Effects of losartan vs candesartan in reducing cardiovascular events in the primary treatment of hypertension

Patient Adherence and Duration of Continuous Treatment With Various Arbs in Patients With Uncomplicated Arterial Hypertension in the USA Based on The Analysis of the Truven Health Analytics MarketScan Database

AIM

To discuss two aspects that can be used to improve the adherence to therapy in patients with arterial hypertension (AH): 1) which of the angiotensin II receptor blockers (ARBs) provides the highest adherence rates; 2) how various factors influence adherence rates.

MATERIAL AND METHODS

An analysis of one of the world's largest clinical practice databases, Truven Health Analytics MarketScan (currently Merative MarketScan), was performed. The analysis included data on patients of both sexes aged 30 to 65 years who had been diagnosed with uncomplicated AH (at least once between March 1, 2012 and January 1, 2018) and prescribed monotherapy with one of ARBs. The exclusion criteria were heart failure and the treatment with two or more ARBs (simultaneously or sequentially) during the treatment period. Ultimately, the study included 717,099 patients with uncomplicated AH, who were divided into four groups based on the prescribed drug: azilsartan (n=4276), candesartan (n=6023), losartan (n=586,857), and valsartan (n=119,943). Adherence to treatment was evaluated by two parameters: duration of continuous therapy and medication possession ratio (MPR). The individual effect of each factor (specific ARB used for therapy, patient gender, age, initial ARB dose, patient co-payment per day of treatment) on the adherence to treatment was assessed using a regression analysis.

RESULTS

The adherence to the ARB therapy was generally high. The MPR was the lowest in the azilsartan group and the highest in the candesartan group. However, the parameters that potentially influenced both the MPR and the duration of continuous therapy (patient's gender and age, initial ARB dose, co-payment size) differed significantly between the groups receiving different ARBs. The regression analysis showed that both adherence parameters and the duration of continuous therapy were higher in patients receiving candesartan than in patients receiving azilsartan, losartan or valsartan, when the effect on the adherence of other factors available for study (age, gender, initial dose of the drug, and the absolute size of co-payment for a day of therapy) was excluded. The lowest adherence to therapy was observed in the azilsartan treatment group (p<0.01).

CONCLUSION

The study provided data for comparing the adherence of patients with uncomplicated AH to the therapy with different ARBs. Further study of adherence to treatment will provide additional data that will allow an optimal selection of drugs for the treatment of AH in patients with potentially poor adherence.

Comparison Between Fimasartan Versus Other Angiotensin Receptor Blockers in Patients With Heart Failure After Acute Myocardial Infarction

BACKGROUNDS

Fimasartan is the most recently developed, potent, and long-acting angiotensin II receptor blocker (ARB). However, data are limited regarding treatment effects of fimasartan in patients with heart failure.

METHODS

Between 2010 and 2016, patients who underwent coronary revascularization for myocardial infarction (MI) with heart failure and prescription of ARB at hospital discharge were enrolled from the Korean nationwide medical insurance data. Clinical outcomes were compared between patients receiving fimasartan and those receiving other ARBs (candesartan, valsartan, losartan, telmisartan, olmesartan, and irbesartan). The primary outcome was a composite of all-cause death, recurrent MI, hospitalization for heart failure, and stroke.

RESULTS

Of 2,802 eligible patients, fimasartan was prescribed to 124 patients (4.4%). During a median follow-up of 2.2 years (interquartile range, 1.0-3.9), 613 events of the primary outcome occurred. There was no significant difference in the primary outcome between patients receiving fimasartan and those receiving other ARBs (adjusted hazard ratio [HR], 0.82; 95% confidence interval [CI], 0.46-1.45). Compared with patients receiving other ARBs, those receiving fimasartan had comparable incidence of all-cause death (adjusted HR, 0.70; 95% CI, 0.30-1.63), recurrent MI (adjusted HR, 1.28; 95% CI, 0.49-3.34), hospitalization for heart failure (adjusted HR, 0.70; 95% CI, 0.27-1.84), and stroke (adjusted HR, 0.59; 95% CI, 0.18-1.96).

CONCLUSION

In this nationwide cohort, fimasartan, compared with other ARBs, had comparable treatment effects for a composite of all-cause death, recurrent MI, hospitalization for heart failure, and stroke in patients with heart failure after MI.

TMAO Suppresses Megalin Expression and Albumin Uptake in Human Proximal Tubular Cells Via PI3K and ERK Signaling

Trimethylamine-N-oxide (TMAO) is a uremic toxin, which has been associated with chronic kidney disease (CKD). Renal tubular epithelial cells play a central role in the pathophysiology of CKD. Megalin is an albumin-binding surface receptor on tubular epithelial cells, which is indispensable for urine protein reabsorption. To date, no studies have investigated the effect of TMAO on megalin expression and the functional properties of human tubular epithelial cells. The aim of this study was first to identify the functional effect of TMAO on human renal proximal tubular cells and second, to unravel the effects of TMAO on megalin-cubilin receptor expression. We found through global gene expression analysis that TMAO was associated with kidney disease. The microarray analysis also showed that megalin expression was suppressed by TMAO, which was also validated at the gene and protein level. High glucose and TMAO was shown to downregulate megalin expression and albumin uptake similarly. We also found that TMAO suppressed megalin expression via PI3K and ERK signaling. Furthermore, we showed that candesartan, dapagliflozin and enalaprilat counteracted the suppressive effect of TMAO on megalin expression. Our results may further help us unravel the role of TMAO in CKD development and to identify new therapeutic targets to counteract TMAOs effects.

Ulcerative colitis progression: a retrospective analysis of disease burden using electronic medical records

BACKGROUND

Ulcerative colitis (UC) is a debilitating inflammatory bowel disease. Present knowledge regarding UC disease progression over time is limited.

OBJECTIVE

To assess UC progression to severe disease along with disease burden and associated factors.

METHODS

Electronic medical records linked with Swedish national health registries (2005-2015) were used to identify disease progression of UC. Odds of all-cause and disease-related hospitalization within 1 year were compared between patients with disease progression and those without. Annual indirect costs were calculated based on sick leave, and factors related to UC progression were examined.

RESULTS

Of the 1,361 patients with moderate UC, 24% progressed to severe disease during a median of 5.2 years. Severe UC had significantly higher odds for all-cause (OR [odds ratio] 1.47, 95% CI [confidence interval]: 1.12-1.94, P < 0.01) and UC-related hospitalization (OR 2.47, 95% CI: 1.76-3.47, P < 0.0001) compared to moderate disease. Average sick leave was higher in patients who progressed compared to those who did not (64.4 vs 38.6 days, P < 0.001), with higher indirect costs of 151,800 SEK (16,415 €) compared with 92,839 SEK (10,039 €) (P < 0.001), respectively. UC progression was related to young age (OR 1.62, 95% CI: 1.17-2.25, P < 0.01), long disease duration (OR 1.09, 95% CI: 1.03-1.15, P < 0.001), and use of corticosteroids (OR 2.49, 95% CI: 1.67-3.72, P < 0.001).

CONCLUSION

Disease progression from moderate to severe UC is associated with more frequent and longer hospitalizations and sick leave. Patients at young age with long disease duration and more frequent glucocorticosteroid medication are associated with progression to severe UC.

Developing a short-term prediction model for asthma exacerbations from Swedish primary care patients' data using machine learning - Based on the ARCTIC study

OBJECTIVE

The ability to predict impending asthma exacerbations may allow better utilization of healthcare resources, prevention of hospitalization and improve patient outcomes. We aimed to develop models using machine learning to predict risk of exacerbations.

METHODS

Data from 29,396 asthma patients was collected from electronic medical records and national registers covering clinical and epidemiological factors (e.g. comorbidities, health care contacts), between 2000 and 2013. Machine-learning classifiers were used to create models to predict exacerbations within the next 15 days. Model selection was done using the mean cross validation score of area under precision-recall curve (AUPRC).

RESULTS

The most important predictors of exacerbation were comorbidity burden and previous exacerbations. Model validation on test data yielded an AUPRC = 0.007 (95% CI: ± 0.0002), indicating that historic clinical information alone may not be sufficient to predict a near future risk of asthma exacerbation.

CONCLUSIONS

Supplementation with additional data on environmental triggers, (e.g. weather, pollen count, air quality) and from wearables, might be necessary to improve performance of the short-term predictive model to develop a more clinically useful tool.

Predicting Hospitalization Due to COPD Exacerbations in Swedish Primary Care Patients Using Machine Learning - Based on the ARCTIC Study

Purpose

Chronic obstructive pulmonary disease (COPD) exacerbations can negatively impact disease severity, progression, mortality and lead to hospitalizations. We aimed to develop a model that predicts a patient's risk of hospitalization due to severe exacerbations (defined as COPD-related hospitalizations) of COPD, using Swedish patient level data.

Patients and Methods

Patient level data for 7823 Swedish patients with COPD was collected from electronic medical records (EMRs) and national registries covering healthcare contacts, diagnoses, prescriptions, lab tests, hospitalizations and socioeconomic factors between 2000 and 2013. Models were created using machine-learning methods to predict risk of imminent exacerbation causing patient hospitalization due to COPD within the next 10 days. Exacerbations occurring within this period were considered as one event. Model performance was assessed using the Area under the Precision-Recall Curve (AUPRC). To compare performance with previous similar studies, the Area Under Receiver Operating Curve (AUROC) was also reported. The model with the highest mean cross validation AUPRC was selected as the final model and was in a final step trained on the entire training dataset.

Results

The most important factors for predicting severe exacerbations were exacerbations in the previous six months and in whole history, number of COPD-related healthcare contacts and comorbidity burden. Validation on test data yielded an AUROC of 0.86 and AUPRC of 0.08, which was high in comparison to previously published attempts to predict COPD exacerbation.

Conclusion

Our work suggests that clinically available information on patient history collected via automated retrieval from EMRs and national registries or directly during patient consultation can form the basis for future clinical tools to predict risk of severe COPD exacerbations.

[Evidence-Based Information Which Could Influence Arterial Hypertension Treatment Approach after Publication of SPRINT Trial Results]

The article discusses results of secondary analysis of the data obtained in the SPRINT study and published in recent years. Unresolved issues in the tactics of managing patients with arterial hypertension are discussed. One of such issues is choosing an optimum level of blood pressure (BP) for a subgroup of patients with certain characteristics, including elderly and senile patients, patients with chronic kidney disease, and patients with arterial hypertension who continue smoking. The article discusses calculation of a threshold of risk for complications of cardiovascular diseases, at which a maximum advantage of intensified regimens of antihypertensive therapy could be achieved. In addition, the article addresses approaches to selection of antihypertensive drugs in the current conditions. The authors discussed the role of candesartan in the treatment of arterial hypertension, a sartan most studied in a broad range of patients. The issue of a rapid increase in BP without a damage to target organs is addressed; evidence for the role of captopril in such clinical situation is provided.

Contributions by the Brain Renin-Angiotensin System to Memory, Cognition, and Alzheimer's Disease

Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive neuron losses in memory-associated brain structures that rob patients of their dignity and quality of life. Five drugs have been approved by the FDA to treat AD but none modify or significantly slow disease progression. New therapies are needed to delay the course of this disease with the ultimate goal of preventing neuron losses and preserving memory functioning. In this review we describe the renin-angiotensin II (AngII) system (RAS) with specific regard to its deleterious contributions to hypertension, facilitation of neuroinflammation and oxidative stress, reduced cerebral blood flow, tissue remodeling, and disruption of memory consolidation and retrieval. There is evidence that components of the RAS, AngIV and Ang(1-7), are positioned to counter such damaging influences and these systems are detailed with the goal of drawing attention to their importance as drug development targets. Ang(1-7) binds at the Mas receptor, while AngIV binds at the AT4 receptor subtype, and these receptor numbers are significantly decreased in AD patients, accompanied by declines in brain aminopeptidases A and N, enzymes essential for the synthesis of AngIV. Potent analogs may be useful to counter these changes and facilitate neuronal functioning and reduce apoptosis in memory associated brain structures of AD patients.

Biomimetic nanoparticle technology for cardiovascular disease detection and treatment

Cardiovascular disease (CVD), which encompasses a number of conditions that can affect the heart and blood vessels, presents a major challenge for modern-day healthcare. Nearly one in three people has some form of CVD, with many suffering from multiple or intertwined conditions that can ultimately lead to traumatic events such as a heart attack or stroke. While the knowledge obtained in the past century regarding the cardiovascular system has paved the way for the development of life-prolonging drugs and treatment modalities, CVD remains one of the leading causes of death in developed countries. More recently, researchers have explored the application of nanotechnology to improve upon current clinical paradigms for the management of CVD. Nanoscale delivery systems have many advantages, including the ability to target diseased sites, improve drug bioavailability, and carry various functional payloads. In this review, we cover the different ways in which nanoparticle technology can be applied towards CVD diagnostics and treatments. The development of novel biomimetic platforms with enhanced functionalities is discussed in detail.

Epidemiology of Pulmonary Fibrosis: A Cohort Study Using Healthcare Data in Sweden

Introduction

Data on the epidemiology of idiopathic pulmonary fibrosis (IPF) in Sweden are lacking. This study estimates the incidence and prevalence of IPF in Sweden, and describes the demographic and clinical characteristics and the overall survival of patients with IPF.

Methods

Two cohorts were studied: a national cohort of 17,247 patients with pulmonary fibrosis (ICD-10 code J84.1 with no competing diagnosis) from the Swedish National Patient Register (cohort 1 [C1]); and an electronic medical record-based regional subset of C1 comprising 1755 patients having pulmonary fibrosis and a radiology procedure (C2).

Results

The incidence of pulmonary fibrosis in C1 ranged from 10.4 to 15.4 cases per 100,000 population per year between 2001 and 2015. The prevalence increased from 15.4 to 68.0 cases per 100,000 population per year. Patients ≥ 70 years and men had a higher incidence and prevalence of pulmonary fibrosis. Common comorbidities included respiratory infections and cardiovascular disorders. Approximately one-third of patients in each cohort were hospitalised with pulmonary fibrosis within a year of diagnosis. The median survival time from disease diagnosis was 2.6 years in C1 and 5.2 years in C2. Older patients had a higher risk of hospitalisation and mortality. Women had a better prognosis than men.

Conclusion

This study underscores the importance of pulmonary fibrosis as a cause of respiratory-related morbidity and mortality in Sweden. The stable incidence and increasing prevalence over time suggests longer survival. The higher morbidity and mortality in older patients highlights the importance of early case detection, diagnosis and management for better prognosis.

Funding

F. Hoffmann-La Roche, Ltd./Genentech, Inc.

Electronic supplementary material

The online version of this article (10.1007/s41030-019-0087-9) contains supplementary material, which is available to authorized users.

Candesartan targeting of angiotensin II type 1 receptor demonstrates benefits for hypertension in pregnancy via the NF‑κB signaling pathway

Hypertensive disorders may be a complication of pregnancy and are characterized by the high blood pressure. Evidence suggests that alterations in the renin-angiotensin-aldosterone system and the sympathetic nervous system are associated with gestational hypertension. Angiotensin II type 1 receptor (Ang-IITR) is a potential target in the progression of gestational hypertension. Candesartan is selective Ang-IITR antagonist that may act against vasoconstriction and reduces peripheral vascular resistance. The aim of the present study was to evaluate the efficacy of Candesartan and the underlying molecular mechanism of the nuclear factor-κB (NF-κB) signaling pathway in the progression of gestational hypertension in a mouse model. Expression and activity of Ang-IITR was evaluated in a mouse model of gestational hypertension prior to and post-treatment of Candesartan both in vitro and in vivo. It was determined whether Candesartan treatment reduces higher blood pressure activated the renal renin-angiotensin system and a prognostic marker, soluble endoglin, and its associated gene in mice with gestational hypertension. Angiotensin-converting enzyme plasma levels and activity were also evaluated in the present study. Cytoplasmic and nuclear immunostaining of NF-κB and associated proteins transforming growth factor β (TGF-β) and endoglin was enhanced in vascular endothelial cells and mice with gestational hypertension. Soluble fms-like tyrosine kinase 1 (sFlt-1), insulin resistance homeostasis model assessment score and associated cardiovascular risk factors also were measured. Results demonstrated that angiotensin and Ang-IITR expression levels were upregulated in mice with gestational hypertension and were downregulated by Candesartan treatment. Renal renin-angiotensin and soluble endoglin were also improved in mice in the Candesartan-treated group. In addition, Candesartan treatment enhanced NF-κB activity, as well as TGF-β and vascular endothelial growth factor expression which led to improved levels of sFlt-1, insulin resistance homeostasis and associated cardiovascular risk factors. Gestational hypertension was markedly improved by treatment of Candesartan compared with the control. In conclusion, the findings of the present study suggested that the NF-κB signaling pathway may be involved in with Candesartan-mediated Ang-IITR for the treatment of gestational hypertension.

Central-acting therapeutics alleviate respiratory weakness caused by heart failure-induced ventilatory overdrive

Diaphragmatic weakness is a feature of heart failure (HF) associated with dyspnea and exertional fatigue. Most studies have focused on advanced stages of HF, leaving the cause unresolved. The long-standing theory is that pulmonary edema imposes a mechanical stress, resulting in diaphragmatic remodeling, but stable HF patients rarely exhibit pulmonary edema. We investigated how diaphragmatic weakness develops in two mouse models of pressure overload-induced HF. As in HF patients, both models had increased eupneic respiratory pressures and ventilatory drive. Despite the absence of pulmonary edema, diaphragmatic strength progressively declined during pressure overload; this decline correlated with a reduction in diaphragm cross-sectional area and preceded evidence of muscle weakness. We uncovered a functional codependence between angiotensin II and β-adrenergic (β-ADR) signaling, which increased ventilatory drive. Chronic overdrive was associated with increased PERK (double-stranded RNA-activated protein kinase R-like ER kinase) expression and phosphorylation of EIF2α (eukaryotic translation initiation factor 2α), which inhibits protein synthesis. Inhibition of β-ADR signaling after application of pressure overload normalized diaphragm strength, Perk expression, EIF2α phosphorylation, and diaphragmatic cross-sectional area. Only drugs that were able to penetrate the blood-brain barrier were effective in treating ventilatory overdrive and preventing diaphragmatic atrophy. These data provide insight into why similar drugs have different benefits on mortality and symptomatology, despite comparable cardiovascular effects.

Divergent Spatiotemporal Interaction of Angiotensin Receptor Blocking Drugs with Angiotensin Type 1 Receptor

Crystal structures of the human angiotensin II type 1 receptor (AT₁R) complex with the antihypertensive agent ZD7155 (PDB id: 4YAY ) and the blood pressure medication Benicar (PDB id: 4ZUD ) showed that binding poses of both antagonists are similar. This finding implies that clinically used angiotensin receptor blocking (ARB) drugs may interact in a similar fashion. However, clinically observed differences in pharmacological and therapeutic efficacies of ARBs lead to the question of whether the dynamic interactions of AT₁R with ARBs vary. To address this, we performed induced-fit docking (IFD) of eight clinically used ARBs to AT₁R followed by 200 ns molecular dynamic (MD) simulation. The experimental K_i values for ARBs correlated remarkably well with calculated free energy with R² = 0.95 and 0.70 for AT₁R-ARB models generated respectively by IFD and MD simulation. The eight ARB-AT₁R complexes share a common set of binding residues. In addition, MD simulation results validated by mutagenesis data discovered distinctive spatiotemporal interactions that display unique bonding between an individual ARB and AT₁R. These findings provide a reasonably broader picture reconciling the structure-based observations with clinical studies reporting efficacy variations for ARBs. The unique differences unraveled for ARBs in this study will be useful for structure-based design of the next generation of more potent and selective ARBs.

Risk of mortality and recurrent cardiovascular events in patients with acute coronary syndromes on high intensity statin treatment

Several randomized controlled trials have shown a benefit of high-dose intensive statin treatment in reducing risk of death and second cardiovascular disease (CVD) events in patients previously diagnosed with an acute coronary syndrome (ACS). Non-randomized studies in clinical settings support these findings, but large, long-term, observational studies addressing CVD and non-CVD endpoints are lacking. In this retrospective longitudinal study, we followed ACS patients in Sweden during 2001–2012 using national health registry and medical record data. A total of 49,857 patients were identified, of whom 10,092 (20.2%) received high dose statins and 21,174 (42.7%) received no statins. Royston-Parmar parametric time-to-event models were implemented to model hazard for second CVD events and death, stratified by gender and diabetes diagnosis. We found that risk of a second CVD event developed similarly in both treatment groups, but was much higher in the no statin group. Risk of CVD-related death remained relatively constant for the high-statin group, while it increased over time for the no-statin group. Interestingly, males had higher mortality rates in the no-statin group, but not in the high-statin group. All-cause mortality and non-CVD-related death followed similar trends to those observed for CVD-related death. This work provides additional real-world evidence for effect of statins in CVD-related mortality. The hazard functions presented here can provide a basis for future survival modeling and health economic evaluation.

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10,092 ACS patients on high dose and 21,174 on no statins were followed 2001–12.

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Royston-Parmar models were implemented to model hazard for new CVD events and death.

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Risk of a new event developed similarly, but was much higher for those not on statins.

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Risk of death increased over time for the no-statin, but not the high statin, group.

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High statin treatment reduced gender effects on risk of mortality and new events.

Evaluation of the use of Swedish integrated electronic health records and register health care data as support clinical trials in severe asthma: the PACEHR study

Background

In the development of new drugs for severe asthma, it is a challenge from an ethical point of view to randomize severe asthma patients to placebo, and to obtain long-term safety data due to discontinuations. The aim of this study was to evaluate the feasibility of using electronic health record (EHR) data to create a real-world reference population of uncontrolled asthmatic patients to supplement the concurrent control/placebo group in long-term studies of asthma.

Methods

EHR data from 36 primary care centres and a University hospital in Sweden were linked to Swedish mandatory health registers (2005–2013), creating a population covering 33 890 asthma patients, including data on co-morbidities, risk factors and laboratory/respiratory measurements. A severe asthma EHR reference cohort was established. We used logistic regression to estimate the propensity score (probability) of each RCT or EHR patient existing in the EHR cohort given their covariates.

Results

We created an EHR-derived reference cohort of 240 patients, matching the placebo group (N = 151) in an RCT of severe asthma. The exacerbation rate during follow-up in the EHR study population was 1.24 (weighted) compared to 0.9 in the RCT placebo group. Patients in the EHR cohort were of similar age as in the RCT placebo group, 50.6 years versus 50.1 years; had slightly higher body mass index 27.0 kg/m² versus 27.3 kg/m²; and consisted of 40% versus 34% males.

Conclusions

The results indicate that EHRs provide an opportunity to supplement the control group in RCTs of severe diseases.

Fixed-dose combination of nifedipine gastrointestinal therapeutic system and candesartan cilexetil in patients with moderate-to-severe essential hypertension: an open-label, long-term safety and efficacy study

WHAT IS KNOWN AND OBJECTIVE

The nifedipine gastrointestinal therapeutic system (GITS)/candesartan cilexetil (N/C) combination was demonstrated to be an effective, well-tolerated antihypertensive therapy in a short-term study. The current study investigated the long-term safety and efficacy of a fixed-dose combination (FDC) of N/C therapy in moderate-to-severe essential hypertension.

METHODS

A multinational, 70-centre, open-label study of N/C treatment for 28 or 52 weeks at a target dose of N60 mg/C32 mg. The primary assessment included the incidence of treatment-emergent adverse events (TEAEs). Efficacy assessments included change from baseline in systolic and diastolic blood pressure (BP).

RESULTS AND DISCUSSION

A total of 508 patients were enrolled, with 417 (82·1%) completing week 28 of treatment. Of these, 200 patients continued treatment, as planned, to week 52, with 193 (96·5%) completing this period. At least one TEAE or drug-related TEAE were reported in 76·8% and 45·3% patients up to week 28, and in 80·7% and 46·9% up to week 52/end of study. Most TEAEs and drug-related TEAEs to week 52 (93·9% and 95·4%, respectively) were mild or moderate in intensity. Rates of drug-related serious AEs were low (0·6%). TEAE-related discontinuations occurred in 10% patients before week 28 and in no additional patients thereafter. N/C provided substantial, sustained reductions in mean systolic and diastolic BP from baseline: 30·1 ± 18·4 and 12·8 ± 10·7 mmHg, respectively, at week 52.

WHAT IS NEW AND CONCLUSIONS

Nifedipine GITS/candesartan cilexetil FDC at the target dose of 60 mg/32 mg was well tolerated for a study duration up to 52 weeks and provided sustained reductions in systolic and diastolic BP.

Cell membranes… and how long drugs may exert beneficial pharmacological activity in vivo

The time course of the beneficial pharmacological effect of a drug has long been considered to depend merely on the temporal fluctuation of its free concentration. Only in the last decade has it become widely accepted that target-binding kinetics can also affect in vivo pharmacological activity. Although current reviews still essentially focus on genuine dissociation rates, evidence is accumulating that additional micro-pharmacokinetic (PK) and -pharmacodynamic (PD) mechanisms, in which the cell membrane plays a central role, may also increase the residence time of a drug on its target. The present review provides a compilation of otherwise widely dispersed information on this topic. The cell membrane can intervene in drug binding via the following three major mechanisms: (i) by acting as a sink/repository for the drug; (ii) by modulating the conformation of the drug and even by participating in the binding process; and (iii) by facilitating the approach (and rebinding) of the drug to the target. To highlight these mechanisms, we focus on drugs that are currently used in clinical therapy, such as the antihypertensive angiotensin II type 1 receptor antagonist candesartan, the atypical antipsychotic agent clozapine and the bronchodilator salmeterol. Although the role of cell membranes in PK-PD modelling is gaining increasing interest, many issues remain unresolved. It is likely that novel biophysical and computational approaches will provide improved insights in the near future.

Nifedipine plus candesartan combination increases blood pressure control regardless of race and improves the side effect profile: DISTINCT randomized trial results

OBJECTIVES

DISTINCT (reDefining Intervention with Studies Testing Innovative Nifedipine GITS - Candesartan Therapy) aimed to determine the dose-response and tolerability of nifedipine GITS and/or candesartan cilexetil therapy in participants with hypertension.

METHODS

In this 8-week, multinational, multicentre, randomized, double-blind, placebo-controlled study, adults with mean seated DBP of at least 95 to less than 110 mmHg received combination or monotherapy with nifedipine GITS (N) 20, 30 or 60 mg and candesartan cilexetil (C) 4, 8, 16 or 32 mg, or placebo. The primary endpoint, change in DBP from baseline to Week 8, was analysed using the response surface model (RSM); this analysis was repeated for mean seated SBP.

RESULTS

Overall, 1381 participants (mean baseline SBP/DBP: 156.5/99.6 mmHg) were randomized. Both N and C contributed independently to SBP/DBP reductions [P < 0.0001 (RSM)]. A positive dose-response was observed, with all combinations providing statistically better blood pressure (BP) reductions from baseline versus respective monotherapies (P < 0.05) and N60C32 achieving the greatest reduction [-23.8/-16.5 mmHg; P < 0.01 versus placebo (-5.3/-6.7 mmHg) and component monotherapies]. Even very low-dose (N20 and C4) therapy provided significant BP-lowering, and combination therapy was similarly effective in different racial groups. N/C combination demonstrated a lower incidence of vasodilatory adverse events than N monotherapy (18.3 versus 23.6%), including headache (5.5 versus 11.0%; P = 0.003, chi-square test) and peripheral oedema over time (3.6 versus 5.8%; n.s.).

CONCLUSION

N/C combination was effective in participants with hypertension and showed an improved side effect profile compared with N monotherapy.

Population-based study of giant cell tumor of bone in Sweden (1983-2011)

INTRODUCTION

Giant-cell tumor of bone (GCTB) is a locally aggressive histologically benign neoplasm with a less common malignant counterpart. Longitudinal data sources on GCTB are sparse, limited to single institution case series or surgical outcomes studies. The Swedish Cancer Registry is one of the few national population-based databases recording GCTB, representing a unique source to study GCTB epidemiology. We estimated incidence rate (IR) and overall mortality rates based on registry data.

MATERIALS AND METHODS

We identified patients with a GCTB diagnosis in the Swedish Cancer Registry from 1983 to 2011: benign (ICD-7 196.0-196.9; PAD 741) and malignant (PAD 746). Results were stratified by age at diagnosis, gender, and anatomical lesion location.

RESULTS

The cohort included 337 GCTB cases (IR of 1.3 per million persons per year). The majority (n=310) had primary benign GCTB (IR of 1.2 per million per year). Median age at diagnosis was 34 years (range 10-88) with 54% (n=183) females. Malignant to benign ratio for women was 0.095 (16/167) and for men 0.077 (11/143). Incidence was highest in the 20-39 years age group (IR of 2.1 per million per year). The most common lesion sites were distal femur and proximal tibia. Mortality at 20 years from diagnosis was 14% (n=48) and was slightly higher for axial (17%; n=6) and pelvic (17%; n=4) lesions. Recurrence occurred in 39% of primary benign cases and 75% of primary malignant cases.

CONCLUSIONS

In our modern population-based series primary malignant cases were uncommon (8%), peak incidence 20-39 years with slight predominance in women. Recurrence rates remain significant with overall 39% occurring in benign GCTB, and 75% in malignant form. The linkage between databases allowed the first population based estimates of the proportion of patients who received surgery at initial GCTB diagnosis, and those who also received subsequent surgeries.

Nifedipine GITS/Candesartan Combination Therapy Lowers Blood Pressure Across Different Baseline Systolic and Diastolic Blood Pressure Categories: DISTINCT Study Subanalyses

DISTINCT was an 8‐week, double‐blind, randomized study to investigate the antihypertensive efficacy and safety of various nifedipine gastrointestinal treatment system (GITS)/candesartan cilexetil (N/C) dose combinations, vs respective monotherapies or placebo, in patients with diastolic blood pressure (DBP) ≥95 to <110 mm Hg. The current prespecified analysis compared BP reduction in participants with mild vs moderate baseline hypertension (ie, systolic [S]BP <160 mm Hg vs ≥160 mm Hg and DBP <100 mm Hg vs ≥100 mm Hg). A total of 1362 patients were analyzed by descriptive statistics. In all patient subgroups investigated, the NC combinations (ie, N: 20, 30, or 60 mg; C: 4, 8, 16, or 32 mg daily) provided greater SBP and DBP lowering and higher rates of BP control (defined as BP <140/90 mm Hg) than respective monotherapies or placebo, with greatest absolute BP reductions observed in the moderately elevated SBP or DBP subgroups. A trend to dose‐response relationship was observed in each subgroup. In each SBP and DBP subgroup, treatment‐related vasodilatory events (flushing, headache, or edema) were less frequent for patients receiving NC combination therapy than N monotherapy. These analyses support the use of calcium antagonist and angiotensin receptor blocker combination therapy in patients with both mild and moderate hypertension, for whom effective BP normalization and good drug tolerance would greatly reduce the risk of cardiovascular events.

Effects of blood pressure reduction in mild hypertension: a systematic review and meta-analysis

BACKGROUND

Effects of blood pressure reduction in persons with grade 1 hypertension are unclear.

PURPOSE

To investigate whether pharmacologic blood pressure reduction prevents cardiovascular events and deaths in persons with grade 1 hypertension.

DATA SOURCES

Trials included in the BPLTTC (Blood Pressure Lowering Treatment Trialists' Collaboration) and trials identified from a previous review and electronic database searches.

STUDY SELECTION

Patients without cardiovascular disease with blood pressures in the grade 1 hypertension range (140 to 159/90 to 99 mm Hg) who were randomly assigned to an active (antihypertensive drug or more intensive regimen) or control (placebo or less intensive regimen) blood pressure-lowering regimen.

DATA EXTRACTION

Individual-patient data from BPLTTC trials and aggregate data from other trials were extracted. Risk of bias was assessed for all trials.

DATA SYNTHESIS

Individual-patient data involved 10 comparisons from trials where most patients had diabetes, and aggregate data involved 3 comparisons from trials of patients without diabetes. The average blood pressure reduction was about 3.6/2.4 mm Hg. Over 5 years, odds ratios were 0.86 (95% CI, 0.74 to 1.01) for total cardiovascular events, 0.72 (CI, 0.55 to 0.94) for strokes, 0.91 (CI, 0.74 to 1.12) for coronary events, 0.80 (CI, 0.57 to 1.12) for heart failure, 0.75 (CI, 0.57 to 0.98) for cardiovascular deaths, and 0.78 (CI, 0.67 to 0.92) for total deaths. Results were similar in secondary analyses. Withdrawal from treatment due to adverse effects was more common in the active groups.

LIMITATION

Blood pressure reductions and numbers of events were small.

CONCLUSION

Blood pressure-lowering therapy is likely to prevent stroke and death in patients with uncomplicated grade 1 hypertension.

PRIMARY FUNDING SOURCE

Swedish Heart-Lung Foundation, Swedish Research Council, Australian Research Council, and National Health and Medical Research Council of Australia.

The development of small molecule angiotensin IV analogs to treat Alzheimer's and Parkinson's diseases

Alzheimer's (AD) and Parkinson's (PD) diseases are neurodegenerative diseases presently without effective drug treatments. AD is characterized by general cognitive impairment, difficulties with memory consolidation and retrieval, and with advanced stages episodes of agitation and anger. AD is increasing in frequency as life expectancy increases. Present FDA approved medications do little to slow disease progression and none address the underlying progressive loss of synaptic connections and neurons. New drug design approaches are needed beyond cholinesterase inhibitors and N-methyl-d-aspartate receptor antagonists. Patients with PD experience the symptomatic triad of bradykinesis, tremor-at-rest, and rigidity with the possibility of additional non-motor symptoms including sleep disturbances, depression, dementia, and autonomic nervous system failure. This review summarizes available information regarding the role of the brain renin-angiotensin system (RAS) in learning and memory and motor functions, with particular emphasis on research results suggesting a link between angiotensin IV (AngIV) interacting with the AT4 receptor subtype. Currently there is controversy over the identity of this AT4 receptor protein. Albiston and colleagues have offered convincing evidence that it is the insulin-regulated aminopeptidase (IRAP). Recently members of our laboratory have presented evidence that the brain AngIV/AT4 receptor system coincides with the brain hepatocyte growth factor/c-Met receptor system. In an effort to resolve this issue we have synthesized a number of small molecule AngIV-based compounds that are metabolically stable, penetrate the blood-brain barrier, and facilitate compromised memory and motor systems. These research efforts are described along with details concerning a recently synthesized molecule, Dihexa that shows promise in overcoming memory and motor dysfunctions by augmenting synaptic connectivity via the formation of new functional synapses.

Effects of combining azilsartan medoxomil with amlodipine in patients with stage 2 hypertension

Objective

The aim of the study was to measure the effects on blood pressure (BP) of the angiotensin receptor blocker azilsartan medoxomil, in 40 and 80 mg doses, combined with 5 mg of the calcium channel blocker amlodipine and to compare these effects with placebo plus amlodipine 5 mg.

Methods

This was a randomized, controlled, double-blind study of 6 weeks’ duration in 566 patients with stage 2 hypertension. The primary endpoint was 24-h systolic BP by ambulatory monitoring.

Results

The mean age of the participants was 58 years; men and women were equally represented, and baseline 24-h BP (153–154/93 mmHg) and clinic BP (165–166/94–95 mmHg) were similar across the three treatment groups. After 6 weeks, 24-h BP decreased by 25/15 mmHg in both the azilsartan medoxomil/amlodipine 40/5 and 80/5 mg groups. These reductions were each greater than the 14/8 mmHg decrease with placebo plus amlodipine 5 mg (P≤0.001 for both comparisons). All treatments were well tolerated, and adverse events did not increase with the azilsartan medoxomil doses. Edema or fluid retention was less common in both combination groups (2.6 and 2.7%) than with placebo plus amlodipine (7.6%).

Conclusion

Coadministration of azilsartan medoxomil with amlodipine was well tolerated and led to meaningful additional BP reductions compared with placebo plus amlodipine.

Diabetes and CVD risk during angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker treatment in hypertension: a study of 15,990 patients

Differences in clinical effectiveness between angiotensin-converting enzyme inhibitors (ACEis) and angiotensin receptor blockers (ARBs) in the primary treatment of hypertension are unknown. The aim of this retrospective cohort study was to assess the prevention of type 2 diabetes and cardiovascular disease (CVD) in patients treated with ARBs or ACEis. Patients initiated on enalapril or candesartan treatment in 71 Swedish primary care centers between 1999 and 2007 were included. Medical records data were extracted and linked with nationwide hospital discharge and cause of death registers. The 11 725 patients initiated on enalapril and 4265 on candesartan had similar baseline characteristics. During a mean follow-up of 1.84 years, 36 482 patient-years, the risk of new diabetes onset was lower in the candesartan group (hazard ratio (HR) 0.81, 95% confidence interval (CI) 0.69–0.96, P=0.01) compared with the enalapril group. No difference between the groups was observed in CVD risk (HR 0.99, 95% CI 0.87–1.13, P=0.86). More patients discontinued treatment in the enalapril group (38.1%) vs the candesartan group (27.2%). In a clinical setting, patients initiated on candesartan treatment had a lower risk of new-onset type 2 diabetes and lower rates of drug discontinuation compared with patients initiated on enalapril. No differences in CVD risk were observed.

Blood pressure levels and risk of cardiovascular events and mortality in type-2 diabetes: cohort study of 34 009 primary care patients

OBJECTIVE

The optimal blood pressure (BP) in persons with type-2 diabetes is debated. We investigated shapes of the associations of SBP and DBP levels with risk of cardiovascular events and mortality in a large primary care-based sample of diabetic patients.

METHODS

We investigated all 34 009 consecutive cardiovascular disease-free type-2 diabetes patients aged 35 years or older (mean age 64 years) at 84 primary care centers in central Sweden between 1999 and 2008. We followed this cohort until the end of 2009 in national registries for the incidence of major cardiovascular events (a composite endpoint of myocardial infarction, stroke, heart failure, or cardiovascular mortality) or total mortality.

RESULTS

During up to 11 years of follow-up, 6344 patients (18.7%) had a first cardiovascular event, and 6235 died (18.3%). The associations of annually updated SBP and DBP with risk of major cardiovascular events were U-shaped. The lowest risk of cardiovascular events was observed at a SBP of 135-139 mmHg and a DBP of 74-76 mmHg, and the lowest mortality risk at a SBP of 142-150 mmHg and a DBP of 78-79 mmHg, in both antihypertensive drug-untreated and drug-treated persons.

CONCLUSION

In a large primary care-based sample of patients with type-2 diabetes, associations of SBP and DBP with risk of major cardiovascular events and mortality were U-shaped. This may have implications for risk stratification of persons with diabetes.

The burden of preserved ejection fraction heart failure in a real-world Swedish patient population

OBJECTIVES

To evaluate resource use and associated costs in patients with a diagnosis of heart failure with preserved ejection fraction (HF-PEF) in Sweden.

METHODS

This retrospective study identified real-world patients with an ICD-10 diagnosis code for heart failure (I50) for the period between July 1, 2005 and December 31, 2006 from electronic medical records of primary care centers in Uppsala County Council, and in the Swedish patient registry data. Patients were categorized as having HF-PEF (left ventricle ejection fraction [LVEF] > 50%) during the index period. The study assessed medication utilization, outpatient visits, hospitalizations, and associated healthcare costs, as well as the incidence rates and time to all-cause and heart failure mortality following the index period.

RESULTS

The study included 137 HF-PEF patients with a mean age of 77.1 (SD = 9.1) years. Over 50% of HF-PEF patients were female and hypertensive. Nearly all patients received ≥ 1 medication post-index. Patients had an average of 1.5 heart failure related hospitalizations per follow-up year. The average annual per patient cost for the management of a HF-PEF patient was found in Sweden to be Swedish Krona (SEK) 108,246 (EURO [EUR] 11,344). Hospitalizations contributed to more than 80% of the total cost. All-cause mortality over the 18-month study period was 25.5%, and more than 50% of these deaths occurred within 1 year of index.

LIMITATIONS

Due to the limitations of registry data, it is not possible to confirm the HF diagnosis, and therefore the accuracy of registry records must be assumed. Other factors such as short follow-up time, the study-mandated LVEF assessment, and a lack of drug duration data may also have an impact on the study results.

CONCLUSIONS

All-cause mortality was high in the HF-PEF population, with more than half of patients dying within 1 year of study follow-up. Study results also indicate that 60% of HF-PEF patients have ≥ 1 hospitalization during follow-up. Hospitalizations, especially heart failure related admissions, represent a substantial proportion of the total healthcare burden of patients with HF-PEF in Sweden.

Comparative assessment of angiotensin II type 1 receptor blockers in the treatment of acute myocardial infarction: surmountable vs. insurmountable antagonist

BACKGROUND

The mechanisms of antagonism vary between the angiotensin II type 1 receptor blockers (ARBs): insurmountable antagonism and surmountable antagonism. Recent retrospective observational studies suggest that ARBs may not have equivalent benefits in various clinical situations. The aim of this study was to compare the effect of two categories of ARBs on the long-term clinical outcomes of patients with acute myocardial infarction (AMI).

METHODS

We analyzed the large-scale, prospective, observational Korea Acute Myocardial Infarction Registry study, which enrolled 2740 AMI patients. They divided by the prescription of surmountable ARBs or insurmountable ARBs at discharge. Primary outcome was major adverse cardiac events (MACEs), defined as a composite of cardiac death, nonfatal MI, and re-percutaneous coronary intervention, coronary artery bypass graft surgery.

RESULTS

In the overall population, the MACEs rate in 1 year was significantly higher in the surmountable ARB group (14.3% vs. 11.2%, p=0.025), which was mainly due to increased cardiac death (3.3% vs. 1.9%, p=0.031). Matching by propensity-score showed consistent results (MACEs rate: 14.9% vs. 11.4%, p=0.037). In subgroup analysis, the insurmountable ARB treatment significantly reduced the incidence of MACEs in patients with left ventricular ejection fraction greater than 40%, with a low killip class, with ST segment elevation MI, and with normal renal function.

CONCLUSIONS

In our study, insurmountable ARBs were more effective on long-term clinical outcomes than surmountable ARBs in patients with AMI.

Avidity and positive allosteric modulation/cooperativity act hand in hand to increase the residence time of bivalent receptor ligands

Bivalent ligands bear two target-binding pharmacophores. Their simultaneous binding increases their affinity (avidity) and residence time. They become 'bitopic' when the binding sites at the target permit the pharmacophores the exert allosteric modulation of each other's affinity and/or activity. Present simulations reveal that positive cooperativity exacerbates these phenomena, whereas negative cooperativity curtails them, irrespective of whether the association or dissociation rates of the individual pharmacophores are affected. Positive cooperativity delays the attainment of equilibrium binding, yielding 'hemi-equilibrium' conditions and only apparent affinity constants under usual experimental conditions. Monovalent ligands that bind to one of the target sites decrease the bitopic ligand's residence time concentration-wise; their potency depends on their association rate and thereon acting cooperativity rather than on affinity. This stems from the repetitive, very fast reformation of fully bound bitopic ligand-target complexes by rebinding of freshly dissociated pharmacophores. These studies deal with kinetic binding properties (of increasing interest in pharmacology) of bitopic ligands (a promising avenue in medicinal chemistry).

Changes in body mass index following newly diagnosed type 2 diabetes and risk of cardiovascular mortality: a cohort study of 8486 primary-care patients

AIMS

Elevated body mass index (BMI) is associated with an increased risk of type 2 diabetes and cardiovascular disease (CVD). This study explored the association between BMI changes in the first 18 months of newly diagnosed type 2 diabetes and the risk of long-term CVD mortality.

METHODS

A total of 8486 patients with newly diagnosed type 2 diabetes and no previous history of CVD or cancer were identified from 84 primary-care centres in Sweden. During the first year after diagnosis, patients were grouped according to BMI change: 'Increase', or ≥+1 BMI unit; 'unchanged', or between +1 and-1 BMI unit; and 'decrease', or ≤-1 BMI unit. Associations between BMI change and CVD mortality, defined as death from stroke, myocardial infarction or sudden death, were estimated using adjusted Cox proportional hazards models (NCT 01121315).

RESULTS

Baseline mean age was 60.0 years and mean BMI was 30.2kg/m(2). Patients were followed for up to 9 years (median: 4.6 years). During the first 18 months, 53.4% had no change in their BMI, while 32.2% decreased and 14.4% increased. Compared with patients with unchanged BMI, those with an increased BMI had higher risks of CVD mortality (hazard ratio: 1.63, 95% CI: 1.11-2.39) and all-cause mortality (1.33, 1.01-1.76). BMI decreases had no association with these risks compared with unchanged BMI: 1.06 (0.76-1.48) and 1.06 (0.85-1.33), respectively.

CONCLUSION

Increased BMI within the first 18 months of type 2 diabetes diagnosis was associated with an increased long-term risk of CVD mortality. However, BMI decrease did not lower the long-term risk of mortality.

Combination of budesonide/formoterol more effective than fluticasone/salmeterol in preventing exacerbations in chronic obstructive pulmonary disease: the PATHOS study

OBJECTIVES

Combinations of inhaled corticosteroids (ICSs) and long-acting β2 -agonists (LABAs) are recommended for patients with moderate and severe chronic obstructive pulmonary disease (COPD). However, it is not known whether different fixed combinations are equally effective. The aim of this study was to investigate exacerbation rates in primary care patients with COPD treated with budesonide/formoterol compared with fluticasone/salmeterol.

METHODS

Patients with physician-diagnosed COPD and a record of postdiagnosis treatment with a fixed combination of budesonide/formoterol or fluticasone/salmeterol were included. Data from primary care medical records were linked to those from Swedish national hospital, drug and cause of death registers. Pairwise (1 : 1) propensity score matching was carried out at the index date (first prescription) by prescribed fixed ICS/LABA combination. Exacerbations were defined as hospitalizations, emergency visits and collection of oral steroids or antibiotics for COPD. Yearly event rates were compared using Poisson regression.

RESULTS

Matching of 9893 patients (7155 budesonide/formoterol and 2738 fluticasone/salmeterol) yielded two cohorts of 2734 patients, comprising 19 170 patient-years. The exacerbation rates were 0.80 and 1.09 per patient-year in the budesonide/formoterol and fluticasone/salmeterol groups, respectively (difference of 26.6%; P < 0.0001); yearly rates for COPD-related hospitalizations were 0.15 and 0.21, respectively (difference of 29.1%; P < 0.0001). All other healthcare outcomes were also significantly reduced with budesonide/formoterol versus fluticasone/salmeterol.

CONCLUSIONS

Long-term treatment with fixed combination budesonide/formoterol was associated with fewer healthcare utilization-defined exacerbations than fluticasone/salmeterol in patients with moderate and severe COPD.

A Review of the Use of Angiotensin Receptor Blockers for the Prevention of Cardiovascular Events in Patients with Essential Hypertension Without Compelling Indications

OBJECTIVE

To review the role of angiotensin receptor blockers (ARBs) for the prevention of cardiovascular events in patients with essential hypertension without other compelling indications.

DATA SOURCES

Peer-reviewed clinical trials, review articles, and relevant treatment guidelines were identified from MEDLINE and Current Content database (both 1966-November 15, 2012) using the search terms angiotensin receptor blockers (ARBs), azilsartan, candesartan, eprosartan, irbesartan, losartan, olmesartan, telmisartan, valsartan, hypertension, myocardial infarction, stroke, heart failure, and cardiovascular outcomes. Results were limited to human trials published in English. Citations from articles were also reviewed for additional references.

STUDY SELECTION AND DATA EXTRACTION

The focus was on clinical trials evaluating cardiovascular end points of ARBs used in patients with essential hypertension without compelling indications.

DATA SYNTHESIS

Data supporting the use of ARBs for reducing cardiovascular events in patients with essential hypertension without compelling indications are inconsistent. To date, only candesartan and losartan have shown a significant reduction in cardiovascular morbidity within this sizable subgroup of patients. In the Study on Cognition and Prognosis in the Elderly (SCOPE) trial, candesartan showed a 27.8% reduction in nonfatal stroke versus placebo (95% CI 1.3–47.2; p = 0.04). Moreover, losartan demonstrated a decrease in all cardiovascular events compared to atenolol in the Cardiovascular Morbidity and Mortality in the Losartan Intervention for Endpoint Reduction in Hypertension (LIFE) study (RR 0.87; 95% CI 0.77–0.98; p = 0.021).

CONCLUSIONS

Data supporting the use of ARBs for reducing cardiovascular events in patients with essential hypertension without compelling indications are limited and inconclusive. More studies are needed before ARBs can be routinely recommended as first-line therapy for hypertension management in patients without other compelling indications.

Discovery of inhibitors of insulin-regulated aminopeptidase as cognitive enhancers

The hexapeptide angiotensin IV (Ang IV) is a metabolite of angiotensin II (Ang II) and plays a central role in the brain. It was reported more than two decades ago that intracerebroventricular injection of Ang IV improved memory and learning in the rat. Several hypotheses have been put forward to explain the positive effects of Ang IV and related analogues on cognition. It has been proposed that the insulin-regulated aminopeptidase (IRAP) is the main target of Ang IV. This paper discusses progress in the discovery of inhibitors of IRAP as potential enhancers of cognitive functions. Very potent inhibitors of the protease have been synthesised, but pharmacokinetic issues (including problems associated with crossing the blood-brain barrier) remain to be solved. The paper also briefly presents an overview of the status in the discovery of inhibitors of ACE and renin, and of AT1R antagonists and AT2R agonists, in order to enable other discovery processes within the RAS system to be compared. The paper focuses on the relationship between binding affinities/inhibition capacity and the structures of the ligands that interact with the target proteins.

Cost-effectiveness of candesartan versus losartan in the primary preventive treatment of hypertension

Background

Although angiotensin receptor blockers have different receptor binding properties, no comparative randomized studies with cardiovascular event endpoints have been performed for this class of drugs. The aim of this study was to assess the long-term cost-effectiveness of candesartan (Atacand^®) versus generic losartan in the primary preventive treatment of hypertension.

Methods

A decision-analytic model was developed to estimate costs and health outcomes over a patient’s lifetime. Data from a clinical registry study were used to estimate event rates for cardiovascular complications, such as myocardial infarction and heart failure. Costs and quality of life data were from published sources. Costs were in Swedish kronor and the outcome was quality-adjusted life-years (QALYs).

Results

Due to reduced rates of cardiovascular complications, candesartan was associated with a QALY gain and lower health care costs compared with generic losartan (0.053 QALYs gained and reduced costs of approximately 4700 Swedish kronor for women; and 0.057 QALYs gained and reduced costs of approximately 4250 Swedish kronor for men). This result was robust in several sensitivity analyses.

Conclusion

When modeling costs and health outcomes based on event rates for cardiovascular complications from a real-world registry study, candesartan appears to bring a QALY gain and a reduction in costs compared with generic losartan in the primary preventive treatment of hypertension in Sweden.

Are fixed-dose combination antihypertensives suitable as first-line therapy?

OBJECTIVE

To contemplate how initial antihypertensive therapy with fixed-dose combinations (FDC) might be incorporated into clinical practice, based on a compilation of evidence comparing FDCs with monotherapy and loose-dose combinations in varying patient populations.

METHODS

A non-systematic search of PubMed (from 2007 to 2012) was performed for randomized, controlled trials in order to capture the evidence on FDC versus monotherapy and loose-dose combinations as first-line therapy. The literature search focused on calcium channel blocker (CCB)-renin angiotensin system (RAS) blocker combinations. Additionally, any relevant papers known to the authors were included. International recommendations from published hypertension treatment guidelines were also consulted.

RESULTS

The results of this literature review identified two emergent issues. Firstly, there is a discord between antihypertensive use and actual blood pressure (BP) control achieved - despite an increase in the use of antihypertensives over the last 10 years, BP control rates remain low. Secondly, a greater association between BP and cardiovascular risk in Asians may magnify this discrepancy. A number of international guidelines are recommending early combination therapy, such as CCB-RAS blocker combinations in the majority of patients based on the available evidence, with such combinations showing benefits in terms of compliance, BP lowering and control, and safety. Additionally, recent studies have indicated that improved BP control may be achieved with simplified guidelines and the use of FDCs. Overall, these findings indicate that FDC could be used as first-line.

CONCLUSIONS

The findings from this literature review suggest that physicians may need to readdress their approach to antihypertensive treatment. Earlier use of antihypertensive FDC (including first-line) may help to shrink the current gap between antihypertensive use and BP target control achieved. Most guidelines acknowledge that combination therapy is required in the majority of patients, and FDC are regarded as a suitable alternative, having demonstrated better compliance compared with loose-dose combinations.

Automated data extraction--a feasible way to construct patient registers of primary care utilization

INTRODUCTION

Electronic medical records (EMRs) enable analysis of health care data by using data mining techniques to build research databases. Though the reliability of the data extraction process is crucial for the credibility of the final analysis, there are few published validations of this process. In this paper we validate the performance of an automated data mining tool on EMR in a primary care setting.

METHODS

The Pygargus Customized eXtraction Program (CXP) was programmed to find and then extract data from patients meeting criteria for type 2 diabetes mellitus (T2DM) at one primary health care clinic (PHC). The ability of CXP to extract relevant cases was assessed by comparing cases extracted by an EMR integrated search engine. The concordance of extracted data with the original EMR source was manually controlled.

RESULTS

Prevalence of T2DM was 4.0%, which correspond well to previous estimations. By searching for drug prescriptions, diagnosis codes, and laboratory values, 38%, 53%, and 91% of relevant cases were found, respectively. The sensitivity of CXP regarding extraction of relevant cases was 100%. The specificity was 99.9% due to 12 non-T2DM cases extracted. The congruity at single-item level was 99.6%. The 13 incorrect data items were all located in the same structural module.

CONCLUSION

The CXP is a reliable and accurate data mining tool to extract selective data from EMR.

Clozapine, atypical antipsychotics, and the benefits of fast-off D2 dopamine receptor antagonism

Drug-receptor interactions are traditionally quantified in terms of affinity and efficacy, but there is increasing awareness that the drug-on-receptor residence time also affects clinical performance. While most interest has hitherto been focused on slow-dissociating drugs, D(2) dopamine receptor antagonists show less extrapyramidal side effects but still have excellent antipsychotic activity when they dissociate swiftly. Fast dissociation of clozapine, the prototype of the "atypical antipsychotics", has been evidenced by distinct radioligand binding approaches both on cell membranes and intact cells. The surmountable nature of clozapine in functional assays with fast-emerging responses like calcium transients is confirmatory. Potential advantages and pitfalls of the hitherto used techniques are discussed, and recommendations are given to obtain more precise dissociation rates for such drugs. Surmountable antagonism is necessary to allow sufficient D(2) receptor stimulation by endogenous dopamine in the striatum. Simulations are presented to find out whether this can be achieved during sub-second bursts in dopamine concentration or rather during much slower, activity-related increases thereof. While the antagonist's dissociation rate is important to distinguish between both mechanisms, this becomes much less so when contemplating time intervals between successive drug intakes, i.e., when pharmacokinetic considerations prevail. Attention is also drawn to the divergent residence times of hydrophobic antagonists like haloperidol when comparing radioligand binding data on cell membranes with those on intact cells and clinical data.

Resource utilization and cost of heart failure associated with reduced ejection fraction in Swedish patients

AIM

The purpose of this study was to assess healthcare utilization and costs for heart failure patients with reduced ejection fraction (HF-REF) in Sweden.

METHODS AND RESULTS

This was a retrospective, population-based cohort study of patients diagnosed with HF-REF during a period of 18 months at 31 primary care centers in Uppsala County, Sweden. Data was obtained from computerized records from these centers, the Swedish Patient Registry, the Swedish Prescription Registry, the Cause of Death Registry, and a local echocardiography registry maintained by the Department of Physiology, Uppsala University Hospital. Main outcome measures were cardiovascular and heart-failure-related hospitalizations, outpatient visits, medication utilization, mortality (all-cause, cardiovascular, and heart-failure), and healthcare costs for HF-REF patients. During the index period, 252 heart failure patients had a left ventricular ejection fraction measurement ≤ 40% and were categorized as having HF-REF. More than half of the patients had ≥ 1 cardiovascular or heart failure-related hospitalization. On average, patients had >2 such hospitalizations annually. They also averaged ∼1 cardiovascular or heart-failure-related outpatient visit per year. All-cause mortality was high: 15.9% patients died within 1 year after the index date. The mean annual cost per patient for heart-failure-related hospitalizations was SEK 72,613 (EUR 7610). In contrast, annual prescription costs were low, on average 3% of total cost (SEK 3503, EUR 367 per patient)

LIMITATIONS

The main limitations of this study include a short follow-up time and small sample size. Also, certain data were missing, such as echocardiograms (available for only 28% of patients), and information on patients' New York Heart Association (NYHA) functional class, validity period for prescriptions or the units of medication prescribed, and medication dosing. Furthermore, the overall mortality could have been under-estimated, as only the primary cause of death was included in the analysis.

CONCLUSIONS

The main burden associated with HF-REF is related to hospitalizations for heart-failure events. Effective treatment options that decrease hospitalization rates could reduce patients' suffering and potentially offer considerable cost savings.

Cardiovascular events in subgroups of patients during primary treatment of hypertension with candesartan or losartan

Merging data from existing electronic patient records, and electronic hospital discharge and cause of death registers, is a fast and relatively inexpensive method for comparing different treatments with regard to clinical outcome. This study compared the effects of antihypertensive treatment with candesartan or losartan on cardiovascular disease (CVD) using Swedish registers. Patients without previous CVD who were prescribed candesartan (n=7329) or losartan (n=6771) for hypertension during 1999-2007 at 72 Swedish primary care centers were followed for up to 9 years. Both medications were given according to current recommendations, and there was no difference observed in achieved blood pressures. The authors have previously shown that candesartan lowered the risk of all CVD (primary composite end point) more so than losartan (adjusted hazard ratio, 0.86; 95% confidence interval, 0.77-0.96). Candesartan also had a significantly better effect with regards to reducing the development of heart failure, cardiac arrhythmias, and peripheral arterial disease. In the present analysis, the authors found that candesartan, compared with losartan, reduced the risk of all CVD, irrespective of sex, age, previous antihypertensive treatment, baseline blood pressure, and presence of diabetes. These clinical findings may reflect differences between candesartan and losartan in their binding characteristics to the angiotensin type 1 receptor.

Blood pressure-independent effect of candesartan on cardio-ankle vascular index in hypertensive patients with metabolic syndrome

Angiotensin receptor blockers (ARBs) are known to reduce the cardiovascular risk in hypertensive patients. This study was designed to examine the effect of an ARB candesartan on subclinical atherosclerosis assessed by cardio-ankle vascular index (CAVI) in comparison with calcium channel blockers (CCBs) alone in hypertensive patients with metabolic syndrome (MetS). A total of 53 consecutive hypertensive patients with MetS were randomly assigned to the candesartan group, in which candesartan was added on, or the CCBs group, in which CCBs were added on. Clinical and biological parameters were obtained before and after the 12-month treatment period. The primary measure of efficacy was the %change in CAVI. When treated with candesartan, but not CCBs, CAVI significantly decreased from 8.7 to 7.7 by 11%. Blood pressure (BP) significantly decreased with both treatments, but the differences between groups were not significant. The changes in other parameters remained unchanged in both the groups. Analysis of covariance found that both the BP reduction and the therapy difference contributed to the decrease in CAVI, but the BP reduction was not involved in the decrease in CAVI caused by the difference in the therapy. Candesartan may be a better antihypertensive drug than CCBs to improve subclinical atherosclerosis of patients with MetS.

Health-care costs of losartan and candesartan in the primary treatment of hypertension

A recent study of two widely used angiotensin receptor blockers reported a reduced risk of cardiovascular events (−14.4%) when using candesartan compared with losartan in the primary treatment of hypertension. In addition to clinical benefits, costs associated with treatment strategies must be considered when allocating scarce health-care resources. The aim of this study was to assess resource use and costs of losartan and candesartan in hypertensive patients. Resource use (drugs, outpatient contacts, hospitalizations and laboratory tests) associated with losartan and candesartan treatment was estimated in 14 100 patients in a real-life clinical setting. We electronically extracted patient data from primary care records and mandatory Swedish national registers for death and hospitalization. Patients treated with losartan had more outpatient contacts (+15.6%), laboratory tests (+13.8%) and hospitalizations (+13.8%) compared with the candesartan group. During a maximum observation time of 9 years, the mean total costs per patient were 10 369 Swedish kronor (95% confidence interval: 3109–17 629) higher in the losartan group. In conclusion, prescribing candesartan for the primary treatment of hypertension results in lower long-term health-care costs compared with losartan.

Comparison of the efficacy of candesartan and losartan: a meta-analysis of trials in the treatment of hypertension

Informed by the findings from prospective observational studies and randomized outcome trials, guidelines for the management of hypertension acknowledge that the benefit of treatment can be attributed largely to blood pressure (BP) reduction. Therefore, quantification of differential BP lowering of different agents within classes of anti-hypertensives is of practical importance. The objective of this analysis was to compare the efficacy of candesartan and losartan with respect to reduction in systolic and diastolic BP (SBP and DBP). A systematic literature search of databases from 1980 to 1 October 2008 identified 13 studies in which candesartan and losartan were compared in randomized trials in hypertensive patients. Data from 4066 patients were included in the analysis using a random effect model. Mean changes in SBP and DBP were compared for each drug alone and after stratification for dose and for combination with hydrochlorothiazide (HCTZ). On the basis of all the data, the weighted mean difference favoured candesartan-3.22 mm Hg (95% confidence interval (CI) 2.16, 4.29) for SBP and 2.21 mm Hg (95% CI 1.34, 3.07) for DBP. These findings were consistent when analyses according to dose and combination with HCTZ were carried out. Thus, it can be concluded that at currently recommended doses, candesartan is more effective than losartan in lowering BP.