Impact of age on pulmonary artery systolic pressures at rest and with exercise

Optimal Method for Assessing Right Ventricular to Pulmonary Arterial Coupling in Older Healthy Adults: The Multi-Ethnic Study of Atherosclerosis

Right ventricular (RV) to pulmonary arterial (PA) coupling describes the ability of the RV to augment contractility in response to increased afterload. Several echocardiographic indexes of RV-PA coupling have been defined; however, the optimal numerator in the coupling ratio is unclear. We sought to establish which of these ratios is best for assessing RV-PA coupling based on their relations with 6-minute walk distance (6MWD), N-terminal pro-B-type natriuretic peptide (NT-proBNP), and the Kansas City Cardiomyopathy Questionnaire (KCCQ) in aging adults. In this study of 1,611 Multi-Ethnic Study of Atherosclerosis participants who underwent echocardiography at Exam 6, we evaluated the association between different numerators, including tricuspid annular planar systolic excursion (TAPSE), fractional area change (FAC), RV free wall strain, and tissue Doppler imaging S' velocity to pulmonary artery systolic pressure (PASP) with 6MWD, NT-proBNP, and KCCQ score, adjusted for socioeconomic and cardiovascular disease risk factors. Our cohort had a mean age of 73 ± 8 years, 54% female, 17% Chinese American, 22% African American, 22% Hispanic, and 39% White participants. The mean ( ± SD) TAPSE/PASP, FAC/PASP, tissue Doppler imaging S' velocity/PASP, and RV free wall strain:PASP ratios were 0.7 ± 0.2, 1.3 ± 0.3, 0.5 ± 0.1, and 0.8 ± 0.2, respectively. All RV-PA coupling indices decreased with age (p <0.0001 for all). TAPSE:PASP ratio was lower in older (³85 years) female (0.59 ± 0.14) versus male (0.65 ± 0.17) participants (p = 0.01), whereas FAC/PASP ratio was higher in the same female versus male participants (p <0.01). TAPSE/PASP and FAC/PASP ratios were significantly and strongly associated with all NT-proBNP, 6MWD, and KCCQ scores in fully adjusted and receiver operating characteristic analysis. In older community-dwelling adults free of heart failure and pulmonary hypertension, both FAC/PASP and TAPSE:PASP ratios are optimal for assessment of RV-PA coupling based on its association with 6MWD, NT-proBNP, and KCCQ score. FAC/PASP ratio has the additional benefit of reflecting age and gender-related geometric and functional changes.

Stiffening of the human proximal pulmonary artery with increasing age

Adverse effects of large artery stiffening are well established in the systemic circulation; stiffening of the proximal pulmonary artery (PPA) and its sequelae are poorly understood. We combined in vivo (n = 6) with ex vivo data from cadavers (n = 8) and organ donors (n = 13), ages 18 to 89, to assess whether aging of the PPA associates with changes in distensibility, biaxial wall strain, wall thickness, vessel diameter, and wall composition. Aging exhibited significant negative associations with distensibility and cyclic biaxial strain of the PPA (p ≤ 0.05), with decreasing circumferential and axial strains of 20% and 7%, respectively, for every 10 years after 50. Distensibility associated directly with diffusion capacity of the lung (R2 = 0.71, p = 0.03). Axial strain associated with right ventricular ejection fraction (R2 = 0.76, p = 0.02). Aging positively associated with length of the PPA (p = 0.004) and increased luminal caliber (p = 0.05) but showed no significant association with mean wall thickness (1.19 mm, p = 0.61) and no significant differences in the proportions of mural elastin and collagen (p = 0.19) between younger (<50 years) and older (>50) ex vivo samples. We conclude that age-related stiffening of the PPA differs from that of the aorta; microstructural remodeling, rather than changes in overall geometry, may explain age-related stiffening.

Practice guidance for stress echocardiography

Stress echocardiography has been one of the most promising methods for the diagnosis of ischemic heart disease, hypertrophic cardiomyopathy, and pulmonary hypertension. The Japanese Society of Echocardiography produced practical guidance for the implementation of stress echocardiography in 2018. At that time, stress echocardiography was not yet widely disseminated in Japan; therefore, the 2018 practical guidance for the implementation of stress echocardiography included a report on stress echocardiography and a specific protocol to promote its use at many institutions in Japan in the future. And now, an era of renewed interest and enthusiasm surrounding the diagnosis and treatment of valvular heart disease and heart failure with preserved ejection fraction (HFpEF) has come, which are driven by emerging trans-catheter procedures and new recommended guideline-directed medical therapy. Based on the continued evidence of stress echocardiography, the new practical guideline that describes the safe and effective methodology of stress echocardiography is now created by the Guideline Development Committee of the Japanese Society of Echocardiography and is designed to expand the use of stress echocardiography for valvular heart disease and HFpEF, as well as ischemic heart disease, hypertrophic cardiomyopathy, and pulmonary hypertension. The readers are encouraged to perform stress echocardiography which will enhance the diagnosis and management of these patients.

Electrocardiogram Parameters Associated With the Diagnosis of Pulmonary Hypertension in High-Altitude Tibetan Populations: A Retrospective Single-Centre Study

BACKGROUND

Electrocardiogram (ECG) is a commonly used diagnostic method for pulmonary hypertension (PH) in Tibetan areas, but its sensitivity and specificity are not good enough. This study aimed to investigate the ECG parameters associated with the diagnosis of PH in Tibetan areas.

METHODS

Ninety-four PH patients of Tibetan ethnicity who were treated at the hospital between March 2019 and October 2020, and 52 Tibetan individuals as controls, were included. The ECG parameters were compared between groups. Multivariate logistic analysis was performed to identify the ECG parameters that can be used for the diagnosis of PH. The univariate significances of ECG parameters were included in the multivariate analyses, whereas those exhibiting opposite trends between different PH subtypes were excluded.

RESULTS

Two ECG parameters were significant in multivariate analysis. The final model included S wave amplitude in lead V3 (OR 5.81; 95% CI 2.79-12.11; p<0.001) and a negative T wave in leads V1-V3 (OR 0.05; 95% CI 0.01-0.41; p=0.005). The ROC curve analysis on the final model yielded an AUC of 0.830 (95% CI 0.766-0.894; p<0.001), indicating good diagnostic performance. A nomogram for diagnosis of PH was also established using S wave amplitude in lead V3 and a negative T wave in leads V1-V3.

CONCLUSION

The ECG parameters S wave amplitude in lead V3 and a negative T wave in leads V1-V3 were independent factors associated with the diagnosis of PH in high-altitude Tibetan populations.

Transcatheter closure of atrial septal defect in the elderly: a systematic review and meta-analysis

OBJECTIVE

Despite the establishment of transcatheter closure as the treatment of choice in adults with secundum atrial septal defects (ASDs), the effectiveness of this approach in the elderly is disputed. This systematic review and meta-analysis aims to explore the impact of transcatheter ASD closure in patients ≥60 years old.

METHODS

We systematically searched four major electronic databases (PubMed, CENTRAL (Cochrane Central Register of Controlled Trials), Scopus and Web of Science), ClinicalTrials.gov, article references and grey literature. Primary outcomes were the right ventricular end-diastolic diameter (RVEDD) and the New York Heart Association functional class change, whereas secondary outcomes included systolic pulmonary arterial pressure (sPAP), left ventricular end-diastolic diameter (LVEDD), brain natriuretic peptide (BNP), tricuspid valve regurgitation (TR) change, as well as the rate of atrial arrhythmias and all-cause mortality.

RESULTS

In total, 18 single-arm cohorts comprising 1184 patients were included. RVEDD was reduced after ASD closure (standardised mean difference (SMD) -0.9, 95% CI -1.2 to -0.7). Elderly patients had 9.5 times higher odds of being asymptomatic after ASD closure (95% CI 5.06 to 17.79). Furthermore, ASD closure improved sPAP (mean difference (MD) -10.8, 95% CI -14.6 to -7), LVEDD (SMD 0.8, 95% CI 0.7 to 1.0), TR severity (OR 0.39, 95% CI 0.25 to 0.60) and BNP (MD -68.3, 95% CI -114.4 to -22.1). There was a neutral effect of ASD closure on atrial arrhythmias.

CONCLUSIONS

Transcatheter ASD closure is beneficial for the elderly population since it improves functional capacity, biventricular dimensions, pulmonary pressures, TR severity and BNP. However, the incidence of atrial arrhythmias did not change significantly after the intervention.

PROSPERO REGISTRATION NUMBER

CRD42022378574.

Assessment of pulmonary artery stiffness by multiparametric cardiac magnetic resonance-surrogate for right heart catheterization

Background

Cardiac magnetic resonance (CMR) imaging allows for multiparametric assessment of healthy pulmonary artery (PA) hemodynamics. Gender- and aging-associated PA stiffness and pressure alterations have remained clinically unestablished, however may demonstrate epidemiological differences in disease development. The aim of this study is to evaluate the role of CMR as a surrogate for catheter examinations by providing a comprehensive CMR assessment of sex- and age-related reference values for PA stiffness, flow, and pressure.

Methods and Results

PA hemodynamics were studied between gender and age groups (>/<50 years) using phase-contrast CMR. Corresponding correlation analyses were performed. 179 healthy volunteers with a median age of 32.6 years (range 11.3-68.2) were examined. Males demonstrated increased PA compliance (median [interquartile range] or mean ± standard deviation) (20.8 mm2/mmHg [16.6; 25.8] vs. 19.2 ± 7.1 mm2/mmHg; P < 0.033), higher pulse wave velocity (2.00 m/s [1.35; 2.87] vs. 1.73 m/s [1.19; 2.34]; P = 0.018) and a reduced full width half maximum (FWHM) (219 ± 22 ms vs. 235 ± 23 ms; P < 0.001) than females. Mean, systolic, diastolic PA pressure and pulmonary proportional pulse pressure were significantly elevated for males compared to females (P < 0.001). Older subjects (>50 years) exhibited reduced PA elasticity (41.7% [31.0; 52.9] vs. 66.4% [47.7; 83.0]; P < 0.001), reduced PA compliance (15.4 mm2/mmHg [12.3; 20.7] vs. 21.3 ± 6.8 mm2/mmHg; P < 0.001), higher pulse wave velocity (2.59 m/s [1.57; 3.59] vs. 1.76 m/s [1.24; 2.34]; P < 0.001) and a reduced FWHM (218 ± 29 ms vs. 231 ± 21 ms; P < 0.001) than younger subjects.

Conclusions

Velocity-time profiles are dependent on age and gender. PA stiffness indices deteriorate with age. CMR has potential to serve as a surrogate for right heart catheterization.

A structural approach to 3D-printing arterial phantoms with physiologically comparable mechanical characteristics: Preliminary observations

Pulse wave behavior is important in cardiovascular pathophysiology and arterial phantoms are valuable for studying arterial function. The ability of phantoms to replicate complex arterial elasticity and anatomy is limited by available materials and techniques. The feasibility of improving phantom performance using functional structure designs producible with practical 3D printing technologies was investigated. A novel corrugated wall approach to separate phantom function from material properties was investigated with a series of designs printed from polyester-polyurethane using a low-cost open-source fused filament fabrication 3D printer. Nonpulsatile pressure-diameter data was collected, and a mock circulatory system was used to observe phantom pulse wave behavior and obtain pulse wave velocities. The measured range of nonpulsatile Peterson elastic strain modulus was 5.6–19 to 12.4–33.0 kPa over pressures of 5–35 mmHg for the most to least compliant designs respectively. Pulse wave velocities of 1.5–5 m s⁻¹ over mean pressures of 7–55 mmHg were observed, comparing favorably to reported in vivo pulmonary artery measurements of 1–4 m s⁻¹ across mammals. Phantoms stiffened with increasing pressure in a manner consistent with arteries, and phantom wall elasticity appeared to vary between designs. Using a functional structure approach, practical low-cost 3D-printed production of simple arterial phantoms with mechanical properties that closely match the pulmonary artery is possible. Further functional structure design development to expand the pressure range and physiologic utility of dir"ectly 3D-printed phantoms appears warranted.

Hypoxia and hemorheological properties in older individuals

Hypoxia is caused by insufficient oxygen availability for the organism leading to reduced oxygen delivery to tissues and cells. It has been regarded as a severe threat to human health and it is indeed implicated in pathophysiological mechanisms involved in the development and progression of many diseases. Nevertheless, the potential of controlled hypoxia interventions (i.e. hypoxia conditioning) for improving cardio-vascular health is gaining increased attention. However, blood rheology is often a forgotten factor for vascular health while aging and hypoxia exposure are both suspected to alter hemorheological properties. These changes in blood rheology may influence the benefits-risks balance of hypoxia exposure in older individuals. The benefits of hypoxia exposure for vascular health are mainly reported for healthy populations and the combined impact of aging and hypoxia on blood rheology could therefore be deleterious in older individuals. This review discusses evidence of hypoxia-related and aging-related changes in blood viscosity and its determinants. It draws upon an extensive literature search on the effects of hypoxia/altitude and aging on blood rheology. Aging increases blood viscosity mainly through a rise in plasma viscosity, red blood cell (RBC) aggregation and a decrease in RBC deformability. Hypoxia also causes an increase in RBC aggregation and plasma viscosity. In addition, hypoxia exposure may increase hematocrit and modulate RBC deformability, depending on the hypoxic dose, i.e, beneficial effect of intermittent hypoxia with moderate dose vs deleterious effect of chronic continuous or intermittent hypoxia or if the hypoxic dose is too high. Special attention is directed toward the risks vs. benefits of hemorheological changes during hypoxia exposure in older individuals, and its clinical relevance for vascular disorders.

Endothelial Senescence: A New Age in Pulmonary Hypertension

Pulmonary hypertension is an enigmatic, deleterious disease driven by multiple heterogeneous causes with a burgeoning proportion of older patients with complex, chronic comorbidities without adequate treatment options. The underlying endothelial pathophenotypes that direct vasoconstriction and panvascular remodeling remain both controversial and incompletely defined. This review discusses emerging concepts centered on endothelial senescence in pulmonary vascular disease. This principle proposes a more heterogeneous, dynamic pulmonary endothelium in disease; it provides a potentially unifying feature of endothelial dysfunction in pulmonary hypertension irrespective of cause; and it supports a clinically relevant link between aging and pulmonary hypertension like other chronic illnesses. Thus, taking cues from studies on aging and age-related diseases, we present possible opportunities and barriers to diagnostic and therapeutic targeting of senescence in pulmonary hypertension.

The Effects of Healthy Aging on Right Ventricular Structure and Biomechanical Properties: A Pilot Study

Healthy aging has been associated with alterations in pulmonary vascular and right ventricular (RV) hemodynamics, potentially leading to RV remodeling. Despite the current evidence suggesting an association between aging and alterations in RV function and higher prevalence of pulmonary hypertension in the elderly, limited data exist on age-related differences in RV structure and biomechanics. In this work, we report our preliminary findings on the effects of healthy aging on RV structure, function, and biomechanical properties. Hemodynamic measurements, biaxial mechanical testing, constitutive modeling, and quantitative transmural histological analysis were employed to study two groups of male Sprague-Dawley rats: control (11 weeks) and aging (80 weeks). Aging was associated with increases in RV peak pressures (+17%, p = 0.017), RV contractility (+52%, p = 0.004), and RV wall thickness (+38%, p = 0.001). Longitudinal realignment of RV collagen (16.4°, p = 0.013) and myofibers (14.6°, p = 0.017) were observed with aging, accompanied by transmural cardiomyocyte loss and fibrosis. Aging led to increased RV myofiber stiffness (+141%, p = 0.003), in addition to a bimodal alteration in the biaxial biomechanical properties of the RV free wall, resulting in increased tissue-level stiffness in the low-strain region, while progressing into decreased stiffness at higher strains. Our results demonstrate that healthy aging may modulate RV remodeling via increased peak pressures, cardiomyocyte loss, fibrosis, fiber reorientation, and altered mechanical properties in male Sprague-Dawley rats. Similarities were observed between aging-induced remodeling patterns and those of RV remodeling in pressure overload. These findings may help our understanding of age-related changes in the cardiovascular fitness and response to disease.

Frataxin deficiency promotes endothelial senescence in pulmonary hypertension

The dynamic regulation of endothelial pathophenotypes in pulmonary hypertension (PH) remains undefined. Cellular senescence is linked to PH with intracardiac shunts; however, its regulation across PH subtypes is unknown. Since endothelial deficiency of iron-sulfur (Fe-S) clusters is pathogenic in PH, we hypothesized that a Fe-S biogenesis protein, frataxin (FXN), controls endothelial senescence. An endothelial subpopulation in rodent and patient lungs across PH subtypes exhibited reduced FXN and elevated senescence. In vitro, hypoxic and inflammatory FXN deficiency abrogated activity of endothelial Fe-S-containing polymerases, promoting replication stress, DNA damage response, and senescence. This was also observed in stem cell-derived endothelial cells from Friedreich's ataxia (FRDA), a genetic disease of FXN deficiency, ataxia, and cardiomyopathy, often with PH. In vivo, FXN deficiency-dependent senescence drove vessel inflammation, remodeling, and PH, whereas pharmacologic removal of senescent cells in Fxn-deficient rodents ameliorated PH. These data offer a model of endothelial biology in PH, where FXN deficiency generates a senescent endothelial subpopulation, promoting vascular inflammatory and proliferative signals in other cells to drive disease. These findings also establish an endothelial etiology for PH in FRDA and left heart disease and support therapeutic development of senolytic drugs, reversing effects of Fe-S deficiency across PH subtypes.

Fluid-structure interaction in a fully coupled three-dimensional mitral-atrium-pulmonary model

This paper aims to investigate detailed mechanical interactions between the pulmonary haemodynamics and left heart function in pathophysiological situations (e.g. atrial fibrillation and acute mitral regurgitation). This is achieved by developing a complex computational framework for a coupled pulmonary circulation, left atrium and mitral valve model. The left atrium and mitral valve are modelled with physiologically realistic three-dimensional geometries, fibre-reinforced hyperelastic materials and fluid–structure interaction, and the pulmonary vessels are modelled as one-dimensional network ended with structured trees, with specified vessel geometries and wall material properties. This new coupled model reveals some interesting results which could be of diagnostic values. For example, the wave propagation through the pulmonary vasculature can lead to different arrival times for the second systolic flow wave (S2 wave) among the pulmonary veins, forming vortex rings inside the left atrium. In the case of acute mitral regurgitation, the left atrium experiences an increased energy dissipation and pressure elevation. The pulmonary veins can experience increased wave intensities, reversal flow during systole and increased early-diastolic flow wave (D wave), which in turn causes an additional flow wave across the mitral valve (L wave), as well as a reversal flow at the left atrial appendage orifice. In the case of atrial fibrillation, we show that the loss of active contraction is associated with a slower flow inside the left atrial appendage and disappearances of the late-diastole atrial reversal wave (AR wave) and the first systolic wave (S1 wave) in pulmonary veins. The haemodynamic changes along the pulmonary vessel trees on different scales from microscopic vessels to the main pulmonary artery can all be captured in this model. The work promises a potential in quantifying disease progression and medical treatments of various pulmonary diseases such as the pulmonary hypertension due to a left heart dysfunction.

Aging influences pulmonary artery flow and stiffness in healthy individuals: non-invasive assessment using cardiac MRI

AIM

To investigate age-related changes of the pulmonary artery (PA) using cardiac magnetic resonance imaging (cMRI) in healthy subjects.

MATERIALS AND METHODS

A cross-sectional observational study was conducted on apparently healthy subjects who underwent PA velocity-encoded cMRI. cMRI was used to determine PA stiffness parameters such as PA elasticity, relative area change (PA-RAC) and pulse-wave velocity (PA-PWV), and PA flow parameters by subtracting simultaneous forward flow (FF) and backward flow (BF) velocity across the PA cross-section. Data were presented in five age and sex matched groups.

RESULTS

One hundred and fifty subjects (20-70 years, 75 men) met the enrolment criteria. PA elasticity and PA-RAC significantly decreased with age (p<0.001), while PA-PWV, regurgitant volume (V_reg) and backward flow volume (V_BF) increased in the elderly (p<0.001). Linear regression analysis indicated that PA elasticity (r=-0.441, p<0.0001) and PA-RAC (r=-0.484, p<0.0001) were indirectly and negatively associated with advancing age, whereas PA_min (r=0.331, p<0.0001), PA-PWV (r=0.490, p<0.0001), V_Reg (r=0.335, p<0.0001) and V_BF (r=0.349, p<0.0001) were directly associated with age. Multivariate analysis indicated that age was independently associated with V_reg and V_BF, and the addition of PA_min and PA-PWV marginally increased its predictive capacity.

CONCLUSION

Aging significantly increases cMRI-based PA flow and stiffness parameters. These could become relevant markers of subclinical changes of the PA geometry in healthy subjects.

Right Ventricle Mechanics and Function during Stress in Patients with Asymptomatic Primary Moderate to Severe Mitral Regurgitation and Preserved Left Ventricular Ejection Fraction

Background and objectives. Mitral regurgitation (MR) is usually dynamic and increasing with exertion. Stress may provoke symptoms, cause the progression of pulmonary hypertension (PH) and unmask subclinical changes of the left and right ventricle function. The aim of this study was to evaluate changes of right ventricle (RV) functional parameters during stress and to find out determinants of RV function in patients with MR. Materials and methods. We performed a prospective study that included patients with asymptomatic primary moderate to severe MR and preserved left ventricular (LV) ejection fraction (EF) at rest (≥60%). Conventional 2D echocardiography at rest and during stress (bicycle ergometry) and offline speckle tracking analysis were performed. Results. 80 patients were included as MR (50) and control (30) groups. Conventional functional and myocardial deformation parameters of RV were similar in both groups at all stages of exercise (p > 0.05). The grade of MR (p = 0.004) and higher LV global longitudinal strain (p = 0.037) contributed significantly to the changes of tricuspid annular plane systolic excursion (TAPSE) from rest to peak stress. Changes of MR ERA from the rest to peak stress were related to RV free wall longitudinal strain (FWLS) and four chambers longitudinal stain (4CLS) at rest (p = 0.011; r = −0.459 and p = 0.001; r = −0.572, respectively). Significant correlations between LV EF, stroke volume, cardiac output and RV fractional area change, S′, TAPSE, FWLS, 4CLS were obtained. However, systolic pulmonary artery pressure and RV functional, deformation parameters were not related (p > 0.05). Conclusions. Functional parameters of LV during exercise and severity of MR were significant determinants of RV function while PH has no correlation with it in patients with primary asymptomatic moderate to severe MR.

Quantifying the Influence of Wedge Pressure, Age, and Heart Rate on the Systolic Thresholds for Detection of Pulmonary Hypertension

Background The strong linear relation between mean (MPAP) and systolic (SPAP) pulmonary arterial pressure (eg, SPAP=1.62×MPAP) has been mainly reported in precapillary pulmonary hypertension. This study sought to quantify the influence of pulmonary arterial wedge pressure (PAWP), heart rate, and age on the MPAP-SPAP relation. Methods and Results An allometric equation relating invasive MPAP and SPAP was developed in 1135 patients with pulmonary arterial hypertension, advanced lung disease, chronic thromboembolic pulmonary hypertension, or left heart failure. The equation was validated in 60 885 patients from the United Network for Organ Sharing (UNOS) database referred for heart and/or lung transplant. The MPAP/SPAP longitudinal stability was assessed in pulmonary arterial hypertension with repeated right heart catheterization. The equation obtained was SPAP=1.39×MPAP×PAWP^-0.07×(60/heart rate)^0.12×age^0.08 (P<0.001). It was validated in the UNOS cohort (R²=0.93, P<0.001), regardless of the type of organ(s) patients were listed for (mean bias [-1.96 SD; 1.96 SD] was 0.94 [-8.00; 9.88] for heart, 1.34 [-7.81; 10.49] for lung and 0.25 [-16.74; 17.24] mm Hg for heart-lung recipients). Thresholds of SPAP for MPAP=25 and 20 mm Hg were lower in patients with higher PAWP (37.2 and 29.8 mm Hg) than in those with pulmonary arterial hypertension (40.1 and 32.0 mm Hg). In 186 patients with pulmonary arterial hypertension, the predicted MPAP/SPAP was stable over time (0.63±0.03 at baseline and follow-up catheterization, P=0.43). Conclusions This study quantifies the impact of PAWP, and to a lesser extent heart rate and age, on the MPAP-SPAP relation, supporting lower SPAP thresholds for pulmonary hypertension diagnosis in patients with higher PAWP for echocardiography-based epidemiological studies.

Age-related longitudinal change in cardiac structure and function in adults at increased cardiovascular risk

AIM

Heart failure (HF) incidence increases markedly with age. We examined age-associated longitudinal change in cardiac structure and function, and their prediction by age and cardiovascular disease (CVD) risk factors, in a community-based cohort aged ≥60 years at increased CVD risk but without HF.

METHODS AND RESULTS

CVD risk factors were recorded in 3065 participants who underwent a baseline echocardiographic examination, of whom 2358 attended a follow-up examination 3.8 [median, inter-quartile range (IQR) 3.5, 4.2] years later. Median age was 71 (IQR 67, 76) years and 55% of participants were male. Age was associated with longitudinal increase in left ventricular (LV) mass index (LVMI); decrease in LV volumes; increase in LV ejection fraction; decrease in mitral annular systolic velocity; decrease in diastolic function (decreased mitral early diastolic annular velocity (e'); and increase in left atrial volume index, mitral peak early diastolic flow velocity (E)/e' ratio, and tricuspid regurgitant velocity (TR_Vmax ) in men and women, except for TR_Vmax in men). In multivariable analysis, longitudinal increase in LVMI was explained by CVD risk factors alone, whereas age, together with CVD risk factors, independently predicted longitudinal change in all other echocardiographic parameters. CVD risk factors were differentially associated with longitudinal change in different echocardiographic parameters.

CONCLUSIONS

Whereas the increase in LVMI with age was explained by CVD risk factors alone, age, together with risk factors, independently predicted longitudinal change in all other echocardiographic parameters, providing evidence for age-specific mechanisms of change in cardiac structure and function as people age. Age-associated change in LVMI, LV volumes, and diastolic function resembled what might be expected for the evolution of HF with preserved ejection fraction. Given the differential association of different CVD risk factors with longitudinal change in different echocardiographic parameters, therapies aimed at attenuation of age-associated change in cardiac structure and function, and HF evolution, will likely need to address multiple CVD risk factors.

Subclinical impairment of dynamic left ventricular systolic and diastolic function in patients with obstructive sleep apnea and preserved left ventricular ejection fraction

Background

Hypoxia affects myocardial oxygen supply resulting in subclinical cardiac dysfunction in obstructive sleep apnea (OSA) patients, with cardiovascular complications being associated with increased oxidative burst (OB). The aims of our study were to assess left ventricular (LV) dynamic myocardial deformation and diastolic reserve at rest and upon exercise, along with OB determination in this patients subset.

Methods

Conventional echocardiography, Doppler myocardial imaging and LV 2D speckle tracking echocardiography were performed in 55 OSA patients with preserved LV ejection fraction (EF) and 35 age and sex-comparable healthy controls. Peripheral OB levels were evaluated by flow cytometry.

Results

Despite comparable LVEF, LV global longitudinal strain (GLS) was significantly reduced in OSA at rest (− 13.4 ± 3.8 vs − 18.4 ± 3.3 in controls, P <  0.001) and at peak exercise (− 15.8 ± 2.6 vs − 23.4 ± 4.3, P <  0.001). Systolic pulmonary artery pressure (sPAP) and E/E′ ratios increase during effort were higher in OSA than in controls (ΔsPAP 44.3% ± 6.4 vs 32.3% ± 5.5, P <  0.0001, and ΔE/E’ 87.5% ± 3.5 vs 25.4% ± 3.3, P <  0.0001, respectively). The best correlate of E/E′ at peak stress was peak exertion capacity (r = − 0.50, P <  0.001). OB was also increased in OSA patients (P = 0.001) but, unlike OSA severity, was not associated with LV diastolic dysfunction.

Conclusions

Evaluation of diastolic function and myocardial deformation during exercise is feasible through stress echocardiography. OSA patients with preserved LVEF show subclinical LV systolic dysfunction, impaired LV systolic and diastolic reserve, reduced exercise tolerance, and increased peripheral levels of OB. Therapy aimed at increasing LV diastolic function reserve might improve the quality of life and exercise tolerability in OSA patients.

Impact of Pulmonary Hypertension on Survival Following Device Closure of Atrial Septal Defects

Pulmonary hypertension (PH), defined as mean pulmonary arterial pressure ≥25 mm Hg, may be a complication of a secundum atrial septal defect (ASD). This study sought to evaluate the impact of PH at time of ASD device closure on patient survival. A prospectively collected database of ASD closures was utilized. Patients were stratified by age above and below the cohort median (48 years). Survival was analyzed by preprocedural PH status, age cohort, and echocardiographic resolution of PH at 3 months postdevice closure. PH was present in 48 of 228 patients (21.1%) and was more common in the older cohort (31.3% vs 10.6%, p <0.01). ASD size was unrelated to the presence of PH (p = 0.33). Older patients had more medical co-morbidities including diabetes (p = 0.02), hyperlipidemia (p <0.01), and systemic hypertension (p <0.01) compared with younger patients. PH did not impact survival in patients ≤48 years, but PH was associated with fivefold increased risk of death in patients >48 years (p < 0.01). Patients with preprocedural PH and RVSP ≥40 mm Hg at 3-month follow-up continued to have an increased risk of mortality (p <0.01), whereas those with resolution of PH had similar survival to those without PH at time of closure. In conclusion, PH is common in adults with unrepaired ASDs and appears unrelated to defect size. PH in older adults and its persistence closure are strong predictors of a worsened clinical outcome. These patients may benefit from additional risk assessment and advanced medical therapies to mitigate this risk.

Vascular Adaptation of the Right Ventricle in Experimental Pulmonary Hypertension

Optimal right ventricular (RV) function in pulmonary hypertension (PH) requires structural and functional coupling between the RV cardiomyocyte and its adjacent capillary network. Prior investigations have indicated that RV vascular rarefaction occurs in PH, which could contribute to RV failure by reduced delivery of oxygen or other metabolic substrates. However, it has not been determined if rarefaction results from relative underproliferation in the setting of tissue hypertrophy or from actual loss of vessels. It is also unknown if rarefaction results in inadequate substrate delivery to the RV tissue. In the present study, PH was induced in rats by SU5416-hypoxia-normoxia exposure. The vasculature in the RV free wall was assessed using stereology. Steady-state metabolomics of the RV tissue was performed by mass spectrometry. Complementary studies were performed in hypoxia-exposed mice and rats. Rats with severe PH had evidence of RV failure by decreased cardiac output and systemic hypotension. By stereology, there was significant RV hypertrophy and increased total vascular length in the RV free wall in close proportion, with evidence of vessel proliferation but no evidence of endothelial cell apoptosis. There was a modest increase in the radius of tissue served per vessel, with decreased arterial delivery of metabolic substrates. Metabolomics revealed major metabolic alterations and metabolic reprogramming; however, metabolic substrate delivery was functionally preserved, without evidence of either tissue hypoxia or depletion of key metabolic substrates. Hypoxia-treated rats and mice had similar but milder alterations. There is significant homeostatic vascular adaptation in the right ventricle of rodents with PH.

Mitochondrial metabolism in pulmonary hypertension: beyond mountains there are mountains

Pulmonary hypertension (PH) is a heterogeneous and fatal disease of the lung vasculature, where metabolic and mitochondrial dysfunction may drive pathogenesis. Similar to the Warburg effect in cancer, a shift from mitochondrial oxidation to glycolysis occurs in diseased pulmonary vessels and the right ventricle. However, appreciation of metabolic events in PH beyond the Warburg effect is only just emerging. This Review discusses molecular, translational, and clinical concepts centered on the mitochondria and highlights promising, controversial, and challenging areas of investigation. If we can move beyond the "mountains" of obstacles in this field and elucidate these fundamental tenets of pulmonary vascular metabolism, such work has the potential to usher in much-needed diagnostic and therapeutic approaches for the mitochondrial and metabolic management of PH.

The aging heart

As the elderly segment of the world population increases, it is critical to understand the changes in cardiac structure and function during the normal aging process. In this review, we outline the key molecular pathways and cellular processes that underlie the phenotypic changes in the heart and vasculature that accompany aging. Reduced autophagy, increased mitochondrial oxidative stress, telomere attrition, altered signaling in insulin-like growth factor, growth differentiation factor 11, and 5'- AMP-activated protein kinase pathways are among the key molecular mechanisms underlying cardiac aging. Aging promotes structural and functional changes in the atria, ventricles, valves, myocardium, pericardium, the cardiac conduction system, and the vasculature. We highlight the factors known to accelerate and attenuate the intrinsic aging of the heart and vessels in addition to potential preventive and therapeutic avenues. A greater understanding of the processes involved in cardiac aging may facilitate our ability to mitigate the escalating burden of CVD in older individuals and promote healthy cardiac aging.

Long-Term Intermittent Work at High Altitude: Right Heart Functional and Morphological Status and Associated Cardiometabolic Factors

Background: Living at high altitude or with chronic hypoxia implies functional and morphological changes in the right ventricle and pulmonary vasculature with a 10% prevalence of high-altitude pulmonary hypertension (HAPH). The implications of working intermittently (day shifts) at high altitude (hypobaric hypoxia) over the long term are still not well-defined. The aim of this study was to evaluate the right cardiac circuit status along with potentially contributory metabolic variables and distinctive responses after long exposure to the latter condition. Methods: A cross-sectional study of 120 healthy miners working at an altitude of 4,400-4,800 m for over 5 years in 7-day commuting shifts was designed. Echocardiography was performed on day 2 at sea level. Additionally, biomedical and biochemical variables, Lake Louise scores (LLSs), sleep disturbances and physiological variables were measured at altitude and at sea level. Results: The population was 41.8 ± 0.7 years old, with an average of 14 ± 0.5 (range 5-29) years spent at altitude. Most subjects still suffered from mild to moderate symptoms of acute mountain sickness (mild was an LLS of 3-5 points, including cephalea; moderate was LLS of 6-10 points) (38.3%) at the end of day 1 of the shift. Echocardiography showed a 23% mean pulmonary artery pressure (mPAP) >25 mmHg, 9% HAPH (≥30 mmHg), 85% mild increase in right ventricle wall thickness (≥5 mm), 64% mild right ventricle dilation, low pulmonary vascular resistance (PVR) and fairly good ventricle performance. Asymmetric dimethylarginine (ADMA) (OR 8.84 (1.18-66.39); p < 0.05) and insulin (OR: 1.11 (1.02-1.20); p < 0.05) were associated with elevated mPAP and were defined as a cut-off. Interestingly, the correspondence analysis identified association patterns of several other variables (metabolic, labor, and biomedical) with higher mPAP. Conclusions: Working intermittently at high altitude involves a distinctive pattern. The most relevant and novel characteristics are a greater prevalence of elevated mPAP and HAPH than previously reported at chronic intermittent hypobaric hypoxia (CIHH), which is accompanied by subsequent morphological characteristics. These findings are associated with cardiometabolic factors (insulin and ADMA). However, the functional repercussions seem to be minor or negligible. This research contributes to our understanding and surveillance of this unique model of chronic intermittent high-altitude exposure.

The association of N-terminal pro-brain-type natriuretic peptide with hemodynamics and functional capacity in therapy-naive precapillary pulmonary hypertension: results from a cohort study

Background

N-terminal pro-brain-type natriuretic peptide (NT-proBNP) is currently used as a surrogate marker for disease severity in pulmonary hypertension (PH). However, NT-proBNP tends to have a high variability and may insufficiently correlate with hemodynamics and exercise capacity.

Methods

To investigate the association of NT-proBNP with hemodynamics and cardio-pulmonary exercise testing (CPET) in 84 therapy-naive patients with precapillary PH.

Results

NT-proBNP levels were significantly correlated with hemodynamics and CPET parameters except for cardiac index, diffusion capacity, PaO₂ at peak exercise, and peak minute ventilation. NT-proBNP correlated best with hemodynamics and CPET in women and patients >65 years. NT-proBNP correlated better with CPET in pulmonary arterial hypertension compared to chronic thromboembolic PH (CTEPH).

Conclusion

NT-proBNP is associated with disease severity in precapillary PH. The association might be age- and gender-dependent. NT-proBNP may insufficiently correlate with disease severity in CTEPH, possibly due to comorbidity.

The role of genetics in pulmonary arterial hypertension

Group 1 pulmonary hypertension or pulmonary arterial hypertension (PAH) is a rare disease characterized by proliferation and occlusion of small pulmonary arterioles, leading to progressive elevation of pulmonary artery pressure and pulmonary vascular resistance, and right ventricular failure. Historically, it has been associated with a high mortality rate, although, over the last decade, treatment has improved survival. PAH includes idiopathic PAH (IPAH), heritable PAH (HPAH), and PAH associated with certain medical conditions. The aetiology of PAH is heterogeneous, and genetics play an important role in some cases. Mutations in BMPR2, encoding bone morphogenetic protein receptor 2, a member of the transforming growth factor-β superfamily of receptors, have been identified in 70% of cases of HPAH, and in 10-40% of cases of IPAH. Other genetic causes of PAH include mutations in the genes encoding activin receptor-like type 1, endoglin, SMAD9, caveolin 1, and potassium two-pore-domain channel subfamily K member 3. Mutations in the gene encoding T-box 4 have been identified in 10-30% of paediatric PAH patients, but rarely in adults with PAH. PAH in children is much more heterogeneous than in adults, and can be associated with several genetic syndromes, congenital heart disease, pulmonary disease, and vascular disease. In addition to rare mutations as a monogenic cause of HPAH, common variants in the gene encoding cerebellin 2 increase the risk of PAH by approximately two-fold. A PAH panel of genes is available for clinical testing, and should be considered for use in clinical management, especially for patients with a family history of PAH. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.