved tissue perfusion. In addition, we found that p1159 increases cardiac fibroblast migration by activating RhoA pathways via the membrane receptor integrin α4.

SIGNIFICANCE

Our data indicate p1159 treatment reduced adverse LV remodeling post-MI by modulating the deposition, arrangement, and perfusion of the fibrotic scar.

Macrophages in myocardial infarction

The heart contains a population of resident macrophages that markedly expands following injury through recruitment of monocytes and through proliferation of macrophages. In myocardial infarction, macrophages have been implicated in both injurious and reparative responses. In coronary atherosclerotic lesions, macrophages have been implicated in disease progression and in the pathogenesis of plaque rupture. Following myocardial infarction, resident macrophages contribute to initiation and regulation of the inflammatory response. Phagocytosis and efferocytosis are major functions of macrophages during the inflammatory phase of infarct healing, and mediate phenotypic changes, leading to acquisition of an anti-inflammatory macrophage phenotype. Infarct macrophages respond to changes in the cytokine content and extracellular matrix composition of their environment and secrete fibrogenic and angiogenic mediators, playing a central role in repair of the infarcted heart. Macrophages may also play a role in scar maturation and may contribute to chronic adverse remodeling of noninfarcted segments. Single cell studies have revealed a remarkable heterogeneity of macrophage populations in infarcted hearts; however, the relations between transcriptomic profiles and functional properties remain poorly defined. This review manuscript discusses the fate, mechanisms of expansion and activation, and role of macrophages in the infarcted heart. Considering their critical role in injury, repair, and remodeling, macrophages are important, but challenging, targets for therapeutic interventions in myocardial infarction.

Left Ventricular Remodeling after Myocardial Infarction: From Physiopathology to Treatment

Myocardial infarction (MI) is the leading cause of death and morbidity worldwide, with an incidence relatively high in developed countries and rapidly growing in developing countries. The most common cause of MI is the rupture of an atherosclerotic plaque with subsequent thrombotic occlusion in the coronary circulation. This causes cardiomyocyte death and myocardial necrosis, with subsequent inflammation and fibrosis. Current therapies aim to restore coronary flow by thrombus dissolution with pharmaceutical treatment and/or intravascular stent implantation and to counteract neurohormonal activation. Despite these therapies, the injury caused by myocardial ischemia leads to left ventricular remodeling; this process involves changes in cardiac geometry, dimension and function and eventually progression to heart failure (HF). This review describes the pathophysiological mechanism that leads to cardiac remodeling and the therapeutic strategies with a role in slowing the progression of remodeling and improving cardiac structure and function.

Update on Management of Cardiovascular Diseases in Women

Cardiovascular diseases (CVD) have a lower prevalence in women than men; although, a higher mortality rate and a poorer prognosis are more common in women. However, there is a misperception of CVD female risk since women have commonly been considered more protected so that the real threat is vastly underestimated. Consequently, female patients are more likely to be treated less aggressively, and a lower rate of diagnostic and interventional procedures is performed in women than in men. In addition, there are substantial sex differences in CVD, so different strategies are needed. This review aims to evaluate the main gender-specific approaches in CVD.

Low Serum Dehydroepiandrosterone and Dehydroepiandrosterone Sulfate Are Associated With Coronary Heart Disease in Men With Type 2 Diabetes Mellitus

AIMS

Sex hormones play an important role in the pathogenesis of cardiovascular disease (CVD). This cross-sectional study aimed to explore the associations of dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS) with coronary heart disease (CHD) and stroke in middle-aged and elderly patients with type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

A total of 995 patients with T2DM were included in the study analysis. Serum levels of DHEA and DHEAS were quantified using liquid chromatography-tandem mass spectrometry. Binary logistic regression analyses were performed to assess the associations of DHEA and DHEAS with CHD and stroke. Receiver operating characteristic (ROC) curve analysis was performed to determine the optimal DHEA and DHEAS cutoff values for the detection of CHD in men with T2DM.

RESULTS

In men with T2DM, after adjustment for potential confounders in model 3, the risk of CHD decreased with an increasing serum DHEA level [odds ratio (OR) = 0.38, quartile 4 vs. quartile 1; 95% confidence interval (CI) = 0.16-0.90; p = 0.037 for trend). Consistently, when considered as a continuous variable, this association remained significant in the fully adjusted model (OR = 0.59, 95% CI = 0.40-0.87, p < 0.05). When taken as a continuous variable in model 3, serum DHEAS level was also inversely related to the risk of CHD among men (OR = 0.56, 95% CI = 0.38-0.82, p < 0.05). Similarly, this relationship remained statistically significant when DHEAS was categorized into quartiles (OR = 0.27, quartile 4 vs. quartile 1; 95% CI = 0.11-0.67; p = 0.018 for trend). ROC curve analyses revealed that the optimal cutoff values to detect CHD in men with T2DM were 6.43 nmol/L for DHEA and 3.54 μmol/L for DHEAS. In contrast, no significant associations were found between DHEA and DHEAS on the one hand and stroke on the other in men and women with T2DM (all p > 0.05).

CONCLUSIONS

Serum DHEA and DHEAS were significantly and negatively associated with CHD in middle-aged and elderly men with T2DM. This study suggests potential roles of DHEA and DHEAS in CHD pathogenesis.