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

The Role of Two Heart Biomarkers in IgA Nephropathy

Cardiovascular mortality is a leading cause of death in chronic kidney disease (CKD), as is IgA nephropathy (IgAN). The purpose of this study is to find different biomarkers to estimate the outcome of the disease, which is significantly influenced by the changes in vessels (characterized by arterial stiffness) and the heart. In our cross-sectional study, 90 patients with IgAN were examined. The N-terminal prohormone of brain natriuretic peptide (NT-proBNP) was measured as a heart failure biomarker by an automated immonoassay method, while the carboxy-terminal telopeptide of collagen type I (CITP) as a fibrosis marker was determined using ELISA kits. Arterial stiffness was determined by measuring carotid-femoral pulse wave velocity (cfPWV). Renal function and routine echocardiography examinations were performed as well. Based on eGFR, patients were separated into two categories, CKD 1-2 and CKD 3-5. There were significantly higher NT-proBNP (p = 0.035), cfPWV (p = 0.004), and central aortic systolic pressure (p = 0.037), but not CITP, in the CKD 3-5 group. Both biomarker positivities were significantly higher in the CKD 3-5 group (p = 0.035) compared to the CKD 1-2 group. The central aortic systolic pressure was significantly higher in the diastolic dysfunction group (p = 0.034), while the systolic blood pressure was not. eGFR and hemoglobin levels showed a strong negative correlation, while left ventricular mass index (LVMI), aortic pulse pressure, central aortic systolic pressure, and cfPWV showed a positive correlation with NT-proBNP. cfPWV, aortic pulse pressure, and LVMI showed a strong positive correlation with CITP. Only eGFR was an independent predictor of NT-proBNP by linear regression analysis. NT-proBNP and CITP biomarkers may help to identify IgAN patients at high risk for subclinical heart failure and further atherosclerotic disease.

Long-Term Inhalation of Ultrafine Zinc Particles Deteriorated Cardiac and Cardiovascular Functions in Rats of Myocardial Infarction

Substantial ultrafine zinc particles exist in air pollutions. The level of Zn concentrations in serum and tissue could affect patients with myocardial infarction (MI). The aim of the study is to investigate the change of cardiac functions and peripheral hemodynamics in MI rats after long-term inhalation of ultrafine Zn particles. Coronary artery ligation surgery was performed to induce MI in Wistar rats. The inhalation of ultrafine Zn particles was carried out for 6 weeks after the operation. Physiological and hemodynamic measurements and computational biomechanics analysis were demonstrated in eight groups of rats at postoperative 4 and 6 weeks. There was no statistical significance between shams and shams with inhalation of ultrafine Zn particles. There were significant impairments of cardiac and hemodynamic functions in MI rats. In comparison with MI rats, the inhalation of ultrafine Zn particles for 4 weeks slowed down the progression from MI to heart failure, but the inhalation for 6 weeks accelerated the process. The long-term inhalation of ultrafine zinc particles induced excessive accumulation of zinc in serum and tissue, which deteriorated cardiac and hemodynamic dysfunctions in MI rats. The findings suggested the importance for regulating Zn intake of MI patients as well as looking at ways to lower zinc concentrations in air pollutions.

Urinary Proteomic Profile of Arterial Stiffness Is Associated With Mortality and Cardiovascular Outcomes

Background

The underlying mechanisms of arterial stiffness remain not fully understood. This study aimed to identify a urinary proteomic profile to illuminate its pathogenesis and to determine the prognostic value of the profile for adverse outcomes.

Methods and Results

We measured aortic stiffness using pulse wave velocity (PWV) and analyzed urinary proteome using capillary electrophoresis coupled with mass spectrometry in 669 randomly recruited Flemish patients (mean age, 50.2 years; 51.1% women). We developed a PWV‐derived urinary proteomic score (PWV‐UP) by modeling PWV with proteomics data at baseline through orthogonal projections to latent structures. PWV‐UP that consisted of 2336 peptides explained the 65% variance of PWV, higher than 36% explained by clinical risk factors. PWV‐UP was significantly associated with PWV (adjusted β=0.73 [95% CI, 0.67–0.79]; P<0.0001). Over 9.2 years (median), 36 participants died, and 75 experienced cardiovascular events. The adjusted hazard ratios (+1 SD) were 1.46 (95% CI, 1.08–1.97) for all‐cause mortality, 2.04 (95% CI, 1.07–3.87) for cardiovascular mortality, and 1.39 (95% CI, 1.11–1.74) for cardiovascular events (P≤0.031). For PWV, the corresponding estimates were 1.25 (95% CI, 0.97–1.60), 1.35 (95% CI, 0.85–2.15), and 1.22 (95% CI, 1.02–1.47), respectively (P≥0.033). Pathway analysis revealed that the peptides in PWV‐UP mostly involved multiple pathways, including collagen turnover, cell adhesion, inflammation, and lipid metabolism.

Conclusions

PWV‐UP was highly associated with PWV and could be used as a biomarker of arterial stiffness. PWV‐UP, but not PWV, was associated with all‐cause mortality and cardiovascular mortality, implying that PWV‐UP–associated peptides may be multifaceted and involved in diverse pathological processes beyond arterial stiffness.

Pathophysiology of acute heart failure syndrome: a knowledge gap

Although much remains unknown regarding the pathophysiology of acute heart failure (AHF), precipitating events are thought to involve a complex set of interactions between the heart, kidneys, and peripheral vasculature. In addition to these interactions, which are considered the primary abnormalities in patients with AHF, several other organ systems may also be affected and contribute to disease progression. Currently available scientific literature suggests that the natural history and pathophysiology of AHF consists of two phases: (1) an "initiation phase" involving a series of triggering events, and (2) an "amplification phase," in which multiple mechanisms contribute to worsening HF and exacerbate end-organ damage. Biomarkers of cardiac, renal, pulmonary, and other organ function have been identified during episodes of AHF, including brain natriuretic peptide, troponin I, and troponin T; biomarkers associated with AHF have proven to be useful tools for studying the pathophysiology of the syndrome, predicting clinical outcomes, and identifying patient management strategies. Despite considerable advances in recent years, AHF continues to be a leading cause of hospitalization and death in patients with chronic HF. Moreover, AHF remains a major healthcare issue exacting a considerable cost burden. Addressing this ongoing unmet need requires prioritizing efforts to better understand the natural history and pathophysiology of AHF; only then can targeted therapies be developed to prevent rehospitalization in patients with AHF, or at least alter the trajectory of disease progression toward improved clinical outcomes.

Associations between measures of vascular structure and function and systemic circulating blood markers in humans

Examination of relationships between systemic markers and functional measures of arterial structure and function may assist in determining alternative indices of vascular regulation and designing and evaluating interventions to improve arterial structure and function. Twenty young healthy individuals, 20 older healthy men, and 26 individuals with coronary artery disease (CAD), comprising a spectrum of vascular health, participated. Systemic markers of vascular structure and function included: pro‐collagen type I C‐peptide (PIP) – marker of collagen synthesis, C‐telopeptide of type I collagen (CTX) – marker of collagen degradation, endothelin‐1 (ET‐1) ‐ vasoconstrictor, and interleukin‐6 (IL‐6) – inflammatory marker. Functional measures of arterial structure and function included carotid artery distensibility and brachial artery flow‐mediated dilation (FMD). Moderate positive relationships were observed between carotid distensibility and CTX and PIP (r = 0.57, P < 0.0001 and r = 0.47, P < 0.0001). A negative correlation exists between ET‐1 and FMD (r = −0.44, P = 0.0004); however, no relationship was observed between IL‐6 and FMD (P = 0.25). Over a broad range of vascular health, relationships were observed between markers of type I collagen turnover and arterial stiffness and between a marker of vasoconstriction and endothelial function. These results indicate that regulatory links, between the indices examined, exist. Therefore, monitoring systemic markers rather than functional vascular measures, may provide sufficient information about vascular health and should be considered in the design and evaluation of vascular interventions.

Inflammatory Markers in Primary Aldosteronism

Primary aldosteronism (PA) is the most common cause of endocrine hypertension with a high frequency of cardiovascular complications. The unfavorable cardiometabolic profile may be due to aldosterone-mediated activation of inflammatory cells, circulatory cytokines and activation of collagen synthesis in the vessel wall. Aim of our study was to evaluate differences in the levels of hsCRP, IL-6, TNF-α and N-terminal propeptide of collagen I (PINP) in patients with PA and essential hypertension (EH) as a control group, and between the subtypes of PA (aldosterone producing adenoma – APA, idiopathic hyperaldosteronism – IHA). We studied 28 patients with PA (IHA – 10 patients, APA – 12 patients, 6 unclassified) and 28 matched patients with EH. There were no differences in the levels of inflammatory markers between the followed groups [EH vs. PA: TNF-α (5.09 [3.68-6.32] vs. 4.84 [3.62-6.50] pg/ml), IL-6 (0.94 [0.70-1.13] vs. 0.97 [0.71-1.28] pg/ml), hsCRP (0.53 [0.25-1.54] vs. 0.37 [0.31-0.61] mg/l), leukocytes (6.35±1.42 vs. 5.97±1.29 109 l); APA vs. IHA: TNF-α (4.54 [3.62-7.03] vs. 5.19 [4.23-5.27] pg/ml), IL-6 (0.96 [0.63-1.21] vs. 0.90 [0.65-1.06] pg/ml), hsCRP (0.34 [0.29-0.47] vs. 0.75 [0.36-1.11] mg/l), leukocytes (6.37±1.41 vs. 5.71±1.21 109 l)]. Significant differences in the levels of PINP between PA and EH group were observed (35.18 [28.46-41.16] vs. 45.21 [36.95-62.81] μg/l, p≤0.003). No differences in inflammatory markers were observed between the followed groups, we confirmed higher levels of PINP in patients with PA.

Arterial stiffness and coronary artery disease

PURPOSE OF REVIEW

The current traditional risk scores are not sufficient to predict the full incidence of cardiovascular disease. In this brief review, we discuss the pathophysiological mechanisms through which arterial stiffness affects cardiac function and the additive value of markers of arterial stiffness, to detect the presence of coronary artery disease (CAD) and predict adverse outcome in these patients.

RECENT FINDINGS

Arterial stiffness causes early arrival of wave reflections in systole instead of diastole and, thus, increases systolic afterload and reduces diastolic coronary perfusion pressure. Abnormal collagen turnover, cytokines, and metalloproteinase activity are common biochemical links between vascular and myocardial stiffness. Pulse wave velocity, augmentation index, and central pressures measured by simple noninvasive methods are related to atheromatic plaque vulnerability, incidence, severity, and extent of CAD. Recent meta-analyses have shown the additive value of markers of arterial stiffness, and particularly of pulse wave velocity, to detect CAD, predict cardiovascular events, and reclassify patients to a higher cardiovascular risk. Studies assessing whether reduction of arterial stiffness is associated with improved prognosis are lacking.

SUMMARY

Markers of arterial stiffness are useful tools to identify early atherosclerosis and adverse clinical outcomes in young adults and individuals with a modest risk factor profile. Assessing arterial stiffness may facilitate cardiovascular risk stratification beyond traditional risk scores.

Long-Term Structural and Functional Myocardial Adaptations in Healthy Living Kidney Donors: A Pilot Study

BACKGROUND AND AIMS

Compensatory renal hypertrophy following unilateral nephrectomy (UNX) occurs in the remaining kidney. However, the long-term cardiac adaptive process to UNX remains poorly defined in humans. Our goal was to characterize myocardial structure and function in living kidney donors (LKDs), approximately 12 years after UNX.

METHODS AND RESULTS

Cardiac function and structure in 15 Italian LKDs, at least 5 years after UNX (median time from donation = 8.4 years) was investigated and compared to those of age and sex matched U.S. citizens healthy controls (n = 15). Standard and speckle tracking echocardiography (STE) was performed in both LKDs and controls. Plasma angiotensin II, aldosterone, atrial natriuretic peptide (ANP), N terminus pro B-type natriuretic peptide (NT-proBNP), cyclic guanylyl monophosphate (cGMP), and amino-terminal peptide of procollagen III (PIIINP) were also collected. Median follow-up was 11.9 years. In LKDs, LV geometry and function by STE were similar to controls, wall thickness and volumes were within normal limits also by CMR. In LKDs, CMR was negative for myocardial fibrosis, but apical rotation and LV torsion obtained by STE were impaired as compared to controls (21.4 ± 7.8 vs 32.7 ± 8.9 degrees, p = 0.04). Serum creatinine and PIIINP levels were increased [1.1 (0.9-1.3) mg/dL, and 5.8 (5.4-7.6)] μg/L, respectively), while urinary cGMP was reduced [270 (250-355) vs 581 (437-698) pmol/mL] in LKDs. No LKD developed cardiovascular or renal events during follow-up.

CONCLUSIONS

Long-term kidney donors have no apparent structural myocardial abnormalities as assessed by contrast enhanced CMR. However, myocardial deformation of the apical segments, as well as apical rotation, and LV torsion are reduced. The concomitant increase in circulating PIIINP level is suggestive of fibrosis. Further studies, focused on US and EU patients are warranted to evaluate whether these early functional modifications will progress to a more compromised cardiac function and structure at a later time.

Inadequate Blood Pressure Control in Hypertensive Patients Referred for Cardiac Stress Test

The current study examined the degree of blood pressure (BP) control and incidence of myocardial ischemia in hypertensive patients (n=2039) referred for cardiac stress test. Patients were categorized into well-controlled (<140/90 mm Hg), poorly controlled (140-160/90-100 mm Hg), and very poorly controlled (>160/100 mm Hg) groups according to their resting BP. The mean age[±standard error of the mean] of the patients was 68±13 years, and 885 (43.4%) were men. The prevalence of well-controlled hypertension (HTN) was 47.2%, poorly controlled HTN was 29.5%, and very poorly controlled HTN was 23.3%. Evidence of ischemia was seen in 19.8% and 19.3% of the well-controlled and poorly controlled groups, respectively. The very poorly controlled group had the lowest incidence of ischemia (14.3%) (P<.05) compared with the other two groups. Symptoms that mimic ischemic heart disease in hypertensive patients may be partly explained by poorly controlled BP. Quality of care might be improved by optimally controlling BP in patients with angina symptoms prior to ordering diagnostic testing associated with radiation exposure and cost.

Procollagen III N-terminal peptide predicts short-term prognosis and cardiac remodeling in coronary heart disease patients with metabolic syndrome

INTRODUCTION

Many patients with coronary heart disease (CHD) also have metabolic syndrome (MS); however, little is known about the condition of cardiovascular remodeling in these patients. The objective of this study to explore the role of plasma procollagen III N-terminal peptide (PIIINP) in predicting the prognosis and cardiac remodeling in patients with CHD with MS.

METHODS

One hundred eight patients were classified into high and low PIIINP groups according to the median value of plasma PIIINP. Cardiovascular examinations including echocardiogram, carotid color ultrasound examination, coronary angiography and the 6-minute walking test (6MWT) were performed before and after a 1-year follow-up. Readmission for cardiac and cerebrovascular events was assessed during the follow-up period.

RESULTS

Plasma PIIINP level was significantly correlated with age, high-sensitivity C-reactive protein (hs-CRP) and body mass index in a multiple stepwise regression model. There was a positive correlation between the LnPIIINP and an increased left ventricular mass index in partial correlation analysis. The Cox proportional hazard model analysis indicated that the level of PIIINP, left ventricular ejection fraction and hs-CRP were independent predictors of readmission owing to cardiac and cerebrovascular events during the follow-up. A PIIINP value of 4.0 μg/L was the best threshold value for determining the need for readmission.

CONCLUSIONS

PIIINP levels rise with increases in age, hs-CRP and body mass index in patients with CHD with MS, and a high level of PIIINP indicates recent deterioration of cardiac remodeling and exercise tolerance and a poor prognosis.

Associations between collagen synthesis and degradation and aortic function in arterial hypertension

BACKGROUND

Studies have suggested that collagen accumulation in the aortic wall may contribute to the stiff aorta in arterial hypertension. However, data in human hypertension are limited. In this investigation, relations between markers of collagen metabolism and aortic function in patients with arterial hypertension were evaluated.

METHODS

We studied 72 hypertensive patients (age 53 +/- 5 years) and 27 age- and gender-matched normotensive individuals. Elastic properties of the aorta were assessed by aortic pulse wave velocity (carotid-to-femoral pulse wave velocity (PWVc-f)). Free amino-terminal propeptides of precollagen type I (PINP, reflecting collagen I synthesis), serum telopeptides of collagen type I (CITP, an index of collagen I degradation), free amino-terminal propeptides on precollagen type III (PIIINP, reflecting collagen III metabolism), prometalloproteinase-1 (proMMP-1), and tissue inhibitor of metalloproteinase-1 (TIMP-1) levels were determined by commercially available immunoassays.

RESULTS

Patients with arterial hypertension had greater PWVc-f (P = 0.01); and higher levels of PINP/CITP compared to control (P = 0.04). PWVc-f was significantly associated with PINP/CITP ratio (analysis of variance (ANOVA), P = 0.03). Hypertensive patients had significantly higher levels of proMMP-1/TIMP-1 (P = 0.04); PWVc-f was significantly associated with proMMP-1 (ANOVA, P = 0.03) and proMMP-1/TIMP-1 (ANOVA, P = 0.04). Associations between PWVc-f and proMMP-1 and between PWVc-f and PINP/CITP ratio remained significant after adjustment for PWVc-f confounders and antihypertensive treatment.

CONCLUSIONS

Alterations in collagen turnover that favor collagen type I synthesis; as well as proMMP-1 expression are related to increased aortic stiffness in treated hypertensive individuals without left ventricular (LV) hypertrophy.