Long-term follow-up of patients with atherosclerotic renal artery disease.

Atherosclerotic renal artery stenosis (ARAS) is a predictor of increased morbidity and mortality. However, whether ARAS itself accelerates the arteriosclerotic process or whether ARAS is solely the consequence of atherosclerosis is unclear. We imaged renal arteries of 1561 hypertensive patients undergoing coronary angiography and followed this cohort for 9 years (range, 2.4-15.1 years; median, 31.2 months, interquartile range, 13.4/52.9 months). All patients received aspirin, renin-angiotensin system blockade, statins, and beta blockade as indicated. One hundred seventy-one patients had ARAS >50% diameter stenosis and 126 patients an arteriosclerotic plaque (ARAP) without significant stenosis. Blood pressures were not different in ARAS, ARAP, and non-ARAS patients. After adjustment for cardiovascular risk factors by propensity scores and matched pair analysis, ARAS patients had a lower ejection fraction and more coronary artery disease (CAD) than non-ARAS patients. The same was true for brain natriuretic peptide values, troponin I, and highly sensitive C-reative protein. Over 9 years, more ARAS patients died of any cause (34% vs 23%; P < .05). The prevalence of CAD in ARAP patients was higher than in non-ARAS patients and lower than in ARAS patients. The mortality of the ARAP patients at 9 years was 37%, not different from the ARAS patients. Atherosclerotic renal artery disease appears to be a marker for the severity of atherosclerosis rather than a causative factor for atherosclerosis progression.

Guideline adherence in cardiovascular risk assessment and analysis in 15,000 hypertensive German patients in real life: results of the Prospective 3A Registry.

The benefit obtained from antihypertensive treatment is related more to overall cardiovascular risk reduction than to blood pressure levels. Accurate implementation of cardiovascular diagnostics is a key step toward assessment of cardiovascular risk. In the 3A Registry study, data about patient history, concomitant diseases, diagnostic procedures, and medications were prospectively collected. A total of 14,738 patients recruited by 899 physicians in 2008 and 2009 were analyzed. Assessment of cardiovascular risk factors and subclinical end-organ damage (SOD) showed broad differences in the implementation of European Society of Hypertension/European Society of Cardiology recommendations. Electrocardiograms were available in 59% of patients, cholesterol in 71.4%, and glucose in 69.7%. Almost all patients (99.6%) had creatinine measurements performed and microalbuminuria was measured in 8.5%. Metabolic syndrome (MS) had been evaluated in 59.7%. Implementation of diagnostic guidelines was highest in hypertensive patients with diabetes, followed by patients with known cardiovascular disease and established chronic renal insufficiency. For hypertensive patients without known comorbidities, the authors estimated that up to 29% had missed SOD (detection rate <50%) and 13% missed MS due to incomplete assessment of risk factors. This large registry study shows that assessment for cardiovascular risk factors and SOD is incomplete. Major efforts are required to improve comprehensive hypertension management as recommended by current guidelines.

Vitronectin concentrations predict risk in patients undergoing coronary stenting.

BACKGROUND: Vitronectin is a multifunctional protein with a multiple binding domain that interacts with a variety of plasma and cell proteins. Vitronectin binds multiple ligands, including the soluble vitronectin receptor. Abciximab binds equally well to soluble vitronectin receptor and glycoprotein IIb/IIIa, because both share the beta(3) subunit. We tested whether vitronectin concentrations correlate with adverse outcomes in acute coronary syndrome patients. METHODS AND RESULTS: Baseline serum samples (n=233) from a randomized, placebo-controlled trial of abciximab plus stenting (Evaluation of Platelet IIb/IIIa Inhibitor for Stenting EPISTENT) were retrospectively analyzed. We stratified vitronectin concentrations into the 3 lower quartiles (n=178; <49.7 microg/mL) versus the fourth upper quartile (n=55; >or=49.7 microg/mL). The end point was a major adverse cardiovascular event defined as death, myocardial infarction or urgent revascularization at 30 days and 6 months. A higher proportion of patients with baseline vitronectin >or=49.7 microg/mL had major adverse cardiovascular event than patients with baseline vitronectin <49.7 microg/mL at 30 days (18.2% versus 5.6%; P=0.01) and 6 months (20.0% versus 6.2%; P=0.006). When baseline variables not predictive of major adverse cardiovascular event (eg, troponin positive, history of congestive heart failure, diabetes, history of hypertension, smoking status) were excluded from the multivariate model, only baseline vitronectin >or=49.7 microg/mL (at 30 days: OR, 3.23; 95% CI, 1.23, 8.49; at 6 months: OR, 3.36; 95% CI, 1.33, 8.52) and history of myocardial infarction (at 30 days: OR, 5.02; 95% CI, 1.41, 17.9; at 6 months: OR, 3.99; 95% CI, 1.28, 12.43) remained. No interaction occurred between abciximab and vitronectin. CONCLUSIONS: Our findings indicate that vitronectin may be an independent predictor of adverse cardiovascular outcomes following acute stenting.

Macrophages regulate salt-dependent volume and blood pressure by a vascular endothelial growth factor-C-dependent buffering mechanism.

In salt-sensitive hypertension, the accumulation of Na(+) in tissue has been presumed to be accompanied by a commensurate retention of water to maintain the isotonicity of body fluids. We show here that a high-salt diet (HSD) in rats leads to interstitial hypertonic Na(+) accumulation in skin, resulting in increased density and hyperplasia of the lymphcapillary network. The mechanisms underlying these effects on lymphatics involve activation of tonicity-responsive enhancer binding protein (TonEBP) in mononuclear phagocyte system (MPS) cells infiltrating the interstitium of the skin. TonEBP binds the promoter of the gene encoding vascular endothelial growth factor-C (VEGF-C, encoded by Vegfc) and causes VEGF-C secretion by macrophages. MPS cell depletion or VEGF-C trapping by soluble VEGF receptor-3 blocks VEGF-C signaling, augments interstitial hypertonic volume retention, decreases endothelial nitric oxide synthase expression and elevates blood pressure in response to HSD. Our data show that TonEBP-VEGF-C signaling in MPS cells is a major determinant of extracellular volume and blood pressure homeostasis and identify VEGFC as an osmosensitive, hypertonicity-driven gene intimately involved in salt-induced hypertension.

Potential relevance of alpha(1)-adrenergic receptor autoantibodies in refractory hypertension.

BACKGROUND: Agonistic autoantibodies directed at the alpha(1)-adrenergic receptor (alpha(1)-AAB) have been described in patients with hypertension. We implied earlier that alpha(1)-AAB might have a mechanistic role and could represent a therapeutic target. METHODOLOGY/PRINCIPAL FINDINGS: To pursue the issue, we performed clinical and basic studies. We observed that 41 of 81 patients with refractory hypertension had alpha(1)-AAB; after immunoadsorption blood pressure was significantly reduced in these patients. Rabbits were immunized to generate alpha(1)-adrenergic receptor antibodies (alpha(1)-AB). Patient alpha(1)-AAB and rabbit alpha(1)-AB were purified using affinity chromatography and characterized both by epitope mapping and surface plasmon resonance measurements. Neonatal rat cardiomyocytes, rat vascular smooth muscle cells (VSMC), and Chinese hamster ovary cells transfected with the human alpha(1A)-adrenergic receptor were incubated with patient alpha(1)-AAB and rabbit alpha(1)-AB and the activation of signal transduction pathways was investigated by Western blot, confocal laser scanning microscopy, and gene expression. We found that phospholipase A2 group IIA (PLA2-IIA) and L-type calcium channel (Cacna1c) genes were upregulated in cardiomyocytes and VSMC after stimulation with both purified antibodies. We showed that patient alpha(1)-AAB and rabbit alpha(1)-AB result in protein kinase C alpha activation and transient extracellular-related kinase (EKR1/2) phosphorylation. Finally, we showed that the antibodies exert acute effects on intracellular Ca(2+) in cardiomyocytes and induce mesentery artery segment contraction. CONCLUSIONS/SIGNIFICANCE: Patient alpha(1)-AAB and rabbit alpha(1)-AB can induce signaling pathways important for hypertension and cardiac remodeling. Our data provide evidence for a potential clinical relevance for alpha(1)-AAB in hypertensive patients, and the notion of immunity as a possible cause of hypertension.

Aliskiren--mode of action and preclinical data.

Hypertension is one of the major health care problems worldwide since it markedly increases the risk for development of heart disease, stroke, generalized vascular disease, and renal failure. The renin-angiotensin system (RAS) with its major end-product angiotensin II (Ang II) plays a fundamental role in blood pressure regulation through direct and indirect mechanisms. Pharmacologically, we can inhibit the RAS using angiotensin-converting enzyme inhibitors and AT1 receptor blocker. Inhibiting renin directly with a clinically useful drug eluded pharmacologists until recently. However, the once-daily, orally effective, small-molecule, direct renin inhibitor aliskiren has recently changed this state of affairs. Aliskiren, with its 40-h half-life and ideal pharmacokinetics, can now address angiotensin production directly at its rate-limiting step. A novel transgenic rat model outfitted with the human renin and angiotensinogen genes allowed the testing of aliskiren in an animal model. Preclinical data demonstrated that aliskiren prolonged survival, decreased cardiac hypertrophy and the inducibility of arrhythmias, proteinuria, and attenuated inflammation. All these features might result in improved target-organ damage. Studies in humans attest to an effective blood pressure-lowering action, a largely side effect-free profile, and the option of several combination therapies. Aliskiren is the first of a novel antihypertensive drug class. The preclinical data is very promising. Nevertheless, for the evaluation of its potency in humans, we have to wait for more clinical data.

Low-dose renin inhibitor and low-dose AT(1)-receptor blocker therapy ameliorate target-organ damage in rats harbouring human renin and angiotensinogen genes.

We studied the effects of extremely low-dose human renin inhibition (aliskiren) with low angiotensin II receptor blockade (losartan) in a novel double-transgenic rat model harbouring both human renin and angiotensinogen genes. We found that low-dose aliskiren and low-dose losartan effectively reduced mortality and target-organ damage with minimal, non-significant, effects on blood pressure (BP). Our data suggest that renin-angiotensin system (RAS) inhibition ameliorates target-organ damage in an Ang II-driven model of hypertension. Direct renin inhibition is equally efficacious in this regard. Our study does not fully answer the question of BP-lowering versus RAS inhibition. This question is important and was at least partially addressed with our low-dose model.

Recurrent in-stent restenosis is not associated with the angiotensin-converting enzyme D/I, angiotensinogen Thr174Met and Met235Thr, and the angiotensin-II receptor 1 A1166C polymorphism.

Although great progress has been made in reducing renarrowing of the lumen after stenting of coronary arteries, a considerable number of patients develop recurrent in-stent stenosis. Several studies suggest that neointimal proliferation is the crucial pathophysiological process underlying restenosis after stenting. The renin-angiotensin-aldosterone system (RAS) has been implicated in the development of neointimal hyperplasia. We tested the hypothesis that polymorphisms of the RAS genes are associated with recurrent in-stent restenosis (ISR). Coronary stent implantation was performed in 272 patients with clinical symptoms or objective signs of ischemia. At follow-up angiography 6 months after stenting, 81 patients (29.8%) revealed in-stent restenosis. These patients underwent balloon angioplasty and were scheduled for a further 6 months of follow up. One year after initial stenting of the coronary artery, 39 patients displayed no significant angiographic ISR, whereas 42 patients developed recurrent in-stent restenosis (RISR). The survey of specific functional polymorphisms of the RAS, namely the angiotensin-I converting enzyme (ACE) D/I, the angiotensinogen (AGT) T174M and M235T, and A1166C of the angiotensin-II receptor 1 (AGTR1), revealed that the incidence RISR in the high-risk cohort was not associated with any of the polymorphisms examined in this study.

Lactate in a laubenpieper.

Acid-base disorders seldom kill; however, the mechanisms and associated complications certainly do. We recently encountered a patient with a mysterious lactic acidosis. The patient proved to be a most capable teacher of important lessons.