Pharmacology

Effect of ketoconazole-mediated CYP3A4 inhibition on clinical pharmacokinetics of panobinostat (LBH589), an orally active histone deacetylase inhibitor (Article)

Hamberg, P. — 2011-06-27T00:00:00Z

Purpose: Panobinostat is partly metabolized by CYP3A4 in vitro. This study evaluated the effect of a potent CYP3A inhibitor, ketoconazole, on the pharmacokinetics and safety of panobinostat. Methods: Patients received a single panobinostat oral dose on day 1, followed by 4 days wash-out period. On days 5-9, ketoconazole was administered. On day 8, a single panobinostat dose was co-administered with ketoconazole. Panobinostat was administered as single agent three times a week on day 15 and onward. Results: In the presence of ketoconazole, there was 1.6- and 1.8-fold increase in Cmaxand AUC of panobinostat, respectively. No substantial change in Tmaxor half-life was observed. No difference in panobinostat-pharmacokinetics between patients carrying CYP3A5*1/*3 and CYP3A5*3/*3 alleles was observed. Most frequently reported adverse events were gastrointestinal related. Patients had asymptomatic hypophosphatemia (64%), and urine analysis suggested renal phosphate wasting. Conclusions: Co-administration of panobinostat with CYP3A inhibitors is feasible as the observed increase in panobinostat PK parameters was not considered clinically relevant. Considering the variability in exposure following enzyme inhibition and the fact that chronic dosing of panobinostat was not studied with CYP3A inhibitors, close monitoring of panobinostat-related adverse events is necessary.

Journal metrics for the Netherlands heart journal (Article)

Wall, E.E. van der — 2011-04-01T00:00:00Z

Aortic Pathology and the Role of the Renin-Angiotensin System (Doctoral Thesis)

Moltzer, E. — 2011-03-23T00:00:00Z

Thoracic aortic aneurysms (TAAs) are a potential life-threatening disease with limited pharmacological treatment options. Current treatment options are aimed at lowering aortic hemodynamic stress, predominantly with beta-blockers. Increasing evidence supports a role for the renin-angiotensin system (RAS) in aneurysm development. RAS blockade would not only lower blood pressure, but might also target the molecular pathways involved in aneurysm formation, in particular the transforming growth factor-beta (TGF-β)- and extracellular signalregulated kinase (ERK) 1/2 pathways. Indeed, the angiotensin II type 1 (AT1) receptor blocker losartan was effective in lowering aortic root growth in mice and patients with Marfan syndrome. RAS inhibition, which is currently possible at three levels (renin, ACE and the AT1 receptor), is always accompanied by a rise in renin due to interference with the negative feedback loop between renin and angiotensin II. Only during AT1 receptor blockade will this result in stimulation of the non-blocked angiotensin II type 2 (AT2) receptor. This review summarizes the clinical aspects of TAAs, provides an overview of the current mouse models for TAAs, and focuses on the RAS as a new target for TAA treatment, discussing in particular the possibility that AT2 receptor stimulation might be crucial in this regard. If true, this would imply that AT1 receptor blockers (and not ACE inhibitors or renin inhibitors) should be the preferred treatment option for TAAs.

Pharmacological evidence that Ca2+ channels and, to a lesser extent, K+ channels mediate the relaxation of testosterone in the canine basilar artery (Article)

Ramírez-Rosas, M.B. — 2011-03-01T00:00:00Z

Testosterone induces vasorelaxation through non-genomic mechanisms in several isolated blood vessels, but no study has reported its effects on the canine basilar artery, an important artery implicated in cerebral vasospasm. Hence, this study has investigated the mechanisms involved in testosterone-induced relaxation of the canine basilar artery. For this purpose, the vasorelaxant effects of testosterone were evaluated in KCl- and/or PGF 2α-precontracted arterial rings in vitro in the absence or presence of several antagonists/inhibitors/blockers; the effect of testosterone on the contractile responses to CaCl2 was also determined. Testosterone (10-180 μM) produced concentration-dependent relaxations of KCl- or PGF2α-precontracted arterial rings which were: (i) unaffected by flutamide (10 μM), dl-aminoglutethimide (10 μM), actinomycin D (10 μM), cycloheximide (10 μM), SQ 22,536 (100 μM) or ODQ (30 μM); and (ii) significantly attenuated by the blockers 4-aminopyridine (KV; 1 mM), BaCl2 (KIR; 30 μM), iberiotoxin (BKCa2+; 20 nM), but not by glybenclamide (KATP; 10 μM). In addition, testosterone (31, 56 and 180 μM) and nifedipine (0.01-1 μM) produced a concentration-dependent blockade of the contraction to CaCl 2 (10 μM to 10 mM) in arterial rings depolarized by 60 mM KCl. These results, taken together, show that testosterone relaxes the canine basilar artery mainly by blockade of voltage-dependent Ca2+ channels and, to a lesser extent, by activation of K+ channels (KIR, KV and BKCa2+). This effect does not involve genomic mechanisms, production of cAMP/cGMP or the conversion of testosterone to 17β-estradiol.

A pharmacogenetic analysis of determinants of hypertension and blood pressure response to angiotensin-converting enzyme inhibitor therapy in patients with vascular disease and healthy individuals (Article)

Brugts, J.J. — 2011-03-01T00:00:00Z

Aims: To investigate whether genetic variation in the renin-angiotensin- aldosterone system (RAAS) and kallikrein-bradykinin pathways is related to hypertension and blood pressure (BP) response to angiotensin-converting enzyme (ACE) inhibitor therapy in stable coronary artery disease (CAD) patients. Methods and Results: In 8907 stable CAD patients from the EUROPA trial, 52 haplotype-tagging single-nucleotide polymorphisms (SNPs) in 12 candidate genes within the RAAS and kallikrein-bradykinin pathways were investigated for association with hypertension (defined as BP 160/95 mmHg or use of antihypertensives) and BP response to ACE inhibitors, during a 4-week run-in period. All analyses were adjusted for age, sex, body mass index and creatinine clearance and corrected for multiple testing. Results: Hypertension was present in 28.3% of the patients (n = 2526); median BP reduction after perindopril was 10/4 mmHg. Four polymorphisms, located in the ACE (rs4291), angiotensinogen (rs5049) and (pro)renin receptor (rs2968915; rs5981008) genes were significantly associated with hypertension in two vascular disease populations of CAD (EUROPA) and cerebrovascular disease (PROGRESS; n = 3571). A cumulative profile demonstrated a stepwise increase in the prevalence of hypertension, mounting to a 2-3-fold increase (P for trend <0.001). Similar associations on hypertension were observed for angiotensinogen in a healthy population (n = 2197). In addition, genetic polymorphisms were identified that significantly modified the BP reduction by ACE inhibitor therapy; however, the observed BP differences were small and did not remain significant after permutation analysis. Conclusion: This large genetic association study identified genetic determinants of hypertension in three cohorts of patients with vascular disease and healthy individuals.

Associations between cardiovascular parameters and uteroplacental Doppler (blood) flow patterns during pregnancy in women with congenital heart disease: Rationale and design of the Zwangerschap bij Aangeboren Hartafwijking (ZAHARA) II study (Article)

Balci, A. — 2011-02-01T00:00:00Z

Background: Previous research has shown that women with congenital heart disease (CHD) are more susceptible to cardiovascular, obstetric, and offspring events. The causative pathophysiologic mechanisms are incompletely understood. Inadequate uteroplacental circulation is an important denominator in adverse obstetric events and offspring outcome. The relation between cardiac function and uteroplacental perfusion has not been investigated in women with CHD. Moreover, the effects of physiologic changes on pregnancy-related events are unknown. In addition, long-term effects of pregnancy on cardiac function and exercise capacity are scarce. Methods: Zwangerschap bij Aangeboren Hartafwijking (ZAHARA) II, a prospective multicenter cohort study, investigates changes in and relations between cardiovascular parameters and uteroplacental Doppler flow patterns during pregnancy in women with CHD compared to matched healthy controls. The relation between cardiovascular parameters and uteroplacental Doppler flow patterns and the occurrence of cardiac, obstetric, and offspring events will be investigated. At 20 and 32 weeks of gestation, clinical, neurohumoral, and echocardiographic evaluation and fetal growth together with Doppler flow measurements in fetal and maternal circulation are performed. Maternal evaluation is repeated 1 year postpartum. Implications: By identifying the factors responsible for pregnancy-related events in women with CHD, risk stratification can be refined, which may lead to better pre-pregnancy counseling and eventually improve treatment of these women.

Modulation of α2C adrenergic receptor temperature-sensitive trafficking by HSP90 (Article)

Filipeanu, C.M. — 2011-02-01T00:00:00Z

Decreasing the temperature to 30°C is accompanied by significant enhancement of α2C-AR plasma membrane levels in several cell lines with fibroblast phenotype, as demonstrated by radioligand binding in intact cells. No changes were observed on the effects of low-temperature after blocking receptor internalization in α2C-AR transfected HEK293T cells. In contrast, two pharmacological chaperones, dimethyl sulfoxide and glycerol, increased the cell surface receptor levels at 37°C, but not at 30°C. Further, at 37°C α2C-AR is co-localized with endoplasmic reticulum markers, but not with the lysosomal markers. Treatment with three distinct HSP90 inhibitors, radicicol, macbecin and 17-DMAG significantly enhanced α2C-AR cell surface levels at 37°C, but these inhibitors had no effect at 30°C. Similar results were obtained after decreasing the HSP90 cellular levels using specific siRNA. Co-immunoprecipitation experiments demonstrated that α2C-AR interacts with HSP90 and this interaction is decreased at 30°C. The contractile response to endogenous α2C-AR stimulation in rat tail artery was also enhanced at reduced temperature. Similar to HEK293T cells, HSP90 inhibition increased the α2C-AR contractile effects only at 37°C. Moreover, exposure to low-temperature of vascular smooth muscle cells from rat tail artery decreased the cellular levels of HSP90, but did not change HSP70 levels. These data demonstrate that exposure to low-temperature augments the α2C-AR transport to the plasma membrane by releasing the inhibitory activity of HSP90 on the receptor traffic, findings which may have clinical relevance for the diagnostic and treatment of Raynaud Phenomenon.

Pregnancy in women with corrected tetralogy of Fallot: Occurrence and predictors of adverse events (Article)

Balci, A. — 2011-02-01T00:00:00Z

Background: In women with corrected tetralogy of Fallot (ToF), pregnancy is associated with maternal cardiac, obstetric, and offspring complications. Our aim is to investigate the magnitude and determinants of pregnancy outcome in women with corrected ToF. Methods: In this retrospective international multicenter study using 2 congenital heart disease registries, 204 women with corrected ToF were identified. Within this group, 74 women had 157 pregnancies, including 30 miscarriages and 4 terminations of pregnancy. Detailed information on each completed pregnancy (n = 123) was obtained using medical records and supplementary interviews. Results: Cardiovascular events occurred during 10 (8.1%) pregnancies, mainly (supra)ventricular arrhythmias. Obstetric and offspring events occurred in 73 (58.9%) and 42 (33.9%) pregnancies, respectively, including offspring mortality in 8 (6.4%). The most important predictor was use of cardiac medication before pregnancy (odds ratio for cardiac events 11.7, 95% CI 2.2-62.7; odds ratio for offspring events 8.4, 95% CI 1.4-48.6). In pregnancies with cardiovascular events, significantly more small-for-gestational-age children were born (P value < .01). Conclusions: Cardiovascular, obstetric, and offspring events occur frequently during pregnancies in women with ToF. Maternal use of cardiovascular medication is associated with pregnancy outcome, and maternal cardiovascular events during pregnancy are highly associated with offspring events.

Neurovascular Pharmacology of Prospective Antimigraine Drugs (Doctoral Thesis)

Chan, K.Y. — 2011-01-26T00:00:00Z

Migraine is a paroxysmal neurovascular disorder, which affects a significant proportion of the population. Since dilatation of cranial blood vessels is likely to be responsible for the headache experienced in migraine, many experimental models for the study of migraine have focussed on this feature. The current review discusses a model that is based on the constriction of carotid arteriovenous anastomoses in anaesthetized pigs, which has during the last decades proven to be of great value in identifying potential antimigraine drugs acting via a vascular mechanism. Further, the use of human isolated blood vessels in migraine research is discussed. Thirdly, we describe an integrated neurovascular model, where dural vasodilatation in response to trigeminal perivascular nerve stimulation can be studied. Such a model not only allows an in-depth characterization of directly vascularly acting drugs, but also of drugs that are supposed to act via inhibition of vasodilator responses to endogenous neuropeptides, or of drugs that inhibit the release of these neuropeptides. We discuss the use of this model in a study on the influence of female sex hormones on migraine. Finally, the implementation of this model in mice is considered. Such a murine model allows the use of genetically modified animals, which will lead to a better understanding of the ion channel mutations that are found in migraine patients.

Plasma apolipoprotein M responses to statin and fibrate administration in type 2 diabetes mellitus (Article)

Kappelle, P.J.W.H. — 2010-11-01T00:00:00Z

Purpose: Plasma apolipoprotein M (apoM) is potentially anti-atherogenic, and has been found to be associated positively with plasma total, LDL and HDL cholesterol in humans. ApoM may, therefore, be intricately related to cholesterol metabolism. Here, we determined whether plasma apoM is affected by statin or fibrate administration in patients with diabetes mellitus. Methods: Fourteen type 2 diabetic patients participated in a placebo-controlled crossover study which included three 8-week treatment periods with simvastatin (40 mg daily), bezafibrate (400 mg daily), and their combination. Results: ApoM was decreased by 7% in response to simvastatin (P< 0.05 from baseline and placebo), and remained unchanged during bezafibrate and combined simvastatin. +. bezafibrate administration. Plasma apoM concentrations correlated positively with apoB-containing lipoprotein measures at baseline and during placebo (P< 0.02 to P< 0.001), but these relationships were lost during all lipid lowering treatment periods. Conclusions: This study suggests that, even though plasma apoM is lowered by statins, apoM metabolism is to a considerable extent independent of statin- and fibrate-affected pathways involved in cholesterol homeostasis.

Cardiac angiotensin II: Does it have a function? (Article)

Danser, A.H.J. — 2010-11-01T00:00:00Z

Effect of the calcitonin gene-related peptide (CGRP) receptor antagonist telcagepant in human cranial arteries (Article)

Edvinsson, L. — 2010-10-01T00:00:00Z

Introduction: Calcitonin gene-related peptide (CGRP) is a neuronal messenger in intracranial sensory nerves and is considered to play a significant role in migraine pathophysiology. Materials and methods: We investigated the effect of the CGRP receptor antagonist, telcagepant, on CGRP-induced cranial vasodilatation in human isolated cerebral and middle meningeal arteries. We also studied the expression of the CGRP receptor components in cranial arteries with immunocytochemistry. Concentration response curves to aCGRP were performed in human isolated cerebral and middle meningeal arteries in the absence or presence of telcagepant. Arterial slices were stained for RAMP1, CLR and actin in a double immunofluorescence staining. Results: In both arteries, we found that: (i) telcagepant was devoid of any contractile or relaxant effects per se; (ii) pretreatment with telcagepant antagonised the aCGRP-induced relaxation in a competitive manner; and (iii) immunohistochemistry revealed expression and co-localisation of CLR and RAMP1 in the smooth muscle cells in the media layer of both arteries. Conclusions: Our findings provide morphological and functional data on the presence of CGRP receptors in cerebral and meningeal arteries, which illustrates a possible site of action of telcagepant in the treatment of migraine.

Clinical correlates of arterial lactate levels in patients with ST-segment elevation myocardial infarction at admission: A descriptive study (Article)

Vermeulen, R.P. — 2010-09-09T00:00:00Z

Introduction: Blood lactate measurements can be used as an indicator of hemodynamic impairment and relate to mortality in various forms of shock. Little is known at the moment concerning the clinical correlates of systemic lactate in patients with ST-segment elevation myocardial infarction (STEMI).Methods: To assess the relation of systemic arterial lactate levels in STEMI patients with clinical correlates at presentation in the catheterization laboratory, we measured arterial lactate levels with a rapid point-of-care technique, immediately following femoral sheath insertion. The study population (n = 1,176) was divided into tertiles with lactate levels ≤1.1 (n = 410), 1.2 to 1.7 (n = 398) and ≥1.8 mmol/l (n = 368). We compared both baseline characteristics and outcome measures of the three lactate groups.Results: Factors independently associated with higher lactate levels were hypotension, heart rate, thrombolysis in myocardial infarction (TIMI) flow 0 to 1, diabetes and non-smoking. Mortality at 30 days in the three groups was 2.0%, 1.5% and 6.5%. The latter group also showed lower blush grades and greater enzymatic infarct sizes. An intra aortic balloon pump (IABP) was used more frequently in patients with higher lactate levels (4.2%, 7.6% and 14.7%).Conclusions: In STEMI patients, impaired hemodynamics, worse TIMI flow and non-smoking were related to increased arterial lactate levels. Higher lactate levels were independently related with 30-day mortality and an overall worse response to percutaneous coronary intervention (PCI). In particular, acute mortality was related to admission lactates ≥1.8 mmol/L. Point-of-care measurement of arterial lactate at admission in patients with STEMI has the potential to improve acute risk stratification.

Characterization of the calcitonin gene-related peptide receptor antagonist telcagepant (MK-0974) in human isolated coronary arteries (Article)

Chan, K.Y. — 2010-09-01T00:00:00Z

The sensory neuropeptide calcitonin gene-related peptide (CGRP) plays a role in primary headaches, and CGRP receptor antagonists are effective in migraine treatment. CGRP is a potent vasodilator, raising the possibility that antagonism of its receptor could have cardiovascular effects. We therefore investigated the effects of the antimigraine CGRP receptor antagonist telcagepant (MK-0974) [N-[(3R,6S)-6-(2,3-difluorophenyl)-2-oxo-1-(2,2,2- trifluoroethyl) azepan-3-yl]-4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridine-1- yl)piperidine-1-carboxamide] on human isolated coronary arteries. Arteries with different internal diameters were studied to assess the potential for differential effects across the coronary vascular bed. The concentration- dependent relaxation responses to human αCGRP were greater in distal coronary arteries (i.d. 600-1000 μm; Emax= 83 ± 7%) than proximal coronary arteries (i.d. 2-3 mm; Emax= 23 ± 9%), coronary arteries from explanted hearts (i.d. 3-5 mm; Emax= 11 ± 3%), and coronary arterioles (i.d. 200-300 μm; Emax= 15 ± 7%). Telcagepant alone did not induce contraction or relaxation of these coronary blood vessels. Pretreatment with telcagepant (10 nM to 1 μM) antagonized αCGRP-induced relaxation competitively in distal coronary arteries (pA2= 8.43 ± 0.24) and proximal coronary arteries and coronary arterioles (1 μM telcagepant, giving pKB= 7.89 ± 0.13 and 7.78 ± 0.16, respectively). αCGRP significantly increased cAMP levels in distal, but not proximal, coronary arteries, and this was abolished by pretreatment with telcagepant. Immunohistochemistry revealed the expression and colocalization of the CGRP receptor elements calcitonin-like receptor and receptor activity-modifying protein 1 in the smooth muscle cells in the media layer of human coronary arteries. These findings in vitro support the cardiovascular safety of CGRP receptor antagonists and suggest that telcagepant is unlikely to induce coronary side effects under normal cardiovascular conditions. Copyright

Predictors of pregnancy complications in women with congenital heart disease (Article)

Drenthen, W. — 2010-09-01T00:00:00Z

Aims:Data regarding pregnancy outcome in women with congenital heart disease (CHD) are limited.Methods and results: In 1802 women with CHD, 1302 completed pregnancies were observed. Independent predictors of cardiac, obstetric, and neonatal complications were calculated using logistic regression. The most prevalent cardiac complications during pregnancy were arrhythmias (4.7) and heart failure (1.6). Factors independently associated with maternal cardiac complications were the presence of cyanotic heart disease (corrected/uncorrected) (P < 0.0001), the use of cardiac medication before pregnancy (P < 0.0001), and left heart obstruction (P < 0.0001). New characteristics were mechanical valve replacement (P = 0.0014), and systemic (P = 0.04) or pulmonary atrioventricular valve regurgitation related with the underlying (moderately) complex CHD (P = 0.03). A new risk score for cardiac complications is proposed. The most prevalent obstetric complications were hypertensive complications (12.2). No correlation of maternal characteristics with adverse obstetric outcome was found. The most prevalent neonatal complications were premature birth (12), small for gestational age (14), and mortality (4). Cyanotic heart disease (corrected/uncorrected) (P = 0.0003), mechanical valve replacement (P = 0.03), maternal smoking (P = 0.007), multiple gestation (P = 0.0014), and the use of cardiac medication (P = 0.0009) correlated with adverse neonatal outcome.Conclusion: In our tertiary CHD cohort, cardiac, obstetric, and neonatal complications were frequently encountered, and (new) correlations of maternal baseline data with adverse outcome are reported. A new risk score for adverse cardiac complications is proposed, although prospective validation remains necessary.

Angiotensin II induces phosphorylation of the thiazide-sensitive sodium chloride cotransporter independent of aldosterone (Article)

Lubbe, N. van der — 2010-08-18T00:00:00Z

We studied here the independent roles of angiotensin II and aldosterone in regulating the sodium chloride cotransporter (NCC) of the distal convoluted tubule. We adrenalectomized three experimental and one control group of rats. Following surgery, the experimental groups were treated with either a high physiological dose of aldosterone, a non-pressor, or a pressor dose of angiotensin II for 8 days. Aldosterone and both doses of angiotensin II lowered sodium excretion and significantly increased the abundance of NCC in the plasma membrane compared with the control. Only the pressor dose of angiotensin II caused hypertension. Thiazides inhibited the sodium retention induced by the angiotensin II non-pressor dose. Both aldosterone and the non-pressor dose of angiotensin II significantly increased phosphorylation of NCC at threonine-53 and also increased the intracellular abundance of STE20/SPS1-related, proline alanine-rich kinase (SPAK). No differences were found in other modulators of NCC activity such as oxidative stress responsive protein type 1 or with-no-lysine kinase 4. Thus, our in vivo study shows that aldosterone and angiotensin II independently increase the abundance and phosphorylation of NCC in the setting of adrenalectomy; effects are likely mediated by SPAK. These results may explain, in part, the hormonal control of renal sodium excretion and the pathophysiology of several forms of hypertension.Kidney International advance online publication, 18 August 2010; doi:10.1038/ki.2010.290.

Mast cell degranulation mediates bronchoconstriction via serotonin and not via renin release (Article)

Krop, M. — 2010-08-01T00:00:00Z

To verify the recently proposed concept that mast cell-derived renin facilitates angiotensin II-induced bronchoconstriction bronchial rings from male Sprague-Dawley rats were mounted in Mulvany myographs, and exposed to the mast cell degranulator compound 48/80 (300μg/ml), angiotensin I, angiotensin II, bradykinin or serotonin (5-hydroxytryptamine, 5-HT), in the absence or presence of the renin inhibitor aliskiren (10μmol/l), the ACE inhibitor captopril (10μmol/l), the angiotensin II type 1 (AT1) receptor blocker irbesartan (1μmol/l), the mast cell stabilizer cromolyn (0.3mmol/l), the 5-HT2A/2C receptor antagonist ketanserin (0.1μmol/l) or the α1-adrenoceptor antagonist phentolamine (1μmol/l). Bath fluid was collected to verify angiotensin generation. Bronchial tissue was homogenized to determine renin, angiotensinogen and serotonin content. Compound 48/80 contracted bronchi to 24±4% of the KCl-induced contraction. Ketanserin fully abolished this effect, while cromolyn reduced the contraction to 16±5%. Aliskiren, captopril, irbesartan and phentolamine did not affect this response, and the angiotensin I and II levels in the bath fluid after 48/80 exposure were below the detection limit. Angiotensin I and II equipotently contracted bronchi. Captopril shifted the angiotensin I curve ≈10-fold to the right, whereas irbesartan fully blocked the effect of angiotensin II. Bradykinin-induced constriction was shifted ≈100-fold to the left with captopril. Serotonin contracted bronchi, and ketanserin fully blocked this effect. Finally, bronchial tissue contained serotonin at micromolar levels, whereas renin and angiotensinogen were undetectable in this preparation. In conclusion, mast cell degranulation results in serotonin-induced bronchoconstriction, and is unlikely to involve renin-induced angiotensin generation.

Diagnostic criteria in patients with complex regional pain syndrome assessed in an out-patient clinic (Article)

Bodegraven Hof, E.A.M. van — 2010-08-01T00:00:00Z

Background: Specific criteria have been described and accepted worldwide for diagnosing patients with complex regional pain syndrome (CRPS). Nevertheless, a clear-cut diagnosis cannot be confirmed in a number of cases. Aim: The objective of this study was to investigate the effectiveness of the described diagnostic criteria used by several clinical disciplines. Methods: We included 195 patients who were referred to our pain clinic within a period of 1 year. Data were collected on patient characteristics, signs, symptoms, disease-related medication, and the background of the referring clinicians. Results: The Harden and Bruehl criteria were confirmed in 95 patients (49%). These patients used a higher than average number of analgesics, opiates, and anti-oxidants, and frequently received prescriptions for benzodiazepines instead of anti-depressants. The mean disease duration was 29 ± 4.6 months and the mean visual analogue score for pain was 8.1 ± 0.19. A subgroup of patients had a colder temperature in the affected extremity compared with the unaffected extremity. This subgroup showed a longer disease duration and higher visual analogue scale pain. Conclusion: The diagnostic criteria used to determine CRPS should be further improved. A large number of referred patients experienced substantial pain, without receiving adequate medication. Disease-related medication is unrelated to CRPS-specific disease activity. Knowledge of underlying mechanisms is warranted before an adequate pharmaceutical intervention can be considered.

Genetic determinants of treatment benefit of the angiotensin-converting enzyme-inhibitor perindopril in patients with stable coronary artery disease (Article)

Brugts, J.J. — 2010-08-01T00:00:00Z

Aims The efficacy of angiotensin-converting enzyme (ACE)-inhibitors in stable coronary artery disease (CAD) may be increased by targeting the therapy to those patients most likely to benefit. However, these patients cannot be identified by clinical characteristics. We developed a genetic profile to predict the treatment benefit of ACE-inhibitors exist and to optimize therapy with ACE-inhibitors. Methods and resultsIn 8907 stable CAD patients participating in the randomized placebo-controlled EUROPA-trial, we analysed 12 candidate genes within the pharmacodynamic pathway of ACE-inhibitors, using 52 haplotype-tagging-single nucleotide polymorphisms (SNPs). The primary outcome was the reduction in cardiovascular mortality, non-fatal myocardial infarction, and resuscitated cardiac arrest during 4.2 years of follow-up. Multivariate Cox regression was performed with multiple testing corrections using permutation analysis. Three polymorphisms, located in the angiotensin-II type I receptor and bradykinin type I receptor genes, were significantly associated with the treatment benefit of perindopril after multivariate adjustment for confounders and correction for multiple testing. A pharmacogenetic score, combining these three SNPs, demonstrated a stepwise reduction of risk in the placebo group and a stepwise decrease in treatment benefit of perindopril with an increasing scores (interaction P < 0.0001). A pronounced treatment benefit was observed in a subgroup of 73.5 of the patients [hazard ratio (HR) 0.67; 95 confidence interval (CI) 0.56-0.79], whereas no benefit was apparent in the remaining 26.5 (HR 1.26; 95 CI 0.97-1.67) with a trend towards a harmful effect. In 1051 patients with cerebrovascular disease from the PROGRESS-trial, treated with perindopril or placebo, an interaction effect of similar direction and magnitude, although not statistically significant, was observed. Conclusion The current study is the first to identify genetic determinants of treatment benefit of ACE-inhibitor therapy. We developed a genetic profile which predicts the treatment benefit of ACE-inhibitors and which could be used to optimize therapy.

Drug mechanisms to help in managing resistant hypertension in obesity (Article)

Jansen, P.M. — 2010-08-01T00:00:00Z

Obesity is a major risk factor for the development of hypertension. Because the prevalence of obesity is increasing worldwide, the prevalence of obesity hypertension is also increasing. Importantly, hypertension in obesity is commonly complicated by dyslipidemia and type 2 diabetes mellitus and hence imposes a high cardiovascular disease risk. Furthermore, obesity is strongly associated with resistant hypertension. Activation of the sympathetic nervous system and the renin-angiotensin system, leading to renal sodium and water retention, links obesity with hypertension. There is also evidence for the release of factors by visceral adipose tissue promoting excessive aldosterone production, and a more central role of aldosterone in obesity hypertension is emerging. Randomized studies evaluating the effect of different classes of antihypertensive agents in obesity hypertension are scarce, short-lasting, and small. Considering the emerging role of aldosterone in the pathogenesis of obesity hypertension, mineralocorticoid receptor antagonism may play a more central role in the pharmacologic treatment of obesity hypertension in the near future.