The relation between myocardial cyclic variation of integrated backscatter and serum concentrations of procollagen propeptides in hypertensive patients

Left ventricular remodeling and dysfunction in primary aldosteronism

Primary aldosteronism (PA) is a common cause of secondary hypertension and is associated with worse cardiovascular outcomes. The elevated aldosterone in PA leads to left ventricular (LV) remodeling and dysfunction. In recent decades, clinical studies have demonstrated worse LV remodeling including increased LV mass and cardiac fibrosis in patients with PA compared to patients with essential hypertension. Several mechanisms may explain the process of aldosterone-induced LV remodeling, including directly profibrotic and hypertrophic effects of aldosterone on myocardium, increased reactive oxygen species and profibrotic molecules, dysregulation of extracellular matrix metabolism, endothelium dysfunction and circulatory macrophages activation. LV remodeling causes LV diastolic and systolic dysfunction, which may consequently lead to clinical complications such as heart failure, atrial fibrillation, ischemic heart disease, and other vascular events. Adequate treatment with adrenalectomy or medical therapy can improve LV remodeling and dysfunction in PA patients. In this review, we discuss the mechanisms of aldosterone-induced LV remodeling and provide an up-to-date review of clinical research about LV remodeling-related heart structural changes, cardiac dysfunction, and their clinical impacts on patients with PA.

[Galactin-3: diagnostic and prognostic value in patients with chronic heart failure]

Now there is a relevant development of the new biomarkers capable to serve as the instrument of early diagnostics of a disease for the purpose of selection of a pharmacotherapy and further monitoring of its efficiency. Galektin-3 is the atypical representative of the family of galektin. Its participation in fibrosis, remodeling of heart, the immunologic answer and inflammatory reactions are shown. Prognostic value is discussed and diagnostic opportunities of Galektin-3 at CHF are widely studied and take root into clinical practice. Now a great deal of research devoted to the studying of Galektin-3, possibilities of its use as a biomarker at diagnostics, forecasting of outcomes and the choice of therapeutic strategy at other cardiovascular diseases has been conducted.

IL-6 trans-signalling contributes to aldosterone-induced cardiac fibrosis

Aims

An excess of aldosterone results in cardiac remodelling and fibrosis. Interleukin-6 (IL-6) is a key mediator in the fibrotic process; however, the effect of aldosterone on the expression of IL-6 remains unclear. We investigated whether aldosterone induces the expression of IL-6 and thereby contributes to the fibrotic process.

Methods and results

In this clinical study, we prospectively enrolled 25 patients with primary aldosteronism (PA) and 26 patients with essential hypertension (EH). The PA patients had higher plasma IL-6 levels, left ventricular mass index, degree of myocardial fibrosis, and more impaired diastolic function than the EH patients. In addition, plasma IL-6 levels were positively correlated with 24-h urinary aldosterone and echocardiographic parameters. In cell studies, we investigated the possible molecular mechanism how aldosterone-induced IL-6 secretion and the further effects of collagen production. Aldosterone significantly induced IL-6 protein and mRNA production in human umbilical vein endothelial cells. Intracellular signalling occurred through the mineralocorticoid receptor/PI3K/Akt/NF-kB pathway. In cardiac fibroblasts, IL-6 trans-signalling played a critical role in aldosterone-induced IL-6-enhanced fibrosis-related factor expression. To further investigate the role of IL-6 trans-signalling in aldosterone-induced cardiac fibrosis, we measured the severity of myocardial fibrosis in aldosterone infusion mice models including an IL-6 chemical inhibitor and Sgp130 Knockin Transgenic Mice. Mice receiving recombinant soluble gp130 and Sgp130 Knockin Transgenic Mice prevented myocardial fibrosis and cardiac hypertrophy by aldosterone infusion.

Conclusions

IL-6 trans-signalling contributes to aldosterone-induced cardiac fibrosis.

Effects of 12 weeks of atorvastatin therapy on myocardial fibrosis and circulating fibrosis biomarkers in statin-naïve patients with hypertension with atherosclerosis

The purpose of this study was to assess the effects of 12 weeks of atorvastatin treatment on myocardial fibrosis in patients with hypertension with atherosclerosis. 15 statin-naïve participants (11 males; mean age 67±10 years) with atherosclerosis were given atorvastatin (40 mg/day) for 12 weeks and underwent echocardiography including ultrasonic tissue characterization by cyclic variation of integrated backscatter (CVIBS). Serum galectin-3 and fibrosis markers including aminoterminal propeptide of type III procollagen (PIIINP), matrix metalloproteinase-2, metalloproteinase-9, and tissue inhibitor of metalloproteinase-1 (TIMP-1) were also analyzed. After 12 weeks of atorvastatin (40 mg/day) treatment, serum total cholesterol and low-density lipoprotein cholesterol decreased significantly (204±31 to 140±24 mg/dL and 133±26 to 69±17 ng/mL, respectively, both p<0.001). In myocardial fibrosis analysis, CVIBS increased significantly (6.6±1.9 to 8.5±2.7 dB, p=0.024). In addition, the circulating fibrosis markers serum PIIINP and TIMP-1 decreased significantly (9.5±2.7 to 6.4±1.4 ng/mL, p=0.012 and 299±65 to 250±45 ng/mL, p=0.024, respectively). 12 weeks of medium dose atorvastatin treatment resulted in a significant reduction in myocardial fibrosis as evaluated by morphofunctional parameters and plasma markers of tissue fibrosis.

Trial registration number

NTC00172419; results.

The relation among aldosterone, galectin-3, and myocardial fibrosis: a prospective clinical pilot follow-up study

Primary aldosteronism has been associated with myocardial fibrosis, and is the most common cause of secondary hypertension. We previously showed that aldosterone can induce the secretion of galectin-3. The aim of this study was to investigate the association between myocardial fibrosis and plasma galectin-3 level in patients with primary aldosteronism. We prospectively analyzed 11 patients with aldosterone-producing adenoma (APA) who received adrenalectomy from December 2006 to October 2008, and 17 patients with essential hypertension as controls. Levels of plasma galectin-3 were determined in both groups, and both groups underwent echocardiography with cyclic variations of integrated backscatter (CVIBS) to characterize tissue initially and 1 year after surgery in the APA group. Diastolic blood pressure, concentration of plasma aldosterone and aldosterone-renin ratio were significantly higher, and serum potassium level and plasma renin activity significantly lower in the APA group compared to the controls. In addition, left ventricular mass index was significantly higher and CVIBS significantly lower in the APA group (7.3±2.0 vs 9.2±1.7 dB, p=0.015). Furthermore, the concentration of plasma galectin-3 was significantly higher in the APA group (2.1±0.9 vs 1.1±0.6 ng/mL, p=0.005) compared to the controls. CVIBS was correlated to plasma galectin-3 level. In the APA group, CVIBS increased significantly (7.3±2.0 to 9.2±2.4 dB, p=0.032) and plasma galectin-3 decreased (2.1±0.9 to 1.2±0.6, p=0.049) 1 year postadrenalectomy. The patients with APA had increased myocardial fibrosis, and this was associated with a higher plasma galectin-3 level. Both increased myocardial fibrosis and plasma galectin-3 level recovered at least partially after adrenalectomy.

TRIAL REGISTRATION NUMBER

200611031R; Results.

Protective effect of Sheng-Mai Yin, a traditional Chinese preparation, against doxorubicin-induced cardiac toxicity in rats

Background

Sheng-Mai Yin (SMY), a modern Chinese formula based on Traditional Chinese Medicine theory, has been used to treat cardiovascular diseases in Eastern Asia. Our study focuses on the cardioprotection of SMY against doxorubicin (DOX)-induced cardiac toxicity in vivo.

Methods

Rats were injected with DOX (2.5 mg/kg) in six injections over a 2-week period. SMY was administrated intragastrically at the dose of 8.35, 16.7 and 33.4 g/kg, or 16.7 g/kg only twice a day concurrently with DOX for the 2-weeks. A series of assays were performed to detect the effects of SMY on: (i) heart weight index (HWI) and left ventricular mass index (LVMI); (ii) cardiac function; (iii) heart tissue morphology; (iv) the contents of carboxy terminal propeptide of procollagen typeI (PICP), amino terminal propeptide of procollagen type III (PШNP), transforming growth factor-β1 (TGF-β1), B-type natriuretic peptide (BNP), monocyte chemoattractant protein-1 (MCP-1), interferon gamma (INF-γ) and interleukin 6 (IL-6) by ELISA; (v) the mRNA levels of TGF-β1 and toll-like receptor-2 (TLR2); and (vi) protein level of TGF-β1.

Results

Rats treated with SMY displayed the reductions of BNP and CK-MB increased by DOX in a dose-dependent manner. Moderate dose of SMY exhibited the correction for the increased HWI, LVMI, and the injured cardiac function, as well as the collagen accumulation. In addition, cardioprotection of SMY against DOX-induced cardiac toxicity was demonstrated by the reduction of myocardial fibrosis, characterized by the suppression of PICP, PШNP and TGF-β1, as well as the anti-inflammation and the regulation for cardiac immune microenvironment, characterized by the inhibition of TLR2, MCP-1, INF-γ and IL-6.

Conclusions

SMY may protect heart function through the restriction of myocardial fibrosis induced by DOX, which suggests the potentially therapeutic effect of SMY on DOX-induced cardiomyopathy.

Influence of Renal Sympathetic Denervation on Cardiac Extracellular Matrix Turnover and Cardiac Fibrosis

BACKGROUND

Renal sympathetic denervation (RSD) represents an effective treatment option for patients with resistant arterial hypertension (HT). Extracellular matrix (ECM) turnover and deposition are essential processes in HT-related cardiovascular remodeling, fibrosis, and cardiac hypertrophy and contribute to hypertensive heart disease.

OBJECTIVES

The primary aim of the present study was to examine the effect of RSD on increased collagen turnover as reflected by serum levels of amino-terminal pro-peptides (PINP, PIIINP) and a carboxyl-terminal pro-peptide (PICP), specific biomarkers for cardiac ECM turnover and cardiovascular fibrosis.

METHODS

A total of 100 consecutive patients (mean age: 65.9±10.1 years) undergoing RSD were included in this study. A therapeutic response was defined as an office systolic blood pressure (SBP) reduction of >10mm Hg 6 months after RSD. Venous serum samples for measurement of PICP, PINP, and PIIINP were collected prior to and 6 months after RSD.

RESULTS

A significant reduction in the office SBP of 24.3 mm Hg (SBP baseline: 166.9±14.3 mm Hg (P < 0.001) was documented 6 months after RSD. At this time point, the serum levels of PICP, PINP, and PIIINP (P < 0.01) were significantly decreased compared to baseline values in patients with an increased collagen turnover, showing significant differences comparing BP responders and nonresponders.

CONCLUSION

In addition to the effective blood pressure reduction in response to RSD, this study demonstrates a positive effect of RSD on biomarkers reflecting cardiovascular ECM turnover and deposition. These results suggest a beneficial effect of RSD on cardiovascular fibrosis, hypertensive heart disease, and end-organ damage in high-risk patients.

Procollagen type III amino terminal peptide and myocardial fibrosis: A study in hypertensive patients with and without left ventricular hypertrophy

INTRODUCTION AND OBJECTIVES

An exaggerated accumulation of type I and type III fibrillar collagens occurs throughout the free wall and interventricular septum of patients with primary hypertension and left ventricular hypertrophy (LVH). In the present study the serum concentration of procollagen type III amino terminal peptide (PIIIP) was measured to determine the value of this peptide as a potential marker of ventricular fibrosis in hypertensive patients, particularly those with LVH.

METHODS

The study population consisted of patients with never-treated mild to moderate essential hypertension and 30 normotensive control subjects. Clinical, echocardiographic, electrocardiographic and biochemical parameters were assessed in all patients.

RESULTS

Heart rate, body mass index and levels of blood pressure were increased in hypertensives, particularly those with LVH, compared to normotensive controls. Posterior wall thickness, left ventricular (LV) mass and LV mass index, and serum PIIIP concentration were also increased in hypertensives, with significant differences between the two hypertensive groups. The ratio between maximal early and late transmitral flow velocity measured during diastole was lower in hypertensives, particularly those with LVH, than in normotensive controls.

CONCLUSIONS

The increase in PIIIP indicates that type III collagen synthesis increases in hypertensives, particularly those with LVH, implying that alterations in the heart in hypertension are the result not solely of hypertrophied LV muscle, but also of increased collagen deposition within the ventricular wall and around the coronary vessels. Thus, measurement of serum PIIIP could be a practical and useful tool in the non-invasive assessment of myocardial remodeling in hypertension.

Influence of serum adiponectin level and SNP +45 polymorphism of adiponectin gene on myocardial fibrosis

Adiponectin plays an important role in the development of hypertension, atherosclerosis, and cardiomyocyte hypertrophy, but very little was known about the influence of serum adiponectin or the adiponectin gene polymorphism on myocardial fibrosis. Our study investigates the influence of the SNP +45 polymorphism of the adiponectin gene and serum levels of adiponectin on myocardial fibrosis in patients with essential hypertension. A case-control study was conducted on 165 hypertensive patients and 126 normotensive healthy controls. The genotypes of adiponectin gene polymorphisms were detected by the polymerase chain reaction (PCR) method. Serum concentrations of procollagen were measured by a double antibody sandwich enzyme-linked immunosorbent assay (ELISA) in all subjects. The integrated backscatter score (IBS) was measured in the left ventricular myocardium using echocardiography. The serum levels of adiponectin in hypertensive patients were significantly lower than those in the normal control group ((2.69±1.0) μg/ml vs. (4.21±2.89) μg/ml, respectively, P<0.001). The serum levels of type-I procollagen carboxyl end peptide (PICP) and type-III procollagen ammonia cardinal extremity peptide (PIIINP) in the hypertension group were significantly higher than those in the control group. In the hypertension group, serum levels of adiponectin were significantly and negatively related to the average acoustic intensity and corrected acoustic intensity of the myocardium (r=0.46 and 0.61, respectively, P<0.05 for both). The serum levels of PICP and PIIINP were significantly different among the three genotypes of SNP +45 (P<0.01). Logistic regression analyses showed that sex and genotype (GG+GT) were the major risk factors of myocardial fibrosis in hypertensive patients (OR=5.343 and 3.278, respectively, P<0.05). These data suggest that lower levels of adiponectin and SNP +45 polymorphism of the adiponectin gene are likely to play an important role in myocardial fibrosis in hypertensive patients.

Rationale and design of a randomized trial on the impact of aldosterone antagonism on cardiac structure and function in diabetic cardiomyopathy

Development of a cardiomyopathy in diabetes mellitus is independent of traditional risk factors, with no clinical trials targeting specific therapeutic interventions. Myocardial fibrosis is one of the key mechanisms and aldosterone is a key mediator of myocardial fibrosis. We propose that aldosterone antagonism will improve cardiac function. We aim to evaluate the efficacy of selective aldosterone receptor antagonism with eplerenone added to optimal medical treatment in improving cardiac structure and function in diabetic cardiomyopathy. We will randomize 130 patients with type 2 diabetes mellitus, stable metabolic control and impaired left ventricular (LV) systolic or diastolic function, to either eplerenone (target dose 50mg) or matching placebo, in addition to optimal medical therapy for 12 months. The primary endpoints are changes in LV systolic and diastolic function, measured by echocardiographic 2-dimensional speckle tracking strain and strain rate and tissue Doppler imaging. The secondary endpoints include changes in echocardiographic markers and plasma biomarkers of collagen turnover; left atrial dimensions and function, incidence of atrial fibrillation and changes in exercise capacity and dyspnea score. The present study will assess whether specific aldosterone antagonism with eplerenone in addition to standard therapy will prevent progression or reverse cardiac dysfunction in diabetic cardiomyopathy using sensitive, robust and quantifiable echocardiographic measures that allow early detection of change. The study may offer a new direction in the management of this condition.

WITHDRAWN: Association between the levels of carboxy-terminal propeptide of type I procollagen and aldosterone in patients with primary aldosteronism and essential hypertension

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Adrenalectomy reverses myocardial fibrosis in patients with primary aldosteronism

OBJECTIVE

Primary aldosteronism is the most frequent cause of secondary hypertension and is associated with more prominent left ventricular hypertrophy and increased myocardial fibrosis. However, the reversibility of cardiac fibrosis is still unclear. Our objective was to investigate myocardial fibrosis in primary aldosteronism patients and its change after surgery.

METHOD

We prospectively analyzed 20 patients with aldosterone-producing adenoma (APA) who received adrenalectomy from December 2006 to October 2008 and 20 patients with essential hypertension were enrolled as the control group. Plasma carboxy-terminal propeptide of procollagen type I (PICP) determination and echocardiography including ultrasonic tissue characterization by cyclic variation of integrated backscatter (CVIBS) were performed in both groups and 1 year after operation in the APA group.

RESULTS

APA patients had significantly higher SBP and DBP, higher plasma aldosterone concentration (PAC), higher aldosterone-renin ratio (ARR), lower serum potassium levels, and lower plasma renin activity (PRA) than patients with essential hypertension. In echocardiography, APA patients had a higher left ventricular mass index than essential hypertension patients. APA patients had significantly lower CVIBS (6.2 ± 1.5 vs. 8.7 ± 2.0 dB, P < 0.001) and higher plasma PICP levels (107 ± 27 vs. 85 ± 24 μg/l, P = 0.009) than essential hypertension patients. In the correlation study, CVIBS is correlated with log-transformed PRA and log-transformed ARR and PICP is correlated with log-transformed PRA, log-transformed PAC, and log-transformed ARR. One year after adrenalectomy, CVIBS increased significantly (6.2 ± 1.5 to 7.3 ± 1.7 dB, P = 0.033) and plasma PICP levels decreased (107 ± 27 vs. 84 ± 28 μg/l, P = 0.026).

CONCLUSION

Increases in collagen content in the myocardium of APA patients may be reversed by adrenalectomy.

[Effects of Chinese herbal medicine Xuefu Zhuyu Decoction on angiotensin II-induced proliferation and extracellular matrix synthesis of rat cardiac fibroblasts]

OBJECTIVE

To investigate the effects of Xuefu Zhuyu Decoction, a compound Chinese herbal medicine, on the proliferation and extracellular matrix synthesis of cardiac fibroblasts (CFs) from neonatal rats induced by angiotensin II, and to explore the mechanism of Xuefu Zhuyu Decoction in improving myocardial fibrosis.

METHODS

CFs derived from neonatal rats were cultured with enzymatic dissociation to establish a cell model of cardiac fibrosis induced by angiotensin II in vitro. CFs were divided into 6 groups, including blank control group, angiotensin II group, valsartan-medicated serum group, and 5%, 10% and 15% Xuefu Zhuyu decoction-medicated serum group. CFs in the blank control group were incubated with normal rat serum; CFs in the other groups were stimulated with angiotensin II at a dose of 10-6 mol/L, and then incubated with normal rat serum and 5%, 10% and 15% Xuefu Zhuyu decoction-medicated serum for 24 h, respectively. Methyl thiazolyl tetrazolium assay was employed to measure CF proliferation, and collagen synthesis was detected by analysis of the hydroxyproline in CFs. Radioimmunoassay was used to measure concentrations of procollagen III and hyaluronic acid. Enzyme-linked immunosorbent assay was used to measure fibronectin expression.

RESULTS

Compared with the blank control group, angiotensin II induced cardiac fibroblast proliferation, stimulated DNA and collagen syntheses (P<0.01), and increased fibronectin, hyaluronic acid and procollagen III concentrations (P<0.01). Xuefu Zhuyu decoction-medicated serum inhibited CF proliferation and DNA and collagen syntheses (P<0.05), and decreased the concentrations of fibroectin, hyaluronic acid and procollagen III (P<0.01).

CONCLUSION

Angiotensin II can induce cardiac fibrosis, stimulate cardiac fibroblast proliferation and extracellular matrix synthesis, while Xuefu Zhuyu Decoction can prevent cardiac fibrosis, the mechanism of which may be related to inhibiting CF proliferation and extracellular matrix synthesis.

Diagnosis and treatment of myocardial fibrosis in hypertensive heart disease

Although hypertensive heart disease (HHD) is clinically characterized by development of left ventricular hypertrophy in the absence of a cause other than arterial hypertension, changes in the composition of myocardial tissue also develop in arterial hypertension, leading to structural remodeling of the myocardium (eg, fibrosis). Myocardial fibrosis is the major determinant of diastolic dysfunction/failure in patients with HHD. Recent available data on the determination of serum concentrations of collagen-derived serum peptides, as well as quantitative analysis of echoreflectivity to address the presence of fibrosis in the myocardium of hypertensive patients, are promising. In addition, preliminary data suggest that the goal of reducing myocardial fibrosis is achievable using specific pharmacological agents in patients with HHD.

Clinical and echocardiographic correlates of plasma procollagen type III amino-terminal peptide levels in the community

BACKGROUND

Left ventricular remodeling is characterized by increased collagen deposition in the extracellular matrix. Levels of plasma procollagen type III amino-terminal peptide (PIIINP), a marker of collagen turnover, are elevated in the setting of recent myocardial infarction, heart failure, and cardiomyopathy. Whether plasma PIIINP levels are a useful indicator of subclinical left ventricular abnormalities in ambulatory individuals has not been studied.

METHODS

We examined 967 Framingham Heart Study participants (mean age, 56 years; 60% women) who underwent routine echocardiography and measurement of plasma PIIINP levels. All participants were free of prior myocardial infarction or heart failure. Multivariable regression analyses were performed to examine the clinical and echocardiographic correlates of PIIINP levels.

RESULTS

Plasma PIIINP levels increased with age and body mass index but did not significantly correlate with other cardiovascular risk factors including hypertension and diabetes. In multivariable models, there was no association between plasma PIIINP levels and left ventricular mass (P = .89), left ventricular fractional shortening (P = .15), left ventricular end-diastolic dimension (P = .51), or left atrial size (P = .68). Plasma PIIINP levels were positively correlated with tissue inhibitor of metalloproteinase-1 levels (multivariable-adjusted, P = .001).

CONCLUSIONS

The use of biomarkers of extracellular matrix turnover has generated recent interest, with plasma PIIINP being the most commonly studied biomarker in acute settings. However, our findings in a large, community-based cohort suggest that plasma PIIINP has limited use for the detection of structural heart disease in ambulatory individuals.

Association of amino-terminal propeptide of type III procollagen and acute myocardial rejection in male patients receiving heart transplantation

BACKGROUND

The amino-terminal propeptides of type I and III procollagens (PINP and PIIINP) are markers reflecting the status of collagen turnover. We hypothesized that measurement of these serum procollagen propeptides could be used to non-invasively assess acute rejection in heart transplant recipients.

METHODS

In heart transplant recipients, endomyocardial biopsy specimens taken at 6 and 12 months after surgery were used for study. PINP and PIIINP were measured postoperatively at 3, 6, and 12 months.

RESULTS

A total of 20 male heart transplant patients and seven male control subjects were enrolled. Five patients showed rejection 6 months after transplantation (group 1), while 15 patients showed no rejection (group 2). In group 2 patients, serum PINP and PIIINP levels decreased significantly 6 months after transplantation. In contrast, elevation of serum PINP and PIIINP levels persisted in group 1 patients 6 months after transplantation. At 6 months after transplantation, group 1 patients had significantly higher PIIINP levels than group 2 patients (p=0.025) and controls (p=0.003). After immunosuppressive therapy, all group 1 patients were free of rejection 12 months after transplantation and serial serum PIIINP levels decreased significantly in these patients.

CONCLUSIONS

Serum PIIINP levels represent a non-invasive method to reflect the occurrence and resolution of acute rejection.

Relationship between myocardial ultrasonic integrated backscatter and mitochondria of the myocardium in dogs

OBJECTIVE

This study aimed to explore the relationship between integrated backscatter (IBS) and mitochondria in arrested myocardium.

METHODS

Twelve open-chest dogs were randomly divided into two groups: one group with cardiac arrest in systole and the other with cardiac arrest in diastole. IBS images at parasternal papillary muscle short-axis view were stored at different time frames (0, 30, and 60 min after cardiac arrest). The values of ultrasonic IBS were obtained using the acoustic densitometry technique. After ultrasound examination, tissue samples of corresponding times were harvested and observed under the transmission electron microscope. The microscopic images were analyzed using a computer imaging analysis system to obtain the stereological parameters of mitochondria. The correlation between IBS and the stereological parameters was analyzed.

RESULTS

After cardiac arrest, swollen mitochondria with electron-lucent matrix could be observed in some myofibers following the progression of time. The alteration of IBS correlated well with that of mitochondrial stereological parameters, such as volume density (Vv), surface density (Sv), average volume (v), average surface area (s), and specific surface (Rsv, ratio between surface and volume).

CONCLUSION

Mitochondria might be an important scatterer in the myocardium for IBS.

The relation of amino-terminal propeptide of type III procollagen and severity of coronary artery disease in patients without myocardial infarction or hibernation

OBJECTIVES

The association of cardiac fibrosis and coronary artery disease (CAD) in patients without infarction or hibernation is unclear. We investigated the relationship between serum concentrations of procollagen propeptides and severity of CAD in such patients.

DESIGN AND METHODS

Forty-six patients (32 men; mean age 64 years) with chest pain were enrolled. All patients received stress thallium-201 single photon emission computed tomography (SPECT) and analysis of the serum levels of the amino-terminal propeptide of type I and III procollagen (PINP and PIIINP).

RESULTS

In patients with thallium-201 perfusion defects, the number of diseased vessels was associated significantly with PIIINP (p=0.024) rather than PINP (p=0.613). Follow-up serum PINP and PIIINP levels after coronary intervention (mean 84 days) revealed no significant decrease.

CONCLUSIONS

Serum PIIINP level is significantly associated with the severity of CAD in patients without myocardial infarction or hibernation.

New directions in the assessment and treatment of hypertensive heart disease

PURPOSE OF REVIEW

This article will review briefly the emerging new concepts in the diagnosis and treatment of myocardial fibrosis in patients with hypertensive heart disease.

RECENT FINDINGS

Although hypertensive heart disease is characterized clinically by development of left-ventricular hypertrophy in the absence of a cause other than arterial hypertension, changes in the composition of myocardial tissue also develop in arterial hypertension leading to structural remodeling of the myocardium (e.g. fibrosis). Recent available data on the determination of serum concentrations of collagen-derived serum peptides and quantitative analysis of echoreflectivity to address the presence of fibrosis in the myocardium of hypertensive patients are promising. In addition, preliminary data suggest that the goal of reducing myocardial fibrosis is achievable in patients with hypertensive heart disease using specific antihypertensive agents (e.g. those interfering with angiotensin II).

SUMMARY

The time has come to revisit the current management of hypertensive heart disease simply focused on detecting left-ventricular hypertrophy and controlling blood pressure to reduce left-ventricular mass. It is necessary to develop new approaches aimed at assessing and repairing alterations of myocardial structure and protect myocardial function and, in so doing, to reduce in a more-effective manner adverse risk associated with hypertensive heart disease.

The use of collagen-derived serum peptides for the clinical assessment of hypertensive heart disease

Given the importance of fibrous tissue in leading to myocardial dysfunction and failure in hypertensive heart disease, non-invasive assessment of fibrosis could prove a clinically useful tool in hypertensive patients, particularly given the potential for cardioprotective and cardioreparative pharmacological strategies. In this regard, an emerging experimental and clinical experience holds promise for the assessment of various serum peptides arising from the metabolism of collagen types I and III in arterial hypertension. More specifically, the measurement of serum concentrations of procollagen type I carboxy-terminal propeptide (a peptide that is cleaved from procollagen type I during the synthesis of fibril-forming collagen type I) may provide indirect diagnostic information on both the extent of myocardial fibrosis and the ability of antihypertensive treatment to diminish collagen type I synthesis and reduce myocardial fibrosis in hypertensive patients. The available data set the stage for large and long-term trials to definitively validate this approach.