Anemia predicts thromboembolic events, bleeding complications and mortality in patients with atrial fibrillation: insights from the RE-LY trial.

BACKGROUND: Anemia may predispose to thromboembolic events or bleeding in anticoagulated patients with atrial fibrillation (AF). OBJECTIVES: To investigate whether anemia is associated with thromboembolic events and bleeding in patients with AF. PATIENTS AND METHODS: We retrospectively analyzed the RE-LY trial database, which randomized 18 113 patients with AF and a risk of stroke to receive dabigatran or warfarin for a median follow-up of 2 years. Cox regression analysis was used to determine whether anemia predicted cardiovascular events and bleeding complications in these patients. RESULTS: Anemia was present in 12% of the population at baseline, and the presence of anemia was associated with a higher risk of thromboembolic cardiovascular events, including the composite endpoint of all-cause mortality or myocardial infarction (adjusted hazard ratio [HR] 1.50, 95% confidence interval [CI] 1.32-1.71) and the primary RE-LY outcome of stroke or systemic embolism (adjusted HR 1.41, 95% CI 1.12-1.78). Anemia was also associated with a higher risk of major bleeding complications (adjusted HR 2.14, 95% CI 1.87-2.46) and discontinuation of anticoagulants (adjusted HR 1.40, 95% CI 1.28-1.79). The association between anemia and outcome was similar irrespective of cardiovascular comorbidities, randomized treatment allocation, or prior use of warfarin. The incidence of events was lower in patients with transient anemia than in patients in whom anemia was sustained (adjusted HR 0.66, 95% CI 0.49-0.91). CONCLUSIONS: Anemia is associated with an increased risk of thromboembolic events, bleeding complications and mortality in anticoagulated patients with AF. These findings suggest that patients with anemia should be monitored closely during all types of anticoagulant treatment.

Telomere length loss due to smoking and metabolic traits.

OBJECTIVES: Human age-dependent telomere attrition and telomere shortening are associated with several age-associated diseases and poorer overall survival. The aim of this study was to determine longitudinal leucocyte telomere length dynamics and identify factors associated with temporal changes in telomere length. DESIGN AND METHODS: Leucocyte telomere length was measured by quantitative polymerase chain reaction in 8074 participants from the Prevention of Renal and Vascular End-stage Disease (PREVEND) study, an ongoing community-based prospective cohort study initiated in 1997. Follow-up data were available at two time-points up to 2007. Leucocyte telomere length was measured, on between one and three separate occasions, in a total of 16 783 DNA samples. Multilevel growth models were created to identify the factors that influence leucocyte telomere dynamics. RESULTS: We observed an average attrition rate of 0.47 ± 0.16 relative telomere length units (RTLUs) per year in the study population aged 48 (range 39-60) years at baseline. Annual telomere attrition rate increased with age (P < 0.001) and was faster on average in men than in women (P for interaction 0.043). The major independent factors determining telomere attrition rate were active smoking (approximately tripled the loss of RTLU per year, P < 0.0001) and multiple traits of the metabolic syndrome (waist-hip ratio, P = 0.007; blood glucose level, P = 0.045, and HDL cholesterol level, P < 0.001). CONCLUSIONS: Smoking and variables linked to the metabolic syndrome are modifiable lifestyle factors that accelerate telomere attrition in humans. The higher rate of cellular ageing may mediate the link between smoking and the metabolic syndrome to an increased risk of several age-associated diseases.

Cholesteryl ester transfer protein polymorphisms, statin use, and their impact on cholesterol levels and cardiovascular events.

The association of nonfunctional variants of the cholesteryl ester transfer protein (CETP) with efficacy of statins has been a subject of debate. We evaluated whether three functional CETP variants influence statin efficacy. The effect of CETP genotype on achieved levels of high-density lipoprotein cholesterol (HDLc), low-density lipoprotein cholesterol (LDLc), and total cholesterol during statin treatment was estimated by meta-analysis of the linear regression outcomes of three studies (11,021 individuals). The effect of these single-nucleotide polymorphisms (SNPs) on statin response in protecting against myocardial infarction (MI) was estimated by meta-analysis of statin × SNP interaction terms from logistic regression in five studies (16,570 individuals). The enhancer SNP rs3764261 significantly increased HDLc by 0.02 mmol/l per T allele (P = 6 × 10(-5)) and reduced protection against MI by statins (interaction odds ratio (OR) = 1.19 per T allele; P = 0.04). Focusing on functional CETP variants, we showed that in carriers of the rs3764261 T variant, HDLc increased more during statin treatment, and protection against MI by statins appeared to be reduced as compared with those in noncarriers.

The fibrosis marker galectin-3 and outcome in the general population.

OBJECTIVE: Galectin-3 is involved in fibrosis and inflammation and plays a role in heart failure, renal disease, obesity and cancer. We aimed to establish the relationship between galectin-3 and cardiovascular (CV) risk factors and mortality in the general population. DESIGN AND SUBJECTS: This study included 7968 subjects from the Prevention of REnal and Vascular ENd-stage Disease (PREVEND) cohort, with a median follow-up of approximately 10 years. Plasma galectin-3 was measured in baseline samples. MAIN OUTCOME MEASURES: We investigated the relationships between galectin-3 levels, demographic characteristics and risk factors of CV disease. We determined the prognostic value for all-cause, CV and cancer mortality. RESULTS: The mean age of the population was 50 ± 13 years. Mean blood pressure was 129/74 mmHg, mean cholesterol was 5.7 ± 1.1 mmol L(-1) and median galectin-3 was 10.9 ng mL(-1) [interquartile range (IQR) 9.0-13.1]. Galectin-3 levels correlated with a wide range of risk factors of CV disease, including blood pressure, serum lipids, body mass index, renal function and N-terminal pro-B-type natriuretic peptide (P < 0.0001). We observed a strong association between galectin-3 and age. Furthermore, we found a gender interaction, with female subjects (n = 4001) having higher median galectin-3 levels (11.0 ng mL(-1) , IQR 9.1-13.4 vs. men (n = 3967) 10.7 ng mL(-1) , IQR 8.9-12.8; P < 0.0001), and galectin-3 levels in women more strongly correlated with risk factors of CV disease. After correction for the classical CV risk factors (smoking, blood pressure, cholesterol and diabetes), galectin-3 levels independently predicted all-cause mortality (hazard ratio per SD galectin-3 1.09, 95% CI 1.01-1.19; P = 0.036), but not CV and cancer mortality separately. CONCLUSIONS: Galectin-3 is associated with age and risk factors of CV disease, with a strong gender interaction for these correlations. Galectin-3 predicts all-cause mortality in the general population.

Vitamin D biology in heart failure: molecular mechanisms and systematic review.

Vitamin D has recently been suggested as an important mediator of blood pressure and cardiovascular disease, including heart failure. In patient with heart failure, low vitamin D levels are associated with adverse outcome and correlate with established clinical correlates and biomarkers. Many precursor states of heart failure, such as hypertension, atherosclerosis, and diabetes are more prevalent in subjects with low vitamin D levels. Recent experimental data have provided clues how vitamin D might exert cardioprotective effects. The steroid hormone vitamin D regulates gene expression of many genes that play a prominent role in the progression of heart failure, such as cytokines and hormones. Specifically, vitamin D is a negative regulator of the hormone renin, the pivotal hormone of the renin-angiotensin system. Mechanistic insights were gained by studying mice deficient for the vitamin D receptor, which develop hypertension and adverse cardiac remodeling mediated via the renin-angiotensin system. Furthermore, vitamin D receptor is expressed in the heart and regulated under pro-hypertrophic stimuli and vitamin D as receptor has been associated with the expression of other hypertrophic genes such as natriuretic peptides. So, epidemiological data and mechanistic studies have provided strong support for a potentially cardioprotective effect of vitamin D. It remains unclear if vitamin D supplementation is beneficial in preventing heart failure or if it could be a therapeutic addendum in the treatment of heart failure. This review summarizes current knowledge on vitamin D and its biology in heart failure.

Apoptosis during CABG surgery with the use of cardiopulmonary bypass is prominent in ventricular but not in atrial myocardium.

Objectives. We aimed to compare the rate of apoptosis after cardiopulmonary bypass (CPB) and cardioplegic arrest during coronary artery bypass grafting (CABG) surgery between atrial and ventricular tissue.Methods. During CABG surgery with CPB and cardioplegic arrest, sequential biopsies were taken from the right atrial appendage and left ventricular anterior wall before CPB and after aortic cross clamp release. Change in number of apoptotic cells and biochemical markers of myocardial ischaemia and renal dysfunction were assessed.Results. CPB was associated with a transient small, but significant increase in CK (1091+/-374%), CK-MB (128+/-38%), troponin-T (102+/-13%) and NT-proBNP (1308+/-372%) levels (all: p<0.05). A higher number of apoptotic cells as assessed by caspase-3 staining was found in the ventricular biopsies taken after aortic cross clamp release compared with the biopsies taken before CPB (5.3+/-0.6 vs. 14.0+/-1.5 cells/microscopic field, p<0.01). The number of apoptotic cells in the atrial appendage was not altered during CPB. Correlation between the duration of aortic cross clamp time and the change in caspase-3 positive cells in the left ventricular wall was of borderline significance (r of 0.58, p=0.08). Similar results were obtained from TUNEL staining for apoptosis.Conclusion. CABG surgery with CPB and cardioplegic arrest is associated with an elevated rate of apoptosis in ventricular but not in atrial myocardial tissue. Ventricular tissue may be more sensitive to detect changes than atrial tissue, and may be more useful to investigate the protective effects of therapeutic intervention. (Neth Heart J 2010;18:236-42.).

Cardiac gene expression profiling - the quest for an atrium-specific biomarker.

Biomarkers are gaining increasing interest to predict risk but also to aid in diagnostics. Tissue-specific biomarkers are of utmost importance to detect diseases of respective organs. As of yet there are no atrium-specific biomarkers for risk stratification of atrial disease, such as atrial fibrillation. Bioinformatics such as mRNA microarrays can help to detect tissue-enriched and possibly tissue-specific expressed genes that can be targets for biomarkers. We describe an approach to identify genes preferably expressed in atrial cardiomyocytes compared with ventricular cardiomyocytes by RNA microarray and confirmed by quantitative real-time polymerase chain reaction. By this approach we identified several atrium-enriched genes but also ventricle-enriched genes. As expected atrial natriuretic peptide (ANP) mRNA showed higher expression in atrial cardiomyocytes while with adrenergic stimulation expression was almost as high in ventricular as in atrial cells. Brain-type natriuretic peptide (BNP), however, was not different between atrial and ventricular cells giving a possible explanation for increased levels of NT-proBNP in atrial fibrillation patients. Interesting identified candidates are serpine1 and ltbp2 as atrium-enriched genes whereas alpha-adrenergic receptor subtype 1b and S100A1 expression was significantly higher in ventricular cells. The identified genes need to be confirmed in human tissue and might ultimately be tested as potential biomarkers for atrial stress. (Neth Heart J 2010;18:610-4.).

Ultrasound and microbubble-targeted delivery of therapeutic compounds: ICIN Report Project 49: Drug and gene delivery through ultrasound and microbubbles.

The molecular understanding of diseases has been accelerated in recent years, producing many new potential therapeutic targets. A noninvasive delivery system that can target specific anatomical sites would be a great boost for many therapies, particularly those based on manipulation of gene expression. The use of microbubbles controlled by ultrasound as a method for delivery of drugs or genes to specific tissues is promising. It has been shown by our group and others that ultrasound increases cell membrane permeability and enhances uptake of drugs and genes. One of the important mechanisms is that microbubbles act to focus ultrasound energy by lowering the threshold for ultrasound bioeffects. Therefore, clear understanding of the bioeffects and mechanisms underlying the membrane permeability in the presence of microbubbles and ultrasound is of paramount importance. (Neth Heart J 2009;17:82-6.).

Rescue of arterial function by angiotensin-(1-7): towards improvement of endothelial function by drug-eluting stents.

PURPOSE: To explore the hypothesis that stent placement decreases dilator function of various arteries outside the stented segment and that angiotensin- (1-7) improves this function, and to assess the contribution of dilator signal compounds. A further objective was to test the hypothesis that on-stent delivery of Ang-(1-7) reduces neointima formation and improves endothelial function. METHODS: Abdominal aortic stenting or sham operation was performed in the rat four weeks after stenting and treatment with intravenous saline or Ang-(1-7) infusion (24 mug/kg/h); vasomotor function in isolated thoracic aorta and brachial and iliac artery was measured in organ baths. Furthermore, Ang-(1-7)-eluting stents were designed and placed in rat abdominal aorta. Neointima formation and aortic function were tested after four weeks. RESULTS: Relaxation of the thoracic aorta to metacholine was decreased after stenting compared with shams due to a decrease in nitric oxide-mediated response (67% reduction in maximal NO-dependent response). Ang-(1-7) restored the response mainly through increased prostaglandin- and possibly also endothelial-derived hyperpolarising factor-mediated relaxation. Relaxation in the brachial artery decreased after stenting (maximal response dropped by 50%), whilst contractions to phenylephrine increased. Ang-(1-7) normalised vasomotor function. Iliac artery function remained unaltered after stenting but Ang-(1-7) increased maximal relaxations by 65%. Delivery of Ang-(1-7) by means of a drug-eluting stent improved endothelial function. CONCLUSION: Stenting differentially affects dilator and contractile function in various arterial beds. Ang-(1-7) both improves dilator function and normalises contractile function. Delivery of protective peptides such as Ang-(1-7) from the stent is a new therapy option that merits further development and exploration. (Neth Heart J 2008;16:293-8.).

Regenerative cell therapy and pharmacotherapeutic intervention in heart failure: Part 1: Cardiovascular progenitor cells, their functions and sources.

It has been postulated that bone marrow derived endothelial progenitor cells (BM-EPCs) are essential for neovascularisation and endothelial repair and are involved in pharmacological treatment, and even its potential targets. There is no doubt that the ultimate success of angiogenic cell therapy will be determined by an appropriate stimulation of certain angiogenic progenitor cell subpopulations. Unfortunately, the biology of EPCs is still poorly understood. In particular, the understanding of endogenous microenvironments within the progenitor cell niches is critical, and will provide us with information about the signalling systems that supply a basis to develop rational pharmacotherapy to enhance the functional activity of endogenous or transplanted progenitor cells. The final success of clinical improvement of progenitor cell-mediated vascular repair and angiogenic therapy depends on a better understanding of EPC biology and a smart therapeutic design. In the first part of this review we first briefly discuss the possible involvement of progenitor cells in chronic heart failure. In part 2 we focus on factors that beneficially affect BMEPCs, with an emphasis on pharmacological molecular pathways involved in BM-EPC-induced neovascularisation. (Neth Heart J 2008;16:305-9.).

Regenerative cell therapy and pharmacotherapeutic intervention in heart failure: Part 2: Pharmacological targets, agents and intervention perspectives.

Regenerative medicine represents a promising perspective on therapeutic angiogenesis in patients with cardiovascular disease, including heart failure. However, previous or ongoing clinical trials show ambiguous outcomes with respect to the benefit of regenerative therapy by means of bone marrow stem cell infusion in myocardial infarction patients. Therefore, it is necessary to set up a rational therapeutic strategy in the treatment of congestive heart failure. Chemokines, cytokines and growth factors, as well as pharmaceutical agents, may have an impact on endothelial progenitor cell (EPC) physiology and thus can provide targets for pharmacological intervention. Indeed, EPCs and stem cell niches both in bone marrow and myocardial tissue can be treated as an integral target for recruitment of EPCs from the bone marrow to the cardiac ischaemic niche. In this article, we individually place the signalling factors in their specified context, and explain their roles in the various phases of neovascularisation (see Part 1). (Neth Heart J 2008;16:337-43.).

[Value of basic and intensive management of patients with heart failure; results of a randomised controlled clinical trial]. / Waarde van lichte en intensieve begeleiding van patiënten met hartfalen; resultaten van het COACH-onderzoek.

OBJECTIVE: To determine the efficacy of 2 nurse-directed programmes of different intensity for the counselling and follow-up of patients hospitalised for heart failure, compared with standard care by a cardiologist. DESIGN: Multicentre randomised clinical trial (www.trialregister.nl: NCT 98675639). METHOD: A total of 1023 patients were randomized after hospitalisation for heart failure to 1 of 3 treatment strategies: standard care provided by a cardiologist, follow-up care from a cardiologist with basic counselling and support by a nurse specialising in heart failure, or follow-up care from a cardiologist with intensive counselling and support by a nurse specialising in heart failure. Primary end points were the time to rehospitalisation due to heart failure or death and the number of days lost to rehospitalisation or death during the 18-month study period. Data were analysed on an intent-to-treat basis. RESULTS: Mean patient age was 71 years, 38% were women, 50% had mild heart failure and 50% had severe heart failure. During the study, 411 patients (40%) were rehospitalised due to heart failure or died from any cause: 42% in the control group, and 41% and 38% in the basic and intensive support groups, respectively (differences not significant). The time to rehospitalisation or death was similar in the 3 groups: hazard ratios for the basic and intensive support groups versus the control group were 0.96 (95% CI: 0.76-1.21; p = 0.73) and 0.93 (95% CI: 0.73-1.17; p = 0.53), respectively. The number of days lost to rehospitalisation or death was 39,960 in the control group; this number was 15% less in the intervention groups, but the difference was not significant. However, there was a trend toward lower mortality in the intervention groups. In all 3 groups, more visits occurred than planned, which may have had a considerable effect on care, notably in the control group. CONCLUSION: The results of this study indicated that the provision of additional counselling and support by a nurse specialising in heart failure as an adjuvant to intensive follow-up care provided by a cardiologist does not always lead to a reduction in rehospitalisation frequency.

[Telomeres and biological ageing in cardiovascular disease]. / Telomeren en biologische veroudering bij hart- en vaatziekten.

The striking variability in the age of onset of and the manifestation/ absence of manifestation of cardiovascular diseases is inadequately explained by conventional risk factors, but may be explained by variation in biological age. Telomere length is possibly a reliable marker of biological age, shorter telomeres reflecting more advanced age. The initial telomere length ofa person is mainly determined by genetic factors. Moreover, the telomere length shortens with each cell division, and exposition to harmful environmental factors also results in shorter telomeres. Leukocytes of patients with atherosclerosis and heart failure display remarkably shorter telomeres compared to leukocytes of healthy subjects of similar age. Conventional cardiovascular risk factors are also associated with telomere length. If telomeres are indeed causally involved in the pathogenesis of cardiovascular disease, this might provide new avenues for future preventive and therapeutic strategies.

N-terminal pro B-type natriuretic peptide levels predict newly detected atrial fibrillation in a population-based cohort.

BACKGROUND: B-type natriuretic peptide (BNP) is secreted from cardiomyocytes and may reflect haemodynamic abnormalities predisposing to atrial fibrillation (AF). We aimed to investigate whether N-terminal pro BNP (NT-proBNP) is associated with newly detected AF in subjects obtained from the general population. METHODS: From the PREVEND programme (n=8592), we selected all subjects with an available baseline and four-year electrocardiogram and NTproBNP levels at baseline. We excluded subjects with AF at baseline and subjects with a serum creatinine >2.0 mg/dl. RESULTS: In total, 6494 subjects were eligible for the prospective analysis (aged 49+/-12 years, 49.7% men). At four years, AF was detected in 41 (0.6%) subjects. Median NT-proBNP levels at baseline in subjects with newly detected AF after four years was 62.2 (22.6 to 208.5) pg/ml as compared with 35.7 (15.9 to 68.7) pg/ml in those with sinus rhythm (p=0.001). Each 1 standard deviation increment in natural log transformed NT-proBNP was associated with a 54% (5% to 126%, p=0.028) increase in risk for AF after adjustment for other risk factors predisposing to AF. NT-proBNP levels above the sex-specific 80th percentile (97 pg/ml in women and 60 pg/ml in men) were associated with a multivariate odds ratio of 2.65 (1.22 to 5.76, p=0.01) for the occurrence of AF. CONCLUSION: Plasma levels of NT-proBNP predict newly detected AF in subjects obtained from the general population independent of cardiovascular risk factors predisposing to AF. (Neth Heart J 2008;16:73-8.).

Angiotensin II type 2 receptor vasoactivity in internal mammary arteries of patients with coronary artery disease.

BACKGROUND: Several animal studies suggested that the angiotensin II type 2 (AT2) receptor subtype mediates vasodilation, yet the results in human arteries are less well described and more inconsistent. Therefore, we evaluated the role of the AT2 receptor stimulation on the vasotonus of human internal mammary arteries. METHODS: Internal mammary arteries were obtained from 50 patients undergoing coronary bypass surgery. The expression of angiotensin II type 1 (AT1) receptor and AT2 receptor mRNA was determined by using real-time polymerase chain reaction. In addition, angiotensin II and CGP42112A concentration-response curves (concentration range: 10(-10) M to 10(-6) M) were constructed in absence or presence of candesartan (10(-5) M) and/or the AT2 receptor-antagonist PD-123319 (10(-6) M) and/or the alpha receptor antagonist phentolamine. RESULTS: Both AT1 and AT2 receptor protein and mRNA were detected, and higher AT2 receptor mRNA expression levels were associated with increased contractile response to angiotensin II. Angiotensin II caused vasoconstriction up to 41.1 +/- 6.5% of the maximal response to phenylephrine, and PD123319 significantly reduced this response (28.6 +/- 9.6%, P < 0.001). Candesartan completely blocked the angiotensin II-mediated response (1.4 +/- 3.1%, P < 0.001 versus control), and additional blockade of the AT2 receptor with PD123319 did not change this effect (1.8 +/- 5.1%). Phentolamine (10(-5) M) caused attenuation and rightward shift of the angiotensin II concentration response curves. The AT2 receptor agonist CGP42112A did not induce a significant response. CONCLUSION: Although AT2 receptor mRNA is present in human internal mammary arteries, AT2 receptor stimulation does not mediate vasodilation in these arteries.