Progression of cardiovascular damage: the role of renin-angiotensin system blockade

Anti-hypertensive and composition as well as pharmacokinetics and tissues distribution of active ingredients from Alpinia zerumbet

Alpinia zerumbet is a food flavor additive and a traditional medicine herb around the world. Several studies have reported that A. zerumbet has excellent effects on a variety of cardiovascular diseases, but its potential hypertensive applications, and pharmacokinetic features of main active substances have not been fully investigated. The mechanism of anti-hypertension with ethyl acetate extracts of A. zerumbet fruits (AZEAE) was evaluated by L-NNA-induced hypertensive rats and L-NAME-injured human umbilical vein endothelial cells (HUVECs). Blood pressure, echocardiographic cardiac index and H&E staining were used to preliminary evaluate the antihypertensive effect of AZEAE, the levels of TNF-α, IL-6, and IL-1β were evaluated by ELISA, and the proteins expression of IL-1β, IL-18, AGTR1, VCAM, iNOS, EDN1 and eNOS were also evaluated. In addition, isolation, identification, and activity screening of bioactive compounds were carried ou. Next, pharmacokinetics and tissues distribution of dihydro-5,6-dehydrokavain (DDK) in vivo were measured, and preliminary absorption mechanism was conducted with Caco-2 cell monolayers. AZEAE remarkably enhanced the state of hypertensive rats. Twelve compounds were isolated and identified, and five compounds were isolated from this plant for the first time. The isolated compounds also exhibited good resistance against injury of HUVECs. Moreover, pharmacokinetics and Caco-2 cell monolayers demonstrated AZEAE had better absorption capacity than DDK, and DDK exhibited differences in tissues distribution and gender difference. This study was the first to assess the potential hypertensive applications of A. zerumbet in vivo and vitro, and the first direct and concise study of the in vivo behavior of DDK and AZEAE.

Impact of ACEIs and ARBs-related adverse drug reaction on patients' clinical outcomes: a cohort study in UK primary care

BACKGROUND

Adverse drug reaction (ADR) related to angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) may negatively affect patients' treatment outcomes.

AIM

To investigate the impact of ACEIs/ARBs-related ADR consultation on cardiovascular disease (CVD) events and all-cause mortality.

DESIGN AND SETTING

Propensity score-matched cohort study of ACEIs/ARBs between 2004 and 2019 using UK IQVIA medical research data.

METHOD

ADR consultations were identified using standardised designated codes. Propensity scores were calculated based on comorbidities, concomitant medications, frailty, and polypharmacy. Cox's proportional hazard regression model was used to compare the outcomes between patients in ADR and non-ADR groups. In the secondary analysis, treatment- pattern changes following the ADR were examined and the subsequent outcomes were compared.

RESULTS

Among 1 471 906 eligible users of ACEIs/ARBs, 13 652 (0.93%) patients had ACEIs/ARBs- related ADR consultation in primary care. Patients with ACEIs/ARBs-related ADR consultation had an increased risk of subsequent CVD events and all- cause mortality in both primary prevention (CVD events: adjusted hazard ratio [aHR] 1.22, 95% confidence interval [CI] = 1.05 to 1.43; all-cause mortality: aHR 1.14, 95% CI = 1.01 to 1.27) and secondary prevention cohorts (CVD events: aHR 1.13, 95% CI = 1.05 to 1.21; all-cause mortality: aHR 1.15, 95% CI = 1.09 to 1.21). Half (50.19%) of patients with ADR continued to use ACEIs/ARBs, and these patients had a reduced risk of mortality (aHR 0.88, 95% CI = 0.82 to 0.95) compared with those who discontinued using ACEIs/ARBs.

CONCLUSION

This study provides information on the burden of ADR on patients and the health system. The findings call for additional monitoring and treatment strategies for patients affected by ADR to mitigate the risks of adverse clinical outcomes.

Comparison Between Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers in Patients with Unstable Angina with Preserved Left Ventricular Systolic Function

The present study evaluated the clinical results of angiotensin-converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) treatment in patients with unstable angina (UA) with preserved left ventricular systolic function who underwent percutaneous coronary intervention (PCI) due to uncertainty regarding the long-term prognosis using ACEI or ARB. A total of 1627 UA patients with preserved left ventricular systolic function after PCI were enrolled. After propensity score matching, there were no differences in major adverse cardiovascular and cerebrovascular events (MACCEs) (hazard ratio (HR) = .860, 95% confidence interval (CI): .465-1.590, P = .630), all-cause death (HR = .334, 95% CI: .090-1.238, P = .101), nonfatal myocardial infarction (HR = 4.929, 95% CI: .576-42.195, P = .145), stroke (HR = 1.049, 95% CI: .208-5.290, P = .954) and target vessel revascularization (TVR) (HR = 1.276, 95% CI: .537-3.031, P = .581) between the ACEI and ARB groups. In conclusion, prognoses were comparable between ACEI or ARB treatment in UA patients who had preserved left ventricular systolic function after PCI.

Insulin Resistance and Vitamin D Deficiency: A Link Beyond the Appearances

Vitamin D is a steroid hormone that plays a key role in the regulation of body homeostasis, including cardiovascular function. Although the chronic deficiency of vitamin D is associated with cardiovascular risk factors, as well as with an adverse prognosis, randomized controlled trials have failed in demonstrating that dietary vitamin D supplementation could ameliorate the prognosis of patients with cardiovascular diseases, and suggested that vitamin D deficiency is the expression of the effects of other determinants of cardiovascular risk. Thus, the supplementation of vitamin D is not sufficient to improve the cardiovascular risk profile and prognosis. Insulin resistance is a complex phenomenon that plays a key role in the pathogenesis of conventional cardiovascular risk factors. Interestingly, defects of vitamin D and insulin resistance have a superimposable epidemiological distribution. According to the common view, Insulin resistance is considered the direct or indirect consequence of vitamin D deficiency. However, it is also reasonable to speculate that the deficit or the impaired action of vitamin D, in some circumstances, could be the result of the same pathogenic mechanisms responsible of insulin resistance development. In this case, vitamin D deficiency could be considered an epiphenomenon of insulin resistance. Insulin resistance is a reversible condition, being possibly ameliorated by physical activity and hypocaloric diets. Notably, both physical exercise and energy-restricted dietary regimens are associated with an increase of vitamin D levels. These findings indicate that improving insulin resistance condition is a necessary step to ameliorate vitamin D supplementation-based strategies in cardiovascular prevention.

Genetic Polymorphisms of Very Important Pharmacogene Variants in the Blang Population from Yunnan Province in China

Background

We aimed to enrich the pharmacogenomic information of a Blang population (BP) from Yunnan Province in China.

Methods

We genotyped 55 very important pharmacogene (VIP) variants from the PharmGKB database and compared their genotype distribution (GD) in a BP with that of 26 populations by the χ² test. The minor allele frequency (MAF) distribution of seven significantly different single-nucleotide polymorphisms (SNPs) was conducted to compare the difference between the BP and 26 other populations.

Results

Compared with the GD of 55 loci in the BP, among 26 studied populations, GWD, YRI, GIH, ESN, MSL, TSI, PJL, ACB, FIN and IBS were the top-10 populations, which showed a significantly different GD >35 loci. CHB, JPT, CDX, CHS, and KHV populations had a significantly different GD <20 loci. A GD difference of 27–34 loci was found between the BP and 11 populations (LWK, CEU, ITU, STU, PUR, CLM, GBR, ASW, BEB, MXL and PEL). The GD of five loci (rs750155 (SULT1A1), rs4291 (ACE), rs1051298 (SLC19A1), rs1131596 (SLC19A1) and rs1051296 (SLC19A1)) were the most significantly different in the BP as compared with that of the other 26 populations. The genotype frequency of rs1800764 (ACE) and rs1065852 (CYP2D6) was different in all populations except for PEL and LWK, respectively. MAFs of rs1065852 (CYP2D6) and rs750155 (SULT1A1) showed the largest fluctuation between the BP and SAS, EUR, AFR and AMR populations.

Conclusion

Our data can provide theoretical guidance for safe and efficacious personalized drug use in the Blang population.

Population Genetic Difference of Pharmacogenomic VIP Variants in the Tibetan Population

Background

Genetic variation influences drug reaction or adverse prognosis. The purpose of this research was to genotype very important pharmacogenetic (VIP) variants in the Tibetan population.

Methods and Materials

Blood samples from 200 Tibetans were randomly collected and 59 VIP variants were genotyped, and then compared our data to 26 other populations in the 1000 project to further analyze and identify significant difference.

Results

The results showed that on comparing with most of the 26 populations from the 1000 project, rs4291 (ACE), rs1051296 (SLC19A1) and rs1065852 (CYP2D6) significantly differed in the Tibetan population. Furthermore, three significant loci were related to drug response. In addition, the allele frequency of Tibetans least differed from that of East Asian populations, and most differed from that of Americans.

Conclusion

Three significant loci of variation ACE rs4291, SLC19A1 rs1051296 and CYP2D6 rs1065852 were associated with drug response. This result will contribute to improving the information of the Tibetan in the pharmacogenomics database, and providing a theoretical basis for clinical individualised drug use in Tibetans.

ACE2 activator diminazene aceturate exerts renoprotective effects in gentamicin-induced acute renal injury in rats

Acute Kidney Injury (AKI) comprises a rapidly developed renal failure and is associated with high mortality rates. The Renin-Angiotensin System (RAS) plays a pivotal role in AKI, as the over-active RAS axis exerts major deleterious effects in disease progression. In this sense, the conversion of Angiotensin II (Ang II) into Angiotensin-(1-7) (Ang-(1-7)) by the Angiotensin-converting enzyme 2 (ACE2) is of utmost importance to prevent worse clinical outcomes. Previous studies reported the beneficial effects of oral diminazene aceturate (DIZE) administration, an ACE2 activator, in renal diseases models. In the present study, we aimed to evaluate the therapeutic effects of DIZE administration in experimental AKI induced by gentamicin (GM) in rats. Our findings showed that treatment with DIZE improved renal function and tissue damage by increasing Ang-(1-7) and ACE2 activity, and reducing TNF-α. These results corroborate with a raising potential of ACE2 activation as a strategy for treating AKI.

Prognostic Impacts of Comorbid Significant Coronary Stenosis and Coronary Artery Spasm in Patients With Stable Coronary Artery Disease

BACKGROUND Stable coronary artery disease is caused by a variable combination of organic coronary stenosis and functional coronary abnormalities, such as coronary artery spasm. Thus, we examined the clinical importance of comorbid significant coronary stenosis and coronary spasm. METHODS AND RESULTS We enrolled 236 consecutive patients with suspected angina who underwent acetylcholine provocation testing for coronary spasm and fractional flow reserve (FFR) measurement. Among them, 175 patients were diagnosed as having vasospastic angina (VSA), whereas the remaining 61 had no VSA (non-VSA group). The patients with VSA were further divided into the following 3 groups based on angiography and FFR: no organic stenosis (≤50% luminal stenosis; VSA-alone group, n=110), insignificant stenosis of FFR>0.80 (high-FFR group, n=36), and significant stenosis of FFR≤0.80 (low-FFR group, n=29). The incidence of major adverse cardiovascular events, including cardiovascular death, nonfatal myocardial infarction, urgent percutaneous coronary intervention, and hospitalization attributed to unstable angina was evaluated. All patients with VSA received calcium channel blockers, and 28 patients (95%) in the low-FFR group underwent a planned percutaneous coronary intervention. During a median follow-up period of 656 days, although the incidence of major adverse cardiovascular events was low and comparable among non-VSA, VSA-alone, and high-FFR groups, the low-FFR group had an extremely poor prognosis (non-VSA group, 1.6%; VSA-alone group, 3.6%; high-FFR group, 5.6%; low-FFR group, 27.6%) (P<0.001). Importantly, all 8 patients with major adverse cardiovascular events in the low-FFR group were appropriately treated with percutaneous coronary intervention and calcium channel blockers. CONCLUSIONS These results indicate that patients with VSA with significant coronary stenosis represent a high-risk population despite current guideline-recommended therapies, suggesting the importance of routine coronary functional testing in this population.

Reflections of the Angiotensin Receptor Blocker Recall by the FDA and Repercussions on Healthcare

PURPOSE

Beginning in July of 2018, the FDA issued a voluntary recall regarding the presence of a contaminant found in the manufacturing of valsartan. What would ensue has become a largely unprecedented sequence of alarming events since the FDA began reporting public recalls, withdrawals and safety alerts on their website in 2016. Since then, the United States has been significantly impacted by drug recalls affecting angiotensin receptor blockers. This report arms clinicians with additional guidance and provides a framework for responding appropriately to future similar incidents and includes an overview of the angiotensin receptor blockers, and their effects and safety profiles.

METHODS

This report includes a review of data from all pertinent clinical and scientific sources including information from the FDA's inspection documents and recall website. Additional information is provided on the specific bottles including all lot numbers, expiration dates, etc. RESULTS: The recalls/withdrawals are attributable to the presence of cancer-causing contaminants identified during the manufacturing process from drug manufacturers abroad. The root causes behind the recalls and subsequent shortage appear multifactorial, and stem to a certain extent from the outsourcing of medication manufacturing overseas and lack of quality checks and appropriate oversight.

CONCLUSIONS

This inherent issue is not likely to resolve soon and has eroded the public trust of/in the healthcare system and the pharmaceutical industry. Patients and healthcare providers are significantly affected and should have a full understanding of the matter in order to guide appropriate response and actions.

Comparison of clinical outcomes between angiotensin-converting-enzyme inhibitors and ARBs in patients with acute myocardial infarction with dyslipidemia after a successful stent implantation

OBJECTIVE

Currently, there are limited comparative data concerning long-term major clinical outcomes following the angiotensin-converting-enzyme inhibitors (ACEIs) and angiotensin II type 1 (AT1) receptor blockers (ARBs) therapy in patients with acute myocardial infarction (AMI) with dyslipidemia after a successful stent implantation. Therefore, we investigated major clinical outcomes for 2 years following the ACEIs and ARBs therapy in these patients.

METHODS

A total of 3015 patients with AMI who underwent a successful stent implantation and were prescribed ACEIs (n=2175) or ARBs (n=840) were enrolled into the study from the Korea AMI Registry (KAMIR). The major clinical endpoint was the occurrence of major adverse cardiac events (MACEs) defined as all-cause death, recurrent myocardial infarction (Re-MI), and any repeat-revascularization-comprised target lesion revascularization (TLR), target vessel revascularization (TVR), and non-TVR.

RESULTS

After the adjustment, the cumulative incidence of all-cause death in the ARBs group was significantly higher than in the ACEIs group [adjusted hazard ratio (aHR), 2.277; 95% confidence interval (CI), 1.154-4.495; p=0.018]. The cumulative incidences of MACEs (aHR, 1.305; 95% CI, 0.911-1.869; p=0.146), cardiac death, Re-MI, any repeat revascularization, TLR, TVR, and non-TVR were similar between the two groups. In addition, an advanced age (≥65 years), decreased left ventricular ejection fraction (&lt;50&percnt;), and cardiopulmonary resuscitation on admission were meaningful independent predictors for all-cause death in this study.

CONCLUSION

ACEIs were a preferred treatment modality when compared to ARBs for patients with AMI with dyslipidemia who underwent a successful stent implantation to reduce the incidences of all-cause death during a 2-year follow-up. However, additional research is required to determine the clinical implications of these results.

Clinical Implications of SARS-CoV-2 Interaction With Renin Angiotensin System: JACC Review Topic of the Week

Severe acute respiratory-syndrome coronavirus-2 (SARS-CoV-2) host cell infection is mediated by binding to angiotensin-converting enzyme 2 (ACE2). Systemic dysregulation observed in SARS-CoV was previously postulated to be due to ACE2/angiotensin 1-7 (Ang1-7)/Mas axis downregulation; increased ACE2 activity was shown to mediate disease protection. Because angiotensin II receptor blockers, ACE inhibitors, and mineralocorticoid receptor antagonists increase ACE2 receptor expression, it has been tacitly believed that the use of these agents may facilitate viral disease; thus, they should not be used in high-risk patients with cardiovascular disease. Based on the anti-inflammatory benefits of the upregulation of the ACE2/Ang1-7/Mas axis and previously demonstrated benefits of lung function improvement in SARS-CoV infections, it has been hypothesized that the benefits of treatment with renin-angiotensin system inhibitors in SARS-CoV-2 may outweigh the risks and at the very least should not be withheld.

Monotherapy versus combination therapy of statin and renin-angiotensin system inhibitor in ST-segment elevation myocardial infarction

Background

The beneficial effects of statin and renin–angiotensin system inhibitor (RASI) are well-known. In this retrospective cohort study, 2-year clinical outcomes were compared between monotherapy and combination therapy with statin and RASI in ST-segment elevation myocardial infarction (STEMI) patients after stent implantation.

Methods

A total of 17,414 STEMI patients were enrolled and divided into the three groups (group A: 2448 patients, statin alone; group B: 2431 patients, RASI alone; and group C: 12,535 patients, both statin and RASI). The principal clinical endpoint was the occurrence of major adverse cardiac events (MACEs) defined as all-cause death, recurrent myocardial infarction, and any repeat revascularization.

Results

After adjustment, the cumulative incidences of MACEs in group A (adjusted hazard ratio [aHR] 1.337; 95% confidence interval [CI] 1.064–1.679; p = 0.013) and in group B (aHR 1.375; 95% CI 1.149–1.646; p = 0.001) were significantly higher than in group C. The cumulative incidence of all-cause death in group A was significantly higher than that in group C (aHR 1.539; 95% CI 1.014–2.336; p = 0.043). The cumulative incidences of any repeat revascularization (aHR 1.317; 95% CI 1.031–1.681; p = 0.028), target lesion vascularization, and target vessel vascularization in group B were significantly higher than in group C.

Conclusions

A statin and RASI combination therapy significantly reduced the cumulative incidence of MACEs compared with a monotherapy of these drugs. Moreover, the combination therapy showed a reduced all-cause death rate compared with statin monotherapy, and a decreased repeat revascularization rate compared with RASI monotherapy.

ACE Inhibitors Versus ARBs in Patients With NSTEMI With Preserved LV Systolic Function Who Underwent PCI With New Generation Drug-Eluting Stents

The relative superiority of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) on long-term clinical outcomes in patients with non-ST-segment elevation myocardial infarction (NSTEMI) with preserved left ventricular systolic function in the era of new generation drug-eluting stents is not well established. A total of 6436 patients with NSTEMI (ACEIs group: n = 3965 vs ARBs group: n = 2471) were enrolled. The major clinical end point was the occurrences of major adverse cardiac events (MACEs), defined as all-cause death, recurrent myocardial infarction (re-MI), and any repeat revascularization. After propensity score matching analysis, the cumulative incidences of MACEs (hazard ratio, 1.334; 95% confidence interval, 1.045-1.703; P = .021), any repeat revascularization, and target vessel revascularization (TVR) in the ARB group were significantly higher than that in the ACEI group. However, the cumulative incidences of all-cause death, cardiac death, re-MI, target lesion revascularization, and non-TVR were similar between the 2 groups. Hence, although the mortality and re-MI reduction benefits were similar between the 2 groups, the ACEIs group showed more prominent ability to decrease the occurrences of MACEs, any repeat revascularization, and TVR compared to the ARBs group in these patients during a 2-year follow-up period.

A comparison between statin with ACE inhibitor or ARB therapy in STEMI patients who underwent successful PCI with drug-eluting stents

BACKGROUND AND AIMS

Studies of the comparative clinical outcomes between statin with angiotensin converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) in ST-segment elevation myocardial infarction (STEMI) patients are limited. We compared 2-year clinical outcomes between statin with ACEI or ARB therapy in STEMI patients after successful percutaneous coronary intervention (PCI) with drug-eluting stents (DES).

METHODS

A total of 11,706 STEMI patients were enrolled and separated into two groups: the ACEI group (statin + ACEI, n = 8705) and the ARB group (statin + ARB, n = 3001). The primary endpoint was major adverse cardiac events (MACE) defined as all-cause death, recurrent MI (re-MI), and any coronary revascularization. Secondary endpoints were the individual components of MACE and target vessel failure (TVF).

RESULTS

After propensity score-matched (PSM) analysis, two PSM groups (2729 pairs, n = 5458, C-statistic = 0.675) were generated. The cumulative incidences of MACE, re-MI, and any coronary revascularization were similar between the two groups. However, the cumulative incidences of all-cause death (hazard ratio [HR], 1.548; 95% confidence interval [CI], 1.091-2.197; p = 0.014) and cardiac death (HR, 1.850; 95% CI, 1.218-2.811; p = 0.004) were significantly higher in the ARB group compared with the ACEI group after PSM analysis.

CONCLUSIONS

The combination of statin with ACEI may be the preferred treatment strategy to reduce mortality rates in STEMI patients after successful PCI with DES rather than statin with ARB in this study during a 2-year follow-up period.

A gender-specific association of the polymorphism Ile197Met in the kininogen 1 gene with plasma irbesartan concentrations in Chinese patients with essential hypertension

This study was conducted to explore interactions in the association of the kininogen (KNG1) Ile197Met polymorphism and gender with plasma concentrations of irbesartan in Chinese patients with essential hypertension. A total of 1100 subjects with essential hypertension received a daily oral dose of 150 mg irbesartan for twenty-eight consecutive days. High-performance liquid chromatography-fluorescence (HPLC) was used to detect plasma irbesartan concentrations on day 28. The KNG1 Ile197Met gene polymorphism was determined using high-throughput TaqMan technology. The frequency distribution of KNG1 Ile197Met genotype conformed to the Hardy-Weinberg equilibrium. After 28 days of treatment, patients with the GG genotype had significantly lower irbesartan concentrations (P = 0.033) compared to homozygous TT genotype carriers. After stratifying by gender, male G allele carriers had significantly lower irbesartan concentrations (GG, P = 0.015; TG, P = 0.015, respectively) relative to TT genotype after adjusting for age, region, body mass index (BMI), smoking, and alcohol consumption. However, there was no significant difference in female subjects. A further test for a multiplicative interaction between the KNG1 Ile197Met polymorphism and gender in association with ln-plasma irbesartan concentrations in a multiple linear regression model was also significant (P for interaction = 0.033). This is the first study to suggest that gender may influence the association of the Ile197Met variant of KNG1 with ln-plasma irbesartan concentration. This finding may indicate that the interaction of gender and the KNG1 Ile197Met gene polymorphism can influence plasma trough irbesartan concentrations, which may contribute to a better development of personalized hypertensive treatment in Chinese patients.

Soluble (pro)renin receptor in preeclampsia and diabetic pregnancies

Women with preexisting or gestational diabetes mellitus have an increased risk for developing preeclampsia. Diabetes and pregnancy are both characterized by very high prorenin levels and renin-angiotensin system activation. Prorenin bound to the (pro)renin receptor has enzymatic activity. We hypothesized that soluble (pro)renin receptor levels are elevated in high-risk pregnancies. Third trimester maternal blood samples from complicated pregnancies (n = 165), (preeclampsia [n = 76], diabetes mellitus [type I diabetes, n = 35; type II diabetes, n = 11; gestational diabetes mellitus, n = 43]), and healthy pregnancies (n = 49) were analyzed for prorenin, renin, and soluble (pro)renin receptor. There were no significant differences in prorenin or renin levels between the study groups in a multivariate model. In the group of women with gestational diabetes, soluble (pro)renin receptor concentrations were significantly higher compared with healthy pregnancies or preeclampsia. Soluble (pro)renin receptor did not correlate with renin or prorenin levels for any of the study groups. Our results show that soluble (pro)renin receptor is dysregulated in pregnancies affected by diabetes mellitus, but not in preeclampsia. Alterations in circulating soluble (pro)renin receptor are unrelated to renin/prorenin in pregnancy, but may be of pathophysiological relevance in diabetic pregnancies in a renin-angiotensin system-independent manner.

Angiotensin II type 2 receptor (AT2R) in renal and cardiovascular disease

Angiotensin II (Ang II) is well-considered to be the principal effector of the renin-angiotensin system (RAS), which binds with strong affinity to the angiotensin II type 1 (AT1R) and type 2 (AT2R) receptor subtype. However, activation of both receptors is likely to stimulate different signalling mechanisms/pathways and produce distinct biological responses. The haemodynamic and non-haemodynamic effects of Ang II, including its ability to regulate blood pressure, maintain water-electrolyte balance and promote vasoconstriction and cellular growth are well-documented to be mediated primarily by the AT1R. However, its biological and functional effects mediated through the AT2R subtype are still poorly understood. Recent studies have emphasized that activation of the AT2R regulates tissue and organ development and provides in certain context a potential counter-regulatory mechanism against AT1R-mediated actions. Thus, this review will focus on providing insights into the biological role of the AT2R, in particular its actions within the renal and cardiovascular system.

Angiotensin-Converting Enzyme Inhibition and Parathyroid Hormone Secretion

BACKGROUND

Prior studies suggest that renin-angiotensin-aldosterone system (RAAS) inhibitors decrease parathyroid hormone (PTH) secretion.

OBJECTIVE

To evaluate the effect of angiotensin-converting enzyme inhibitors (ACEi) on serum PTH in participants with and without primary hyperparathyroidism (P-HPT).

METHODS

An open-label, single-arm, pilot study whereby participants with and without P-HPT had PTH were evaluated before and after 1 week of maximally tolerated lisinopril therapy.

RESULTS

A total of 12 participants with, and 15 participants without, P-HPT successfully completed the protocol. Following 1 week of lisinopril, participants with P-HPT had a decrease in systolic blood pressure (SBP) (-6.4 mmHg, P < 0.01), an increase in plasma renin activity (PRA) (+1.50 ng/mL/h, P = 0.06), and a decrease in PTH (79.5 (21.6) to 70.9 (19.6) pg/mL, ∆ = -8.6 pg/mL, P = 0.049); however, serum and urine calcium did not change. In contrast, although 1 week of lisinopril significantly decreased SBP and increased PRA among participants without P-HPT, there were no changes in PTH or calcium.

CONCLUSION

In this short pilot investigation, 1 week of maximally titrated ACEi did not impact PTH in participants without P-HPT, but resulted in a modest and marginally significant reduction of PTH but not calcium, among participants with P-HPT. This trial is registered with ClinicalTrials.gov NCT01691781.

Activation of Renal (Pro)Renin Receptor Contributes to High Fructose-Induced Salt Sensitivity

A high-fructose diet is shown to induce salt-sensitive hypertension, but the underlying mechanism largely remains unknown. The major goal of the present study was to test the role of renal (pro)renin receptor (PRR) in this model. In Sprague-Dawley rats, high-fructose intake increased renal expression of full-length PRR, which were attenuated by allopurinol. High-fructose intake also upregulated renal mRNA and protein expression of sodium/hydrogen exchanger 3 and Na/K/2Cl cotransporter, as well as in vivo Na/K/2Cl cotransporter activity, all of which were nearly completely blocked by a PRR decoy inhibitor PRO20 or allopurinol treatment. Parallel changes were observed for indices of intrarenal renin-angiotensin-system including renal and urinary renin and angiotensin II levels. Radiotelemetry demonstrated that high-fructose or a high-salt diet alone did not affect mean arterial pressure, but the combination of the 2 maneuvers induced a ≈10-mm Hg increase of mean arterial pressure, which was blunted by PRO20 or allopurinol treatment. In cultured human kidney 2 cells, both fructose and uric acid increased protein expression of soluble PRR in a time- and dose-dependent manner; fructose-induced PRR upregulation was inhibited by allopurinol. Taken together, our data suggest that fructose via uric acid stimulates renal expression of PRR/soluble PRR that stimulate sodium/hydrogen exchanger 3 and Na/K/2Cl cotransporter expression and intrarenal renin-angiotensin system to induce salt-sensitive hypertension.

Impact of ACE2 gene polymorphism on antihypertensive efficacy of ACE inhibitors

Angiotensin-converting enzyme 2 (ACE2), a newly discovered member of renin-angiotensin-aldosterone system, counterbalances the actions of angiotensin-converting enzyme. The objective of our study was to assess the association between rs2106809 polymorphism in ACE2 gene and the blood pressure response to ACE inhibitors in untreated hypertensive patients. After a 2-week, double-blind placebo run-in period, either benazepril or imidapril was administered for 6 weeks to 497 patients with mild to moderate essential hypertension. The achieved changes in BP were analyzed for their association with genotypes at ACE2 gene loci. In female hypertensive patients, the genotype frequency of ACE2 rs2106809 was 36.7%, 45.2% and 18.1% for CC, CT and TT genotypes, respectively. After 6 weeks of treatment, the reductions in diastolic blood pressure were significantly greater in female patients carrying the CC or CT genotype compared with those carrying the TT genotype (9.62±6.83 or 10.2±7.2 versus 6.81±6.31 mm Hg, respectively; P=0.045, analysis of variance (ANOVA)). Moreover, the reductions in mean arterial pressure were significantly greater in female patients carrying the CC or CT genotype compared with those carrying the TT genotype (12.1±7.5 or 12.0±7.9 versus 8.38±6.83 mm Hg, respectively; P=0.035, ANOVA). In male hypertensive patients, the genotype frequency of ACE2 rs2106809 was 58.1% and 41.9% for C and T genotypes, respectively. However, no association could be observed in males. We conclude that ACE2 rs2106809 is an important predictive factor of the response to antihypertensive treatment with ACE inhibitors in Chinese female hypertensive patients.

Quantification of systemic renin-angiotensin system peptides of hypertensive black and white African men established from the RAS-Fingerprint®

Objective:

The objective of this study was to make use of a quantitative and qualitative approach comparing the systemic renin-angiotensin system (RAS) of hypertensive black and white African men by using RAS equilibrium analysis.

Materials and methods:

This sub-study involved 23 black (n = 15) and white (n = 8) hypertensive men aged 39.5–41 years, living in the North West Province of South Africa. The RAS-Fingerprinting was determined with LC-MS/MS quantification of angiotensin peptides. Blood pressure and other variables were determined with known methods.

Results:

The main finding of this study was the significant lower Ang I (<5.0 and 45.1 pg/ml; p = 0.005) and Ang II (15.6 and 123.9 pg/ml; p ⩽ 0.001) encountered in the hypertensive black African men compared to their white counterparts. Levels of Ang 1-5 (downstream metabolite of Ang 1-7) (1.8 and 3.0 pg/ml), were detected in black and white hypertensive men, respectively.

Conclusions:

The observed differences between circulating RAS components, which are reflected via equilibrium angiotensin levels, point to a distinctive molecular regulation of the RAAS in the two study cohorts. The increased peripheral resistance observed in hypertensive black individuals might take over a dominant role in control of blood pressure in this study population. A novel highly sensitive LC-MS/MS method resolved the issue of peptide recovery variations during sample preparation by using internal standards for each individual angiotensin metabolite.

Pomegranate peel extract attenuates oxidative stress by decreasing coronary angiotensin-converting enzyme (ACE) activity in hypertensive female rats

Based on the antioxidant properties of pomegranate, this study was designed to investigate the effects of pomegranate peel extract on damage associated with hypertension and aging in a spontaneously hypertensive rat (SHR) model. The influence of pomegranate consumption was examined on systolic blood pressure (SBP), angiotensin-converting enzyme (ACE) coronary activity, oxidative stress, and vascular morphology. Four- or 28-wk-old SHR model rats were treated for 30 d, with terminal experimental animal age being 8 and 32 wk, respectively, with either pomegranate extract (SHR-PG) or filtered water (SHR). Data showed significant reduction in SBP and coronary ACE activity in both age groups. The levels of superoxide anion, a measure of oxidative stress, were significantly lower in animals in the SHR-PG group compared to SHR alone. Coronary morphology demonstrated total increases in vascular wall areas were in the SHR group, and pomegranate peel extract diminished this effect. Pomegranate peel extract consumption conferred protection against hypertension in the SHR model. This finding was demonstrated by marked reduction in coronary ACE activity, oxidative stress, and vascular remodelling. In addition, treatment was able to reduce SBP in both groups. Evidence indicates that the use of pomegranate peel extract may prove beneficial in alleviating coronary heart disease.

Triple Combination Therapy for Global Cardiovascular Risk: Atorvastatin, Perindopril, and Amlodipine

Statins, angiotensin-converting enzyme (ACE) inhibitors, and calcium channel blockers (CCBs) have markedly changed the clinical progression of patients with coronary artery disease (CAD). The goal of this paper is to review the rationale and evidence for combining these three drug classes in hypertensive patients with hypercholesterolemia or CAD. Data sources include a literature search for publications on the use of a statin combined with various antihypertensive drugs in patients with hypertension and hypercholesterolemia or stable CAD. Hypercholesterolemia and hypertension constitute major physiological risk factors of ischemic heart disease. Current guidelines recommend a global approach to risk management, using agents that address as many risk factors as possible. Dual combination therapies are an important component of guideline-recommended therapy in hypertension. Our review of the literature indicates that triple therapy with a statin, ACE inhibitor, and CCB is associated with a significant reduction in major cardiovascular events. For example, a post hoc analysis in 1056 patients with stable CAD participating in the EUROPA trial indicated that the addition of perindopril to a CCB and a lipid-lowering agent was associated with a 46 % reduction in the composite of cardiovascular death, myocardial infarction, and resuscitated cardiac arrest (p = 0.023). In addition, single pill formulations are known to result in better adherence to the treatment. Single-pill formulations that combine a statin, an ACE inhibitor, and a CCB appear to offer an effective approach to the management of global cardiovascular risk.

Fixed-Dose Combinations of Renin-Angiotensin System Inhibitors and Calcium Channel Blockers in the Treatment of Hypertension: A Comparison of Angiotensin Receptor Blockers and Angiotensin-Converting Enzyme Inhibitors

Fixed-dose combinations (FDCs) of different regimens are recommended in guidelines for the treatment of hypertension. However, clinical studies comparing FDCs of angiotensin receptor blocker (ARB)/calcium channel blocker (CCB) and angiotensin-converting enzyme inhibitor (ACE inhibitor)/CCB in hypertensive patients are lacking.Using a propensity score matching of 4:1 ratio, this retrospective claims database study compared 2 FDC regimens, ARB/CCB and ACE inhibitor/CCB, in treating hypertensive patients with no known atherosclerotic cardiovascular disease. All patients were followed for at least 3 years or until the development of major adverse cardiovascular events (MACEs) during the study period. In addition, the effect of medication adherence on clinical outcomes was evaluated in subgroup analysis based on different portions of days covered.There was no significant difference in MACE-free survival (hazard ratio [HR]: 1.21; 95% confidence interval [CI]: 0.98-1.50; P = 0.08) and survival free from hospitalization for heart failure (HR: 1.15; 95% CI: 082-1.61; P = 0.431), new diagnosis of chronic kidney disease (HR: 0.98; 95% CI: 071-1.36; P = 0.906), and initiation of dialysis (HR: 0.99; 95% CI: 050-1.92; P = 0.965) between the 2 study groups. The results remained the same within each subgroup of patients with different adherence statuses.ARBs in FDC regimens with CCBs in the present study were shown to be as effective as ACE inhibitors at reducing the risks of MACEs, hospitalization for heart failure, new diagnosis of chronic kidney disease, and new initiation of dialysis in hypertensive patients, regardless of the medication adherence status.

IL-1β and IL-18: inflammatory markers or mediators of hypertension?

Chronic inflammation in the kidneys and vascular wall is a major contributor to hypertension. However, the stimuli and cellular mechanisms responsible for such inflammatory responses remain poorly defined. Inflammasomes are crucial initiators of sterile inflammation in other diseases such as rheumatoid arthritis and gout. These pattern recognition receptors detect host-derived danger-associated molecular patterns (DAMPs), such as microcrystals and reactive oxygen species, and respond by inducing activation of caspase-1. Caspase-1 then processes the cytokines pro-IL-1β and pro-IL-18 into their active forms thus triggering inflammation. While IL-1β and IL-18 are known to be elevated in hypertensive patients, no studies have examined whether this occurs downstream of inflammasome activation or whether inhibition of inflammasome and/or IL-1β/IL-18 signalling prevents hypertension. In this review, we will discuss some known actions of IL-1β and IL-18 on leukocyte and vessel wall function that could potentially underlie a prohypertensive role for these cytokines. We will describe the major classes of inflammasome-activating DAMPs and present evidence that at least some of these are elevated in the setting of hypertension. Finally, we will provide information on drugs that are currently used to inhibit inflammasome/IL-1β/IL-18 signalling and how these might ultimately be used as therapeutic agents for the clinical management of hypertension.

Association between Angiotensin I-Converting Enzyme Insertion/Deletion Polymorphism and Prognosis of Kidney Transplantation: A Meta-Analysis

PURPOSE

Angiotensin I-converting enzyme (ACE) is crucial in the renin-angiotensin-aldosterone system. ACE insertion/deletion (I/D) polymorphism is a common genetic variation of this gene and is associated with several disease phenotypes. However, the results of published studies on the influence of this polymorphism on renal transplantation are inconsistent. Therefore, a meta-analysis was performed to evaluate the association between ACE I/D polymorphism and prognosis of kidney transplantation.

METHODS

A meta-analysis was performed based on 21 case-control studies from 12 publications (1497 cases and 2029 controls) and 10 studies with quantitative values from 5 publications (814 patients). Pooled odds ratios (ORs) and weighted mean differences (WMDs) with their corresponding 95% confidence intervals (CIs) were used to estimate associations.

RESULTS

ACE I/D polymorphism was found to be associated with acute rejection (AR) in genotypes DD+ID versus II (OR = 1.62, 95% CI = 1.14-2.29) and with serum creatinine concentration after renal transplantation in genotypes DD versus ID (WMD = 13.12, 95% CI = 8.09-18.16). Stratified analysis revealed that recipients transplanted within a year had higher serum creatinine concentrations in the DD versus ID model. No significant association was found between hypertension and ACE I/D polymorphism.

CONCLUSION

ACE I/D polymorphism is associated with AR and allograft function after kidney transplantation.

Association between angiotensin-converting enzyme inhibitors and troponin in acute coronary syndrome

BACKGROUND

Cardiovascular disease is the leading cause of mortality in the western world and its treatment should be optimized to decrease severe adverse events.

OBJECTIVE

To determine the effect of previous use of angiotensin-converting enzyme inhibitors on cardiac troponin I measurement in patients with acute coronary syndrome without ST-segment elevation and evaluate clinical outcomes at 180 days.

METHODS

Prospective, observational study, carried out in a tertiary center, in patients with acute coronary syndrome without ST-segment elevation. Clinical, electrocardiographic and laboratory variables were analyzed, with emphasis on previous use of angiotensin-converting enzyme inhibitors and cardiac troponin I. The Pearson chi-square tests (Pereira) or Fisher's exact test (Armitage) were used, as well as the non-parametric Mann-Whitney's test. Variables with significance levels of <10% were submitted to multiple logistic regression model.

RESULTS

A total of 457 patients with a mean age of 62.1 years, of whom 63.7% were males, were included. Risk factors such as hypertension (85.3%) and dyslipidemia (75.9%) were the most prevalent, with 35% of diabetics. In the evaluation of events at 180 days, there were 28 deaths (6.2%). The statistical analysis showed that the variables that interfered with troponin elevation (> 0.5 ng / mL) were high blood glucose at admission (p = 0.0034) and ST-segment depression ≥ 0.5 mm in one or more leads (p = 0.0016). The use of angiotensin-converting inhibitors prior to hospitalization was associated with troponin ≤ 0.5 ng / mL (p = 0.0482). The C-statistics for this model was 0.77.

CONCLUSION

This study showed a correlation between prior use of angiotensin-converting enzyme inhibitors and reduction in the myocardial necrosis marker troponin I in patients admitted for acute coronary syndrome without ST-segment elevation. However, there are no data available yet to state that this reduction could lead to fewer severe clinical events such as death and re-infarction at 180 days.

Combination therapy in the extended cardiovascular continuum: a focus on perindopril and amlodipine

The progression of cardiovascular disease could be regarded as following atherosclerosis-related and age-related pathways. The starting points for these pathways are different--risk factors or aortic ageing--but they conclude in the same way: end-stage heart disease. Together these interlinked pathways form the extended cardiovascular continuum. Renin-angiotensin-aldosterone system (RAAS) inhibitors have been shown to interrupt or slow the progression of cardiovascular disease along one pathway, the cardiovascular atherosclerotic continuum. Cardiovascular protection with RAAS inhibitors varies; different RAAS inhibitors offer different levels of protection. Similarly, calcium channel blockers (CCBs) also have clearly shown protective effect of cardiovascular system, especially as it regards cerebrovascular disease risk. The AngloScandinavian Cardiac Outcomes Trial (ASCOT) showed that a combination of the angiotensin-converting enzyme (ACE) inhibitor perindopril and CCB amlodipine offered better cardiovascular protection in at-risk hypertensive patients than beta-blocker and thiazide. By attenuating the deleterious effects of cardiovascular disease at multiple stages of the extended cardiovascular continuum on top of lowering blood pressure (BP), perindopril and amlodipine could interrupt and slow the progression of cardiovascular disease. These antihypertensive agents have complementary vascular effects that enhance cardiovascular protection and reduce side-effects. Evidence from ASCOT shows that antihypertensive and vascular effects of amlodipine with and without perindopril have translated into real-life clinical benefits. A strategy using ACE inhibitors and CCBs, such as perindopril and amlodipine, to target multiple stages in both pathways of cardiovascular disease could effectively reduce cardiovascular risk and lower BP.

Effects of Tulbaghia violacea Harv. (Alliaceae) rhizome methanolic extract on kidney function and morphology in Dahl salt-sensitive rats

ETHNOPHARMACOLOGICAL RELEVANCE

Tulbaghia violacea has been used traditionally for the treatment of several ailments, including hypertension. The herb has been shown to have antihypertensive properties which have been attributed to its angiotensin-converting enzymeinhibitory (ACEI) activity. It could, therefore, prove beneficial in ameliorating renal pathology associated with hypertension. To evaluate the effects of long-term administration of Tulbaghia violacea on renal function and morphology in the Dahl salt-sensitive (DSS) rat model.

MATERIALS AND METHODS

Male DSS rats were treated intra-peritoneally (i.p.) as follows: methanolic extract of Tulbaghia violacea: (TVL) (50 mg/kg/b.w.), captopril: (CAP) (25 mg/kg/b.w.), or distilled water, control: (CON) (3 ml/kg/b.w.). Blood pressure (BP) was measured bi-weekly, whilst 24-h urine volumes and electrolyte concentrations were assessed weekly. Animals were sacrificed on day 49 by halothane overdose. Blood was removed for determination of plasma and serum electrolytes. Left kidney tissues were harvested for the determination of nuclear factor-kappaβ (NF-kβ) and transforming growth factor-β (TGF-β) gene expressions.

RESULTS

TVL significantly reduced mean arterial pressure (MAP) and diastolic blood pressure (DBP). TVL showed reduced blood urea nitrogen, serum creatinine, total protein in urine as well as increased serum total protein. TVL decreased thiobarbituric acid reactive substances (TBARS) and increased glutathione peroxidase (GPx) and superoxide dismutase (SOD) activity and nitric oxide significantly. NF-kβ and TGF-β) gene expressions were significantly reduced in TVL and CAP treated rats. Moreover, renal morphology improved significantly in TVL and CAP treated animals.

CONCLUSION

TVL and CAP demonstrated marked improvement in renal function and morphology.

The renin-angiotensin system: a possible contributor to migraine pathogenesis and prophylaxis

The presence of a tissue-based renin-angiotensin system, independent of the systemic one, has been identified in several organs including the brain. Experimental models have suggested the involvement of the renin-angiotensin system in neurogenic inflammation, susceptibility to oxidative stress, endothelial dysfunction, and neuromodulation of nociceptive transmission, thus potentially contributing to the pathogenesis of migraine. Genetic factors that increase susceptibility to migraine may include angiotensin-converting enzyme polymorphism, although available data are controversial. Clinical studies have suggested that angiotensin-converting enzyme inhibitors and angiotensin receptor blockers may be effective in migraine prophylaxis. However, further research should clarify whether the postulated preventive effect is attributable to a pharmacological action over and above the antihypertensive effect and should test their tolerability in subjects with normal blood pressure values. In patients with contraindications or not responding to conventional prophylactic drugs and in patients with comorbid arterial hypertension, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers may be used for migraine prophylaxis.

Renin-angiotensin system in the kidney: What is new?

The renin-angiotensin system (RAS) has been known for more than a century as a cascade that regulates body fluid balance and blood pressure. Angiotensin II(Ang II) has many functions in different tissues; however it is on the kidney that this peptide exerts its main functions. New enzymes, alternative routes for Ang IIformation or even active Ang II-derived peptides have now been described acting on Ang II AT₁ or AT₂ receptors, or in receptors which have recently been cloned, such as Mas and AT₄. Another interesting observation was that old members of the RAS, such as angiotensin converting enzyme (ACE), renin and prorenin, well known by its enzymatic activity, can also activate intracellular signaling pathways, acting as an outside-in signal transduction molecule or on the renin/(Pro)renin receptor. Moreover, the endocrine RAS, now is also known to have paracrine, autocrine and intracrine action on different tissues, expressing necessary components for local Ang II formation. This in situ formation, especially in the kidney, increases Ang II levels to regulate blood pressure and renal functions. These discoveries, such as the ACE2/Ang-(1-7)/Mas axis and its antangonistic effect rather than classical deleterious Ang II effects, improves the development of new drugs for treating hypertension and cardiovascular diseases.

Interactions between adrenal-regulatory and calcium-regulatory hormones in human health

PURPOSE OF REVIEW

To summarize the evidence characterizing the interactions between adrenal-regulating and calcium-regulating hormones, and the relevance of these interactions to human cardiovascular and skeletal health.

RECENT FINDINGS

Human studies support the regulation of parathyroid hormone (PTH) by the renin-angiotensin-aldosterone system (RAAS): angiotensin II may stimulate PTH secretion via an acute and direct mechanism, whereas aldosterone may exert a chronic stimulation of PTH secretion. Studies in primary aldosteronism, congestive heart failure, and chronic kidney disease have identified associations between hyperaldosteronism, hyperparathyroidism, and bone loss, which appear to improve when inhibiting the RAAS. Conversely, elevated PTH and insufficient vitamin D status have been associated with adverse cardiovascular outcomes, which may be mediated by the RAAS. Studies of primary hyperparathyroidism implicate PTH-mediated stimulation of the RAAS, and recent evidence shows that the vitamin D-vitamin D receptor complex may negatively regulate renin expression and RAAS activity. Ongoing human interventional studies are evaluating the influence of RAAS inhibition on PTH and the influence of vitamin D receptor agonists on RAAS activity.

SUMMARY

Although previously considered independent endocrine systems, emerging evidence supports a complex web of interactions between adrenal-regulating and calcium-regulating hormones, with implications for human cardiovascular and skeletal health.

Glutathionylation mediates angiotensin II-induced eNOS uncoupling, amplifying NADPH oxidase-dependent endothelial dysfunction

Background

Glutathionylation of endothelial nitric oxide synthase (eNOS) “uncouples” the enzyme, switching its function from nitric oxide (NO) to O₂^•− generation. We examined whether this reversible redox modification plays a role in angiotensin II (Ang II)‐induced endothelial dysfunction.

Methods and Results

Ang II increased eNOS glutathionylation in cultured human umbilical vein endothelial cells (HUVECs), rabbit aorta, and human arteries in vitro. This was associated with decreased NO bioavailability and eNOS activity as well as increased O₂^•− generation. Ang II‐induced decrease in eNOS activity was mediated by glutathionylation, as shown by restoration of function by glutaredoxin‐1. Moreover, Ang II‐induced increase in O₂^•− and decrease in NO were abolished in HUVECs transiently transfected, with mutant eNOS rendered resistant to glutathionylation. Ang II effects were nicotinamide adenine dinucleotide phosphate (NADPH) oxidase dependent because preincubation with gp 91ds‐tat, an inhibitor of NADPH oxidase, abolished the increase in eNOS glutathionylation and loss of eNOS activity. Functional significance of glutathionylation in intact vessels was supported by Ang II‐induced impairment of endothelium‐dependent vasorelaxation that was abolished by the disulfide reducing agent, dithiothreitol. Furthermore, attenuation of Ang II signaling in vivo by administration of an angiotensin converting enzyme (ACE) inhibitor reduced eNOS glutathionylation, increased NO, diminished O₂^•−, improved endothelium‐dependent vasorelaxation and reduced blood pressure.

Conclusions

Uncoupling of eNOS by glutathionylation is a key mediator of Ang II‐induced endothelial dysfunction, and its reversal is a mechanism for cardiovascular protection by ACE inhibition. We suggest that Ang II‐induced O₂^•− generation in endothelial cells, although dependent on NADPH oxidase, is amplified by glutathionylation‐dependent eNOS uncoupling.

Outcomes of patients treated through the Canadian Fabry disease initiative

BACKGROUND

The Canadian Fabry disease initiative (CFDI) tracks outcomes of subjects with Fabry disease treated enzyme replacement therapy (ERT) given to subjects who meet evidence-based treatment guidelines and cardiovascular risk factor modification.

METHODS

We report 5 year follow-up data on 362 subjects for a composite endpoint (death, neurologic or cardiovascular events, development of end-stage renal disease or sustained increase in serum creatinine of 50% from baseline).

RESULTS

At enrollment, 86 subjects had previously received ERT (Cohort 1a) and 67 subjects were newly started (Cohort 1b) and randomized to agalsidase alfa or agalsidase beta. 209 subjects did not initially meet ERT criteria (Cohort 1c), 25 of whom met ERT criteria in follow-up and were moved to Cohort 1b (total N=178 ERT treated subjects). Use of supportive therapies such as aspirin (78%), renin-angiotensin blockade (59%), and statins (55%) was common in ERT treated subjects. In Cohort 1a, 32 subjects met the composite endpoint with 8 deaths. In Cohort 1b, 16 subjects met the composite endpoint with 1 death. Cohort 1b had fewer clinical events than Cohort 1a (p=0.039) suggesting that the treatment protocol was effective in targeting subjects at an earlier stage. 19.4% of Cohort 1b subjects on agalsidase alfa and 13.3% on agalsidase beta had a clinical event (p=0.57). 10 Cohort 1c subjects had clinical events, none of which would have been prevented by earlier use of ERT.

CONCLUSIONS

Cardiovascular risk factor modification and targeted use of ERT reduce the risk of adverse outcomes related to Fabry disease.

Angiotensin II receptor antagonists in acute coronary syndromes

BACKGROUND

It is well known that inappropriate or exaggerated activity of the renin-angiotensin system might contribute to the development of systemic hypertension with consequent organ injury and associated increased risk of acute cardiovascular (CV) diseases. This review will discuss evidence form basic research and clinical studies, investigating the efficacy of angiotensin II receptor blockers (ARBs) in the management of acute coronary syndromes (ACS).

MATERIALS AND METHODS

This narrative review is based on the material found on MEDLINE and PubMed up to June 2013. We looked for the terms 'angiotensin, AT1 receptor, ACE inhibitors' in combination with 'acute coronary syndromes, acute myocardial infarction, pathophysiology'.

RESULTS

Preclinical studies showed relevant protective effects of ARBs to reduce adverse cardiac remodelling in animal models of acute cardiac ischaemia. However, although recommended in Consensus guidelines as a good alternative to angiotensin-converting enzyme inhibitors (ACEIs), clinical studies did not confirm a superior efficacy of the ARBs as compared to ACEIs. As a matter of fact for some authors, these drugs might potentially have deleterious effects increasing the CV risk.

CONCLUSIONS

Emerging evidence from clinical trials suggests that the use of ARBs in ACS might be controversial, and caution should be used for their clinical use to replace ACEIs in ACS.

Constitutive activity in the angiotensin II type 1 receptor: discovery and applications

The pathophysiological actions of the renin-angiotensin system hormone, angiotensin II (AngII), are mainly mediated by the AngII type 1 (AT1) receptor, a GPCR. The intrinsic spontaneous activity of the AT1 receptor in native tissues is difficult to detect due to its low expression levels. However, factors such as the membrane environment, interaction with autoantibodies, and mechanical stretch are known to increase G protein signaling in the absence of AngII. Naturally occurring and disease-causing activating mutations have not been identified in AT1 receptor. Constitutively active mutants (CAMs) of AT1 receptor have been engineered using molecular modeling and site-directed mutagenesis approaches among which substitution of Asn(111) in the transmembrane helix III with glycine or serine results in the highest basal activity of the receptor. Transgenic animal models expressing the CAM AT1 receptors that mimic various in vivo disease conditions have been useful research tools for discovering the pathophysiological role of AT1 receptor and evaluating the therapeutic potential of inverse agonists. This chapter summarizes the studies on the constitutive activity of AT1 receptor in recombinant as well as physiological systems. The impact of the availability of CAM AT1 receptors on our understanding of the molecular mechanisms underlying receptor activation and inverse agonism is described.

RAAS inhibition and mortality in hypertension

The renin-angiotensin-aldosterone system (RAAS) regulates the body's hemodynamic equilibrium, circulating volume, and electrolyte balance, and is a key therapeutic target in hypertension, the world's leading cause of premature mortality. Hypertensive disorders are strongly linked with an overactive RAAS, and RAAS inhibitors, like angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs), are routinely used to treat high blood pressure (BP). BP reduction is one of the main goals of current European hypertension guidelines. Oral ACE inhibitors, the oldest category of RAAS inhibitor, were commercially released over 30 years ago in the early 1980s, over a decade before the first ARBs became available. The introduction of ACE inhibitors heralded major changes in the way hypertension and cardiovascular disease were treated. Although the decision of the medical community to replace older ACE inhibitors with more modern ARBs in the 1990s was debatable, it did nevertheless allow scientists to learn more about the angiotensin receptors involved in RAAS stimulation. This and much else of value have been discovered since RAAS inhibitors first became available, but some surprising gaps in our knowledge exist. Until recently, the effect of RAAS inhibition on mortality in hypertension was unknown. This question was recently addressed by a meta-analysis of randomized controlled trials in populations who received contemporary antihypertensive medication. The results of this meta-analysis have helped elucidate the long-term consequences of treatment with RAAS inhibitors on mortality in hypertension. This article will consider the differences between RAAS inhibitors in terms of pharmacological and clinical effects and analyze the impact of the main types of RAAS inhibitor, ACE inhibitors and ARBs, on mortality reduction in hypertensive patients with reference to this latest meta-analysis.

Inhibition of ubiquitin protein expression and 20S proteasome activity by irbesartan prevents post-infarction ventricular remodeling and decreases TNF-α generation

Myocardial infarction (MI) may induce severe alterations of the cardiac contractile function that may, in turn, lead to heart failure (HF). The ubiquitin-proteasome system (UPS) plays a critical role in cardiac remodeling following MI. Angiotensin II type 1 receptor (AT1R) blockers effectively prevent left ventricular (LV) remodeling. However, it has not been elucidated whether the preventive effect of AT1R-blockers on LV remodeling is mediated through the UPS pathway. In the present study, with the use of cardiac morphometric parameters, haemodynamic measurements and enzyme-linked immunosorbent assay, we demonstrated that post-ischemic HF rats exhibited a significant increase in ventricular remodeling and irbesartan was effective in reversing cardiac remodeling. The expression of TNF-α, ubiquitin protein and 20S proteasome were significantly increased in the MI control group and irbesartan was shown to dose-dependently inhibit the expression of TNF-α, ubiquitin protein and 20S proteasome. In conclusion, it was hypothesized that UPS signaling is involved in ventricular remodeling following MI and the mechanism underlying the effect of irbesartan on ventricular remodeling may be associated with the downregulation of the expression of TNF-α, ubiquitin protein and 20S proteasome.

Aliskiren and amlodipine in the management of essential hypertension: meta-analysis of randomized controlled trials

Background

Aliskiren is a novel renin-angiotensin aldosterone system (RAAS) inhibitor, the combination therapy of aliskiren and amlodipine for blood pressure control have been reported recently. The primary objective of this analysis is to review recently reported randomized controlled trials (RCTs) to compare antihypertensive effects and adverse events between mono (amlodipine or aliskiren alone) and combination therapy of both medicines.

Methods

Databases for the search included Pubmed, Embase and the Cochrane Central Register of Controlled Trials. Revman v5.0 statistical program was used to analyze the data. Weighted mean differences (WMD) with a 95% confidence interval (CI) were used for the calculation of continuous data, and relative risk (RR) with a 95% CI was used for dichotomous data.

Results

We analyzed the data from 7 RCTs for a total of 6074 participants in this meta-analysis. We found that the aliskiren/amlodipine combination therapy had a stronger effect in lowering blood pressure as compared with the monotherapy using aliskiren (SBP: WMD = −10.42, 95% CI −13.03∼−7.82, P<0.00001; DBP: WMD = −6.60, 95% CI −7.22∼−5.97, P<0.00001) or amlodipine (SBP: WMD = −4.85, 95% CI −6.88∼−2.81, P<0.00001; DBP: WMD = −2.91, 95% CI −3.85∼−1.97, P<0.00001). No differences were found in terms of adverse events between combination therapy and monotherapy, except for the rates of peripheral edema and hypokalaemia which were significantly lower in the combination therapy than in the amlodipine monotherapy (RR = 0.78, 0.66∼0.92, P = 0.004; RR = 0.51, 0.27∼0.97, P = 0.04). Similar antihypertensive effects were found in both obese (body mass index > = 30 kg/m²) hypertensive and non-obese (body mass index <30 kg/m²) hypertensive patients. Moreover, there was no difference with the blood pressure lowering or adverse effects with regards to the combination therapy in both subgroups.

Conclusion

We found that aliskiren/amlodipine combination therapy provided a more effective blood pressure reduction than monotherapy with either drug without increase in the occurrence of adverse events.