Association of aortic stiffness and wave reflections with coronary flow reserve in women without obstructive coronary artery disease: An ancillary study from the National Heart, Lung, and Blood Institute-sponsored Women's Ischemia Syndrome Evaluation (WISE)

Novel diagnostic approaches and management of coronary microvascular dysfunction

The mechanism underlying ischaemic heart disease (IHD) has been primarily attributed to obstructive coronary artery disease (CAD). However, non-obstructive coronary arteries are identified in >50% of patients undergoing elective coronary angiography, recently leading to growing interest in the investigation and management of angina/ischaemia with non-obstructive coronary arteries (ANOCA/INOCA). INOCA is an umbrella term encompassing a multiple spectrum of possible pathogenetic entities, including coronary vasomotor disorders which consist of two major endotypes: coronary microvascular dysfunction (CMD) and vasospastic angina. Both conditions can coexist and be associated with concomitant obstructive CAD. Particularly, CMD refers to myocardial ischaemia due to reduced vasodilatory capacity of coronary microcirculation secondary to structural remodelling or impaired resting microvascular tone (functional) or a combination of both. CMD is not a benign condition and is more prevalent in women presenting with chronic coronary syndrome compared to men. In this setting, an impaired coronary flow reserve has been associated with increased risk of major adverse cardiovascular events. ANOCA/INOCA patients also experience impaired quality of life and associated increased healthcare costs. Therefore, research in this scenario has led to better definition, classification, and prognostic stratification based on the underlying pathophysiological mechanisms. The development and validation of non-invasive imaging modalities, invasive coronary vasomotor function testing and angiography-derived indices provide a comprehensive characterisation of CMD. The present narrative review aims to summarise current data relating to the diagnostic approach to CMD and provides details on the sequence that therapeutic management should follow.

Arterial stiffness assessment in coronary microvascular dysfunction and heart failure with preserved ejection fraction: An initial report from the WISE-CVD continuation study

Background

Heart failure with preserved ejection fraction (HFpEF) is the most common cardiac complication in patients with coronary microvascular dysfunction (CMD), yet its underlying pathways remain unclear. Aortic pulse-wave velocity (aPWV) is an indicator of large artery stiffness and a predictor for cardiovascular disease. However, aPWV in CMD and HFpEF is not well characterized and may provide understanding of disease progression.

Methods

Among participants without obstructive coronary artery disease, we evaluated 51 women with suspected CMD and 20 women and men with evidence of HFpEF. All participants underwent aPWV measurement (SphygmoCor, Atcor Medical) with higher aPWV indicating greater vascular stiffness. Cardiac magnetic resonance imaging (CMRI) assessed left ventricular (LV) ejection fraction, CMD via myocardial perfusion reserve index (MPRI), and ventricular remodeling via LV mass-volume ratio. . Statistical analysis was performed using Wilcoxon rank sum tests, Pearson correlations and linear regression analysis.

Results

Compared to the suspected CMD group, the HFpEF participants were older (65 ± 12 vs 56 ± 11 yrs., p = 0.002) had higher BMI (31.0 ± 4.3 vs 27.8 ± 6.7 kg/m2, p = 0.013), higher aPWV (10.5 ± 2.0 vs 8.0 ± 1.6 m/s, p = 0.05) and lower MPRI (1.5 ± 0.3 vs1.8 ± 0.3, p = 0.02), but not remodeling. In a model adjusted for cardiovascular risk factors, the HFpEF group had a lower LVEF (estimate -4.78, p = 0.0437) than the suspected CMD group.

Conclusions

HFpEF participants exhibit greater arterial stiffness and lower myocardial perfusion reserve, with lower LVEF albeit not remodeling, compared to suspected CMD participants. These findings suggest arterial stiffness may contribute to progression from CMD to HFpEF. Prospective work is needed and ongoing.

Ascending Aorta 4D Time to Peak Distention Sexual Dimorphism and Association with Coronary Plaque Burden Severity in Women

Coronary artery disease (CAD) risk and plaque scores are often subjective and biased, particularly in mid-age asymptomatic women, whose CAD risk assessment has been historically underestimated. In this study, a new automatic ascending aorta time-to-peak-distention (TPD) analysis was developed for fast screening and as an independent surrogate for subclinical atherosclerosis in asymptomatic women. CCTA was obtained in 50 asymptomatic adults. Plaque burden segment involvement score (SIS) and automatic TPD were obtained from all subjects. Logistic regression analyses were performed to investigate the association between CAD risk scores and TPD with severe coronary plaque burden (SIS>5). TPD, individually, was found to be a significant predictor of SIS>5. Additionally, sex was a significant effect modifier of TPD, with a stronger statistically significant association with women. Four-dimensional aortic time-to-peak distention could supplement conventional CCTA analysis and offer a quick objective screening tool for plaque burden severity and CAD risk stratification, especially in women.

Association of Growth Differentiation Factor 15 with Arterial Stiffness and Endothelial Function in Subpopulations of Patients with Coronary Artery Disease: A Proof-of-Concept Study

BACKGROUND

Growth-differentiation factor-15 (GDF-15) is a biomarker belonging to the transforming growth factor-beta cytokine superfamily, which is linked to many pathological conditions, including inflammation and myocardial injury. Pulse wave velocity (cfPWV) and augmentation index (AIx) are indices of arterial stiffness, which are associated with the severity of coronary artery disease (CAD). Flow-mediated dilatation (FMD) is a well-studied surrogate marker of endothelial-dependent dysfunction and systemic inflammation.

OBJECTIVE

In this proof-of-concept study, we aimed to investigate the relationship between circulating GDF-15, endothelial dysfunction, and indices of arterial stiffness in different settings of coronary artery disease and myocardial injury.

METHODS

In this cross-sectional single-center study, we enrolled patients (n = 22) after interventional treatment for acute myocardial infarction (AMI), patients (n = 11) admitted with chest pain and elevated cardiac enzymes but without evidence of obstructing CAD (MI-NOCAD) in percutaneous coronary angiography (CAG), and patients (n = 20) who underwent CAG according to indications without evident obstructive CAD in CAG (NOCAD). FMD was assessed at the brachial artery. AIx of the central aortic pressure and cfPWV were estimated by applanation tonometry at the radial and carotid-femoral site, respectively, with a validated acquisition system (Sphygmo- Cor, AtCor Medical, Sydney (NSW), Australia). ELISA was used to determine circulating GDF- 15 serum levels (R&D Systems, Minneapolis, MN). Clinical and demographic data and values of routine biochemical biomarkers were obtained. The highest high-sensitive cardiac Troponin I (hsTpnI) value during hospitalization was also recorded. Left ventricular ejection fraction (LVEF) was assessed with a transthoracic echocardiogram.

RESULTS

Patients with AMI were older, had worse LVEF, higher values of hsTpnI and increased circulating GDF-15 levels. Importantly, AMI patients had increased cfPWV values, deteriorated AIx values, blunted FMD and worse serum creatinine levels compared to MI-NOCAD and NOCAD patients, respectively, whereas MI-NOCAD and NOCAD did not differ from each other significantly on these biomarkers. Both AMI and MI-NOCAD patients presented a higher but comparable white blood cell count than NOCAD patients. A strong linear correlation between GDF-15 and cfPWV, hsTpnI, AIx, white blood cell count and creatinine but not with FMD was demonstrated in the general study population.

CONCLUSION

This proof-of-concept study showed that higher circulating levels of GDF-15, an inflammatory biomarker, were associated significantly with increased arterial stiffness only in AMI patients, whereas elevated GDF-15 demonstrated a linear relationship with the severity of the myocardial injury.

Ventricular-arterial coupling: definition, pathophysiology and therapeutic targets in cardiovascular disease

INTRODUCTION

The heart and arterial system are equally affected by arteriosclerosis/atherosclerosis. There is a constant interaction between the left ventricular (LV) function and the arterial system, termed ventricular-arterial coupling (VAC), which reflects the global cardiovascular efficiency. VAC is traditionally assessed by echocardiography as the ratio of effective arterial elastance (E_a) over end-systolic elastance (E_es) (E_a/E_es). However, the concept of VAC is evolving and new methods have been proposed such as the ratio of pulse wave velocity (PWV) to global longitudinal strain (GLS) and myocardial work index.

AREA COVERED

This clinical review presents the hemodynamic background of VAC, its clinical implications and the impact of therapeutic interventions to normalize VAC. The review also summarizes the detrimental effects of cardio-metabolic risk factors on the aorta and LV, and provides an update on arterial load and its impact on LV function. The narrative review is based upon a systemic search of the bibliographic database PubMed for publications on VAC.

EXPERT OPINION

Newer methods such as PWV/GLS-ratio may be a superior marker of VAC than the traditional echocardiographic E_a/E_es in predicting target organ damage and its association with clinical outcomes. Novel anti-diabetic drugs and optimal antihypertensive treatment may normalize VAC in high-risk patients.

Standard exercise stress testing attenuates peripheral microvascular function in patients with suspected coronary microvascular dysfunction

BACKGROUND

The effect of exercise on the microvasculature of patients with suspected coronary microvascular dysfunction (CMD), assessed by reactive hyperemia peripheral arterial tonometry (RH-PAT; EndoPAT), is unknown. The present study aimed to determine if standard clinical exercise stress testing (GXT) affected peripheral microvascular function, as determined by the reactive hyperemia index (RHI and LnRHI), in patients with suspected CMD.

METHODS

In a cross-sectional study, patients (n = 76) were grouped based on whether the GXT was performed; 1) prior to (exercisers; n = 30), or 2) after the vascular assessment (non-exercisers; n = 46). Patients with an adenosine index of microvascular resistance > 25, adenosine coronary flow reserve (CFR) < 2.0, and/or acetylcholine CFR < 1.5 were considered to have CMD (n = 42). RHI and LnRHI quantified finger pulse amplitude hyperemia following 5 min of forearm ischemia.

RESULTS

LnRHI was lower in patients with CMD compared to patients without CMD, while LnRHI was also lower in exercisers compared to non-exercisers (LnRHI: CMD Non-Exercisers: 0.63 ± 0.25; CMD Exercisers: 0.54 ± 0.19; No CMD Non-Exercisers: 0.85 ± 0.23; No CMD Exercisers: 0.63 ± 0.26; Condition and Exercise Main Effects: Both P < 0.01). In patients who did not exercise prior to the vascular assessment, the receiver operating characteristic curve (ROC) for LnRHI to predict CMD was 0.76 (95% CI: 0.62-0.91; P < 0.01). However, in patients who performed exercise prior to the vascular assessment, the ROC for LnRHI to predict CMD was 0.60 (95% CI: 0.40-0.81; P = 0.34).

CONCLUSIONS

CMD is associated with impaired peripheral microvascular function and preceding acute exercise is associated with further reductions of LnRHI. Further, acute exercise abolished the capacity for RH-PAT to predict the presence of CMD in patients with chest pain and non-obstructive coronary arteries. RH-PAT measurements in patients with suspected CMD should not be conducted after exercise has been performed.

Association of aortic stiffness with cognitive decline: Whitehall II longitudinal cohort study

Aortic stiffness is associated with an increased risk of cardio- and cerebrovascular disease and mortality and may increase risk of dementia. The aim of the present study is to examine the association between arterial stiffness and cognitive decline in a large prospective cohort study with three repeated cognitive assessment over 7 years of follow-up. Aortic pulse wave velocity (PWV) was measured among 4300 participants (mean ± standard deviation age 65.1 ± 5.2 years) in 2007-2009 and categorized based on the tertiles: (lowest third: < 7.41 m/s), (middle third: 7.41-8.91 m/s), and (highest third: > 8.91 m/s). A global cognitive score was calculated in 2007-2009, 2012-2013, and 2015-2016 based on responses to memory, reasoning and fluency tests. Standardized global cognitive score (mean = 0, SD = 1) in highest third versus lowest third of PWV category was lower at baseline (- 0.12, 95% CI - 0.18, - 0.06). Accelerated 7-year cognitive decline was observed among individuals with the highest PWV [difference in 7-year cognitive change for highest third versus lowest third PWV: - 0.06, 95% CI - 0.11, - 0.01, P < 0.01]. Higher aortic stiffness was associated with faster cognitive decline. Clinicians may be able to use arterial stiffness severity as an indicator to administer prompt treatments to prevent or delay the onset of cognitive decline or dementia. Future studies need to determine whether early intervention of vascular stiffness is effective in delaying these outcomes.

Even "WISE-R?"-an Update on the NHLBI-Sponsored Women's Ischemia Syndrome Evaluation

PURPOSE OF REVIEW

For over 20 years, the Women's Ischemia Syndrome Evaluation (WISE), a program sponsored by the National Heart, Lung, and Blood Institute, has explored diverse and important aspects of ischemic heart disease in women.

RECENT FINDINGS

Women with symptoms and signs of ischemia but no significant epicardial obstructive coronary artery disease (INOCA) were documented to be at elevated risk for recurrent angina hospitalization, major adverse cardiac events, death, and health resource consumption rivaling those with obstructive coronary disease. WISE investigators have advanced our understanding of cardiovascular outcomes, systemic manifestations, psychological variables, socioeconomic factors, genetic contributions, hormonal status, advanced imaging, coronary functional findings, biomarkers, patient-reported outcomes, and treatments pertaining to women with this disease entity. This review delves into the WISE findings subsequent to a prior review1, postulates directions for future research, and asks are we "Even 'WISE-R?'".

Impaired coronary microcirculation is associated with left ventricular diastolic dysfunction in end-stage chronic kidney disease patients

INTRODUCTION

Coronary vascular dysfunction, as assessed by coronary flow reserve (CFR) in the left anterior descending coronary artery, is found in various conditions including end-stage chronic kidney disease (CKD). Currently, we investigated the associations of CFR with echocardiographic indices of systolic and diastolic cardiac function and identified independent predictors of CFR in hemodialysis patients.

METHODS

End-stage CKD patients treated with hemodialysis (n = 29) without known cardiovascular disease were recruited from a Hemodialysis Unit in Northwestern Greece. A thorough echocardiographic evaluation including CFR measurement following dipyridamole infusion was performed in all participants. Arterial stiffness was assessed by measurement of carotid-femoral pulse wave velocity and aortic augmentation index.

RESULTS

The mean age of the patients was 63 years, and mean duration of hemodialysis was 2.9 years. CFR was 1.60 ± 0.37 while dipyridamole caused a significant increase in E'_sep , S_lat , E'_lat , and Stroke volume (P < .05 for all). Independent predictors of CFR were posterior wall thickness (B -0.408, P = .013) and dipyridamole-induced changes in Tei index (B -0.425, P = .007). A severely decreased CFR < 1.5 was observed in 52% of the patients. E/E' ratio (B 10.84, P = .014) was the single independent predictor of severely decreased CFR.

CONCLUSIONS

In end-stage CKD patients on hemodialysis without known cardiovascular disease, impaired coronary vascular function was prevalent and related to increased left ventricular wall thickness, increased filling pressures, and dipyridamole-induced deteriorated myocardial function independently of the presence of wall-motion abnormalities. Further studies are required to clarify the prognostic role of dipyridamole-induced cardiac changes in hemodialysis patients.

Heart failure with preserved ejection fraction: Similarities and differences between women and men

The syndrome of heart failure (HF) with preserved ejection fraction (HFpEF) is now recognized to account for up to half of HF cases and is the dominant form of HF in older adults, especially women. Multiple factors conspire in this predilection of HFpEF for older women. This review will discuss the epidemiology, pathophysiology, prognosis, and treatment of HFpEF with emphasis on the similarities and differences in cardiovascular aging changes, and the differential impact of comorbidities in women versus men. Responses to pharmacologic and lifestyle interventions are also reviewed. We conclude by suggesting future directions for both prevention and treatment of this common and highly morbid cardiovascular disorder.

Takotsubo syndrome - fatal prognosis of patients with low body mass index in 5-year follow-up

INTRODUCTION

The clinical courses of takotsubo syndrome (TS) and of acute coronary syndromes (ACS) seem to be very similar. However, there is limited knowledge about risk factors of poor outcomes. Low body mass index worsens the prognosis of patients with cardiovascular diseases, especially those undergoing surgical treatment. The aim of the study was to evaluate the influence of the body mass index (BMI) on the prognosis in patients diagnosed with TS.

MATERIAL AND METHODS

Eighty patients aged 15-89 (mean: 67.9 years), 74 women and 6 men with TS diagnosis according to Mayo Clinic diagnostic criteria were divided into 3 groups: low body mass (BMI < 18.5 kg/m²), normal body mass (18.5 ≥ BMI < 25 kg/m²) and excessive body mass (BMI ≥ 25 kg/m²).

RESULTS

Patients with low BMI were older, but with less prevalent risk factors such as hypertension, hypercholesterolemia and positive family history of coronary artery disease and more frequent risk factors such as cigarette smoking, chronic obstructive pulmonary disease (COPD), depressive and anxiety disorders as well as malignancy. They also had higher haemoglobin, lower troponin, creatine kinase, C-reactive protein and lipid fractions. The highest annual, 3-year and 5-year mortality was observed in the group with BMI < 18.5 kg/m². None of the patients with low BMI survived the 5-year follow-up period (100% vs. 25% vs. 15.2%; p < 0.0001). In group III, mortality among overweight patients (25 ≥ BMI < 30 kg/m²) was 8.3%, and in obese people (BMI ≥ 30 kg/m²) 1 out 5 patients died during follow-up.

CONCLUSIONS

The majority of typical cardiovascular risk factors are less frequently observed in patients with TS and low body mass. Early prognosis for TS patients and low BMI is relatively favourable, whereas the 5-year follow-up is associated with extremely high mortality. Overweight patients have the best prognosis in the long-term follow-up.

Aortic Stiffness Is Associated with Coronary Microvascular Dysfunction in Patients with Non-obstructive Coronary Artery Disease

Objective Associations between aortic stiffness and cardiovascular disease events are mediated in part by pathways that include coronary microvascular dysfunction (CMD) and remodeling. However, the relationship between aortic stiffness and CMD remains unclear. The present study aimed to determine whether aortic stiffness causes CMD as evaluated by the hyperemic microvascular resistance index (hMVRI) in patients with non-obstructive coronary artery disease (CAD). Methods The intracoronary physiological variables in 209 coronary arteries were evaluated in 121 patients with non-obstructive CAD (fractional flow reserve >0.80) or reference vessels. The cardio-ankle vascular index (CAVI) as a measure of aortic stiffness and atherosclerotic risk factors were also measured. Results Univariate analyses showed that hMVRI correlated with age (β=0.24, p=0.007), eicosapentaenoic acid (EPA; β=-0.18, p=0.048), EPA/arachidonic acid (AA) (EPA/AA) ratio (β=-0.22, p=0.014) and CAVI (β=0.30, p=0.001). A multivariate regression analysis identified CAVI (β=0.25, p=0.007) and EPA/AA ratio (β=-0.26, SE=0.211, p=0.003) as independent determinants of hMVRI. Conclusion Aortic stiffness may cause CMD in patients with non-obstructive CAD via increased coronary microvascular resistance. Aortic stiffness is associated with CMD which is evaluated as hyperemic microvascular resistance in patients with non-obstructive CAD.

Wave reflections and global arterial compliance during normal human pregnancy

Profound changes occur in the maternal circulation during pregnancy. Routine measures of arterial function - central systolic pressure (CSP) and augmentation index (AIx) - decline during normal human pregnancy. The objectives of this study were twofold: (1) explore wave reflection indices besides CSP and AIx that are not routinely reported, if at all, during normal human pregnancy; and (2) compare wave reflection indices and global arterial compliance (gAC) obtained from carotid artery pressure waveforms (CAPW) as a surrogate for aortic pressure waveforms (AOPW) versus AOPW synthesized from radial artery pressure waveforms (RAPW) using a generalized transfer function. To our knowledge, a comparison of these two methods has not been previously evaluated in the context of pregnancy. Ten healthy women with normal singleton pregnancies were studied using applanation tonometry (SphygmoCor) at pre-conception, and then during 10-12 and 33-35 gestational weeks. CSP and AIx declined, and gAC increased during pregnancy as previously reported. As a consequence of the rise in gAC, the return of reflected waves of lesser magnitude from peripheral reflection sites to the aorta was delayed that, in turn, reduced systolic duration of reflected waves, augmentation index, central systolic pressure, LV wasted energy due to reflected waves, and increased brachial-central pulse pressure. For several wave reflection indices, those derived from CAPW as a surrogate for AOPW versus RAPW using a generalized transfer function registered greater gestational increases of arterial compliance. This discordance may reflect imprecision of the generalized transfer function for some waveform parameters, though potential divergence of carotid artery and aortic pressure waveforms during pregnancy cannot be excluded.

Noninvasive Assessment of Myocardial Perfusion in Different Blood Pressure Phenotypes and Its Association With Arterial Stiffness Indices

BACKGROUND

We investigated for the first time whether patients with recent-onset, uncomplicated hypertension and different hypertension phenotypes exhibit altered values of subendocardial viability ratio (SEVR), a surrogate measure of myocardial perfusion that correlates with the ratio of subendocardial to subepicardial blood flow. We additionally explored whether SEVR correlates with arterial stiffness in a population free from the long-term effects of essential hypertension.

METHODS

Nontreated individuals free from any known health problems were classified as true hypertensives (THs), white-coat hypertensives (WCHs), masked hypertensives (MHs), and normotensives. SEVR was noninvasively calculated with applanation tonometry in the radial artery. Carotid-femoral pulse wave velocity, central and peripheral pulse pressure (PP), augmentation index, and central systolic/diastolic blood pressure (BP) were assessed with applanation tonometry. Total arterial compliance index was calculated with impedance cardiography.

RESULTS

In a total of 150 participants, normotensive individuals exhibited the highest values of SEVR (162.9 ± 25.3%), whereas SEVR appeared to be similar in MHs (150.2 ± 22.1%), WCHs (148.1 ± 20.4%), and THs (149.9 ± 24.8%) (P = 0.017). In the univariate analysis, SEVR significantly correlated with central systolic BP, peripheral PP, and total arterial compliance index. The association between SEVR and both central (P = 0.017) and peripheral PP (P = 0.003) remained significant after adjustment for heart rate and other parameters.

CONCLUSIONS

SEVR, an alternative tool to the invasive assessment of microvascular coronary perfusion, presents different values across patients with divergent BP phenotypes and correlated with arterial stiffness, even in the absence of overt cardiovascular disease. Future studies need to address the potential utility of this easily implementable marker as a screening test for myocardial ischemia.

Arterial Stiffness is Related to Impaired Exercise Capacity in Patients With Coronary Artery Disease and History of Myocardial Infarction

BACKGROUND

Augmented arterial stiffness and reduced cardiorespiratory fitness are associated with increased morbidity and mortality from coronary artery disease (CAD). The relationship between exercise capacity and arterial stiffness is independent of known influencing variables in CAD. This study aimed to analyse the interaction between exercise capacity, arterial stiffness and early vascular ageing in patients with CAD.

METHODS

This cross-sectional study included 96 CAD patients with myocardial infarction (55.9±10.9years, 81 men) referred to cardiac rehabilitation. Arterial stiffness was assessed using carotid-femoral pulse wave velocity (cf-PWV). Cardiopulmonary exercise test was performed to measure VO₂peak. Comparisons of VO₂peak across cf-PWV risk threshold values (high-risk cf-PWV≥10m/s) and tertile groups, and across cf-PWV threshold values and age groups (younger group<60 years) were performed. Correlation tests were used to study the association between pair of variables.

RESULTS

Patients with high-risk cf-PWV had lower VO₂peak than those with low-risk cf-PWV (p<0.001). VO₂peak decreased across tertiles of cf-PWV, showing significantly lower values in the third tertile (p<0.001). There were no differences in the VO₂peak between younger patients with high-risk cf-PWV and older patients irrespective of their cf-PWV values. VO₂peak showed an upward trend in younger patients with low-risk cf-PWV compared to their age-mates with high-risk cf-PWV (p=0.09). VO₂peak was strongly and inversely correlated with cf-PWV (r=-0.502, p<0.001).

CONCLUSIONS

Arterial stiffening is associated with lower cardiorespiratory fitness in CAD patients with myocardial infarction. When its values are above risk threshold, exercise capacity is impaired regardless of the relationship between age and arterial stiffness.

Left ventricular remodeling and arterial afterload in older women with uncontrolled and controlled hypertension

OBJECTIVE

The prevalence of hypertension increases with advancing age in women. Blood pressure control is more difficult to achieve in older women, and despite well-controlled blood pressure, the cardiovascular mortality remains high. However, the underlying mechanisms are not understood.

METHODS

Nineteen women with uncontrolled hypertension on drug treatment (70 ± 2 [SE] years, ambulatory awake blood pressure; 152 ± 2/84 ± 2 mm Hg), 19 with controlled hypertension (68 ± 1 years, 128 ± 2/71 ± 2 mm Hg), and 31 healthy normotensive women (68 ± 1 years, 127 ± 1/73 ± 1 mm Hg) were recruited. Participants were weaned from antihypertensive drugs and underwent 3 weeks of run-in before cardiac-vascular assessments. Left ventricular morphology was evaluated with cardiac magnetic resonance imaging. Arterial load and vascular stiffness were measured via ultrasound and applanation tonometry.

RESULTS

Left ventricular mass normalized by body surface area was not different between hypertension groups (uncontrolled vs controlled: 50.0 ± 1.7 vs 51.8 ± 2.3 g/m), but it was lower in the normotensive group (41.7 ± 0.9 g/m; one-way analysis of variance [ANOVA] P = 0.004). Likewise, central pulse wave velocity was not different between hypertension groups (11.5 ± 0.6 vs 11.1 ± 0.5 m/s) and lower in the normotensive group (9.1 ± 0.3 m/s; 1-way ANOVA P = 0.0001). Total peripheral resistance was greater in uncontrolled hypertension (HTN) compared with normotensive group (2051 ± 323 vs 1719 ± 380 dyns/cm), whereas controlled HTN group (1925 ± 527 dyns/cm) was not different to either groups.

CONCLUSION

Regardless of current blood pressure control, hypertensive older women exhibited increased cardiac mass and arterial stiffness compared with normotensives. Future large-scale longitudinal studies are warranted to directly investigate the mechanisms for the high cardiovascular mortality among older hypertensive women with well-controlled blood pressure.

Central diastolic pressure decay mediates the relationship between aortic stiffness and myocardial viability: potential implications for aortosclerosis-induced myocardial ischemia

OBJECTIVE

Stiffening of the aorta often precedes coronary events, but little is known about the aetiological mechanism. We hypothesized that the predisposition to myocardial ischemia could be attributable to aortosclerosis-induced alterations in the central haemodynamics during diastole.

METHODS

Using noninvasive tonometry and ultrasonography, we investigated the arterial pressure pulse waveforms, pulse wave velocities (PWVs) and compliance in 222 patients with hypertension. The diastolic pressure decay was quantified by fitting a mono-exponential curve as P(t) =  P0e [λ: decay index; P0: end-systolic pressure; t: time from end-systole]. The myocardial oxygen supply/demand balance was estimated from the subendocardial viability index (SVI).

RESULTS

The aortic pressure decay fit to an exponential curve significantly (R = 0.98 ± 0.02) and more closely than the radial pressure decay (P < 0.001). The aortic decay index (median, 0.59 s) was associated with the aortic PWV and compliance (but not with the peripheral PWV or resistance), even after controlling for age, sex, renal function, diabetes and hypercholesterolemia (P < 0.001). Also, both the aortic PWV and compliance (together with the augmentation index) were related to the SVI, although these relationships were no longer significant after accounting for the decay index. Mediation analysis revealed substantial mediating effects of the decay index on the relationship between aortic PWV or compliance and SVI (75-100%), despite the lack of similar effects of the augmentation index.

CONCLUSION

Aortic stiffening with reduced compliance potentially impairs myocardial viability by accelerating the diastolic exponential decay (rather than through enhancing late-systolic augmentation) of the central blood pressure, thus predisposing hypertensive patients to ischemic heart disease.

Ischemia and No Obstructive Coronary Artery Disease (INOCA): Developing Evidence-Based Therapies and Research Agenda for the Next Decade

The Cardiovascular Disease in Women Committee of the American College of Cardiology, in conjunction with interested parties (from the National Heart, Lung, and Blood Institute, American Heart Association, and European Society of Cardiology), convened a working group to develop a consensus on the syndrome of myocardial ischemia with no obstructive coronary arteries. In general, these patients have elevated risk for a cardiovascular event (including acute coronary syndrome, heart failure hospitalization, stroke, and repeat cardiovascular procedures) compared with reference subjects and appear to be at higher risk for development of heart failure with preserved ejection fraction. A subgroup of these patients also has coronary microvascular dysfunction and evidence of inflammation. This document provides a summary of findings and recommendations for the development of an integrated approach for identifying and managing patients with ischemia with no obstructive coronary arteries and outlines knowledge gaps in the area. Working group members critically reviewed available literature and current practices for risk assessment and state-of-the-science techniques in multiple areas, with a focus on next steps needed to develop evidence-based therapies. This report presents highlights of this working group review and a summary of suggested research directions to advance this field in the next decade.

The relationship between cardio-ankle vascular index and subclinical atherosclerosis evaluated by cardiac computed tomographic angiography

BACKGROUND

The cardio-ankle vascular index (CAVI) is a new noninvasive index to evaluate arterial stiffness. We investigated whether CAVI can predict severity, extent, and burden of coronary artery disease by comparing results with cardiac computed tomographic angiography (CCTA).

HYPOTHESIS

CAVI may predict the presence of subclinical atherosclerosis.

METHODS

We prospectively enrolled 95 patients (66% male; mean age, 50 ± 16 years) who underwent both CCTA and CAVI consecutively. We evaluated if CAVI correlated with (1) severe stenosis (≥50%); (2) plaque extent, determined by a segment-involvement score (SIS), defined by the total number of coronary artery segments containing any plaque; and (3) plaque burden, determined by a segment-stenosis score (SSS), defined by the extent of obstruction of coronary luminal diameter in individual coronary artery segments.

RESULTS

Bivariate analysis showed a statistically significant relationship not only between CAVI and SIS, but also between CAVI and SSS (r² = 0.4, P < 0.0001 for SIS; r² = 0.36, P < 0.0001 for SSS). Multivariable logistic analysis demonstrated that CAVI is significantly associated with SSS >5 (odds ratio [OR]: 2.3, 95% confidence interval [CI]: 1.1-7.8, P = 0.03) and SIS >5 (OR: 2.3, 95% CI: 1.1-5.8, P = 0.02), but not severe stenosis (OR: 1.7, 95% CI: 0.9-4.3, P = 0.13), after adjusting for age, sex, chest pain, hypertension, dyslipidemia, family history, diabetes, and current smoking.

CONCLUSIONS

We demonstrated that CAVI had a significant relationship with subclinical coronary atherosclerosis evaluated by CCTA, especially in relation to plaque burden and plaque extent, but not severe stenosis. Thus, CAVI may reflect coronary atherosclerosis burden more than severity.

Effects of shear stress on endothelial cells: go with the flow

Haemodynamic forces influence the functional properties of vascular endothelium. Endothelial cells (ECs) have a variety of receptors, which sense flow and transmit mechanical signals through mechanosensitive signalling pathways to recipient molecules that lead to phenotypic and functional changes. Arterial architecture varies greatly exhibiting bifurcations, branch points and curved regions, which are exposed to various flow patterns. Clinical studies showed that atherosclerotic plaques develop preferentially at arterial branches and curvatures, that is in the regions exposed to disturbed flow and shear stress. In the atheroprone regions, the endothelium has a proinflammatory phenotype associated with low nitric oxide production, reduced barrier function and increased proadhesive, procoagulant and proproliferative properties. Atheroresistant regions are exposed to laminar flow and high shear stress that induce prosurvival antioxidant signals and maintain the quiescent phenotype in ECs. Indeed, various flow patterns contribute to phenotypic and functional heterogeneity of arterial endothelium whose response to proatherogenic stimuli is differentiated. This may explain the preferential development of endothelial dysfunction in arterial sites with disturbed flow.

Large Artery Stiffness Assessment Using SphygmoCor Technology

Large artery stiffness assessment has been an integral part of the SphygmoCor technology since 1998. Aortic stiffness is approximated with non-invasive measurement of carotid-femoral pulse wave velocity, with improvements made with time to make the assessment procedure quicker and more user independent. Also standard in the devices is the ability to reliably calculate the central aortic waveform shape from a peripheral pressure waveform from either the brachial or radial artery. This waveform contains much information beyond peak and trough (systolic and diastolic pressure). Relative waveform features such as the augmentation index, wave reflection magnitude, reflection time index, and subendocardial viability ratio are parameters that are influenced by the stiffness of systemic arteries. This article briefly describes these parameters related to large artery stiffness and provides reference to validation and repeatability studies relative to the clinical use of the SphygmoCor devices. It is beyond the scope to review here the 424 original research articles that have employed SphygmoCor devices in measuring arterial stiffness. Instead, the method of measurement across the devices is described, including tonometry, volumetric displacement through cuff placement around limbs, and ambulatory monitoring. Key population and subpopulation studies are cited where the average stiffness parameter progression with age and gender, as measured by SphygmoCor devices, is quantified in the healthy and general population. Finally, with reference to guidelines from working groups on arterial stiffness and hypertension, the clinical utility of large artery stiffness measurement is discussed in the context of the arterial stiffness parameters provided by the SphygmoCor systems.

Predictive value of the augmentation index derived vascular age in patients with newly diagnosed atherosclerosis

Early detection of atherosclerosis, i.e., in occupational health screening programs could reduce the rate of cardiovascular events in the working population. Changes of the augmentation index (AIX) correlate with changes of the arterial stiffness induced by aging, atherosclerosis, or arterial hypertension and have a prognostic value for cardiovascular events. Their diagnostic yield should be increased by normalizing the AIX to age, in terms of a calculating the vascular age (VA). In this pilot study, 30 patients (mean age 65.3 ± 8.8 years, 21 male) with suspected coronary heart disease underwent a duplex ultrasound of the carotid arteries and a measurement of the ankle brachial index in addition to the coronary angiography. The AIX was recorded with a portable device (Vascular Explorer), and the VA was calculated. Atherosclerosis was found in 24 patients. They were older than the patients without atherosclerosis, but there was no age dependency found for the distribution pattern or severity of atherosclerosis. In patients with findings of atherosclerosis, the calculated VA was higher than the chronological age, and these differences were significant in patients below 65 years of age. Comparing patients in higher blood pressure classes with patients in lower classes, significantly higher AIX, VA, and differences to the chronological age were found. The VA, deduced from the noninvasively obtained AIX, is a promising candidate for screening programs for atherosclerosis, i.e., in occupational health screening programs.

Role of heart rate in the relation between regional body fat and subendocardial viability ratio in women

Subendocardial viability ratio (SEVR) is a measure of left ventricular function, specifically; it is an index of myocardial perfusion relative to left ventricular workload. Women have lower SEVR than men, partly due to a faster resting heart rate that reduces diastolic time (i.e., time for myocardial perfusion). It is unclear if body fat relates to SEVR, thus the purpose of this study was to examine the relation between body fat and SEVR in women. Twenty-eight middle-aged (31-45 years) and 31 older (60-80 years) women were examined. Radial artery applanation tonometry was used to calculate SEVR from a synthesized central aortic pressure wave. Dual-energy X-ray absorptiometry was used to assess body composition including fat in the trunk, legs, android and gynoid regions. Body fat was not related (P>.05) with SEVR in older women. In middle-aged women, all measures of regional fat were correlated with heart rate (range, r=.49-.59, P≤.01) and SEVR (range, r=.43-.53, P≤.01). Android-to-gynoid ratio was identified as the strongest predictor (r(2) =-.26, P<.01) of SEVR among measures of regional fat. Middle-aged women with lower android-to-gynoid fat ratio had higher SEVR (1.96±0.33 vs 1.66±0.20, P=.009) than women with higher fat ratio, even after adjusting for age, height, daily physical activity, and aortic mean pressure (P=.02). Adjusting for heart rate or diastolic time abolished the difference in SEVR between groups (1.80±0.09 vs 1.82±0.09, P=.56). These results suggest that middle-aged women with a greater distribution of fat in the abdomen have poorer left ventricular function that is dependent on the negative influence of heart rate on diastolic time.

Effects of statin therapy on augmentation index as a measure of arterial stiffness: A systematic review and meta-analysis

OBJECTIVE

To evaluate the effects of statin therapy on augmentation index (AIx) as a measure of arterial stiffness using a meta-analysis of clinical trials.

METHODS

The search included PubMed-Medline, Embase, SCOPUS, Web of Science and Google Scholar databases to identify randomized controlled trials investigating the effects of statin therapy on arterial stiffness measured as AIx. A random-effects model and generic inverse variance method were used for quantitative data synthesis. Sensitivity analysis was conducted using the leave-one-out method. Random-effects meta-regression was performed using unrestricted maximum likelihood method to evaluate the impact of potential confounders.

RESULTS

18 trials examining the effects of statin therapy on arterial stiffness were included. A significant reduction in aortic AIx following statin therapy was proven (WMD: -2.40%, 95% CI: -4.59, -0.21, p=0.032; I(2): 51.20%). HR-adjusted AIx 75% values also revealed a significant improvement by statin therapy (WMD: -5.04%, 95% CI: -7.81, -2.27, p<0.001; I(2): 0%), but not when analysis was restricted to unadjusted AIx values (WMD: -2.30%, 95% CI: -4.83, 0.23, p=0.075; I(2): 53.83%). There was no significant change in carotid (WMD: -2.75%, 95% CI: -8.06, 2.56, p=0.309; I(2): 26.86%) and peripheral (WMD: 0.25%, 95% CI: -3.31, 3.82, p=0.889; I(2): 72.19%) AIx due to statin treatment. There was also no difference in the effect size calculated for different statins subgroups. The impact of statins on AIx was independent of LDL-cholesterol level (slope: 0.05; 95% CI: -0.02, 0.13; p=0.181).

CONCLUSION

Statin therapy causes a significant reduction in aortic AIx which is independent of LDL-cholesterol changes.

Coronary Microvascular Function and Cardiovascular Risk Factors in Women With Angina Pectoris and No Obstructive Coronary Artery Disease: The iPOWER Study

BACKGROUND

The majority of women with angina-like chest pain have no obstructive coronary artery disease when evaluated with coronary angiography. Coronary microvascular dysfunction is a possible explanation and associated with a poor prognosis. This study evaluated the prevalence of coronary microvascular dysfunction and the association with symptoms, cardiovascular risk factors, psychosocial factors, and results from diagnostic stress testing.

METHODS AND RESULTS

After screening 3568 women, 963 women with angina-like chest pain and a diagnostic coronary angiogram without significant coronary artery stenosis (<50%) were consecutively included. Mean age (SD) was 62.1 (9.7). Assessment included demographic and clinical data, blood samples, questionnaires, and transthoracic echocardiography during rest and high-dose dipyridamole (0.84 mg/kg) with measurement of coronary flow velocity reserve (CFVR) by Doppler examination of the left anterior descending coronary artery. CFVR was successfully measured in 919 (95%) women. Median (IQR) CFVR was 2.33 (1.98-2.76), and 241 (26%) had markedly impaired CFVR (<2). In multivariable regression analysis, predictors of impaired CFVR were age (P<0.01), hypertension (P=0.02), current smoking (P<0.01), elevated heart rate (P<0.01), and low high-density lipoprotein cholesterol (P=0.02), but these variables explained only a little of the CFVR variation (r(2)=0.09). CFVR was not associated with chest pain characteristics or results from diagnostic stress testing.

CONCLUSION

Impaired CFVR was detected in a substantial proportion, which suggests that coronary microvascular dysfunction plays a role in the development of angina pectoris. CFVR was associated with few cardiovascular risk factors, suggesting that CFVR is an independent parameter in the risk evaluation of these women. Symptom characteristics and results from stress testing did not identify individuals with impaired CFVR.