Repaired coarctation of the aorta, persistent arterial hypertension and the selfish brain.

BACKGROUND: It has been estimated that 20-30% of repaired aortic coarctation (CoA) patients develop hypertension, with significant cardiovascular morbidity and mortality. Vertebral artery hypoplasia (VAH) with an incomplete posterior circle of Willis (ipCoW; VAH + ipCoW) is associated with increased cerebrovascular resistance before the onset of increased sympathetic nerve activity in borderline hypertensive humans, suggesting brainstem hypoperfusion may evoke hypertension to maintain cerebral blood flow: the "selfish brain" hypothesis. We now assess the "selfish brain" in hypertension post-CoA repair. METHODS: Time-of-flight cardiovascular magnetic resonance angiography from 127 repaired CoA patients (34 ± 14 years, 61% male, systolic blood pressure (SBP) 138 ± 19 mmHg, diastolic blood pressure (DBP) 76 ± 11 mmHg) was compared with 33 normotensive controls (42 ± 14 years, 48% male, SBP 124 ± 10 mmHg, DBP 76 ± 8 mmHg). VAH was defined as < 2 mm and ipCoW as hypoplasia of one or both posterior communicating arteries. RESULTS: VAH + ipCoW was more prevalent in repaired CoA than controls (odds ratio: 5.8 [1.6-20.8], p = 0.007), after controlling for age, sex and body mass index (BMI). VAH + ipCoW was an independent predictor of hypertension (odds ratio: 2.5 [1.2-5.2], p = 0.017), after controlling for age, gender and BMI. Repaired CoA subjects with VAH + ipCoW were more likely to have difficult to treat hypertension (odds ratio: 3.3 [1.01-10.7], p = 0.049). Neither age at time of CoA repair nor any specific repair type were significant predictors of VAH + ipCoW in univariate regression analysis. CONCLUSIONS: VAH + ipCoW predicts arterial hypertension and difficult to treat hypertension in repaired CoA. It is unrelated to age at time of repair or repair type. CoA appears to be a marker of wider congenital cerebrovascular problems. Understanding the "selfish brain" in post-CoA repair may help guide management. JOURNAL SUBJECT CODES: High Blood Pressure; Hypertension; Magnetic Resonance Imaging (MRI); Cardiovascular Surgery; Cerebrovascular Malformations.

Cerebrovascular Variants and the Role of the Selfish Brain in Young-Onset Hypertension.

BACKGROUND: Variants in the posterior anatomy of the cerebral circulation are associated with hypertension and lower cerebral blood flow in midlife (age ≈55 years); however, whether these variants are a result of aging or long-term exposure to high blood pressure is unclear. Additionally, the role these variants play in early onset of hypertension (<40 years) and poor cerebral perfusion in this population is unknown. METHODS: We retrospectively examined whether specific cerebrovascular variants (vertebral artery hypoplasia and absent/hypoplastic posterior communicating arteries (an incomplete posterior circle of Willis) measured via magnetic resonance angiography) were associated with a diagnosis of hypertension in 220 young adults (<40 years; n=164 primary hypertensive [mean age±SD, 32±6 years] and n=56 [30±6 years] normotensive adults). Whether cerebrovascular variants were associated with lower cerebral blood flow (phase-contrast angiography) was measured in the hypertensive group only (n=146). RESULTS: Binary logistic regression (adjusted for age, sex, and body mass index) showed that vertebral artery hypoplasia with an incomplete posterior circle of Willis was associated with hypertension diagnosis (P<0.001, odds ratio; 11.79 [95% CI, 3.34-41.58]). Vertebral artery hypoplasia plus an incomplete circle of Willis was associated with lower cerebral blood flow in young adults with hypertension (P=0.0172). CONCLUSIONS: Vertebral artery hypoplasia plus an incomplete posterior circle of Willis independently predicts hypertension in young adults suggesting that this variant is not acquired with aging into midlife. Importantly this variant combination was associated with lower cerebral perfusion, which may have long-term consequences on cerebrovascular health in young adults with hypertension.

A Segmental Approach from Molecular Profiling to Medical Imaging to Study Bicuspid Aortic Valve Aortopathy.

Bicuspid aortic valve (BAV) patients develop ascending aortic (AAo) dilation. The pathogenesis of BAV aortopathy (genetic vs. haemodynamic) remains unclear. This study aims to identify regional changes around the AAo wall in BAV patients with aortopathy, integrating molecular data and clinical imaging. BAV patients with aortopathy (n = 15) were prospectively recruited to surgically collect aortic tissue and measure molecular markers across the AAo circumference. Dilated (anterior/right) vs. non-dilated (posterior/left) circumferential segments were profiled for whole-genomic microRNAs (next-generation RNA sequencing, miRCURY LNA PCR), protein content (tandem mass spectrometry), and elastin fragmentation and degeneration (histomorphometric analysis). Integrated bioinformatic analyses of RNA sequencing and proteomic datasets identified five microRNAs (miR-128-3p, miR-210-3p, miR-150-5p, miR-199b-5p, and miR-21-5p) differentially expressed across the AAo circumference. Among them, three miRNAs (miR-128-3p, miR-150-5p, and miR-199b-5p) were predicted to have an effect on eight common target genes, whose expression was dysregulated, according to proteomic analyses, and involved in the vascular-endothelial growth-factor signalling, Hippo signalling, and arachidonic acid pathways. Decreased elastic fibre levels and elastic layer thickness were observed in the dilated segments. Additionally, in a subset of patients n = 6/15, a four-dimensional cardiac magnetic resonance (CMR) scan was performed. Interestingly, an increase in wall shear stress (WSS) was observed at the anterior/right wall segments, concomitantly with the differentially expressed miRNAs and decreased elastic fibres. This study identified new miRNAs involved in the BAV aortic wall and revealed the concomitant expressional dysregulation of miRNAs, proteins, and elastic fibres on the anterior/right wall in dilated BAV patients, corresponding to regions of elevated WSS.

Myocardial Work: Methodology and Clinical Applications.

A precise and accurate assessment of left ventricular (LV) contractility is of utmost importance in terms of prognosis in most cardiac pathologies. Given the limitations of ejection fraction (EF) and global longitudinal strain (GLS) due to their load dependency, a novel imaging tool called myocardial work (MW) has emerged as a promising method for LV performance evaluation. MW is a novel, less load-dependent method based on computation of myocardial strain-arterial blood pressure curves. This method provides a more detailed assessment of segmental and global LV function incorporating the patient's LV pressure and is derived by brachial artery pressure utilizing an empiric reference curve adjusted to the duration of the isovolumic and ejection phases as determined by echocardiography. The clinical implications of this unique method have been expanding in the last few years, which attest to the robust additive role of MW in routine practice.

Statin use is associated with a significant reduction in cholesterol content of erythrocyte membranes. A novel pleiotropic effect?

PURPOSE: High cholesterol content of erythrocyte membranes (CEM) levels is present in patients with acute coronary syndromes (ACS). Intraplaque hemorrhage and erythrocyte lysis contribute to the deposition of cholesterol on the atherosclerotic plaque and to plaque rupture. With the present study we assessed the effect of statin therapy on CEM levels, a novel marker of coronary artery disease (CAD) instability during a 1-year follow-up in CAD patients. METHODS: 212 consecutive eligible (158 men, 62 +/- 10 years) patients undergoing diagnostic coronary angiography for the assessment of angina pectoris were assessed. The study population comprised of 84 chronic stable angina (CSA) patients and 128 ACS patients. All study participants were commenced on statin treatment in equipotent doses and were followed for up to 1 year (at - 1, - 3, - 6 and - 12 months). RESULTS: Repeated measurements analysis of variance after appropriate adjustment showed a significant decrease (p < 0.001) in CEM content during follow up. CEM levels were decreasing at each time point (1 month : 100 microg/mg 95%CI 94.3-105.6, 3 months : 78.1 microg/mg 95%CI 73.2-83, 6 months : 67.2 microg/mg 95%CI 63.1-71.2, 1 year : 45.3 microg/mg 95%CI 42.2-48.3) compared to admission (112.1 microg/mg 95% CI 105.9-118.3) and to all previous measurements. CONCLUSIONS: The present study showed, that use of statins is associated with a reduction in CEM, an emerging marker of clinical instability and plaque vulnerability in CAD patients. The pleiotropic effects of statins at the cell membrane level represent a promising novel direction for research in CAD.

Interleukin-8 is increased in the membrane of circulating erythrocytes in patients with acute coronary syndrome.

AIMS: Studies have shown that erythrocyte membranes are present within necrotic cores in atherosclerotic plaques, and that circulating erythrocytes in patients with acute coronary syndrome (ACS) have increased total cholesterol content (CEM). Interleukin-8 (IL-8) binds to erythrocytes and during intraplaque haemorrhage it is released into the plaque and thus may contribute to inflammatory cascade and atherosclerotic plaque instability. The present study was undertaken to test the hypothesis that erythrocyte membrane IL-8 is elevated in patients with ACS compared with those with chronic stable angina (CSA). METHODS AND RESULTS: Consecutive patients who presented with CSA (n = 120, 92 men, 62 +/- 9 years), ACS (n = 118, 90 men, 62 +/- 10 years) or with chest pain who had normal coronary arteries (n = 36, 26 men, 60 +/- 7 years), were studied prospectively. IL-8 concentrations in erythrocyte membranes (rIL-8) and in plasma (pIL-8), C-reactive protein (CRP) and CEM were measured. rIL-8 levels [mean +/- 1 SD (standard deviation)] were higher in ACS (102.9 +/- 70.1 pg/mL) compared with CSA (44.7 +/- 22.8 pg/mL) (P < 0.001). No difference in pIL-8 levels between the two coronary artery disease groups was observed (P = 0.280). Serum CRP levels were correlated with rIL-8 levels (r = 0.294, P < 0.001); no association was found between CRP and pIL-8 levels (r = 0.025, P = 0.706). Further, rIL-8 had an independent association with ACS, when CRP and CEM were taken into consideration. CONCLUSION: This study shows for the first time that rIL-8 content was significantly higher in ACS, compared with CSA. These findings endorse results from our previous studies suggesting that erythrocytes may play an important role in the development of unstable atherosclerotic plaque.

Resolution of symptoms and serum peptides of collagen type I turnover in acute heart failure patients.

OBJECTIVES: Myocardial collagen content as a fundamental component of extracellular matrix, is altered in pathological states including heart failure (HF). Serum peptides related to myocardial collagen synthesis and degregation can be measured and may be used as indices of myocardial collagen turnover. The present study was undertaken to assess the hypothesis that resolution of acute decompensation of chronic HF is associated with changes in serum peptides related to collagen synthesis and degregation. METHODS AND RESULTS: Serum concentrations of the amino-terminal propetide of procollagen type I (PINP) and the carboxy-terminal telopeptide of collagen type I (CITP), indices of collagen type I synthesis and degradation, respectively, were determined at the time of admission and discharge in 156 patients (100 men, 68 +/- 10 years) with acute decompensation of chronic HF. A significant decrease (-3.5 ng/ml 95% CI -5.3/-1.6 ng/ml, P < 0.001) of PINP was observed whereas CITP levels were significantly increased (+ 0.04 ng/ml 95% CI 0.01-0.08 ng/ml, P = 0.031) at discharge compared to admission. CONCLUSIONS: Findings of the present study showed that serum indices of myocardial collagen turnover were changed significantly in a short period of time during the improvement of acute decompensation of chronic HF.

Effect of statins on collagen type I degradation in patients with coronary artery disease and atrial fibrillation.

The present study was undertaken to assess the effect of statins on collagen type I degradation and C-reactive protein in patients with coronary artery disease and atrial fibrillation. One hundred six patients with coronary artery disease and atrial fibrillation were studied: 40 (36 men, mean age 72 +/- 8 years) treated with a statin and 66 (48 men, mean age 74 +/- 9 years) not treated with a statin. Serum concentrations of carboxy-terminal telopeptide of collagen type I, an index of collagen type I degradation, and high-sensitivity C-reactive protein were measured in all patients. Carboxy-terminal telopeptide of collagen type I levels were significantly higher (p <0.001) in statin-treated patients (0.64 ng/ml, 95% confidence interval [CI] 0.57 to 0.71) compared with nonstatin-treated patients (0.38 ng/ml, 95% CI 0.31 to 0.44). These changes were independent of cholesterol levels (before or after therapy). Statin-treated patients had significantly lower (p <0.001) C-reactive protein levels (0.25 mg/dl, 95% CI 0.23 to 0.28) compared to statin nonusers (1.1 mg/dl, 95% CI 0.92 to 1.25). In conclusion, this study suggests that therapy with statins in patients with coronary artery disease and atrial fibrillation is associated with an increase in collagen degradation and an attenuation of inflammation, independently of cholesterol lowering.

Serum levels of collagen type-I degradation markers are associated with vascular stiffness in chronic heart failure patients.

BACKGROUND: Chronic heart failure (CHF) induces peripheral vasoconstriction, endothelial dysfunction and arterial stiffness by activation of various neurohormonal pathways. The abnormal collagen turnover observed in CHF may be attributed not only to myocardial remodelling, but also to vascular remodelling. However, the effect of collagen metabolism on progressive large artery stiffening in the setting of CHF is understudied. AIMS: The present study was undertaken to investigate the association between circulating markers of collagen turnover and vascular stiffness in patients with CHF. METHODS: Eighty patients (mean age 65+/-11 years, 68 men) with stable CHF and in sinus rhythm, were studied. Serum concentrations of carboxy-terminal telopeptide of collagen type I (CITP) and amino-terminal propetide of procollagen type I (PINP), markers of collagen type I degregation and synthesis respectively, were measured in all patients. Pulse wave velocity (PWV) and augmentation index (AIx) of aortic pulse wave form, markers of arterial stiffness, were also determined by applanation tonometry. RESULTS: Peripheral PWV was inversely associated with serum CITP levels (r=-0.585, p<0.001). AIx although weakly was negatively correlated with serum CITP levels (r=-0.285, p=0.01). Multiple regression analysis showed that peripheral PWV remained independently associated with serum CITP levels after adjustment for all confounding variables. CONCLUSIONS: Findings from the present study imply a possible link between altered collagen metabolism and peripheral vascular stiffness in CHF.

Age as a Risk Factor for Stroke in Atrial Fibrillation Patients: Implications in Thromboprophylaxis in the Era of Novel Oral Anticoagulants.

Atrial fibrillation is associated with significant morbidity and mortality. There is a strong relationship between atrial fibrillation and aging, thromboembolism, stroke, congestive heart failure and hypertension. In addition, advanced age is a powerful risk factor for stroke and thromboembolism in patients with atrial fibrillation. For many years, vitamin K antagonists were the only approved anticoagulants for the management of atrial fibrillation. Lately new anticoagulants made their appearance and large trials have already shown their superiority against vitamin K antagonists. Since the arrhythmia is encountered frequently in the elderly, it is crucial to identify the beneficial effects of the novel oral anticoagulants in this particular patient population.

Chest pain in patients with arterial hypertension, angiographically normal coronary arteries and stiff aorta: the aortic pain syndrome.

INTRODUCTION: Arterial hypertension is often associated with a stiff aorta as a result of collagen accumulation in the aortic wall and may produce chest pain. In the present study, possible interrelationships between aortic function, collagen turnover and exercise-induced chest pain in patients with arterial hypertension and angiographically normal coronary arteries were investigated. METHODS: Ninety-seven patients with arterial hypertension, angiographically normal coronary arteries and no evidence of myocardial ischemia on nuclear cardiac imaging during exercise test were studied. Of these, 43 developed chest pain during exercise (chest pain group) while 54 did not (no chest pain group). Carotid femoral pulse-wave velocity (PWVc-f) was used to assess the elastic properties of the aorta. Amino-terminal pro-peptides of pro-collagen type I, (PINP, reflecting collagen synthesis), serum telopeptides of collagen type I (CITP, reflecting collagen degradation), pro-metalloproteinase 1 (ProMMP-1), and tissue inhibitor of metalloproteinase 1 (TIMP-1, related to collagen turnover) were measured in plasma by immunoassay. RESULTS: The chest pain group had higher PWVc-f, higher and /CITP ratio, and lower proMMP-1/ TIMP-1 ratio compared to the no chest pain group. PWVc-f (t=2.53, p=0.02) and PINP (t=2.42, p=0.02) were independently associated with the presence of chest pain in multiple regression analysis. CONCLUSIONS: Patients with arterial hypertension, exercise-induced chest pain and angiographically normal coronary arteries, without evidence of exercise-induced myocardial ischemia, had a stiffer aorta compared to those without chest pain. Alterations in collagen type I turnover that favor collagen accumulation in the aortic wall may contribute to aortic stiffening and chest pain in these patients.

Independent and additive prognostic ability of serum carboxy-terminal telopeptide of collagen type-I in heart failure patients: a multi-marker approach with high-negative predictive value to rule out long-term adverse events.

BACKGROUND: Altered myocardial extracellular matrix turnover has been proposed as a major determinant of myocardial remodelling. Carboxy-terminal telopeptide of collagen type-I (CITP) represents a collagen type-I degradation-derived serum peptide. In this study we examined the independent and additive prognostic value of serum concentrations of CITP compared with well-known mortality predictors such as the N-terminal pro-brain natriuretic peptide (NT-proBNP) in chronic heart failure (CHF) patients. METHODS: We studied 196 consecutive patients (126 male, mean age 69 ± 10 years), who were admitted for acute decompensation of the CHF syndrome. The study entry point was determined at the discharge of the patients after achieving a stable compensated status. The primary endpoint was cardiac mortality during a 12-month follow-up. RESULTS: In the multivariate Cox proportional hazard model the levels of CITP remained a predictor of survival (hazards ratio 0.4 95% confidence interval 0.21-0.76, P = 0.005), independent of NT-proBNP levels. The stratified log-rank test (P < 0.001) showed that CHF patients characterized by low levels of both biomarkers had better survival (hazards ratio 0.12 95% confidence interval 0.04-0.35, P < 0.001) compared with patients characterized by high levels of both biomarkers. The negative predictive value of the combined measure for long-term adverse events was 94%. CONCLUSION: Serum levels of CITP were shown to be an independent and strong prognostic marker regarding survival in CHF patients. Furthermore, CITP levels had an additive prognostic value compared with NT-proBNP levels. These findings underline the detrimental role of myocardial fibrosis in the progression of heart failure and suggest a novel multi-marker approach for risk stratification in the CHF syndrome.

Chronic heart failure patients with high collagen type I degradation marker levels benefit more with ACE-inhibitor therapy.

Not all patients respond to angiotensin converting enzyme (ACE)-inhibitor equally. Genetic or other phenotypic variations might be useful in predicting the therapeutic efficacy of these drugs. With the present study we assessed the prognostic impact of ACE-inhibitor in chronic heart failure patients with different degrees of collagen metabolism as assessed by serum levels of a collagen type I degradation marker (CITP). One hundred ninety-six (126 male, 69+/-10 years) chronic heart failure patients were studied prospectively for 12 months regarding survival. Serum concentrations of CITP were measured at study entry. Chronic heart failure patients were divided into groups according to whether (n=114) or not (n=82) they received ACE-inhibitor as well as to their CITP levels. Survival (52.2%) was significantly lower in ACE-inhibitor naive patients with high CITP levels compared to ACE-inhibitor naive patients with low CITP levels (83.3%, P=0.003), to ACE-inhibitor users with low CITP levels (80%, P=0.006) and to ACE-inhibitor users with high CITP levels (70.4%, P=0.015). ACE-inhibitor related improvement in mortality was most predominant in chronic heart failure patients with high CITP levels. CITP levels possibly reflecting an activated status of the renin-angiotensin-aldosterone system, may be of clinical relevance since they identify a subgroup of patients that is more susceptible to treatment with an ACE-inhibitor.

Cholesterol composition of erythrocyte membranes and its association with clinical presentation of coronary artery disease.

OBJECTIVES: Presence of free cholesterol in atherosclerotic plaques is a major determinant of plaque instability. It is hypothesized that extravasated erythrocytes may contribute to free cholesterol accumulation in atherosclerotic plaques through their rich in cholesterol membrane. In this study we assessed whether cholesterol in erythrocyte membranes (CEMs), that is, free (FCEM) versus esterified (ECEM), differs in patients with chronic stable angina (CSA) compared with patients presenting with acute coronary syndromes (ACSs). METHODS: Consecutive angina patients were prospectively assessed; 154 had CSA (118 men, 63 years, 56-69 years) and 164 ACS (124 men, 63 years, 55-71 years). FCEM and ECEM were measured using an enzymatic assay, and protein content was assessed by the Bradford method. RESULTS: FCEM was significantly higher (P<0.001) in the ACS patients group (94.1 microg/mg, IQ 71-116.5 microg/mg) compared with patients with CSA (61.9 microg/mg, IQ 49.3-73.1 microg/mg). ECEM levels were also significantly higher (P<0.001) in ACS patients (23.3 microg/mg, IQ 14.9-47.7 microg/mg) compared with CSA patients (10.8 microg/mg, IQ 8-22.3 microg/mg). In contrast, ratio of free-to-esterified cholesterol (P=0.110) as well as ratio of free-to-total CEM (P=0.109) were not different among CSA and ACS patients. CONCLUSION: Findings of this study show that although free cholesterol is the prevailing form of CEMs, both FCEM and ECEM levels are increased in patients with ACS compared with CSA patients. These findings suggest that it is the quantity of CEM rather than the type of cholesterol present in the erythrocyte membrane that determines plaque progression.