Supra-normal and mildly reduced ejection fraction in women -An overlooked vulnerable subpopulation in heart failure

BACKGROUND

Recently, patients with supra-normal left ventricular ejection fraction (snEF) are reported to have high risk of adverse outcomes, especially in women. We sought to evaluate sex-related differences in the association between LVEF and long-term outcomes in heart failure (HF) patients.

METHODS

The multicenter WET-HF Registry enrolled all patients hospitalized for acute decompensated HF (ADHF). We analyzed 3943 patients (age 77 years; 40.1% female) registered from 2006 to 2017. According to LVEF the patients were divided into the 3 groups: HF with reduced EF (HFrEF), mildly reduced EF (HFmrEF) and preserved EF. The primary endpoint was defined as the composite of cardiac death and ADHF rehospitalization after discharge.

RESULTS

In HFmrEF, implementation of guideline-directed medical therapy (GDMT) such as the combination of renin-angiotensin-system inhibitor (RASi) and β-blocker at discharge was significantly lower in women than men even after adjustment for covariates (p = 0.007). There were no such sex-related differences in HFrEF. Female sex was associated with higher incidence of the primary endpoint and ADHF rehospitalization after adjustment for covariates exclusively in HFmrEF. Restricted cubic spline analysis demonstrated a U-shaped relationship between LVEF and the hazard ratio of the primary endpoint showing higher event rate in HFmrEF and HFsnEF in women, but such relationship was not observed in men (p for interaction = 0.037).

CONCLUSIONS

In women, mrEF and snEF were associated with worse long-term outcomes. Additionally, sex-related differences in the GDMT implementation for HFmrEF highlight the need for further exploration, which might lead to creation of sex-specific guidelines to optimize HF management.

Sex Differences in Cardiac and Clinical Phenotypes and Their Relation to Outcomes in Patients with Heart Failure

Biological sex is one of the major factors characterizing the heart failure (HF) patient phenotype. Understanding sex-related differences in HF is crucial to implement personalized care for HF patients with various phenotypes. There are sex differences in left ventricular (LV) remodeling patterns in the HF setting, namely, more likely concentric remodeling and diastolic dysfunction in women and eccentric remodeling and systolic dysfunction in men. Recently supra-normal EF (snLVEF) has been recognized as a risk of worse outcome. This pathology might be more relevant in female patients. The possible mechanism may be through coronary microvascular dysfunction and sympathetic nerve overactivation from the findings of previous studies. Further, estrogen deficit might play a significant role in this pathophysiology. The sex difference in body composition may also be related to the difference in LV remodeling and outcome. Lower implementation in guideline-directed medical therapy (GDMT) in female HFrEF patients might also be one of the factors related to sex differences in relation to outcomes. In this review, we will discuss the sex differences in cardiac and clinical phenotypes and their relation to outcomes in HF patients and further discuss how to provide appropriate treatment strategies for female patients.

Supra-Normal Left Ventricular Function

Heart failure (HF) is often categorized by left ventricular (LV) ejection fraction (LVEF). A new category of HF characterized by supra-normal LVEF (>65%), named HF with supra-normal ejection fraction (HFsnEF), has been recently proposed. Some studies reported that patients with supra-normal LVEF might have an increased risk of long-term major adverse cardiovascular events and U-shaped mortality patterns. Currently, the prognosis of HFsnEF is not well established but seems to be associated with an increased risk of long-term major adverse cardiovascular events. It has been reported that HFsnEF is more prevalent in women and is associated with higher prevalence of nonischemic HF, higher blood urea nitrogen plasma levels, lower levels of natriuretic peptides, and to be less likely treated with β blockers. The pathophysiology of HFsnEF would be associated with microvascular dysfunction because of microvascular inflammation or reduced coronary flow reserve, and low stroke volume index with smaller cardiac chamber dimensions and concentric LV geometry. In this study, we systematically reviewed published data on patients with s supra-normal LV function and reported its definition, proposed pathophysiology, phenotypes, diagnostic strategy, and prognosis.

Left ventricular ejection fraction and long-term outcomes in women presenting with signs and symptoms of ischaemia

BACKGROUND

Although women are known to have a relatively higher left ventricular ejection fraction (LVEF) compared with men, a sex-neutral LVEF threshold continues to be used for clinical management. We sought to investigate the relationship among high (>65%), normal (55%-65%) and low (<55%) LVEF and long-term all-cause mortality and major adverse cardiovascular events (MACEs) in women presenting with suspected myocardial ischaemia.

METHODS

A total of 734 women from the Women's Ischemia Syndrome Evaluation (WISE) were analysed. LVEF was calculated by invasive left ventriculography. The relationship between baseline characteristics, LVEF and outcomes was evaluated. A multivariable Cox regression model was used to assess the association of LVEF with outcomes, after adjusting for known risk factors.

RESULTS

Low LVEF was associated with higher rates of mortality and MACE compared with normal and high LVEF (p<0.0001). Normal LVEF was associated with higher mortality (p=0.047) and rate of myocardial infarctions (MIs) compared with high LVEF (p=0.03). Low LVEF remained a significant predictor of mortality compared with high LVEF (p=0.013) in a multivariable regression model and normal compared with high LVEF trended towards higher mortality (p=0.16).

CONCLUSION

Among women with suspected ischaemia, women with LVEF above the defined normal threshold (>65%) had lower rates of all-cause mortality and non-fatal MI. Further investigation is needed to determine the optimal LVEF in women.

TRIAL REGISTRATION NUMBER

NCT00000554.

Heart Failure Preserved Ejection Fraction in Women: Insights Learned from Imaging

While the prevalence of heart failure, in general, is similar in men and women, women experience a higher rate of HFpEF compared to HFrEF. Cardiovascular risk factors, parity, estrogen levels, cardiac physiology, and altered response to the immune system may be at the root of this difference. Studies have found that in response to increasing age and hypertension, women experience more concentric left ventricle remodeling, more ventricular and arterial stiffness, and less ventricular dilation compared to men, which predisposes women to developing more diastolic dysfunction. A multi-modality imaging approach is recommended to identify patients with HFpEF. Particularly, appreciation of sex-based differences as described in this review is important in optimizing the evaluation and care of women with HFpEF.

Positive affect as a predictor of non-pharmacological adherence in older Chronic Heart Failure (CHF) patients undergoing cardiac rehabilitation

In Chronic Heart Failure (CHF) patients, psychological and cognitive variables and their association with treatment adherence have been extensively reported in the literature, but few are the investigations in older people. The present study aimed to evaluate the psychological, cognitive, and adherence to treatment profile of older (>65 years) CHF patients, the interrelation between these variables, and identify possible independent predictors of self-reported treatment adherence. CHF inpatients undergoing cardiac rehabilitation were assessed for: anxiety, depression, cognitive impairment, positive and negative affect, and self-reported adherence (adherence antecedents, pharmacological adherence, and non-pharmacological adherence). 100 CHF inpatients (mean age: 74.9 ± 7.1 years) were recruited. 16% of patients showed anxiety and 24.5% depressive symptoms; 4% presented cognitive decline. Cognitive functioning negatively correlated to depression, anxiety, and negative affect (p < 0.01). The adherence antecedents (disease acceptance, adaptation, knowledge, and socio-familiar support) negatively correlated to anxiety (p < 0.05), depression (p < 0.001), and negative affect (p < 0.05), while they positively correlated to positive affect (p < 0.01). Pharmacological adherence negatively correlated to anxiety and negative affect (p < 0.05). Conversely, non-pharmacological adherence and positive affect positively correlated (p < 0.05). Furthermore, depression and anxiety negatively predicted adherence antecedents (β = -0.162, p = 0.037) and pharmacological adherence (β = -0.171, p = 0.036), respectively. Finally, positive affect was found as an independent predictor of non-pharmacological adherence (β = 0.133, p = 0.004). In cardiac rehabilitation, a specific psychological assessment focused on anxiety, depression, and affect can provide useful information to manage CHF older patients' care related to treatment adherence. In particular, positive affect should be targeted in future interventions to foster patients' non-pharmacological adherence.

Characteristics, prognosis, and treatment response in HFpEF patients with high vs. normal ejection fraction

Background

Heart failure with preserved ejection fraction (HFpEF) patients varied by left ventricular ejection fraction (LVEF) have different clinical characteristics, prognosis, and treatment response. With data from our prospective HFpEF cohort, we assessed the possible relationship between clinical characteristics, outcome as well as treatment response and LVEF.

Methods

We compared differences in baseline characteristics and clinical outcomes across LVEF categories (50%≤LVEF <60% vs. LVEF≥60%) in 1,502 HFpEF patients, and determined whether LVEF modified the treatment response. During 5-year follow-up, all-cause mortality was used as the primary endpoints, and composite endpoints (all-cause mortality or HF hospitalization) were set as the secondary endpoint.

Results

Patients with higher LVEF were statistically older, more likely to be women and have a history of atrial fibrillation. Patients with lower LVEF category were more likely to have a history of coronary artery disease. The incidences of all-cause mortality and composite endpoints were higher in patients with higher LVEF. Also, LVEF modified the spironolactone treatment effect for the primary outcome and secondary endpoint with stronger estimated benefits at the lower LVEF category with respect to all-cause mortality (HR 0.734, 95% CI 0.541–0.997, P = 0.048) and all-cause mortality or HF hospitalization (HR 0.767, 95% CI 0.604–0.972, P = 0.029).

Conclusion

The characteristics and outcomes of HFpEF patients varied substantially by LVEF. Patients with higher LVEF encountered more adverse events than those with lower LVEF. The potential efficacy of spironolactone was greatest at the lower category of LVEF spectrum in HFpEF.

Imaging of heart disease in women: review and case presentation

Cardiovascular diseases (CVD) remain the leading cause of mortality worldwide. Although major diagnostic and therapeutic advances have significantly improved the prognosis of patients with CVD in the past decades, these advances have less benefited women than age-matched men. Noninvasive cardiac imaging plays a key role in the diagnosis of CVD. Despite shared imaging features and strategies between both sexes, there are critical sex disparities that warrant careful consideration, related to the selection of the most suited imaging techniques, to technical limitations, and to specific diseases that are overrepresented in the female population. Taking these sex disparities into consideration holds promise to improve management and alleviate the burden of CVD in women. In this review, we summarize the specific features of cardiac imaging in four of the most common presentations of CVD in the female population including coronary artery disease, heart failure, pregnancy complications, and heart disease in oncology, thereby highlighting contemporary strengths and limitations. We further propose diagnostic algorithms tailored to women that might help in selecting the most appropriate imaging modality.

Impaired coronary flow reserve in patients with supra-normal left ventricular ejection fraction at rest

PURPOSE

Recently, a "U" hazard ratio curve between resting left ventricular ejection fraction (LVEF) and prognosis has been observed in patients referred for routine clinical echocardiograms. The present study sought to explore whether a similar "U" curve existed between resting LVEF and coronary flow reserve (CFR) in patients without severe cardiovascular disease (CVD) and whether impaired CFR played a role in the adverse outcome of patients with supra-normal LVEF (snLVEF, LVEF ≥ 65%).

METHODS

Two hundred ten consecutive patients (mean age 52.3 ± 9.3 years, 104 women) without severe CVD underwent clinically indicated rest/dipyridamole stress electrocardiography (ECG)-gated 13 N-ammonia positron emission tomography/computed tomography (PET/CT). Major adverse cardiac events (MACE) were followed up for 27.3 ± 9.5 months, including heart failure, late revascularization, re-hospitalization, and re-coronary angiography for any cardiac reason. Clinical characteristics, corrected CFR (cCFR), and MACE were compared among the three groups categorized by resting LVEF detected by PET/CT. Dose-response analyses using restricted cubic spline (RCS) functions, multivariate logistic regression, and Kaplan-Meier survival analysis were conducted to evaluate the relationship between resting LVEF and CFR/outcome.

RESULTS

An inverted "U" curve existed between resting LVEF and cCFR (p = 0.06). Both patients with snLVEF (n = 38) and with reduced LVEF (rLVEF, LVEF < 55%) (n = 66) displayed a higher incidence of reduced cCFR than those with normal LVEF (nLVEF, 55% ≤ LVEF < 65%) (n = 106) (57.9% vs 54.5% vs 34.3%, p < 0.01, respectively). Both snLVEF (p < 0.01) and rLVEF (p < 0.05) remained independent predictors for reduced cCFR after multivariable adjustment. Patients with snLVEF encountered more MACE than those with nLVEF (10.5% vs 0.9%, log-rank p = 0.01).

CONCLUSIONS

Patients with snLVEF are prone to impaired cCFR, which may be related to the adverse prognosis. Further investigations are warranted to explore its underlying pathological mechanism and clinical significance.

Heart-brain interactions in cardiac and brain diseases: why sex matters

Cardiovascular disease and brain disorders, such as depression and cognitive dysfunction, are highly prevalent conditions and are among the leading causes limiting patient's quality of life. A growing body of evidence has shown an intimate crosstalk between the heart and the brain, resulting from a complex network of several physiological and neurohumoral circuits. From a pathophysiological perspective, both organs share common risk factors, such as hypertension, diabetes, smoking or dyslipidaemia, and are similarly affected by systemic inflammation, atherosclerosis, and dysfunction of the neuroendocrine system. In addition, there is an increasing awareness that physiological interactions between the two organs play important roles in potentiating disease and that sex- and gender-related differences modify those interactions between the heart and the brain over the entire lifespan. The present review summarizes contemporary evidence of the effect of sex on heart-brain interactions and how these influence pathogenesis, clinical manifestation, and treatment responses of specific heart and brain diseases.

Normal sex and age-specific parameters in a multi-ethnic population: a cardiovascular magnetic resonance study of the Canadian Alliance for Healthy Hearts and Minds cohort

BACKGROUND

Despite the growing utility of cardiovascular magnetic resonance (CMR) for cardiac morphology and function, sex and age-specific normal reference values derived from large, multi-ethnic data sets are lacking. Furthermore, most available studies use a simplified tracing methodology. Using a large cohort of participants without history of cardiovascular disease (CVD) or risk factors from the Canadian Alliance for Healthy Heart and Minds, we sought to establish a robust set of reference values for ventricular and atrial parameters using an anatomically correct contouring method, and to determine the influence of age and sex on ventricular parameters.

METHODS AND RESULTS

Participants (n = 3206, 65% females; age 55.2 ± 8.4 years for females and 55.1 ± 8.8 years for men) underwent CMR using standard methods for quantitative measurements of cardiac parameters. Normal ventricular and atrial reference values are provided: (1) for males and females, (2) stratified by four age categories, and (3) for different races/ethnicities. Values are reported as absolute, indexed to body surface area, or height. Ventricular volumes and mass were significantly larger for males than females (p < 0.001). Ventricular ejection fraction was significantly diminished in males as compared to females (p < 0.001). Indexed left ventricular (LV) end-systolic, end-diastolic volumes, mass and right ventricular (RV) parameters significantly decreased as age increased for both sexes (p < 0.001). For females, but not men, mean LV and RVEF significantly increased with age (p < 0.001).

CONCLUSION

Using anatomically correct contouring methodology, we provide accurate sex and age-specific normal reference values for CMR parameters derived from the largest, multi-ethnic population free of CVD to date.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT02220582. Registered 20 August 2014-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT02220582 .

Increased long-term mortality in women with high left ventricular ejection fraction: data from the CONFIRM (COronary CT Angiography EvaluatioN For Clinical Outcomes: An InteRnational Multicenter) long-term registry

AIMS

There are significant sex-specific differences in left ventricular ejection fraction (LVEF), with a higher LVEF being observed in women. We sought to assess the clinical relevance of an increased LVEF in women and men.

METHODS AND RESULTS

A total of 4632 patients from the CONFIRM (COronary CT Angiography EvaluatioN For Clinical Outcomes: An InteRnational Multicenter) registry (44.8% women; mean age 58.7 ± 13.2 years in men and 59.5 ± 13.3 years in women, P = 0.05), in whom LVEF was measured by cardiac computed tomography, were categorized according to LVEF (low <55%, normal 55-65%, and high >65%). The prevalence of high LVEF was similar in both sexes (33.5% in women and 32.5% in men, P = 0.46). After 6 years of follow-up, no difference in mortality was observed in patients with high LVEF in the overall cohort (P = 0.41). When data were stratified by sex, women with high LVEF died more often from any cause as compared to women with normal LVEF (8.6% vs. 7.1%, log rank P = 0.032), while an opposite trend was observed in men (5.8% vs. 6.8% in normal LVEF, log rank P = 0.89). Accordingly, a first order interaction term of male sex and high LVEF was significant (hazard ratios 0.63, 95% confidence intervals 0.41-0.98, P = 0.043) in a Cox regression model of all-cause mortality adjusted for age, cardiovascular risk factors, and severity of coronary artery disease (CAD).

CONCLUSION

Increased LVEF is highly prevalent in patients referred for evaluation of CAD and is associated with an increased risk of death in women, but not in men. Differentiating between normal and hyperdynamic left ventricles might improve risk stratification in women with CAD.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT01443637.

Characterization of the inflammatory-metabolic phenotype of heart failure with a preserved ejection fraction: a hypothesis to explain influence of sex on the evolution and potential treatment of the disease

Accumulating evidence points to the existence of an inflammatory-metabolic phenotype of heart failure with a preserved ejection fraction (HFpEF), which is characterized by biomarkers of inflammation, an expanded epicardial adipose tissue mass, microvascular endothelial dysfunction, normal-to-mildly increased left ventricular volumes and systolic blood pressures, and possibly, altered activity of adipocyte-associated inflammatory mediators. A broad range of adipogenic metabolic and systemic inflammatory disorders - e.g. obesity, diabetes and metabolic syndrome as well as rheumatoid arthritis and psoriasis - can cause this phenotype, independent of the presence of large vessel coronary artery disease. Interestingly, when compared with men, women are both at greater risk of and may suffer greater cardiac consequences from these systemic inflammatory and metabolic disorders. Women show disproportionate increases in left ventricular filling pressures following increases in central blood volume and have greater arterial stiffness than men. Additionally, they are particularly predisposed to epicardial and intramyocardial fat expansion and imbalances in adipocyte-associated proinflammatory mediators. The hormonal interrelationships seen in inflammatory-metabolic phenotype may explain why mineralocorticoid receptor antagonists and neprilysin inhibitors may be more effective in women than in men with HFpEF. Recognition of the inflammatory-metabolic phenotype may improve an understanding of the pathogenesis of HFpEF and enhance the ability to design clinical trials of interventions in this heterogeneous syndrome.

Revisiting the relationship between left ventricular ejection fraction and ventricular-arterial coupling

The aim of this article was to analyse in‐depth the relationship between left ventricular (LV) ejection fraction (EF) (LVEF) and the most commonly used formulas for the calculation of LV elastance (Ees), volume intercept at 0 mmHg pressure (V0), effective arterial elastance (Ea), and ventricular–arterial coupling (VAC) as are validated today. We analyse the mathematical resulting consequences, raising the question on the physiological validity. To our knowledge, some of the following mathematical consequences have never been published. On the basis of studies demonstrating that normal LV dimensions and LVEF have a Gaussian unimodal distribution, we considered that the normal modal LVEF is 62% or very close to it. Expressed as a fraction, it is 0.62, that is, the reciprocal of the Phi number (namely, 1/Φ ~ 0.618). Applying Euclid's mathematical law on the extreme and mean ratio (the golden ratio), we studied the LVEF–VAC relationship in normal hearts. The simplification of the VAC formula (with V0 = 0) leads to false physiological results; V0 extraction from single‐beat Chen's formula leads to high negative results in normal subjects; based on the Euclid law, LVEF and Ea/Ees will be equal for a ratio value of 0.618 (62%) where V0 cannot be different from 0 mL; LVEF and VAC inverse relationship formula (Ea/Ees = 1/LVEF − 1) is reducible to a fundamental property of Phi: 1/Φ = (Φ − 1), being valid only if LVEF = VAC at a 0.618 value; according to this restriction, Vo can only be 0 mL, thus describing a very limited range. The Ea/Ees ratio, owing to its mathematical more dynamic behaviour, can be more sensitive than LVEF, being a valuable clinical tool in patients with heart failure (HF) with reduced EF, acute unstable haemodynamic situations, where Ees and Ea variations are disproportionate. However, the application is doubtful in HF with preserved EF where Ees and Ea may have same‐direction augmentation. The modified VAC formula suffers from oversimplification, reducing it to a dimensionless ratio, which is supposed to approximate non‐linear time‐varying functions. Thus, we advocate for caution and in‐depth understanding when using simplified formulas in clinical practice.

Microvascular dysfunction and sympathetic hyperactivity in women with supra-normal left ventricular ejection fraction (snLVEF)

BACKGROUND

Recently, a new disease phenotype characterized by supra-normal left ventricular ejection fraction (snLVEF) has been suggested, based on large datasets demonstrating an increased all-cause mortality in individuals with an LVEF > 65%. The underlying mechanisms of this association are currently unknown.

METHODS

A total of 1367 patients (352 women, mean age 63.1 ± 11.6 years) underwent clinically indicated rest/adenosine stress ECG-gated ¹³N-ammonia positron emission tomography (PET) between 1995 and 2017 at our institution. All patients were categorized according to LVEF. A subcohort of 698 patients (150 women) were followed for major adverse cardiac events (MACEs), a composite of cardiac death, non-fatal myocardial infarction, cardiac-related hospitalization, and revascularization.

RESULTS

The prevalence of a snLVEF (≥ 65%) was higher in women as compared to that in men (31.3% vs 18.8%, p < 0.001). In women, a significant reduction in coronary flow reserve (CFR, p < 0.001 vs normal LVEF) and a blunted heart rate reserve (% HRR, p = 0.004 vs normal LVEF) during pharmacological stress testing-a surrogate marker for autonomic dysregulation-were associated with snLVEF. Accordingly, reduced CFR and HRR were identified as strong and independent predictors for snLVEF in women in a fully adjusted multinomial regression analysis. After a median follow-up time of 5.6 years, women with snLVEF experienced more often a MACE than women with normal (55-65%) LVEF (log rank p < 0.001), while such correlation was absent in men (log rank p = 0.76).

CONCLUSION

snLVEF is associated with an increased risk of MACE in women, but not in men. Microvascular dysfunction and an increased sympathetic tone in women may account for this association.

Understanding cardiac systolic performance beyond left ventricular ejection fraction

Left ventricular ejection fraction is the critical parameter used for heart failure classification, decision making and assessing prognosis. It is defined as a volumetric ratio and is essentially a composite of arterial and ventricular elastances, but not intrinsic contractility. The clinician should be aware of its numerous limitations when measuring and reporting it. And make a step toward more insightful understanding of hemodynamics.

Drug-induced myocardial dysfunction - recommendations for assessment in clinical and pre-clinical studies

Introduction: Drug-induced myocardial dysfunction is an important safety concern during drug development. Oncology compounds can cause myocardial dysfunction, leading to decreased left ventricular ejection fraction and heart failure via several mechanisms. Cardiovascular imaging has a major role in the early detection and monitoring of cardiotoxicity. Echocardiography is the method of choice because of its widespread availability, low cost, and absence of radiation exposure. Cardiac magnetic resonance imaging can provide better reliability, reproducibility, and accuracy in the detection of drug-induced myocardial dysfunction. In addition, it enables assessment of myocardial edema, fibrosis, and necrosis. Cardiac serologic biomarkers such as troponins and B-type natriuretic peptides are used in combination with imaging during drug development. This article provides a general overview of each imaging modality and practical guidance for early detection and monitoring of cardiotoxicity.Areas covered: Cardiovascular imaging modalities and cardiac biomarkers for monitoring of cardiac function and early detection of drug-induced myocardial dysfunction in drug development.Expert opinion: Some new drugs especially in the oncology field, can cause myocardial dysfunction. Depending on the strength of pre-clinical or clinical data, CV imaging modalities and cardiac biomarkers play an important role in the early detection and mitigation plans for such drugs during their development.

Age- and sex-dependent changes in sympathetic activity of the left ventricular apex assessed by 18F-DOPA PET imaging

BACKGROUND

Sexual dimorphism in cardiac sympathetic outflow has recently gained attention in the context of Takotsubo cardiomyopathy. Previous studies suggest that there are sex- and age-dependent differences in peripheral autonomic control, however, data on cardiac-specific sympathetic activation in aged women and men are lacking.

METHODS AND RESULTS

Regional quantitative analysis of cardiac fluorine-18 (18F)- Dihydroxyphenylalanine (DOPA) uptake was retrospectively performed in 133 patients (69 females, mean age 52.4±17.7 years) referred for assessment of neuroendocrine tumours (NET) by Positron-Emission-Tomography. Cardiac 18F-DOPA uptake was significantly higher in women as compared to men (1.33±0.21 vs. 1.18±0.24, p<0.001). This sex-difference was most pronounced in the apical region of the left ventricle (LV, 1.30±0.24 in women vs. 1.13±0.25 in men, p<0.001) and in individuals >55 years of age (1.39±0.25 in women vs. 1.09±0.24 in men, p<0.001). Women showed a prominent increase in myocardial 18F-DOPA uptake with age with the strongest increase seen in the LV apical region (r = 0.34, p = 0.004). Accordingly, sex and age were selected as significant predictors of LV apical 18F-DOPA uptake in a stepwise linear regression model. No age-dependent changes of cardiac 18F-DOPA uptake were observed in men or in the right ventricular region.

CONCLUSION

Our study suggests that aging is related to sex-specific changes in regional cardiac sympathetic activity. Future studies will have to assess whether the increase in LV apical 18F-DOPA uptake with age in women is of pathogenic relevance for the higher susceptibility of postmenopausal women to conditions associated with increased sympathetic activity.

Differences in Cardiovascular Aging in Men and Women

Cardiovascular diseases increase dramatically with age in both men and women. While it is clear that advanced age allows more time for individuals to be exposed to risk factors in general, there is strong evidence that age itself is a major independent risk factor for cardiovascular disease. Indeed, there are distinct age-dependent cellular, structural, and functional changes in both the heart and blood vessels, even in individuals with no clinical evidence of cardiovascular disease. Studies in older humans and in animal models of aging indicate that this age-related remodeling is maladaptive. An emerging view is that the heart and blood vessels accumulate cellular and subcellular deficits with age and these deficits increase susceptibility to disease in older individuals. Aspects of this age-dependent remodeling of the heart and blood vessels differ between the sexes. There is also new evidence that these maladaptive changes are more prominent in older animals and humans with a high degree of frailty. These observations may help explain why men and women are susceptible to different cardiovascular diseases as they age and why frail older adults are most often affected by these diseases.