Acute Angiotensin II Receptor Blockade Facilitates Parahippocampal Processing During Memory Encoding in High-Trait-Anxious Individuals

Background

Angiotensin II receptor blockers (ARBs) have been associated with preventing posttraumatic stress disorder symptom development and improving memory. However, the underlying neural mechanisms are poorly understood. This study investigated ARB effects on memory encoding and hippocampal functioning that have previously been implicated in posttraumatic stress disorder development.

Methods

In a double-blind randomized design, 40 high-trait-anxious participants (33 women) received the ARB losartan (50 mg) or placebo. At drug peak level, participants encoded images of animals and landscapes before undergoing functional magnetic resonance imaging, where they viewed the encoded familiar images and unseen novel images to be memorized and classified as animals/landscapes. Memory recognition was assessed 1 hour after functional magnetic resonance imaging. To analyze neural effects, whole-brain analysis, hippocampus region-of-interest analysis, and exploratory multivariate pattern similarity analysis were employed.

Results

ARBs facilitated parahippocampal processing. In the whole-brain analysis, losartan enhanced brain activity for familiar images in the parahippocampal gyrus (PHC), anterior cingulate cortex, and caudate. For novel images, losartan enhanced brain activity in the PHC only. Pattern similarity analysis showed that losartan increased neural stability in the PHC when processing novel and familiar images. However, there were no drug effects on memory recognition or hippocampal activation.

Conclusions

Given that the hippocampus receives major input from the PHC, our findings suggest that ARBs may modulate higher-order visual processing through parahippocampal involvement, potentially preserving intact memory input. Future research needs to directly investigate whether this effect may underlie the preventive effects of ARBs in the development of posttraumatic stress disorder.

The role of angiotensin receptor blocker (losartan) on decreasing fibrotic process of corpora cavernosa in priapism model of wistar rats

Background

Priapism induces regulation of Transforming Growth Factor-β1 (TGF-β1) expression and collagen-type-1 deposition. This will replace the normal corpora cavernosa with fibrotic tissue which eventually resulted in erectile dysfunction. It is also known that the fibrosis process of corpora cavernosa is related to Renin-Angiotensin II System (RAS). Angiotensin II receptor blockers (ARB), especially losartan, inhibit the inflammation process and fibrotic tissue formation. This study evaluated the effect of losartan in reducing fibrosis in priapism by evaluating TGF-β1 and collagen-type-1 in cavernous tissue and determined the effect of losartan in preventing fibrosis in priapism model of Wistar rats assessed by the metavir score.

Methods

A total of eighteen male Wistar rats mean were divided into five groups. For the priapism models, we applied negative pressure on the penis to make an artificial erection to mimic the priapism process. The control groups were observed and the treatment groups were orally given losartan 15 mg/kg/day. Corpora cavernosa was harvested for TGF-β1 and collagen-type-1 measurement using an enzyme-linked immunosorbent assay (ELISA). The fibrotic tissue of each rat was then collected and assessed histopathologically with the metavir scoring system.

Results

Penile TGF-β1 concentration in the losartan-treated group was not significantly different on day 10 and day 28 of observation (p10=0,30; p28=0,17). Meanwhile, collagen-type-1 concentration was significantly lower compared to control group (p10=0,002; p28=0,01). There was a significant difference in metavir scores in rats that received losartan and those who did not (p<0,05).

Conclusion

Losartan could suppress the fibrosis process in the priapism model. It could decrease the collagen type 1 deposition during corpora cavernosa tissue regeneration. Based on the metavir score, the group receiving losartan therapy was better than the control group.

A randomised clinical trial study assessing the efficacy of 5% losartan potassium loaded in ethosomal gel to treat human keloids: a trial protocol

BACKGROUND

Keloid is a skin disorder that results from excessive fibrous tissue growth in the area of the initial trauma. Treating keloids can be challenging since the success of various treatments varies from one study to another. Triamcinolone acetonide injection, a standard treatment, can cause undesirable side effects. Meanwhile, the effectiveness of existing topical therapies for keloids is not always reliable. The pro-inflammatory, pro-proliferative, and pro-fibrotic effects of angiotensin II in human skin contribute to keloid formation. Losartan potassium, an angiotensin II blocker, has the potential to act as an anti-keloid agent. Due to the thicker skin structure of a keloid and ease of application, ethosome gel is chosen as a safe and comfortable carrier for losartan potassium, making it a good choice for treating keloids.

METHODS

In this randomised clinical trial, 46 adults with keloids were divided into two treatment groups. One group of 23 participants received 5% losartan potassium loaded in ethosomal gel, while the other group of 23 participants received intralesional injections of 10% triamcinolone acetonide. Over 12 weeks, changes in POSAS 3.0 scores, degree of erythema and pigmentation, surface area, thickness, and pliability of the keloids will be measured at four different times: baseline, 4 weeks, 8 weeks, and 12 weeks. Statistical analysis will be conducted using SPSS software version 24, with a significance level of p < 0.05.

DISCUSSION

Losartan potassium is believed to be beneficial for keloid management because it inhibits the angiotensin II receptor, which plays a role in inflammation, proliferation, and fibrosis. This study examines the efficacy of 5% losartan potassium loaded in ethosomal gel for human keloids.

TRIAL REGISTRATION

Clinicaltrial.gov identifier NCT05893108 . Registered on 7 June 2023.

Timing of prescription of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers in patients hospitalized for acute heart failure with reduced/mildly reduced ejection fraction: a retrospective analysis

Although angiotensin-converting enzyme inhibitors (ACEis) and angiotensin II receptor blockers (ARBs) play critical roles in the treatment of heart failure with reduced or mildly reduced ejection fraction (HFrEF/HFmrEF; left-ventricular ejection fraction ≤ 50%), the ideal timing for initiation in patients with acute heart failure (AHF) is unclear. We sought to clarify the timing and safety of ACEi/ARB prescription relative to hemodynamic stabilization (pre or post) in patients hospitalized with acute HFrEF/HFmrEF. This was a retrospective, observational analysis of electronic data of patients hospitalized for AHF at 17 Japanese hospitals. Among 9107 patients hospitalized with AHF, 2648 had HFrEF/HFmrEF, and 83.0% met the hemodynamic stabilization criteria within 10 days of admission. During hospitalization, 63.5% of patients with HFrEF/HFmrEF were prescribed an ACEi/ARB, 79.4% of which were prescribed pre-stabilization. In a multivariable analysis, patients treated with an ACEi/ARB pre-stabilization were more likely to have comorbid hypertension, diabetes mellitus, or ischemic heart disease. ACEi/ARB prescription timing was not associated with adverse events, including hypotension and renal impairment, and early prescription was associated with a lower incidence of subsequent worsening of HF. In clinical practice, more hospitalized patients with AHF received an ACEi/ARB before compared with after hemodynamic stabilization, and no safety concerns were observed. Moreover, early prescription may be associated with a lower incidence of worsening HF.

Prescription of renin-angiotensin system inhibitors in Japan during the COVID-19 pandemic: interrupted time series study

We surveyed changes in angiotensin-converting enzyme inhibitor (ACEIs) and angiotensin II receptor blocker (ARBs) prescription trends during the coronavirus disease 2019 (COVID-19) pandemic in Japan. Data of 1,605,708 outpatients with hypertension were extracted from the Medical Data Vision database. Trends for prescription of ACEIs and ARBs were assessed by analyzing the proportion of these prescriptions in each month, between April 2018 and November 2020. The proportion of ARBs prescriptions changed significantly in trend between the peri-pandemic and pre-pandemic periods (-0.05%/month, P = 0.012). In contrast, the proportion of ACEIs prescriptions did not change significantly in trend in the peri-pandemic period (0.01%/month, P = 0.189). There was no suggestion that the prescribing of ACEIs and ARBs was affected by the COVID-19 pandemic.

Combination of sacubitril/valsartan and blockade of the PI3K pathway enhanced kidney protection in a mouse model of cardiorenal syndrome

Aims

Angiotensin receptor-neprilysin inhibitor (ARNI) is an established treatment for heart failure. However, whether ARNI has renoprotective effects beyond renin-angiotensin system inhibitors alone in cardiorenal syndrome (CRS) has not been fully elucidated. Here, we examined the effects of ARNI on the heart and kidneys of CRS model mice with overt albuminuria and identified the mechanisms underlying ARNI-induced kidney protection.

Methods and results

C57BL6 mice were subjected to chronic angiotensin II infusion, nephrectomy, and salt loading (ANS); they developed CRS phenotypes and were divided into the vehicle treatment (ANS-vehicle), sacubitril/valsartan treatment (ANS-ARNI), and two different doses of valsartan treatment (ANS-VAL M, ANS-VAL H) groups. Four weeks after treatment, the hearts and kidneys of each group were evaluated. The ANS-vehicle group showed cardiac fibrosis, cardiac dysfunction, overt albuminuria, and kidney fibrosis. The ANS-ARNI group showed a reduction in cardiac fibrosis and cardiac dysfunction compared with the valsartan treatment groups. However, regarding the renoprotective effects characterized by albuminuria and fibrosis, ARNI was less effective than valsartan. Kidney transcriptomic analysis showed that the ANS-ARNI group exhibited a significant enhancement in the phosphoinositide 3-kinase (PI3K)-AKT signalling pathway compared with the ANS-VAL M group. Adding PI3K inhibitor treatment to ARNI ameliorated kidney injury to levels comparable with those of ANS-VAL M while preserving the superior cardioprotective effect of ARNI.

Conclusion

PI3K pathway activation has been identified as a key mechanism affecting remnant kidney injury under ARNI treatment in CRS pathology, and blockading the PI3K pathway with simultaneous ARNI treatment is a potential therapeutic strategy for treating CRS with overt albuminuria.

Sartan blood pressure regulators in classical and biofilm wastewater treatment - Concentrations and metabolism

Sartans are a group of pharmaceuticals widely used to regulate blood pressure. Their concentration levels were monitored in 80 wastewater treatment plants (WWTP) in the Baltic Sea Region, reached from limit of detection up to 6 µg/L. The concentrations were significantly different in different countries, but consistent within the respective country. The degradation of sartans (losartan, valsartan, irbesartan) in moving bed biofilm reactors (MBBRs) that utilize biofilms grown on mobile carriers to treat wastewater was investigated for the first time, and compared with the degradation in a conventional activated sludge (CAS) treatment plant. The results showed the formation of six microbial transformation products (TPs) of losartan, four of valsartan, and four of irbesartan in biological wastewater treatment. Four of these metabolites have not been described in the literature before. Chemical structures were suggested and selected TPs were verified and quantified depending on availability of true standards. Valsartan acid was a common TP of losartan, valsartan, and irbesartan. Losartan and irbesartan also shared one TP: losartan/irbesartan TP335. Based on the mass balance analysis, losartan carboxylic acid is the main TP of losartan, and valsartan acid is the main TP of valsartan during the biotransformation process. For irbesartan, TP447 is likely to be the main TP, as its peak areas were two orders of magnitude higher than those of all the other detected TPs of this compound. The effects of adapting biofilms to different biological oxygen demand (BOD) loading on the degradation of sartans as well as the formation of their TPs were investigated. Compared to feeding a poor substrate (pure effluent wastewater from a CAS), feeding with richer substrate (1/3 raw and 2/3 effluent wastewater) promoted the metabolism of most compounds (co-metabolization). However, the addition of raw wastewater inhibited some metabolic pathways of other compounds, such as from losartan/irbesartan to TP335 (competitive inhibition). The formation of irbesartan TP447 did not change with or without raw wastewater. Finally, the sartans and their TPs were investigated in a full-scale CAS wastewater treatment plant (WWTP). The removal of losartan, valsartan, and irbesartan ranged from 3.0 % to 72% and some of the transformation products (TPs) from human metabolism were also removed in the WWTP. However, some of the sartan TPs, i.e., valsartan acid, losartan carboxylic acid, irbesartan TP443 and losartan TP453, were formed in the WWTP. Relative high amounts of especially losartan carboxylic acid, which was detected with concentrations up to 2.27 µg/L were found in the effluent.

Cancer risk associated with the use of valsartan in Korea: A nationwide cohort study

BACKGROUND

Despite valsartan's widespread use, few studies have explored its potential carcinogenicity. We evaluated the association between valsartan and cancer.

METHODS

We conducted a retrospective cohort study using data from 2002 to 2015 gathered from the National Health Insurance database. Patients with hypertension aged ≥ 30 who used valsartan or other angiotensin II receptor blockers (ARBs) were included. Eligible patients were those with no prior history of the use of any ARBs, diagnosis of cancer, or organ transplantation in the 4 years predating their first use of the drugs of interest. The primary and secondary outcomes included the occurrence of all cancers and site-specific solid cancers, respectively. After applying propensity score (PS) matching, Cox regression was used to calculate the hazard ratios (HRs) and 95 % confidence intervals (CIs).

RESULTS

A total of 1,550,734 individuals were identified as new users of valsartan or other ARBs. Of the 153,047 valsartan users, 16,047 were diagnosed with cancer. No increased risk of overall cancer was observed in valsartan users as compared to other ARB users (aHR = 1.00; 95 % CI, 0.98-1.02). Valsartan was, however, associated with a slightly elevated risk of liver (aHR = 1.09; 95 % CI, 1.01-1.16) and kidney cancer (aHR = 1.11; 95 % CI, 1.02-1.22).

CONCLUSION

Compared with other ARBs, valsartan did not increase the risk of overall cancer. A slightly increased risk for some solid cancers was associated with valsartan use, though the absolute rate difference was small.

Effects of losartan and exercise on muscle mass and exercise endurance of old mice

This study evaluated the effects of angiotensin II type I receptor blocker (ARB) on muscle mass and exercise capacity in healthy older animals. The effects of combined ARB and exercise training were also determined. Eighty 18-month-old mice were randomized into the control group (C), exercise group (E), losartan group (L) and losartan plus exercise group (LE). Mice in the L and LE groups received losartan from drinking water every day. Mice in the E and LE groups trained on a treadmill 30 min per day, 3 days per week for 4 months. Exercise endurance and spontaneous physical activity of mice were measured at baseline and monthly for 4 months. After 4 months of intervention, serum interleukin-6 (IL-6) levels, muscle mass, and muscle fiber cross sectional area (CSA) were measured. Total antioxidant capacity (TAC), lipid peroxidation and IL-6 levels were determined in quadriceps. We found that exercise endurance only increased in the E and LE groups. Muscle TAC levels of E, L, and LE groups were greater than that in the C group. Serum IL-6 and lipid peroxidation levels were not different among groups. LE group, but not E and L groups, had greater muscle mass, larger muscle fiber CSA, and greater muscle IL-6 levels than that in the C group after 4 months of intervention. These results suggest that losartan promotes the adaptions of muscle mass with exercise training in healthy older animals.

Effect of combined farnesoid X receptor agonist and angiotensin II type 1 receptor blocker on ongoing hepatic fibrosis

OBJECTIVE

Nonalcoholic steatohepatitis (NASH) is difficult to diagnose in patients with no symptoms. We aimed to investigate the combined effect of farnesoid X receptor (FXR) agonist, obeticholic acid (OCA), and angiotensin II type 1 receptor blocker (ARB: losartan) on an ongoing hepatic fibrosis in a NASH rat model.

METHODS

Fischer 344 rats were fed with choline-deficient L-amino-acid-defined (CDAA) diet for 16 weeks. After 8-week administration of CDAA diet, OCA, losartan, or a combination of these drugs was administered at a dose of 30 mg/kg/day for 8 weeks by oral gavage. The in vivo and in vitro effects of OCA + losartan and liver fibrosis progression, lipopolysaccharide (LPS), Toll-like receptor 4 (TLR4) regulatory cascade, and gut barrier function were evaluated.

RESULTS

OCA + losartan alleviated hepatic fibrosis progression by suppressing α-SMA expression. It inhibited the proliferation of activated hepatic stellate cell (Ac-HSC) and mRNA expression of hepatic transforming growth factor-β1 (TGF-β1), TLR4, and tissue inhibitor of metalloproteinase-1 (TIMP-1) and decreased the hydroxyproline levels. OCA increased the hepatic matrix metalloproteinase-2 (MMP-2) mRNA expression. OCA decreased the mRNA expression of hepatic LPS-binding protein and intestinal permeability by ameliorating the disruption of CDAA diet-induced zonula occludens-1. Losartan directly inhibited the proliferation of Ac-HSC. The in vitro suppressive effects of OCA + losartan on the mRNA expressions of TGF-β1 and α1(I)-procollagen, TLR4, and TIMP-1 in Ac-HSCs were almost in parallel.

CONCLUSIONS

OCA + losartan suppressed the ongoing hepatic fibrosis by attenuating gut barrier dysfunction and suppressing Ac-HSC proliferation. Combined therapy may be a promising novel approach for NASH with fibrosis.

The use of angiotensin II receptor blocker is associated with greater recovery of cardiac function than angiotensin-converting enzyme inhibitor in dilated cardiomyopathy

AIMS

Angiotensin-converting enzyme inhibitors (ACEis) or angiotensin II receptor blockers (ARBs) have been shown to be associated with recovery of cardiac function in patients with dilated cardiomyopathy (DCM). The aim of this study was to assess comparative effectiveness of ACEis vs. ARBs on recovery of left ventricular ejection fraction (LVEF) among patients with DCM.

METHODS AND RESULTS

We analysed the clinical personal records of DCM, a national database of the Japanese Ministry of Health, Labour and Welfare, from 2003 to 2014. Patients with LVEF < 40% and on either ACEis or ARBs were included. Eligible patients were divided into two groups according to the use of ACEis or ARBs. A one-to-one propensity case-matched analysis was used. The primary outcome was defined as LVEF ≥ 40% at 3 years of follow-up. Out of 4618 eligible patients, 2238 patients received ACEis and 2380 patients received ARBs. Propensity score matching yielded 1341 pairs. Mean age was 56.0 years, 2041 (76.1%) were male, median duration of heart failure was 1 year, and mean LVEF was 27.6%. The primary outcome was observed more frequently in ARB group than in ACEi group (59.8% vs. 54.1%; odds ratio 1.26; 95% confidence interval 1.08-1.47; P = 0.003). The per-protocol analysis showed similar results (62.0% vs. 54.0%; odds ratio 1.39; 95% confidence interval 1.17-1.66; P < 0.001). The change in LVEF from baseline to 3 years of follow-up was greater in ARB group than in ACEi group (15.8 ± 0.4% vs. 14.0 ± 0.4%, P = 0.003). The subgroup analysis showed that this effect was observed independently of systolic blood pressure, heart rate, LVEF, chronic kidney disease, and concomitant use of beta-blockers and mineralocorticoid receptor antagonists.

CONCLUSIONS

The use of ARBs was associated with LVEF recovery more frequently than ACEis among patients with DCM and reduced LVEF.

Effects of the COVID-19 pandemic on heart failure hospitalizations in Japan: interrupted time series analysis

Aims

The Coronavirus Disease 2019 (COVID‐19) pandemic has had unprecedented effects on health care utilization for acute cardiovascular diseases. Although hospitalizations for acute coronary syndrome decreased during the COVID‐19 pandemic, there is a paucity of data on the trends and management of heart failure (HF) cases. Furthermore, concerns have been raised that angiotensin‐converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) may increase susceptibility to COVID‐19. This study aimed to elucidate changes in HF hospitalizations from the COVID‐19 state of emergency in Japan and investigated changes in the prescription of ACEIs and ARBs, and in‐hospital mortality.

Methods and results

We performed an interrupted time series analysis of HF hospitalizations in Japan to verify the impacts of the COVID‐19 state of emergency. Changes in the weekly volume of HF hospitalizations were taken as the primary outcome measure. Between 1 April 2018 and 4 July 2020, 109 429 HF cases required admission. After the state of emergency, an immediate decrease was observed in HF cases per week [−3.6%; 95% confidence interval (CI): −0.3% to −6.7%, P = 0.03]. There was no significant change in the prescription of ACEIs or ARBs after the state of emergency (4.2%; 95% CI: −0.3% to 8.9%, P = 0.07). The COVID‐19 pandemic had no effect on in‐hospital mortality among HF patients (5.3%; 95% CI: −4.9% to 16.6%, P = 0.32).

Conclusions

We demonstrated a decline in HF hospitalizations during the COVID‐19 pandemic in Japan, with no clear evidence of a negative effect on the prescription of ACEIs and ARBs or in‐hospital mortality.

ACEi/ARBs associate with lower incidence of gastrointestinal bleeding in peritoneal dialysis patients

BACKGROUND

Gastrointestinal bleeding (GIB) is widespread in patients with impaired renal function. Whether angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers (ACEi/ARBs) potentially take a crucial role in avoiding GIB incidence among peritoneal dialysis (PD) patients is unknown.

METHODS

Overall, 734 PD patients were enrolled after using propensity score matching. Kaplan-Meier analysis and COX regression were used to explore correlation between ACEi/ARBs and GIB. Competitive risk model was aimed to identify whether other events were confounding factors. Forest plot was applied to assess the influence of ACEI/ARBs on GIB incidence in different groups.

RESULTS

During 8-year follow-up, 89 (12.13%) cases of GIB were recorded. Kaplan-Meier analysis revealed that the incidence of GIB among patients taking ACEi/ARBs was lower than those subjects who had not (log rank = 6.442, P = 0.011). After adjusted different confounding factors, administration of ACEi/ARBs was associated with lowered GIB incidence (adjusted HR = 0.49, 95% CI 0.32-0.77, P = 0.002). In competitive risk model, considering of other events, the incidence of GIB in two groups was still statistically significant (P = 0.010). Subgroup analysis showed ACEi/ARBs taking impeded GIB in the ≥ 60 age group (HR = 0.52, 95% CI 0.28-0.98, P = 0.040).

CONCLUSION

PD patients who were submitted to ACEi/ARBs inclined to have a lower risk for GIB. In this regard, ACEi/ARBs offered a promising choice to GIB.

Commentary on the KDIGO 2021 Clinical Practice Guideline for the Management of Blood Pressure in CKD

PURPOSE OF REVIEW

To summarize and explain the new guideline on blood pressure (BP) management in chronic kidney disease (CKD) published by Kidney Disease: Improving Global Outcomes (KDIGO), an independent global nonprofit organization which develops and implements evidence-based clinical practice guidelines in kidney disease. KDIGO issued its first clinical practice guideline for the Management of Blood Pressure (BP) in Chronic Kidney Disease (CKD) for patients not receiving dialysis in 2012 and now updated the guideline in 2021.

RECENT FINDINGS

Recommendations in this update were developed based on systematic literature reviews and appraisal of the quality of the evidence and strength of recommendation following the "Grading of Recommendations Assessment, Development and Evaluation" (GRADE) approach. The updated guideline includes five chapters covering BP measurement techniques, lifestyle interventions for lowering BP, and management of BP in three target populations, namely adults (with and without diabetes), kidney transplant recipients, and children. A dedicated chapter on BP measurement emphasizing standardized preparation and measurement protocols for office BP measurement is a new addition, following protocols used in large randomized trials of BP targets with pivotal clinical outcomes. Based on the available evidence, and in particular in the CKD subgroup of the SPRINT trial, the 2021 guideline suggests a systolic BP target of <120 mm Hg, based on standardized measurements, for most individuals with CKD not receiving dialysis, with the exception of kidney transplant recipients and children. This recommendation is strictly contingent on the measurement of BP using standardized office readings and not routine office readings.

Severity of COVID-19 infection in ACEI/ARB users in specialty hospitals: A retrospective cohort study

BACKGROUND

The uncertainty about COVID-19 outcomes in angiotensin-converting enzyme inhibitors (ACEI)/angiotensin receptor blockers (ARB) users continues with contradictory findings. This study aimed to determine the effect of ACEI/ARB use in patients with severe COVID-19.

METHODS

This retrospective cohort study was done in two Saudi public specialty hospitals designated as COVID-19 referral facilities. We included 354 patients with a confirmed diagnosis of COVID-19 between April and June 2020, of which 146 were ACEI/ARB users and 208 were non-ACEI/ARB users. Controlling for confounders, we conducted multivariate logistic regression and sensitivity analyses using propensity score matching (PSM) and Inverse propensity score weighting (IPSW) for high-risk patient subsets.

RESULTS

Compared to non-ACEI/ARB users, ACEI/ARB users had an eight-fold higher risk of developing critical or severe COVID-19 (OR = 8.25, 95%CI = 3.32-20.53); a nearly 7-fold higher risk of intensive care unit (ICU) admission (OR = 6.76, 95%CI = 2.88-15.89) and a nearly 5-fold higher risk of requiring noninvasive ventilation (OR = 4.77,95%CI = 2.15-10.55). Patients with diabetes, hypertension, and/or renal disease had a five-fold higher risk of severe COVID-19 disease (OR = 5.40,95%CI = 2.0-14.54]. These results were confirmed in the PSM and IPSW analyses.

CONCLUSION

In general, but especially among patients with hypertension, diabetes, and/or renal disease, ACEI/ARB use is associated with a significantly higher risk of severe or critical COVID-19 disease, and ICU care.

Effects of Angiotensin II Receptor Blockers on Ventricular Hypertrophy in Hypertrophic Cardiomyopathy: A Meta-Analysis of Randomized Controlled Trials

PURPOSE

Animal studies have suggested that angiotensin II receptor blockers (ARBs) can attenuate or reverse the progression of hypertrophic cardiomyopathy, while clinical studies yielded conflicting results. We sought to conduct a meta-analysis to investigate the effect of ARBs in patients with hypertrophic cardiomyopathy.

METHODS

PubMed and EMBASE databases were searched through June 2020. Only randomized controlled trials (RCTs) were included, and each study's quality was assessed using the Jadad scale. The primary outcome was left ventricular mass reduction, and the secondary outcome was the change in left ventricular ejection fraction (LVEF). Data were pooled using the random effects model.

RESULTS

A total of 1294 articles were screened. Five RCTs were included in the final analysis, enrolling 209 patients with hypertrophic cardiomyopathy (101 patients were in the ARB arm). ARB treatment was not associated with either significant left ventricular mass reduction (standardized mean difference: - 0.25; 95% CI: - 0.73, 0.22; p = 0.29) or change in LVEF (weighted mean difference: 0.73%; 95% CI: - 1.10%, 2.56%; p = 0.43). Subgroup analysis showed that losartan, one of the most investigated and commonly used ARBs, was also not associated with significant decreases of left ventricular mass (standardized mean difference: - 0.13; 95% CI: - 0.61, 0.36; p = 0.61).

CONCLUSION

This meta-analysis showed that ARB treatment is not associated with reduced left ventricular mass nor remarkable LVEF change among patients with hypertrophic cardiomyopathy. Further studies with a larger number of patients will be required to confirm these findings.

Severe Sprue-Like Enteropathy and Colitis due to Olmesartan: Lessons Learned From a Rare Entity

Olmesartan is an angiotensin II receptor blocker (ARB) drug approved in 2002 for the treatment of hypertension. Since 2012, there have been reports of a rare adverse effect suspected to be related to its use. The author presents a case of a 63-year-old female with refractory gastrointestinal (GI) symptoms including diarrhea with associated weight loss and severe electrolyte abnormalities necessitating hospitalization. An extensive inpatient evaluation ensued and was initially unremarkable. Esophagogastroduodenoscopy (EGD) discovered an endoscopically normal duodenum that was biopsied and notably revealed villous atrophy and intraepithelial lymphocytosis. Colonoscopy was normal appearing though biopsy findings were significant for nonspecific colitis. The endoscopy findings in the setting of the clinical presentation confirmed the diagnosis of olmesartan-associated enteropathy (OAE). Clinical improvement was noted after cessation of olmesartan and histological resolution was confirmed with repeat EGD post-discharge.

Synergistic reduction in albuminuria in type 2 diabetic mice by esaxerenone (CS-3150), a novel nonsteroidal selective mineralocorticoid receptor blocker, combined with an angiotensin II receptor blocker

Esaxerenone is a novel selective mineralocorticoid receptor (MR) blocker that was recently approved in Japan to treat hypertension. In phase II and III studies, esaxerenone plus a renin–angiotensin system inhibitor markedly reduced the urinary albumin-to-creatinine ratio (UACR) in hypertensive patients with diabetic nephropathy. To evaluate a direct renoprotective effect by MR blockade independent of an antihypertensive effect in the context of diabetic nephropathy, esaxerenone (3 mg/kg), olmesartan (an angiotensin II receptor blocker; 1 mg/kg), or both were orally administered to KK-Ay mice, a type 2 diabetes model, once daily for 56 days. Urinary albumin (Ualb), UACR, and markers, such as podocalyxin, monocyte chemoattractant protein-1 (MCP-1), and 8-hydroxy-2′-deoxyguanosine (8-OHdG), were measured, along with systolic blood pressure (SBP), fasting blood glucose, and serum K⁺ levels. Prior to the initiation of drug administration, KK-Ay mice showed higher blood glucose, insulin, Ualb excretion, and UACR levels than C57BL/6 J mice, a nondiabetic control, indicating the development of diabetic renal injury. Combined treatment with esaxerenone and olmesartan significantly reduced the change in UACR from baseline compared with the change associated with vehicle at week 8 (−1.750 vs. 0.339 g/gCre; P < 0.002) and significantly inhibited the change in Ualb from baseline compared with the change associated with vehicle at week 8 (P < 0.002). The combination treatment also reduced urinary excretion of podocalyxin and MCP-1, but did not influence 8-OHdG excretion, SBP, blood glucose, or serum K⁺ levels. Overall, esaxerenone plus olmesartan treatment ameliorated diabetic nephropathy in KK-Ay mice without affecting SBP, suggesting that the renoprotective effects of esaxerenone could be exerted independently of its antihypertensive effect.

Two cases of advanced stage rapidly progressive diabetic nephropathy effectively treated with combination therapy including RAS blocker, GLP-1 receptor agonist and SGLT-2 inhibitor

We herein report two cases of advanced stage rapidly progressive diabetic nephropathy that were effectively treated with combination therapy including renin-angiotensin-aldosterone system (RAS) blocker [angiotensin II receptor blocker (ARB)], glucagon-like peptide-1 (GLP-1) receptor agonist and sodium glucose transporter-2 (SGLT-2) inhibitor. A 30-year-old woman with advanced stage diabetic nephropathy [estimated glomerular filtration rate (eGFR): 20.7 mL/min/1.73 m²; proteinuria: 13.2 g/gCr], showing a rapidly progressive pattern (annual eGFR change: - 60.0 mL/min/1.73 m²/year), had improvement in proteinuria (5.9 g/gCr) and eGFR change (+ 4.3 mL/min/1.73 m² over 15 weeks) after administration of ARB (irbesartan 25 mg/day), GLP-1 receptor agonist (liraglutide 0.3 mg/day) and SGLT-2 inhibitor (canagliflozin 50 mg/day). A 59-year-old man with advanced stage diabetic nephropathy (eGFR: 32.4 mL/min/1.73 m²; proteinuria: 8.90 g/gCr), showing a rapidly progressive pattern (annual eGFR change: - 21.2 mL/min/1.73 m²/year), had an improvement in proteinuria (0.02 g/gCr) and annual eGFR change (+ 0.1 mL/min/1.73 m²/year) after combination therapy with ARB (olmesartan 40 mg/day), GLP-1 receptor agonist (liraglutide 0.9 mg/day) and SGLT-2 inhibitor (tofogliflozin 10 mg/day). These results suggest that this triple combination therapy has renoprotective effects on advanced stage rapidly progressive diabetic nephropathy.

The clinical efficacy of angiotensin II type1 receptor blockers on inflammatory markers in patients with hypertension: a multicenter randomized-controlled trial; MUSCAT-3 study

Purpose: The purpose of present study was to evaluate the clinical efficacy of irbesartan on the anti-inflammatory and anti-oxidative stress effect in patients with hypertension compared to other ARBs. Further, we assessed the effect of the ARBs on kidney function and urinary albumin excretion. Methods: Eighty-five outpatients with hypertension who took an ARB except irbesartan more than 3 months were assigned into two groups, one continued the same ARB and the other switched the ARB to irbesartan for 6 months. Results: Although blood pressures were equally controlled (continue group: 148 ± 2/79 ± 2 mmHg to 131 ± 2/74 ± 2 mmHg; switch group: 152 ± 2/81 ± 2 mmHg to 132 ± 2/74 ± 2 mmHg; p < 0.001 each), the inflammatory markers (hsCRP, PTX3, MCP-1) and oxidative stress marker (MDA-LDL) did not change after 6 months in both groups. Urinary albumin excretion was significantly reduced only in the switch group without renal function deterioration (switch group 292.4 ± 857.9 mg/gCr to 250.6 ± 906.5 mg/gCr, p = 0.012). Conclusion: These results provide knowledge of the characteristics of irbesartan, suggesting appropriate choice of ARBs in the treatment for hypertension should be considered.

Association Trends Between Antihypertensive Drug Therapies and Diastolic Hypotension in Emirati Patients with Type 2 Diabetes: A Single-Center Retrospective Longitudinal Study

INTRODUCTION

Diabetes mellitus (DM) is associated with multiple complications, including cardiovascular diseases. Previously, it was believed that the latter are mainly caused by hypertension and increased systolic blood pressure. However, recent studies have challenged this concept, by showing that diastolic dysfunction may also be involved in the cardiovascular events that are associated with DM. Pharmacologic management of hypertension in patients with type 2 DM appears to adversely influence diastolic function.

METHODS

Four hundred and eight medical records of hypertensive and obese Emirati patients with type 2 DM were included in the present retrospective study. The main objectives of the present study were (1) to determine the prevalence of low diastolic blood pressure (DBP) and diastolic hypotension in this group of patients and (2) to investigate the associations, if any, between the use of various antihypertensive medications and low DBP and diastolic hypotension.

RESULTS

The results of the present study showed that low DBP (< 70 mmHg) was experienced by 40% of the hypertensive type 2 DM patients, whereas diastolic hypotension (< 60 mmHg) was reported to occur in about 10% of the patients. Another important factor that has been significantly correlated with diastolic hypotension is age (p < 0.01). Association trends have been reported between low DBP and diastolic hypotension and several antihypertensive therapies, including (1) monotherapies such as angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs), (2) dual therapies such as ACE inhibitors in combination with thiazide-like diuretics (THLDs) or beta blockers, and (3) triple therapy combinations of ACE inhibitors with THLDs and potassium-sparing diuretics.

CONCLUSION

The use of antihypertensive medications, in particular ACE inhibitors and ARBs, appears to be a risk factor for the development of low DBP and diastolic hypotension in obese hypertensive Emirati patients with type 2 DM, whereas calcium channel blockers seem to be a safer option for this group of patients.

Pharmacokinetics of a Single Dose of Azilsartan in Pediatric Patients: A Phase 3, Open-Label, Multicenter Study

INTRODUCTION

Azilsartan is an angiotensin II receptor blocker indicated for the treatment of patients with hypertension. The efficacy and safety of azilsartan are established in adults, but have not been evaluated in pediatric patients, nor has its pharmacokinetic profile been determined in pediatric patients.

METHODS

In this phase 3, open-label, multicenter study, we investigated the pharmacokinetics and safety of single doses of azilsartan in six Japanese patients with hypertension, aged 9-14 years. The dose of azilsartan was 5 mg for three patients weighing less than 50 kg, with mean body weight at baseline of 27.5 kg, and 10 mg for three patients weighing at least 50 kg, with mean body weight at baseline of 65.9 kg.

RESULTS

Mean maximum plasma concentration (Cmax) of azilsartan was 888.3 and 831.3 ng/mL and median time to maximum concentration (Tmax) of unchanged azilsartan was 3.0 and 4.0 h, in the 5-mg and 10-mg groups, respectively. Mean areas under the plasma concentration-time curve (AUC) from 0-24 h post-dose (AUC0-24) and 0 h to infinity (AUC0-inf) were 6350.3 and 6635.7 ng h/mL, respectively, in the 5-mg group, and 6871.7 and 7433.3 ng h/mL, respectively, in the 10-mg group. Both doses were well tolerated; no treatment-emergent adverse events considered to be related to azilsartan occurred during the study.

CONCLUSION

Our data suggest that pediatric patients weighing less than 50 kg may have  approximately 2-fold greater exposure to azilsartan than those weighing at least 50 kg at the same dose. Exposure to azilsartan in children weighing at least 50 kg is comparable to that in healthy adults at the same dose.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT02451150.

FUNDING

Takeda Pharmaceutical Co. Ltd.

Improvement of Diurnal Blood Pressure Variation by Azilsartan

Background

Azilsartan is an angiotensin II receptor blocker with a potent antihypertensive effect.

Methods

In a multicenter, prospective, open-label study, 265 patients with poor blood pressure control despite treatment with other angiotensin II receptor blockers were switched to 20 mg/day of azilsartan (patients on standard dosages) or 40 mg/day of azilsartan (patients on high dosages).

Results

Blood pressure was 149/83 mm Hg before switching and was significantly reduced from 1 month after switching until final assessment (132/76 mm Hg, P < 0.001). The pulse rate was 72/min before switching and increased significantly from 3 months after switching until final assessment (74/min, P < 0.005). A significant decrease of home morning systolic and diastolic pressure was observed from 1 and 3 months, respectively. Home morning blood pressure was 143/82 mm Hg before switching and 130/76 mm Hg at final assessment (P < 0.01). The morning-evening difference of systolic blood pressure decreased from 14.6 to 6.6 mm Hg after switching (P = 0.09). The estimated glomerular filtration rate was significantly decreased at 3, 6, and 12 months after switching, and serum uric acid was significantly increased at 12 months. No serious adverse events occurred.

Conclusion

Azilsartan significantly reduced the blood pressure and decreased diurnal variation in patients responding poorly to other angiotensin II receptor blockers.

Angiotensin II receptor blockers suppress the release of stromal cell-derived factor-1α from infarcted myocardium in patients with acute myocardial infarction

BACKGROUND

Although angiotensin II receptor blockers (ARBs) have been shown to have anti-inflammatory effects on infarcted myocardium in experimental models, little is known in humans. Stromal cell-derived factor-1α (SDF-1α), a pro-inflammatory chemokine, is released from infarcted tissue in patients with acute myocardial infarction (AMI). This study examined whether ARBs suppress SDF-1α production in the infarcted lesion in patients with AMI.

METHODS

SDF-1α levels were measured by enzyme-linked immunosorbent assays in plasma obtained from the aortic root (AO) and the anterior interventricular vein (AIV) in 50 patients with an anterior AMI. Measurement of SDF-1α levels and left ventriculography were repeated at discharge and 6 months after AMI. Patients were divided into 2 groups according to treatment with ARBs, which were administered at the discretion of the attending physician after admission.

RESULTS

The AIV-AO gradient of SDF-1α, reflecting SDF-1α release from the infarcted myocardial region, decreased between the time of discharge and 6 months after AMI in patients taking an ARB. In contrast, the SDF-1α transcardiac gradient did not change in patients not taking an ARB. Among the clinical parameters tested, only the use of ARBs was significantly associated with percent changes in the SDF-1α transcardiac gradient from the time of discharge to 6 months after AMI in a linear regression analysis (r=-0.31, p=0.03). The SDF-1α transcardiac gradient 6 months after AMI was inversely correlated with the percent change in left ventricular (LV) ejection fraction (r=-0.52, p<0.01) and positively correlated with the percent change in LV end-diastolic volume index (r=0.57, p<0.01) and LV end-systolic volume index (r=0.54, p<0.01) during 6 months after AMI.

CONCLUSIONS

ARB treatment suppressed SDF-1α release from the infarcted myocardial region, which was associated with improvement in LV dysfunction and adverse remodeling in AMI survivors.

Comparison of effects between calcium channel blocker and diuretics in combination with angiotensin II receptor blocker on 24-h central blood pressure and vascular hemodynamic parameters in hypertensive patients: study design for a multicenter, double-blinded, active-controlled, phase 4, randomized trial

Background

Hypertension is a risk factor for coronary heart disease and stroke, and is one of the leading causes of death. Although over a billion people are affected worldwide, only half of them receive adequate treatment. Current guidelines on antihypertensive treatment recommend combination therapy for patients not responding to monotherapy, but as the number of pills increase, patient compliance tends to decrease. As a result, fixed-dose combination drugs with different antihypertensive agents have been developed and widely used in recent years. CCBs have been shown to be better at reducing central blood pressure and arterial stiffness than diuretics. Recent studies have reported that central blood pressure and arterial stiffness are associated with cardiovascular outcomes. This trial aims to compare the efficacy of combination of calcium channel blocker (CCB) or thiazide diuretic with an angiotensin receptor blocker (ARB).

Methods

This is a multicenter, double-blinded, active-controlled, phase 4, randomized trial, comparing the antihypertensive effects of losartan/amlodipine and losartan/hydrochlorothiazide in patients unresponsive to treatment with losartan. The primary endpoint is changes in mean sitting systolic blood pressure (msSBP) after 4 weeks of treatment. Secondary endpoints are changes in msSBP, mean 24-h ambulatory mobile blood pressure, mean 24-h ambulatory mobile central SBP, mean 24-h ambulatory carotid-femoral pulse wave velocity, ambulatory augmentation index, and microalbuminuria/proteinuria after 20 weeks of treatment. The sample size will be 119 patients for each group in order to confer enough power to test for non-inferiority regarding the primary outcome.

Conclusion

The investigators aim to prove that combination of a CCB with ARB shows non-inferiority in lowering blood pressure compared with a combination of thiazide diuretic and ARB. We also hope to distinguish the subset of patients that are more responsive to certain types of combination drugs. The results of this study should aid physicians in selecting appropriate combination regimens to treat hypertension in certain populations.

Trial registration

ClinicalTrials.gov NCT02294539. Registered 12 November 2014.

Angiotensin-converting enzyme inhibitors versus angiotensin II receptor blockers in acute ST-segment elevation myocardial infarction patients with diabetes mellitus undergoing percutaneous coronary intervention

BACKGROUND

Diabetes Mellitus (DM) is an important factor of adverse cardiovascular events in acute ST-segment elevation myocardial infarction (STEMI) patients. Renin-angiotensin-aldosterone system (RAAS) inhibitors is associated with improved clinical outcomes, however, there are limited data comparing the effectiveness of two different RAAS inhibitors in STEMI patients with DM undergoing percutaneous coronary intervention (PCI) with drug-eluting stents (DES).

METHODS

A total of 3811 eligible STEMI patients with DM were enrolled in Korea Acute Myocardial Infarction Registry (KAMIR). They were stratified into two groups: Angiotensin converting enzyme inhibitors (ACEI) group (n=2691) and angiotensin receptor blockers (ARB) group (n=1120). To adjust baseline confounding factors, we performed propensity score matching (PSM) analysis and evaluated individual and composite major clinical outcomes between the two groups up to 2years.

RESULTS

After PSM, a total of 1049 well-matched pairs were generated. Baseline clinical, angiographic and procedural characteristics were well-balanced between the two groups. The incidence of death, recurrent myocardial infarction (MI), revascularization and major adverse cardiac events (MACE) were not significantly different between the two groups up to 2years, CONCLUSION: In the present study, ACEI and ARB showed comparable effectiveness and safety on individual and composite clinical outcomes in STEMI patients with DM who underwent successful PCI with DES at least up to 2years.

Prospective direct comparison of antihypertensive effect and safety between high-dose amlodipine or indapamide in hypertensive patients uncontrolled by standard doses of angiotensin receptor blockers and amlodipine

OBJECTIVE

When hypertension is uncontrolled by routine treatment with an angiotensin II receptor blocker (ARB) and the calcium channel blocker amlodipine (5 mg), the dose of amlodipine can be increased or a diuretic can be added. We investigated the more effective option in a prospective multicenter open-label study.

METHODS

Hypertensive patients were recruited if the target blood pressure (BP) in The Japanese Society of Hypertension 2009 guideline could not be achieved with standard-dose ARB therapy and amlodipine (5 mg).

PATIENTS

Patients were divided into three groups. Group-1 was switched to a combination of irbesartan (100 mg) and amlodipine (10 mg). Group-2A was changed to a combination of irbesartan (100 mg), amlodipine (5 mg), and indapamide, while Group-2B received a standard-dose ARB and amlodipine (5 mg) plus indapamide. Patients were assigned by their attending physicians and were followed for 6 months. The primary endpoint was the antihypertensive effect of each regimen.

RESULTS

Group-1 contained 85 patients, Group-2A had 49 patients, and Group-2B had 4 patients. We only analyzed Group-1 and Group-2A due to the small size of Group-2B. In both groups, systolic BP and diastolic BP were significantly decreased up to 6 months (all p < 0.001). Reduction of systolic BP was greater in Group-1 than Group-2A after 1 month and 6 months (both p < 0.05). Uric acid was increased in Group-2A after 3 months, but not at 6 months.

CONCLUSION

Although both regimens were effective for reducing BP, increasing amlodipine to 10 mg daily controlled hypertension without elevation of serum uric acid.

Characterizing the time-course of antihypertensive activity and optimal dose range of fimasartan via mechanism-based population modeling

Fimasartan is a novel angiotensin II receptor blocker. Our aims were to characterize the time-course of the antihypertensive activity of fimasartan via a new population pharmacokinetic/pharmacodynamic model and to define its optimal dose range. We simultaneously modelled all fimasartan plasma concentrations and 24-h ambulatory blood pressure monitoring (ABPM) data from 39 patients with essential hypertension and 56 healthy volunteers. Patients received placebo, 20, 60, or 180mg fimasartan every 24h for 28days and healthy volunteers received placebo or 20 to 480mg as a single oral dose or as seven doses every 24h. External validation was performed using data on 560 patients from four phase II or III studies. One turnover model each was used to describe diastolic and systolic blood pressure. The input rates into these compartments followed a circadian rhythm and were inhibited by fimasartan. The average predicted (observed) diastolic blood pressure over 24-h in patients decreased by 10.1±7.5 (12.6±9.2; mean±SD)mmHg for 20mg, 14.2±7.0 (15.1±9.3) mmHg for 60mg, and 15.9±6.8 (11.5±9.9)mmHg for 180mg daily relative to placebo. The model explained the saturation of antihypertensive activity by counter-regulation at high fimasartan concentrations. Drug effect was maximal at approximately 23ng/mL fimasartan for diastolic and 12ng/mL for systolic blood pressure. The proposed mechanism-based population model characterized the circadian rhythm of ABPM data and the antihypertensive effect of fimasartan. After internal and external model validation, 30 to 60mg oral fimasartan given once daily was predicted as optimal dose range.

Tardive akathisia related to the anti-hypertensive agent Sevikar-a case report

BACKGROUND

Tardive akathisia (TA) is a subtype of tardive syndrome, and its etiology is still uncertain. Sevikar is an anti-hypertensive agent containing both amlodipine and olmesartan, and has never been reported to have an adverse reaction in patients with tardive syndrome.

CASE PRESENTATION

A 57-year-old woman who took Sevikar for hypertension for 10 years developed TA one and a half years before receiving any psychiatric treatment. After switching from Sevikar to bisoprolol, she reported obvious improvement in her akathisia.

CONCLUSIONS

It is noteworthy that her TA developed before receiving any antidepressant medication, and that her TA improved after discontinuation of Sevikar. In light of these pharmacodynamic properties, it is therefore concluded that use of amlodipine and olmesartan might have caused TA in this patient. We reported this rare case to remind clinicians to be aware of possible akathisia when using amlodipine and olmesartan in combination as anti-hypertensive agents.

Olmesartan, an angiotensin II receptor blocker inhibits the progression of cataract formation in cadmium chloride induced hypertensive albino rats

AIMS

Previously we found that cadmium chloride (CdCl₂) exposure substantially elevates hypertension and potentiates cataract formation. In the present study, we investigated the protective effects of olmesartan, an angiotensin II receptor blocker against cataractogenesis in the CdCl₂-induced hypertensive animal model.

MAIN METHODS

Male Sprague-Dawley albino rats (150-180g) were randomly selected and assigned to four groups (n=6). Among the four groups, one group (normal) received 0.3% carboxymethyl cellulose (10ml/kg/day, p.o.), another group (CdCl₂ control) received CdCl₂ (0.5mg/kg/day, i.p.), and remaining two groups received olmesartan at two doses level (2 and 4mg/kg/day, p.o.) concurrently with CdCl₂ for six consecutive weeks. Blood pressure and cataract formation were examined biweekly, and pathophysiological parameters in serum and eye lenses were evaluated after six weeks of the experimental protocol.

KEY FINDINGS

The olmesartan treatment significantly restored the blood pressure, lenticular opacity, serum and lens antioxidants (catalase, superoxide dismutase, glutathione peroxidase, and glutathione reduced), and malondialdehyde level. Additionally, it significantly restored the proteins, ions (Na⁺, K⁺, and Ca²⁺), and ATPase pumps activity (Na⁺K⁺ ATPase and Ca²⁺ ATPase) in the lens as compared to CdCl₂ control group.

SIGNIFICANCE

The findings demonstrate that olmesartan potentially inhibits the risk of cataract formation in the hypertensive state via restoration of lenticular oxidative stress, ATPase function, and ionic contents in the eye lenses. The results suggest that angiotensin II receptor blockers play an important role to prevent cataract formation in several pathogenic conditions like hypertension, diabetes, and oxidative stress.

A high sodium intake reduces antiproteinuric response to renin-angiotensin-aldosterone system blockade in kidney transplant recipients

BACKGROUND

Post-transplant proteinuria is associated with lower graft and patient survival. Renin-angiotensin-aldosterone system blockers are used to reduce proteinuria and improve renal outcome. Although it is known that a high salt intake blunts the antiproteinuric effect of ACEI and ARB drugs in non-transplant patients, this effect has not been studied in kidney transplant recipients.

OBJECTIVE

To analyse the relationship between sodium intake and the antiproteinuric effect of ACEI/ARB drugs in kidney transplant recipients.

METHODS

We selected 103 kidney transplant recipients receiving ACEI/ARB drugs for more than 6 months due to proteinuria>1 g/day. Proteinuria was analysed at baseline and at 6 months after starting ACEI/ARB treatment. Salt intake was estimated by urinary sodium to creatinine ratio (uNa/Cr).

RESULTS

Proteinuria fell to less than 1g/day in 46 patients (44.7%). High uNa/Cr was associated with a smaller proteinuria decrease (r=-0.251, P=.011). The percentage proteinuria reduction was significantly lower in patients in the highest uNa/Cr tertile [63.9% (IQR 47.1%), 60.1% (IQR 55.4%), 38.9% (IQR 85.5%), P=.047]. High uNa/Cr independently relates (OR 2.406 per 100 mEq/g, 95% CI: 1.008-5.745, P=.048) to an antiproteinuric response <50% after renin-angiotensin-aldosterone system blockade.

CONCLUSIONS

A high salt intake results in a smaller proteinuria decrease in kidney transplant recipients with proteinuria treated with ACEI/ARB drugs.

Effects of telmisartan and olmesartan on insulin sensitivity and renal function in spontaneously hypertensive rats fed a high fat diet

Although telmisartan, an angiotensin II receptor blocker (ARB), has an agonistic action for proliferator-activated receptor (PPAR)-γ in vitro, it remains to be determined whether telmisartan exerts such an action in vivo using a non-toxic dose (<5 mg/kg in rats). To address the issue, telmisartan (2 mg/kg) and olmesartan (2 mg/kg), another ARB without PPAR-γ agonistic action, were given to spontaneously hypertensive rats (SHR) fed a high fat diet (HFD). HFD decreased plasma adiponectin, and caused insulin resistance, hypertriglyceridemia and renal damage, which were improved by ARBs. Protective effects of telmisartan and olmesartan did not significantly differ. In addition, in vitro study showed that 1 μM of telmisartan did not elevate the mRNA expression of adipose protein 2, which is a PPAR-γ-stimulated adipogenic marker gene, in preadipocytes with 3% albumin. To obtain 1 μM of plasma concentration, oral dose of telmisartan was calculated to be 6 mg/kg, which indicates that PPAR-γ agonistic action is negligible with a non-toxic dose of telmisartan (<5 mg/kg) in rats. This study showed that 2 mg/kg of telmisartan and olmesartan ameliorated insulin resistance, hypertriglyceridemia and renal damage in SHR fed a HFD. As beneficial effects of telmisartan and olmesartan did not significantly differ, these were mediated through the PPAR-γ-independent actions.

The renin-angiotensin-aldosterone-system and right heart failure in congenital heart disease

Adults with congenital heart disease represent a rapidly growing patient group. Dysfunction of the right ventricle is often present, and right heart failure constitutes the main cause of death. Heart failure therapies used in acquired left heart failure are often initiated in adults with right heart failure due to congenital heart disease, but the right ventricle differs substantially from the left ventricle, and the clinical evidence for this treatment strategy is lacking.

In this review, we identified existing clinical studies evaluating the effects of ACE inhibitors, angiotensin II receptor blockers and aldosterone antagonists in adults with congenital heart disease by a systematic literature search. From 13 identified studies no clear evidence of beneficial effects was found, but the design of the studies limits the validity of the results. The studies in general include low numbers of patients, have short follow-up periods and evaluate surrogate endpoints instead of hard clinical endpoints. Specific evaluation of symptomatic patients with a systemic right ventricle indicates that these patients may benefit from RAAS inhibitory treatments, but this requires further investigation.

To conclude, existing studies do not support the use of RAAS inhibitory treatments in right heart failure due to congenital heart disease but contain important limitations. Hence, there is a need for new well-designed trials including higher numbers of patients and validated endpoints to optimize and guide future treatment of this patient group.

Comparison of the relative importance of vascular and plasma drug concentrations to the hypotensive effect of telmisartan in rats

Introduction:

To clarify the importance of the vascular concentration of an angiotensin II receptor blocker (ARB) to its hypotensive effect, the relationships between the drug concentrations in plasma and vascular tissues and the hypotensive effect after administration of an ARB were compared.

Materials and methods:

In spontaneously hypertensive/NDmcr-cp rats (SHR/NDmcr-cp), systolic blood pressure (SBP) and angiotensin II-induced vascular contraction were measured 2 h and 24 h after administration of telmisartan (3 mg/kg). Plasma and vascular concentrations of telmisartan were also measured at 2 h and 24 h.

Results:

SBP was significantly lower 2 h after administration of telmisartan, and the significant hypotensive effect was continued until 24 h. A significant attenuation of angiotensin II-induced vascular contraction at 2 h was also continued until 24 h. No significant difference between 2 h and 24 h was observed both in SBP and angiotensin II-induced vascular contraction. Vascular concentration at 24 h was 90.0% when the concentration at 2 h was assumed to be 100%, and no significant difference was observed. However, the plasma concentration of telmisartan at 2 h was significantly decreased by 88.2% at 24 h.

Conclusion:

The vascular drug concentration, not the plasma drug concentration, may be related to the hypotensive effect after administration of telmisartan.

Impact of use of angiotensin II receptor blocker on all-cause mortality in hemodialysis patients: prospective cohort study using a propensity-score analysis

BACKGROUND

It is controversial whether treatment with an angiotensin II receptor blocker (ARB) or a calcium channel blocker (CCB) improves prognosis of hemodialysis (HD) patients.

METHODS

This study was designed as a multicenter prospective cohort study. HD patients (n = 1071) were enrolled from 22 institutes in January 2009 and followed up for 3 years. Patients with missing data, kidney transplantation or retraction of consent during the follow-up period (n = 204) were excluded, and 867 patients contributed to analysis of mortality. Propensity score (PS) for use of ARB and that for CCB was calculated using a multiple logistic regression model.

RESULTS

ARB and CCB were prescribed in 45.6 and 54.7 % of patients at enrollment. During the 3-year follow-up period, all-cause mortality and cardiovascular mortality rates were 18.8 and 5.1 %, respectively. Kaplan-Meier curves showed that all-cause and cardiovascular mortality rates were lower in the ARB group than in the non-ARB group, though the mortality rates were similar in the CCB group and non-CCB group. In PS-stratified Cox regression analysis, ARB treatment was associated with 34 and 45 % reduction of all-cause death and cardiovascular death, respectively. In PS matching analysis, ARB treatment was associated with a significant reduction (46 % reduction) in the risk of all-cause death. A significant impact of CCB treatment on all-cause or cardiovascular mortality was not detected in PS analysis.

CONCLUSIONS

The use of an ARB, but not a CCB, is associated with reduced all-cause and cardiovascular mortalities in patients on HD.

Comparison of Efficacy of Long-term Oral Treatment with Telmisartan and Benazepril in Cats with Chronic Kidney Disease

Background

The efficacy and benefits of telmisartan in cats with chronic kidney disease (CKD) have not previously been reported.

Hypothesis

Long‐term treatment of cats with CKD using telmisartan decreases urine protein‐to‐creatinine ratio (UP/C) similar to benazepril.

Animals

Two‐hundred and twenty‐four client‐owned adult cats with CKD.

Methods

Prospective, multicenter, controlled, randomized, parallel group, blinded clinical trial with noninferiority design. Cats were allocated in a 1 : 1 ratio to either telmisartan (1 mg/kg; n = 112) or benazepril (0.5–1.0 mg/kg; n = 112) PO q24 h. The primary endpoint was prospectively defined as the change in proteinuria (benazepril:telmisartan) based on a log transformed weighted average of UP/C change from baseline (AUC 0→t/t) as a percentage compared using a confidence interval (CI) approach. Changes of UP/C from baseline were assessed on all study days and corrected for multiple comparisons.

Results

Telmisartan proved noninferior to benazepril in controlling proteinuria (CI, −0.035 to 0.268). At Day 180, UP/C compared to baseline in the telmisartan group was significantly lower (−0.05 ± 0.31; P = .016), whereas in the benazepril group the change (−0.02 ± 0.48) was not statistically significant (P = .136). Similar results were obtained at all assessment points with significant decrease in UP/C occurring with telmisartan but not benazepril.

Conclusion and Clinical Importance

Both telmisartan and benazepril were well tolerated and safe. Telmisartan proved to be noninferior to benazepril and significantly decreased proteinuria relative to baseline at all assessment points whereas benazepril did not.

Impact of candesartan on cardiovascular events after drug-eluting stent implantation in patients with coronary artery disease: The 4C trial

OBJECTIVE

The purpose of this study was to examine the cardiovascular protective effects of candesartan in patients undergoing percutaneous coronary intervention (PCI) with drug-eluting stents (DESs).

BACKGROUND

Candesartan has been reported to reduce cardiovascular events when therapy was started 6 months after PCI with bare-metal stents in patients who survived restenosis. Candesartan started immediately after PCI with DESs was also effective in preventing cardiovascular events.

METHODS

The 4C trial was a multicenter, prospective, randomized, open-label study. A total of 1145 patients at 39 centers in Japan were randomly assigned to receive candesartan plus standard medical treatment or standard medical treatment alone. The primary endpoints were all-cause death, and a composite of non-fatal myocardial infarction (MI), unstable angina pectoris (uAP), congestive heart failure (CHF), and non-fatal cerebrovascular events. The follow-up period was up to 3 years after the index PCI (ClinicalTrials.gov NCT00139386).

RESULTS

The incidence of total death, one of the primary endpoints, was comparable between the two treatment groups (3.8% each, p=0.9702). Another primary endpoint, non-fatal major cardiovascular events, tended to occur more often in the control group than in the candesartan group (9.2% vs. 12.5%, p=0.0985). In contrast, candesartan significantly reduced one of the pre-specified secondary endpoints: cardiovascular events that included non-fatal MI, uAP, and CHF (4.4% vs. 6.7%, p=0.0136). Furthermore, candesartan significantly reduced another secondary endpoint that included cardiovascular events and cardiovascular death (5.0% vs. 7.7%, p=0.0493).

CONCLUSIONS

The 4C trial showed that candesartan administered immediately after PCI with DESs did not improve the prognosis after the index procedure, but did reduce some cardiac-related events for 3 years.

Protective effect of angiotensin II receptor blocker and calcium channel blocker on endothelial vasomotor function after everolimus-eluting stent implantation

BACKGROUND

Endothelial dysfunction after drug-eluting stent implantation has been demonstrated. It may be associated with adverse cardiovascular events during follow-up. Olmesartan, an angiotensin II receptor antagonist, ameliorates endothelial dysfunction. The present study evaluated the protective effect of olmesartan on endothelial function after everolimus-eluting stent (EES) implantation.

METHODS

A total of 40 patients who underwent EES implantation were randomly assigned to the olmesartan group (20 patients with 30 lesions) or the non-olmesartan group (20 patients with 32 lesions). Endothelial function was estimated by measuring the coronary vasoreactivity in the segments 15mm proximal and distal to EES in response to intracoronary infusion of acetylcholine (Ach; 10(-8) and 10(-7)mol/L) at 9-month follow-up. Endothelium-independent vasomotion was assessed after an intracoronary bolus of isosorbide dinitrate.

RESULTS

In both groups, Ach infusion did not induce significant vasoconstriction in the segment either proximal or distal to the EES. The changes in coronary diameter in response to 10(-8)mol/L (-2.0±4.4% vs. -0.6±4.1%, p=0.33) and 10(-7)mol/L (-1.8±7.9% vs. -0.3±7.6%, p=0.57) Ach infusion in the segment proximal to EES were not significantly different between the olmesartan group and the non-olmesartan group. There were no significant differences in vasoconstriction in response to 10(-8)mol/L (-0.8±5.8% vs. -0.9±7.0%, p=0.96) and 10(-7)mol/L (1.8±9.7% vs. -1.8±9.7%, p=0.16) Ach infusion in the segment distal to EES between the 2 groups. Endothelium-independent vasodilation after nitrate infusion did not differ between the 2 groups.

CONCLUSIONS

Endothelial dysfunction is not observed after EES implantation. Olmesartan does not improve endothelial function after EES implantation.

Efficacy and safety of supramaximal titrated inhibition of renin-angiotensin-aldosterone system in idiopathic dilated cardiomyopathy

Aims

The optimal dosing strategies for blocking the renin‐angiotensin‐aldosterone system in idiopathic dilated cardiomyopathy (IDCM) are poorly known. We sought to determine the long‐term efficacy and safety of supramaximal titration of benazepril and valsartan in patients with IDCM.

Methods and results

480 patients with IDCM in New York Heart Association functional class II–IV and with left ventricular ejection fraction ≤35% were randomly assigned to extended‐release metoprolol (mean 152 mg/day, range 23.75–190), low‐dose benazepril (20 mg/day), low‐dose valsartan (160 mg/day), high‐dose benazepril (mean 69 mg/day, range 40–80), and high‐dose valsartan (mean 526 mg/day, range 320–640). After a median follow‐up of 4.2 years, high‐dose benazepril and valsartan, compared with their respective low dosages, resulted in 41% and 52% risk reduction in the primary endpoint of all‐cause death or admission for heart failure (P = 0.042 and 0.002), promoted functional improvement, and reversed remodelling as assessed by New York Heart Association classes, quality‐of‐life scores, and echocardiographic recording of left ventricular ejection fraction, left ventricular end‐diastolic volume, mitral regurgitation, and wall motion score index. Compared with metoprolol, high‐dose valsartan reduced risk for the primary endpoint by 46% (P = 0.006), whereas high‐dose benazepril and both low‐dose groups showed no significant difference. Major adverse events involved hypotension and renal impairment but were largely tolerated.

Conclusions

Supramaximal doses of benazepril and valsartan were well tolerated and produced extra benefit than their low dosages in clinical outcome and cardiac reverse remodelling in patients with IDCM and modest‐severe heart failure. ClinicalTrials.gov identifier: NCT01917149.

Telmisartan aggravates pustular psoriasis

Pustular psoriasis is characterized by abrupt onset of macroscopic pustules associated with erythema and symptoms of burning pain and constitutional symptoms. There are several precipitating factors, both physiological such as pregnancy and routinely prescribed drugs like antihypertensives, antifungals, corticosteroids and progesterone. We present a case of a 50-year-old male patient with pustular psoriasis, well controlled on oral methotrexate, who presented with sudden exacerbation of pustular psoriasis following the use of telmisartan. This case is presented due to the absence of prior reports of telmisartan aggravating pustular psoriasis.

Clinical impacts of additive use of olmesartan in hypertensive patients with chronic heart failure: the supplemental benefit of an angiotensin receptor blocker in hypertensive patients with stable heart failure using olmesartan (SUPPORT) trial

We examined whether an additive treatment with an angiotensin receptor blocker, olmesartan, reduces the mortality and morbidity in hypertensive patients with chronic heart failure (CHF) treated with angiotensin-converting enzyme (ACE) inhibitors, β-blockers, or both. In this prospective, randomized, open-label, blinded endpoint study, a total of 1147 hypertensive patients with symptomatic CHF (mean age 66 years, 75% male) were randomized to the addition of olmesartan (n = 578) to baseline therapy vs. control (n = 569). The primary endpoint was a composite of all-cause death, non-fatal acute myocardial infarction, non-fatal stroke, and hospitalization for worsening heart failure. During a median follow-up of 4.4 years, the primary endpoint occurred in 192 patients (33.2%) in the olmesartan group and in 166 patients (29.2%) in the control group [hazard ratio (HR) 1.18; 95% confidence interval (CI), 0.96–1.46, P = 0.112], while renal dysfunction developed more frequently in the olmesartan group (16.8 vs. 10.7%, HR 1.64; 95% CI 1.19–2.26, P = 0.003). Subgroup analysis revealed that addition of olmesartan to combination of ACE inhibitors and β-blockers was associated with increased incidence of the primary endpoint (38.1 vs. 28.2%, HR 1.47; 95% CI 1.11–1.95, P = 0.006), all-cause death (19.4 vs. 13.5%, HR 1.50; 95% CI 1.01–2.23, P = 0.046), and renal dysfunction (21.1 vs. 12.5%, HR 1.85; 95% CI 1.24–2.76, P = 0.003). Additive use of olmesartan did not improve clinical outcomes but worsened renal function in hypertensive CHF patients treated with evidence-based medications. Particularly, the triple combination therapy with olmesartan, ACE inhibitors and β-blockers was associated with increased adverse cardiac events. This study is registered at clinicaltrials.gov-NCT00417222.

Cardioprotective effect of valsartan in mice with short-term high-salt diet by regulating cardiac aquaporin 1 and angiogenic factor expression

Hypertension is the most common risk factor for various cardiovascular and cerebrovascular diseases that affects approximately 61 million, or 25% of the population in United States. The dietary salt intake is one of the most important but modifiable factors for hypertension. In the current study, we aim to elucidate the role of aquaporin 1 in high-salt-induced hypertension and cardiac injuries and whether angiotensin II receptor blocker valsartan could ameliorate the effect of high salt on blood pressure. Mice were fed with normal diet, high-salt diet in the presence or absence of valsartan for 4 weeks. The body weight gain, feeding behavior, blood pressure, and cardiac pathology changes were monitored after 4 weeks. The expression of aquaporin 1, vascular endothelial growth factor, transforming growth factor β1, and basic fibroblast growth factor were analyzed using quantitative real-time polymerase chain reaction, Western blot, and immunohistochemical staining. Valsartan partially reversed the effects of high-salt diet on hypertension, cardiac injuries such as fibrosis and inflammatory cell infiltration, and inhibition of aquaporin 1 and angiogenic factors; valsartan alone did not exert such effects. The current data demonstrated that the reduction of cardiac aquaporin 1 and angiogenic factor expression level might be associated with high-salt-induced hypertension and cardiac injuries in mice, which could be ameliorated by angiotensin II receptor blocker treatment.

Influence of angiotensin II receptor blocker combination tablet prescription on drug number and cost

OBJECTIVES

Combination therapy using an angiotensin II receptor blocker is expected to promote medication adherence and alleviate economic burden among patients by reducing the number of drugs taken, and thereby to lower associated medical costs. In the present retrospective study, we conducted a survey on the use of angiotensin II receptor blocker-containing combination tablets as anti-hypertensive drugs, in particular angiotensin II receptor blocker/diuretic and angiotensin II receptor blocker/calcium channel blocker combinations, in order to investigate the number of prescribed drugs and drug cost.

METHODS

We performed a retrospective study of patients who visited the outpatient clinic of GifuMunicipalHospital and received anti-hypertensive agents between June 2006 and December 2011.

RESULTS

No reductions in the number of prescribed drugs or drug cost were seen following a change in prescription to an angiotensin II receptor blocker/diuretic. Patients receiving an angiotensin II receptor blocker/calcium channel blocker had a significant reduction in the number of prescribed drugs and a slight decrease in drug cost.

CONCLUSION

In this study, a reduction in the number of prescribed drugs and a decrease in economic burden were not observed after prescription of angiotensin II receptor blocker-containing combination tablets. In order to assess the usefulness of angiotensin II receptor blocker combination tablets, further studies are necessary to investigate their hypotensive effects, safety profile, and other factors.

Impact of socio-economic factors on the long-term effectiveness of antihypertensive treatment with an angiotensin II receptor blocker: an observational study

OBJECTIVE

To investigate the role of socio-economic factors on the therapeutic effectiveness of and therapeutic adherence to the angiotensin II receptor blocker (ARB) olmesartan (OM) alone or in combination with hydrochlorothiazide in the treatment of arterial hypertension.

RESEARCH DESIGN AND METHODS

In a multi-center, open-label, prospective and long-term observational study, data from hypertensive patients treated with OM were analyzed at baseline, month 3 and month 12 within the context of patients' socio-economic status (SES), determined using pre-defined criteria by physicians in outpatient practices and including multivariate analysis.

RESULTS

Overall, 7724 patients were assigned to three subgroups representing low, medium and high socio-economic status. Baseline conditions differed significantly between the subgroups. Patients of low SES had worse nutritional habits, less physical activity and more concomitant medication compared to patients of high SES. Cardiovascular risk factors were more common in the low SES group as were concomitant diseases such as heart failure, coronary heart disease, atherosclerosis and renal failure. OM therapy led to a significant decrease in blood pressure (23.0/11.6 mmHg) in all patients. The blood pressure target of <140/90 mmHg was achieved in about 70% of the documented population. Effectiveness was comparable between patients with low, medium or high SES. Treatment adherence was high in the overall population with only minor differences between the subgroups. In total the incidence of adverse events (AEs) was 1.6% documented in 98 patents (1.3%) during the course of the study. Of this total number only 1.0% was related to the drug, matching the percentage expressed in the Summary of Product Characteristics (SmPC).

CONCLUSIONS

The ARB OM is effective and well tolerated in all patients, irrespective of their socio-economic status. The risk status and the established cardiovascular disease of hypertensive patients are strongly influenced by the SES. To validate these interesting data a randomized controlled trial is needed.

Peroxisome proliferator-activated receptors for hypertension

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors belonging to the nuclear receptor superfamily, which is composed of four members encoded by distinct genes (α, β, γ, and δ). The genes undergo transactivation or transrepression under specific mechanisms that lead to the induction or repression of target gene expression. As is the case with other nuclear receptors, all four PPAR isoforms contain five or six structural regions in four functional domains; namely, A/B, C, D, and E/F. PPARs have many functions, particularly functions involving control of vascular tone, inflammation, and energy homeostasis, and are, therefore, important targets for hypertension, obesity, obesity-induced inflammation, and metabolic syndrome in general. Hence, PPARs also represent drug targets, and PPARα and PPARγ agonists are used clinically in the treatment of dyslipidemia and type 2 diabetes mellitus, respectively. Because of their pleiotropic effects, they have been identified as active in a number of diseases and are targets for the development of a broad range of therapies for a variety of diseases. It is likely that the range of PPARγ agonist therapeutic actions will result in novel approaches to lifestyle and other diseases. The combination of PPARs with reagents or with other cardiovascular drugs, such as diuretics and angiotensin II receptor blockers, should be studied. This article provides a review of PPAR isoform characteristics, a discussion of progress in our understanding of the biological actions of PPARs, and a summary of PPAR agonist development for patient management. We also include a summary of the experimental and clinical evidence obtained from animal studies and clinical trials conducted to evaluate the usefulness and effectiveness of PPAR agonists in the treatment of lifestyle-related diseases.

Losartan improves measures of activity, inflammation, and oxidative stress in older mice

Sarcopenia is an age-related decline in skeletal muscle mass and function that is multifactorial in etiology. Age-related changes in the renin-angiotensin system (RAS), increased oxidative stress, and chronic inflammation likely all contribute to its development. Losartan, an angiotensin II type I receptor blocker (ARB) decreases RAS activity and likely influences oxidative stress and inflammation. Given this, we hypothesized that losartan would improve activity levels and parameters related to inflammation and oxidative stress in older mice. We sought to test this hypothesis by comparing functional and molecular parameters between 18-month-old C57BL/6 mice treated with 50-70 mg/kg/day of losartan over a 4 month-period and age- and gender-matched mice receiving placebo. Losartan treatment significantly improved several activity measurements during treatment period compared to placebo controlled group, including increased time on treadmill, traveling activity, standing activity, and decreased grid contacts (p-values<0.05, 0.001, 0.01; and 0.04 respectively). Grip strength did not improve in treatment group relative to control group over time. Serum IL-6 level in the treated group was significantly lower than that in the control group at the end of treatment (30.3±12.9 vs. 173.0±59.5pg/ml, p<0.04), and mRNA expression of antioxidant enzymes catalase (3.9±0.9 vs. 1.0±0.4) and glutathione peroxidase (4.7±1.1 vs. 1.0±0.4) was significantly higher (p-value: 0.02, and 0.03 respectively) in quadriceps muscle after 4 months of treatment in treated and control groups. These results support the hypothesis that chronic losartan treatment improves skeletal muscle related activity measures in older mice, and that it is associated with more favorable relevant biological profiles in the treatment group. Additional studies are needed to 1) further quantify this functional improvement, 2) further identify mechanisms that influence this improvement, and 3) provide additional rationale for translating these findings into older adults.

Combining irbesartan and trichlormethiazide enhances blood pressure reduction via inhibition of sympathetic activity without adverse effects on metabolism in hypertensive rats with metabolic syndrome

Sympathoexcitation and oxidative stress in the brain have pivotal roles in hypertension with metabolic syndrome (MetS). Here, we examined whether oral administration of irbesartan (IRB) and trichlormethiazide (TCM) decreases blood pressure (BP) via inhibiting sympathetic activity through anti-oxidant effects in the brain of spontaneously hypertensive rats (SHR-cp). IRB/TCM treatment decreased BP more profoundly than IRB monotherapy. Urinary norepinephrine excretion and oxidative stress in the brain were decreased in both IRB and IRB/TCM groups without any adverse effect on the metabolic profile. These findings suggest that IRB/TCM profoundly decreases BP in SHR-cp by inhibiting sympathetic activity via anti-oxidant effects in the brain.

Comparison of the effects of angiotensin II receptor antagonist monotherapy and combination therapy with a diuretic on cardiac function in spontaneously hypertensive rats

OBJECTIVE

Losartan, an angiotensin II receptor blocker (ARB), has been reported to promote sodium excretion and show an enhanced antihypertensive effect when used in combination with hydrochlorothiazide (HCTZ). We investigated the effects of losartan monotherapy and combination therapy together with HCTZ on cardiac function in hypertensive rats using echocardiography.

METHODS

Spontaneously hypertensive rats (n = 21) fed on high-salt diet (8 % NaCl) for 13 weeks were randomly assigned to rats without medication (HS, n = 7), those medicated with ARB (ARB, losartan 30 mg/kg/day, n = 8), and those with ARB and HCTZ (ARB + HCTZ, losartan 30 mg/kg/day + HCTZ 10 mg/kg/day, n = 6). Blood pressure measurements and echocardiography were performed at 13, 17, and 29 weeks of age. After the end of the protocol, the proportion of cardiac muscle fibrosis was measured histologically.

RESULTS

In the HS group, blood pressure and left ventricular mass/body weight (LV mass/BW) increased, and % fractional shortening (%FS) and early diastolic mitral annular velocity (e') decreased significantly with age. In the ARB group, although blood pressure and %FS were maintained, LV mass/BW increased with age as in the HS group, and e' decreased. In the ARB + HCTZ group, blood pressure decreased and LV mass/BW, %FS, and e' were maintained. The progression of myocardial fibrosis was clearly prevented in rats treated with ARB.

CONCLUSION

ARB was shown to inhibit systolic disorder and myocardial fibrosis in hypertensive rats. Combination therapy proved to be more effective than monotherapy and is also effective in inhibiting diastolic disorders.