Klara Komici

β-adrenergic receptor responsiveness in aging heart and clinical implications.

Elderly healthy individuals have a reduced exercise tolerance and a decreased left ventricle inotropic reserve related to increased vascular afterload, arterial-ventricular load mismatching, physical deconditioning and impaired autonomic regulation (the so called “β-adrenergic desensitization”). Adrenergic responsiveness is altered with aging and the age-related changes are limited to the β-adrenergic receptor density reduction and to the β-adrenoceptor-G-protein(s)-adenylyl cyclase system abnormalities, while the type and level of abnormalities change with species and tissues. Epidemiological studies have shown an high incidence and prevalence of heart failure in the elderly and a great body of evidence correlate the changes of β-adrenergic system with heart failure pathogenesis. In particular it is well known that: (a) levels of cathecolamines are directly correlated with mortality and functional status in heart failure, (b) β1-adrenergic receptor subtype is down-regulated in heart failure, (c) heart failure-dependent cardiac adrenergic responsiveness reduction is related to changes in G proteins activity. In this review we focus on the cardiovascular β-adrenergic changes involvement in the aging process and on similarities and differences between aging heart and heart failure.

Oral Anticoagulation Therapy in Heart Failure Patients in Sinus Rhythm: A Systematic Review and Meta-Analysis

Background Heart failure (HF) patients show high morbidity and mortality rate with increased risk of malignant arrhythmia and thromboembolism. Anticoagulation reduces embolic event and death rates in HF patients with atrial fibrillation, but if antithrombotic therapy is beneficial in patients with HF in sinus rhythm is still debated. Methodology and Principal Findings We conducted a systematic review of prospective, randomized controlled trials (RCTs) to assess the efficacy and safety of oral anticoagulant therapies (OATs) compared to antiplatelet treatment in HF patients in sinus rhythm. MEDLINE, Web of Science, CENTRAL and Scopus databases were searched up to May 2012. Four RCTs were identified and a total of 3663 patients were included in the meta-analysis. Patients with both ischemic and non-ischemic HF were included. There was no significant difference in mortality (odds ratio (OR) 1.01, 95% confidence interval (CI) 0.86 to 1.19) between OATs group and antiplatelet drug group. OATs have reduced ischemic stroke risk (OR 0.49, 95% CI 0.32 to 0.74), but have increased major bleeding risk (OR 2.01, 95% CI 1.40 to 2.88) compared to antiplatelet treatment. Conclusion In HF patients in sinus rhythm OATs do not show a better risk-benefit profile compared to antiplatelet treatment in cardioembolism prevention. Warfarin and aspirin seem to be similar in reducing mortality. Warfarin reduces the incidence of ischemic stroke, but increases major bleedings. Thus, it is possible to speculate that aspirin prescription be indicated in patients with high risk of bleeding, whereas warfarin could be preferred in patients with high thromboembolic risk.

Autonomic dysfunction in Alzheimer's disease: tools for assessment and review of the literature.

Autonomic dysfunction is very common in patients with dementia, and its presence might also help in differential diagnosis among dementia subtypes. Various central nervous system structures affected in Alzheimers disease are also implicated in autonomic nervous system regulation, and it has been hypothesized that the deficit in central cholinergic function observed in Alzheimers disease could likely lead to autonomic dysfunction. Several feasible tests can be used in clinical practice for the assessment of parasympathetic and sympathetic functions, especially in terms of cardiovascular autonomic modulation. In this review, we describe the different tests available and the evidence from the literature which indicate a definite presence of autonomic dysfunction in dementia at various degrees. Importantly, the recognition of dysautonomia, besides possibly being an early marker of dementia, would help prevent the disabling complications which increase the risk of morbidity, institutionalization, and mortality in these individuals.

Vascular Endothelial Growth Factor Blockade Prevents the Beneficial Effects of β-Blocker Therapy on Cardiac Function, Angiogenesis, and Remodeling in Heart Failure

Background—Impaired angiogenesis in the post-myocardial infarction heart contributes to the progression to heart failure. The inhibition of vascular endothelial growth factor (VEGF) signaling has been shown to be crucial for the transition from compensatory hypertrophy to cardiac failure. Importantly, &bgr;-adrenergic receptor blocker therapy has been also shown to improve myocardial perfusion by enhancing neoangiogenesis in the failing heart. Methods and Results—Eight weeks from surgically induced myocardial infarction, heart failure rats were randomized to receive bisoprolol (B) or vehicle. At the end of a 10-week treatment period, echocardiography revealed reduced cardiac diameters and improved cardiac function in B-treated compared with vehicle-treated rats. Moreover, B treatment was associated with increased cardiac angiogenesis and in vivo coronary perfusion and reduced cardiac fibrosis. Importantly, 2 weeks after B treatment was started, increased cardiac VEGF expression and Akt and endothelial NO synthase activation were observed by comparing B-treated with drug-untreated failing hearts. To test whether the proangiogenic effects of B act via activation of VEGF pathway, rats were intravenously injected with adenoviral vector encoding a decoy VEGF receptor (Ad-Flk) or a control adenovirus (Ad-C), at the start of the treatment with B. After 10 weeks, histological analysis revealed reduced capillary and coronary perfusion in B-treated plus Ad-Flk rats compared with B-treated plus Ad-C rats. Moreover, VEGF inhibition counteracted the positive effects of B on cardiac function and remodeling. Conclusions—&bgr;-Blockade promotes cardiac angiogenesis in heart failure via activation of VEGF signaling pathway. &bgr;-Blocker–induced enhancement of cardiac angiogenesis is essential for the favorable effects of this therapy on cardiac function and remodeling.

β-adrenergic receptors and g protein-coupled receptor Kinase-2 in Alzheimer's disease: A new paradigm for prognosis and therapy?

Alzheimers disease (AD) is a devastating form of dementia that imposes a severe burden on health systems and society. Although several aspects of AD pathogenesis have been elucidated over the last few decades, many questions still need to be addressed. In fact, currently available medications only provide symptomatic improvement in patients with AD without affecting disease progression. The β-adrenergic receptor (β-AR) system can be considered a possible target that deserves further exploration in AD. The central noradrenergic system undergoes substantial changes in the course of AD and β-ARs have been implicated not only in amyloid formation in AD brain but also in amyloid-induced neurotoxicity. Moreover, clinical evidence suggests a protective role of β-AR blockers on AD onset. In addition to that, post-receptor components of β-AR signaling seem to have a role in AD pathogenesis. In particular, the G protein coupled receptor kinase 2, responsible for β-AR desensitization and downregulation, mediates amyloid-induced β-AR dysfunction in neurons, and its levels in circulating lymphocytes of AD patients are increased and inversely correlated with patients cognitive status. Therefore, there is an urgent need to gain further insight on the role of the adrenergic system components in AD pathogenesis in order to translate preclinical and clinical knowledge to more efficacious prognostic and therapeutic strategies.

Impact of diabetes mellitus on lymphocyte GRK2 protein levels in patients with heart failure

Diabetes mellitus (DM) is associated with impaired prognosis in patients with heart failure (HF), but pathogenic mechanisms are unclear. In the failing heart, elevated β‐adrenergic receptor (β‐AR) activation by catecholamines causes G‐protein‐coupled receptor kinase‐2 (GRK2) upregulation which is responsible for β‐AR signalling dysfunction. Importantly, GRK2 expression, measured in peripheral lymphocytes of HF patients, correlates with levels of this kinase in the failing myocardium reflecting the loss of hemodynamic function. Moreover, HF‐related GRK2 protein overexpression promotes insulin resistance by interfering with insulin signalling. The aim of this study was to assess lymphocyte GRK2 protein levels in HF patients with and without DM.

Prognostic Value of Lymphocyte G Protein-Coupled Receptor Kinase-2 Protein Levels in Patients With Heart Failure.

RATIONALE Sympathetic nervous system hyperactivity is associated with poor prognosis in patients with heart failure (HF), yet routine assessment of sympathetic nervous system activation is not recommended for clinical practice. Myocardial G protein-coupled receptor kinase-2 (GRK2) is upregulated in HF patients, causing dysfunctional β-adrenergic receptor signaling. Importantly, myocardial GRK2 levels correlate with levels found in peripheral lymphocytes of HF patients. OBJECTIVE The independent prognostic value of blood GRK2 measurements in HF patients has never been investigated; thus, the purpose of this study was to evaluate whether lymphocyte GRK2 levels predict clinical outcome in HF patients. METHODS AND RESULTS We prospectively studied 257 HF patients with mean left ventricular ejection fraction of 31.4±8.5%. At the time of enrollment, plasma norepinephrine, serum NT-proBNP, and lymphocyte GRK2 levels, as well as clinical and instrumental variables were measured. The prognostic value of GRK2 to predict cardiovascular (CV) death and all-cause mortality was assessed using the Cox proportional hazard model including demographic, clinical, instrumental, and laboratory data. Over a mean follow-up period of 37.5±20.2 months (range, 3-60 months), there were 102 CV deaths. Age, left ventricular ejection fraction, New York Heart Association class, chronic obstructive pulmonary disease, chronic kidney disease, N-terminal-pro brain natriuretic peptide, and lymphocyte GRK2 protein levels were independent predictors of CV mortality in HF patients. GRK2 levels showed an additional prognostic and clinical value over demographic and clinical variables. The independent prognostic value of lymphocyte GRK2 levels was also confirmed for all-cause mortality. CONCLUSIONS Lymphocyte GRK2 protein levels can independently predict prognosis in patients with HF.

Changes of plasma norepinephrine and serum N-terminal pro-brain natriuretic peptide after exercise training predict survival in patients with heart failure

BACKGROUND Short-term changes of neurohormones can give important prognostic information in heart failure (HF) patients. In this study, we evaluate whether changes in plasma Norepinephrine (NE) and serum N-terminal pro-brain natriuretic peptide (NT-proBNP) after exercise training predict cardiac mortality in HF patients. METHODS AND RESULTS We enrolled 221 HF patients (mean age 72.5 ± 10.2 year) followed-up for a mean period of 27.64 ± 10.7 months. All pts underwent a 3-month exercise training. Before training, clinical examination, echocardiography, peak VO2 determination, and blood draw for NT-proBNP and NE measurements were performed. Primary end-point was cardiac related mortality. Eighty-six-nine percent of patients were in NYHA class III, mean left ventricular ejection fraction (LVEF) was 32.5 ± 10.4%, and mean peak VO2 was 12.36 ± 1.45 ml/kg/min. At baseline, mean NT-proBNP was 2111.4 ± 1145.6 pg/ml and mean NE was 641.8 ± 215.3 pg/ml. One hundred-one subjects died for cardiac causes. Training was associated with a significant increase of peak VO2 and LVEF, whereas NE, NT-proBNP, and heart rate decreased. Multiple Cox proportional hazards regression analysis was performed using delta% values (post vs pre-training) of LVEF, heart rate, NE, and NT-proBNP along with baseline covariates, revealing delta value of NE as the strongest predictor of cardiac mortality. Noteworthy, training reduced NT-proBNP in both survivor and non-survivor patients, while a lack of reduction of NE was observed in non survivors. CONCLUSIONS In our HF population, short-term changes of NE after exercise training independently predicted long-term cardiac mortality.

microRNA in Cardiovascular Aging and Age-Related Cardiovascular Diseases.

Over the last decades, life expectancy has significantly increased although several chronic diseases persist in the population, with aging as the leading risk factor. Despite improvements in diagnosis and treatment, many elderlies suffer from cardiovascular problems that are much more frequent in an older, more fragile organism. In the long term, age-related cardiovascular diseases (CVDs) contribute to the decline of quality of life and ability to perform normal activities of daily living. microRNAs (miRNAs) are a class of small non-coding RNAs that regulate gene expression at the posttranscriptional level in both physiological and pathological conditions. In this review, we will focus on the role of miRNAs in aging and age-related CVDs as heart failure, hypertension, atherosclerosis, atrial fibrillation, and diabetes mellitus. miRNAs are key regulators of complex biological mechanisms, representing an exciting potential therapeutic target in CVDs. Moreover, one major challenge in geriatric medicine is to find reliable biomarkers for diagnosis, prognosis, and prediction of the response to specific drugs. miRNAs represent a very promising tool due to their stability in the circulation and unique signature in CVDs. However, further studies are needed to investigate their translational potential in the real clinical practice.

Risk of acute myocardial infarction after transurethral resection of prostate in elderly

BackgroundBenign prostatic hyperplasia is a frequent disease among elderly, and is responsible for considerable disability. Benign prostatic hyperplasia can be clinically significant due to lower urinary tract symptoms that take place because the gland is enlarged and obstructs urine flow. Transurethral resection of the prostate remains the gold standard treatment for patients with moderate or severe symptoms who need active treatment or who either fail or do not want medical therapy. Moreover, perioperative and postoperative surgery complications as cardiovascular ones still occur. The incidence of acute myocardial infarction in patients undergoing transurethral resection of the prostate is controversial. The first studies showed an increase in mortality and relative risk of death from myocardial infarction in transurethral resection of the prostate group vs open prostatectomy but these results are in contrast with more recent data.DiscussionGiven the conflicting evidence of the studies in the literature, in this review we are going to discuss the factors that may influence the risk of myocardial infarction in elderly patients undergoing prostate surgery. We analyzed the possible common factors that lead to the development of myocardial infarction and benign prostatic hyperplasia (cardiovascular and metabolic), the stressor factors related to prostatectomy (surgical and haemodynamic) and the risk factors specific of the elderly population (comorbidity and therapies).SummaryAlthough transurethral resection of the prostate is considered at low risk for severe complications, there are several reports indicating that cardiovascular events in elderly patients undergoing this surgical operation are more common than in the general population. Several cardio-metabolic, surgical and aging-related factors may help explain this observation but results in literature are not concord, especially due to the fact that most data derive from retrospective studies in which selection bias cannot be excluded. Subsequently, further studies are necessary to clarify the incidence of acute myocardial infarction in old people.