Agnese Ricotta

Plasma osteopontin reveals left ventricular reverse remodelling following cardiac resynchronization therapy in heart failure

BACKGROUND Cardiac resynchronization therapy (CRT) promotes left ventricular (LV) reverse remodelling and affects myocardial collagen turnover in heart failure (HF) patients. Osteopontin (OPN) is a matrix glycoprotein required for the activation of fibroblasts upon TGF-β1 stimulation. In humans, plasma OPN and OPN-expressing lymphocytes correlate with the severity of HF. We sought to evaluate whether plasma OPN and TGF-β1 reflect LV reverse remodelling following CRT. METHODS Eighteen patients (12 men, mean age 65 ± 11 years) undergoing CRT were studied. Patients underwent baseline clinical and echocardiographic evaluation, and assessment of plasma OPN and TGF-β1. The evaluation was repeated 8.5 ± 4 months after device implantation. Eight healthy age- and sex-matched subjects served as controls. RESULTS In HF patients, baseline plasma OPN and TGF-β1 were higher as compared to control subjects (OPN: 99 ± 48 vs 59 ± 22 ng/ml; p<0.05; TGF-β1: 15.9 ± 8.0 vs 9.3 ± 5.6 ng/ml; p<0.05). At follow-up, 12 patients responded to CRT and showed LV reverse remodelling, whereas 6 did not. Plasma OPN decreased in CRT responders (108 ± 47 vs 84 ± 37 ng/ml; p=0.03) and increased in non-responders (79 ± 58 vs 115 ± 63 ng/ml; p<0.01). TGF-β1 showed a trend towards reduction in responders (17.5 ± 8.7 vs 10.2 ± 8.9 ng/ml; p=0.08) and was unchanged in non-responders. A significant correlation (r=-0.56; p=0.01) was found between relative changes of LVESV and plasma OPN. CONCLUSIONS CRT-induced LV reverse remodelling is reflected by changes in plasma OPN. Circulating OPN may represent a marker of LV dilation/impairment and an indicator of the response to HF therapies promoting LV reverse remodelling.

Spatial QT Dispersion Predicts Nonsustained Ventricular Tachycardia and Correlates with Confined Systodiastolic Dysfunction in Hypertrophic Cardiomyopathy.

Objectives: An increased dispersion of myocardial repolarization represents one of the mechanisms underlying the arrhythmic risk in hypertrophic cardiomyopathy (HCM). We investigated spatial myocardial repolarization dispersion indices in HCM patients with nonsustained ventricular tachycardia (NSVT) and, contextually, their main clinical determinants. Methods: Fifty-two well-matched HCM outpatients were categorized into two groups according to the presence or the absence of NSVT at 24-hour Holter electrocardiogram (ECG) monitoring. Each patient underwent a clinical examination, including Doppler echocardiogram integrated with tissue Doppler imaging, cardiac magnetic resonance, and 12-lead surface ECG to calculate the dispersion for the following intervals: QRS, Q-Tend (QTe), Q-Tpeak, Tpeak-Tend (TpTe), J-Tpeak, and J-Tend. Results: The NSVT group showed only QTe dispersion and TpTe dispersion values to be significantly higher than their counterparts. NSVT occurrence was independently predicted by late gadolinium enhancement presence (p = 0.021) and QTe Bazett dispersion (p = 0.030), the latter strongly associated with the myocardial performance index (MPI) obtained at the basal segment of the interventricular septum (p = 0.0004). Conclusion: Our data support QTe dispersion as an easy and noninvasive tool for identifying HCM patients with NSVT propensity. The strong relationship between QTe dispersion and MPI allows us to hypothesize an intriguing link between electrical instability and confined myocardial areas of systodiastolic dysfunction.

NT-proAtrial Natriuretic Peptide as a possible biomarker of cardiopulmonary involvement in sarcoidosis

BACKGROUND Lung diffusion for carbon monoxide (DLCO) has been shown to associate with the risk of pulmonary arterial hypertension development and, most likely, with right ventricular (RV) myocardial dysfunction in sarcoidosis patients. Besides its known role as a marker of left ventricular dysfunction, experimental evidence suggests a role of NT-proAtrial Natriuretic Peptide (NT-proANP) also in modulating pulmonary circulation. We therefore investigated possible relationships between NT-proANP, lung diffusion impairment and RV dysfunction. METHODS Thirty-two pulmonary sarcoidosis outpatients and eighteen volunteers underwent full clinical assessment, including full lung function tests and Doppler echocardiography integrated with tissue Doppler imaging (TDI) study. Resting circulating NT-proBNP and NT-proANP plasma levels were also determined. RESULTS NT-proANP and RV-myocardial performance index (RV-MPI) were significantly higher in those patients with the greatest DLCO impairment, whereas no differences were found for NT-proBNP values. At multivariable analysis, only DLCO (β: -0.496; standard error: 3.38; p=0.000) and RV-MPI (β: 0.373; standard error: 6.56; p=0.031) remained significantly associated with NT-proANP levels. CONCLUSIONS Our finding may support a key role of NT-proANP in the complex mechanisms underlying modulation of lung function. An early increase in pulmonary vascular resistance may stimulate NT-proANP increase, thus explaining its association with signs of early RV myocardial dysfunction. This hypothesis warrants further confirmation.

Atrial Natriuretic Peptide Single Nucleotide Polymorphisms in Patients with Nonfamilial Structural Atrial Fibrillation

Background Atrial natriuretic peptide (ANP) has antihypertrophic and antifibrotic properties that are relevant to AF substrates. The -G664C and rs5065 ANP single nucleotide polymorphisms (SNP) have been described in association with clinical phenotypes, including hypertension and left ventricular hypertrophy. A recent study assessed the association of early AF and rs5065 SNPs in low-risk subjects. In a Caucasian population with moderate-to-high cardiovascular risk profile and structural AF, we conducted a case-control study to assess whether the ANP -G664C and rs5065 SNP associate with nonfamilial structural AF. Methods 168 patients with nonfamilial structural AF and 168 age- and sex-matched controls were recruited. The rs5065 and -G664C ANP SNPs were genotyped. Results The study population had a moderate-to-high cardiovascular risk profile with 86% having hypertension, 23% diabetes, 26% previous myocardial infarction, and 23% left ventricular systolic dysfunction. Patients with AF had greater left atrial diameter (44 ± 7 vs. 39 ± 5 mm; P < 0.001) and higher plasma NTproANP levels (6240 ± 5317 vs. 3649 ± 2946 pmol/mL; P < 0.01). Odds ratios (ORs) for rs5065 and -G664C gene variants were 1.1 (95% confidence interval [CI], 0.7-1.8; P = 0.71) and 1.2 (95% CI, 0.3-3.2; P = 0.79), respectively, indicating no association with AF. There were no differences in baseline clinical characteristics among carriers and noncarriers of the −664C and rs5065 minor allele variants. Conclusions We report lack of association between the rs5065 and -G664C ANP gene SNPs and AF in a Caucasian population of patients with structural AF. Further studies will clarify whether these or other ANP gene variants affect the risk of different subpheno-types of AF driven by distinct pathophysiological mechanisms.

Angiotensin Receptor Antagonists to Prevent Sudden Death in Heart Failure: Does the Dose Matter?

International guidelines recommend ICD implantation in patients with severe left ventricular dysfunction of any origin only after careful optimization of medical therapy. Indeed, major randomized clinical trials suggest that suboptimal use of fundamental drugs, such as ACE inhibitors (ACE-i) and beta-blockers, may affect ICD shock-free survival, sudden cardiac death (SCD), and overall mortality. While solid evidence in favour of pharmacological therapy based on ACE-i with or without beta-blockers is available, data on SCD in HF patients treated with angiotensin receptor blockers (ARBs) are limited. The present paper systematically analyses the impact of ARBs on SCD in HF and reviews the contributory role of the renin-angiotensin system (RAS) to the establishment of arrhythmic substrates. The following hypothesis is supported: (1) the RAS is a critical component of the electrical remodelling of the failing myocardium, (2) RAS blockade reduces the risk of SCD, and (3) ARBs represent a powerful tool to improve overall survival and possibly reduce the risk of SCD provided that high doses are employed to achieve optimal AT1-receptor blockade.

Low-dose angiotensin receptor blockers as an alternative to ACE-inhibitors increase the risk of appropriate ICD interventions in heart failure

doi:10.1016/j.ijcard.2010.04.057 established that right ventricle provides powerful influential signals to the prognosis of the patients with systolic heart failure[3]. However, in the study by Monteiro et al., no information was provided concerning right heart chambers, failure of which is thought to be quite common in patients with advanced heart failure. Furthermore, it was previously shown that right ventricle could be the source of higher natriuretic peptides [4], as it was shown in the table of the current paper that higher CA-125 levels were associated with higher natriuretic peptides. Unfortunately, no information was present concerning pericardial effusion, where similar cellular source might be secreting the substance, either in the paper. We think right heart should not be omitted in this scenario, though, CA-125 was simply stratifying the risk. Because, there may be further risk categories. Since, mesothelial cells are thought to be the major source of CA-125 levels, it is not surprising to observe that failure of right heart could bring about increased serum levels up on further hemodynamic load on splanchnic bed, where there is abundance of these cells. The authors of this manuscript have certified that they comply with the Principles of Ethical Publishing in the International Journal of Cardiology [5].

Extracellular matrix remodelling in myocardial hypertrophy and failure: focus on osteopontin

Cardiac remodelling refers to molecular and cellular changes of the myocardium, as well as adapting alterations in size, shape and function of the heart in response to changing loading conditions. It represents the final common pathway of different heart diseases, and is recognized as a crucial aspect of cardiac and myocardial dysfunction and a well established determinant of the clinical course of heart failure.Osteopontin is an extracellular matrix glycoprotein secreted by osteoblasts, osteoclasts, macrophages, T cells, vascular smooth muscle cells, fibroblasts and cardiomyocytes. Osteopontin is not expressed in healthy cardiac tissue, although its expression can be triggered by pressure or volume overload, hypoxia and angiotensin II. Indeed, osteopontin has been reported in macrophages and interstitial tissues early after myocardial infarction and in cardiac macrophage-like cells of inflammatory lesions in experimental models of cardiomyopathy. Pressure overload is associated with osteopontin overexpression as well. Indeed, myocardial osteopontin messenger RNA is upregulated in rats following renovascular hypertension or aortic banding. In humans, a significant correlation exists between increased osteopontin immunoreactivity in cardiac myocytes and impaired left ventricular function or cardiomyocyte hypertrophy in patients with dilated cardiomyopathy.The present article focuses on the role of osteopontin in myocardial hypertrophy and remodelling. In general, evidence supports the concept that osteopontin plays a crucial role in extracellular matrix remodelling following myocardial adaptation to hypertrophic, inflammatory and neurohormonal stimuli in the overloaded heart.

QT spatial dispersion and sudden cardiac death in hypertrophic cardiomyopathy: Time for reappraisal

BACKGROUND The 12-lead surface electrocardiographic (ECG) analysis is able to provide independent predictors of prognosis in several cardiovascular settings, including hypertrophic cardiomyopathy (HCM). The present single-center study investigated the possible ability of several ECG-derived variables in stratifying sudden cardiac death (SCD) risk and, possibly, in improving the accuracy of the 2014 European Society of Cardiology guidelines. METHODS A total of 221 consecutive HCM outpatients were recruited and prospectively followed. All of them underwent a full clinical and instrumental examination, including a 12-lead surface ECG to calculate the dispersion for the following intervals: QRS, Q-Tend (QT), Q-Tpeak (QTp), Tpeak-Tend (TpTe), J-Tpeak (JTp), and J-Tend (JT). The study composite end-point was SCD, aborted SCD, and appropriate implantable cardioverter defibrillator (ICD) interventions. RESULTS During a median follow-up of 4.4 years (25th-75th interquartile range: 2.4-9.4 years), 23 patients reached the end-point at 5-years (3 SCD, 3 aborted SCD, 17 appropriate ICD interventions). At multivariate analysis, the spatial QT dispersion corrected according to Bazetts formula (QTcd) remains independently associated to the study endpoint over the HCM Risk-SCD score (C-index 0.737). A QTcd cut-off value of 93ms showed the best accuracy in predicting the SCD endpoint within the entire HCM study cohort (sensitivity 56%, specificity 75%, positive predictive value 22%, negative predictive value 97%). CONCLUSION Our data suggest that the QTcd might be helpful in SCD risk stratification, particularly in those HCM categories classified at low-intermediate SCD risk according to the contemporary guidelines.

Vascular Senescence at the Crossroad between Oxidative Stress and Nitric Oxide Pathways

Mitochondria play a critical role in maintaining the bioenergetic status of cells under physiological conditions. However, reduction of oxygen to generate free radicals occurs at various sites in the mitochondrial respiratory chain, affecting the availability of key regulators of vascular homeostasis. Indeed, several studies suggest that mitochondrial-derived reactive oxygen species (ROS) are involved in endothelial dysfunction, which triggers the development and progression of atherosclerosis in aging individuals and animal models. Among the potential mechanisms underlying age-related impairment of endothelial function, reduction of nitric oxide (NO) bioavailability due to its reaction with oxygen-derived free radicals plays a pivotal role.The present article focuses on the pathophysiology of vascular senescence and explores the interactions of ROS and NO pathways relevant to cardiovascular aging.