Analysis of antihypertensive effects of statins

Oxidative stress and early atherosclerosis: novel antioxidant treatment

Atherosclerotic lesions initiate in regions characterized by low shear stress and reduced activity of endothelial atheroprotective molecules such as nitric oxide, which is the key molecule managing vascular homeostasis. The generation of reactive oxygen species from the vascular endothelium is strongly related to various enzymes, such as xanthine oxidase, endothelial nitric oxide synthase and nicotinamide-adenine dinucleotide phosphate oxidase. Several pharmaceutical agents, including angiotensin converting enzyme inhibitors, angiotensin receptors blockers and statins, along with a variety of other agents, have demonstrated additional antioxidant properties beyond their principal role. Reports regarding the antioxidant role of vitamins present controversial results, especially those based on large scale studies. In addition, there is growing interest on the role of dietary flavonoids and their potential to improve endothelial function by modifying the oxidative stress status. However, the vascular-protective role of flavonoids and especially their antioxidant properties are still under investigation. Indeed, further research is required to establish the impact of the proposed new therapeutic strategies in atherosclerosis.

Antiplatelet and Lipid-lowering Drugs in Hypertension

Antiplatelet therapy, and low-dose acetylsalicylic acid (ASA) in particular, is recommended in hypertensive patients with previous cardiovascular events and is considered in hypertensive patients with reduced renal function or a high cardiovascular (CV) risk, provided blood pressure is well-controlled. Acetylsalicylic acid is not recommended in low-to-moderate risk hypertensive patients in whom absolute benefit and harm are equivalent. Further trials evaluating antithrombotic therapy including newer agents in hypertension are needed. Women at high and moderate risk of pre-eclampsia are advised to take a low dose of ASA daily from 12 weeks of gestation until delivery. In addition to their lipid-lowering effects, statins induce a small blood pressure reduction. The 2013 European Society of Hypertension (ESH)/European Society of Cardiology (ESC) guidelines recommend using statin therapy in hypertensive patients at moderate-to-high CV risk to achieve the target low-density lipoprotein (LDL) cholesterol value <3 mmol/l (115 mg/dl). For individuals with manifest CV disease or at very high CV risk, a more aggressive LDL target of <1.8 mmol/l (70 mg/dl) is recommended.

From hypertension to stroke: mechanisms and potential prevention strategies

Stroke is a major cause of disability and death worldwide. Prevention aimed at risk factors of stroke is the most effective strategy to curb the stroke pandemic. Hypertension is one of the most important risk factors for stroke. Despite the substantial evidence of the benefits of lowering blood pressure, conventional treatment does not normalize the burden of major cardiovascular events in patients with hypertension. Fully understanding the factors involved in the hypertension-induced stroke helps to develop new strategies for stroke prevention. Antihypertensive therapies selected should have positive blood pressure-independent effects on stroke risk. This review summarizes the factors involved in the hypertension-induced stroke, such as oxidative stress, inflammation, and arterial baroreflex dysfunction, and potential strategies for its prevention, therefore, provides clues for clinicians.

Effects of HMG-CoA reductase inhibitors on the pharmacokinetics of losartan and its main metabolite EXP-3174 in rats: possible role of CYP3A4 and P-gp inhibition by HMG-CoA reductase inhibitors

The present study was designed to investigate the effects of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (atorvastatin, pravastatin, simvastatin) on the pharmacokinetics of losartan and its active metabolite EXP-3174 in rats. Pharmacokinetic parameters of losartan and EXP-3174 in rats were determined after oral and intravenous administration of losartan (9 mg/kg) without and with HMG-CoA reductase inhibitors (1 mg/kg). The effect of HMG-CoA reductase inhibitors on P-gp and cytochrome (CYP) 3A4 activity were also evaluated. Atorvastatin, pravastatin and simvastatin inhibited CYP3A4 activities with IC₅₀ values of 48.0, 14.1 and 3.10 μmol/l, respectively. Simvastatin (1-10 μmol/l) enhanced the cellular uptake of rhodamine-123 in a concentration-dependent manner. The area under the plasma concentration-time curve (AUC₀₋∞) and the peak plasma concentration of losartan were significantly (p < 0.05) increased by 59.6 and 45.8%, respectively, by simvastatin compared to those of control. The total body clearance (CL/F) of losartan after oral administration with simvastatin was significantly decreased (by 34.8%) compared to that of controls. Consequently, the absolute bioavailability (F) of losartan after oral administration with simvastatin was significantly increased by 59.4% compared to that of control. The metabolite-parent AUC ratio was significantly decreased by 25.7%, suggesting that metabolism of losartan was inhibited by simvastatin. In conclusion, the enhanced bioavailability of losartan might be mainly due to inhibition of P-gp in the small intestine and CYP3A subfamily-mediated metabolism of losartan in the small intestine and/or liver and to reduction of the CL/F of losartan by simvastatin.

Add-on-Statin Extended Release Nicotinic Acid/Laropiprant but Not the Switch to High-Dose Rosuvastatin Lowers Blood Pressure: An Open-Label Randomized Study

Introduction. Nicotinic acid (NA) and statins have been associated with reductions in blood pressure (BP). Patients and Methods. We recruited 68 normotensive and hypertensive dyslipidemic patients who were treated with a conventional statin dose and had not achieved lipid targets. Patients were randomized to switch to high-dose rosuvastatin (40 mg/day) or to add-on current statin treatment with extended release (ER) NA/laropiprant (1000/20 mg/day for the first 4 weeks followed by 2000/40 mg/day for the next 8 weeks) for 3 months. Results. Switching to rosuvastatin 40 mg/day was not associated with significant BP alterations. In contrast, the addition of ER-NA/laropiprant to current statin treatment resulted in a 7% reduction of systolic BP (from 134 ± 12 to 125 ± 10 mmHg, P < .001 versus baseline and P = .01 versus rosuvastatin group) and a 5% reduction of diastolic BP (from 81 ± 9 to 77 ± 6 mmHg, P = .009 versus baseline and P = .01 versus rosuvastatin group). These reductions were significant only in the subgroup of hypertensives and were independent of the hypolipidemic effects of ER-NA/laropiprant. Conclusions. Contrary to the switch to high-dose rosuvastatin, the addition of ER-NA/laropiprant to statin treatment was associated with significant reductions in both systolic and diastolic BP.

The role of statins in chronic kidney disease

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality not only amongst the general population, but also in patients with chronic kidney disease (CKD). Persons with CKD are much more likely to die of CVD than to experience kidney failure. Clinical trials have demonstrated that statins are gaining widespread acceptance as a principal therapy for the primary and secondary prevention of atherosclerosis and CVD. In CKD patients the role of statins in primary prevention of CVD remains to be clarified. The absolute benefit of treatment with a statin seems to be greater among nondialysis-dependent-CKD patients. Studies in end-stage renal disease patients on dialysis did not confirm these results. Recently, however, the Study of Heart and Renal Protection (SHARP) has suggested that statins with ezetimibe may be beneficial even in dialysis patients. Clinical studies with statins on proteinuria reduction and renal disease progression have yielded conflicting results. Some studies have shown a prominent reduction in proteinuria, while other studies have shown that statins had no effect or may cause proteinuria at high doses. This review examines the clinical evidence of the observed benefits of kidney function with the use of this drug category in CKD patients.

Current role of statins in the treatment of essential hypertension

IMPORTANCE OF THE FIELD

Hypertension and hyperlipidemia often co-exist and seem to be interrelated through common pathophysiological pathways. Drugs employing beneficial effects in both conditions could be advantageous in a concerted effective management of patients at high cardiovascular risk. Statins are known to enhance cardiovascular protection beyond their lipid-lowering capacity.

AREAS COVERED IN THIS REVIEW

MEDLINE was searched, up to January 2010, for studies assessing the effect of statin treatment on blood pressure control in various populations or animal models of hypertension. The potential mechanisms implicated in the putative antihypertensive action of statins are also reviewed.

WHAT THE READER WILL GAIN

To learn about the role of statins as potential antihypertensive drugs in various populations. Clinical advice for the use of statins either as monotherapy or in combination with antihypertensive drugs in high-risk populations is also provided.

TAKE HOME MESSAGE

Statins may exert a mild, but clinically relevant, antihypertensive effect which is probably mediated by mechanisms that are independent of their lipid-lowering effects. Patients with high BP levels at baseline as well as those treated with ACE inhibitors and calcium channel blockers are expected to benefit more in this regard.

Essential hypertension: is there a role for inflammatory mechanisms?

Inflammation is a key feature in the initiation, progression, and clinical implications of cardiovascular disorders, including essential hypertension. Increasing evidence shows that activation of renin-angiotensin-aldosterone system and enhanced local production of angiotensin II have been implicated in the pathophysiology of inflammation. Besides being a potent vasoactive peptide, angiotensin II regulates the inflammatory process. Specifically, it increases vascular permeability, participates in the recruitment of inflammatory cells and their adhesion to the activated endothelium, and regulates cell growth and fibrosis. Reactive oxygen species are implicated at every stage in inflammation and activate multiple intracellular signaling molecules and transcription factors associated with inflammatory responses, such as nuclear factor-kappa B and activator protein-1. Other components of the renin-angiotensin-aldosterone system, including aldosterone and/or mineralocorticoid receptor, induce the production of reactive oxygen species and participate in vascular inflammation. Several studies suggest a role of endothelin-1 as an important mediator of chronic inflammation and there is an increasing interest in the relationship between endothelin-1 and reactive oxygen species. These data may have great impact on future therapeutic strategies.

Role and significance of statins in the treatment of hypertensive patients

BACKGROUND

Statins are the first-line drug therapy in the treatment of hypercholesterolemia. The beneficial clinical impact of statins on the cardiovascular system results not only from their lipid-lowering action but also from other effects. Recently, it has been suggested that statins can reduce blood pressure, especially in hypertensive patients.

AIM

The role of the hypotensive action of statins and other mechanisms which reduce cardiovascular risk in hypertensive patients are discussed in this review.

METHODS

Electronic databases searched were [MEDLINE (1966 - February 2009), EMBASE and SCOPUS (1965 - February 2009), DARE (1966 -- February 2009)]. Additionally, abstracts from national and international cardiovascular meetings were studied to identify unpublished studies. The main data search terms were: blood pressure, hypertension, hypercholesterolemia and statins.

FINDINGS

At present, it is difficult to unequivocally assess the impact of statins on blood pressure. However, according to most authors, the impact of statins on the decrease in BP is slight, but significant, especially among patients with hypertension.

Implementation of guidelines for the management of arterial hypertension. The impulsion study

This study assessed the effects of a pilot best practice implementation enhancement program on the control of hypertension. We enrolled 697 consecutive known hypertensive patients with other vascular risk factors but free from overt vascular disease. There was no “control” group because it was considered unethical to deprive high-risk patients from “best medical treatment”. Following a baseline visit, previously trained physicians aimed to improve adherence to lifestyle measures and drug treatment for hypertension and other vascular risk factors. Both at baseline and at study completion (after 6 months), a 1-page form was completed showing if patients achieved treatment targets. If not, the reasons why were recorded. This program enhanced compliance with lifestyle measures and increased the use of evidence-based medication. There was a substantial increase in the number of patients who achieved treatment targets for blood pressure (p<0.0001) and other vascular risk factors. In non-diabetic patients (n=585), estimated vascular risk (PROCAM risk engine) was significantly reduced by 41% (p<0.0001). There was also a 12% reduction in vascular risk according to the Framingham risk engine but this did not achieve significance (p=0.07). In conclusion, this is the first study to increase adherence to multiple interventions in hypertensive patients on an outpatient basis, both in primary care and teaching hospitals. Simple, relatively low cost measures (e.g. educating physicians and patients, distributing printed guidelines/brochures and completing a 1-page form) motivated both physicians and patients to achieve multiple treatment goals. Further work is needed to establish if the improvement observed is sustained. [ClinicalTrials.gov NCT00416611].

The patterns of antihypertensive drug prescription by cardiologists in Kerman province of Iran, 2006

PURPOSE

This study was performed to evaluate the antihypertensive prescribing pattern by cardiologists in outpatients attending private clinics in Kerman province, Iran during 1 year period, 2006.

METHODS

Using random sampling method, 1102 prescriptions issued by cardiologists were investigated. The prescriptions of outpatients which contain at least one antihypertensive medication were separated for further analysis. Using World Health Organization (WHO) standard drug indicators, we evaluate the quality and quantity of prescriptions. The indices were compared between different sex groups by SPSS 11.5 software.

RESULTS

About 39% of the patients were male. The average age of the individuals was 57.3 +/- 13. The mean number of drugs per prescription was 2.84 +/- 0.7, but the average of antihypertensive drugs per prescription was 1.4 +/- 0.3, similarly in both sexes. The most prescribed drug class was beta-blockers (46.2%) followed by calcium channel blockers (CCBs) (19.2%), angiotensin-converting enzyme (ACE) inhibitors (13.7%), diuretics (10.3%), angiotensin receptor blockers (ARBs) (9.2%) and other antihypertensive agents (1.5%). Most of the hypertensive patients (69.6%) were treated with a single drug while 31.4% of the patients received more than one drug. There was not a significant gender difference between the types of drug class used. Statins and acetyl salicylic acid (ASA) were prescribed as cardiovascular disease preventive drugs in 10.2 and 38% of hypertensive patients, respectively.

CONCLUSION

The mean numbers of drugs per prescription by cardiologists in Kerman province of Iran were not in agreement with WHO standard drug use indicators. Lower using rate of diuretics, statins and ASA need a comprehensive reassessment of the medical management of hypertensive patients.

A randomised study comparing the efficacy and safety of rosuvastatin with atorvastatin for achieving lipid goals in clinical practice in Asian patients at high risk of cardiovascular disease (DISCOVERY-Asia study)

BACKGROUND

Most studies investigating the benefits of statins have focused on North American and European populations. This study focuses on evaluating the lipid-lowering effects of rosuvastatin and atorvastatin in Asian patients.

OBJECTIVES

The DIrect Statin COmparison of LDL-C Values: an Evaluation of Rosuvastatin therapY (DISCOVERY)-Asia study is one of nine independently powered studies assessing the efficacy of starting doses of statins in achieving target lipid levels in different countries worldwide. DISCOVERY-Asia was a 12-week, randomised, open-label, parallel-group study conducted in China, Hong Kong, Korea, Malaysia, Taiwan, and Thailand.

RESULTS

A total of 1482 adults with primary hypercholesterolaemia and high cardiovascular risk (> 20%/10 years, type 2 diabetes, or a history of coronary heart disease) were randomised in a 2 : 1 ratio to receive rosuvastatin 10 mg once daily (o.d.) or atorvastatin 10 mg o.d. The percentage of patients achieving the 1998 European Joint Task Force low-density lipoprotein cholesterol (LDL-C) goal of < 3.0 mmol/L at 12 weeks was significantly higher in the rosuvastatin group (n = 950) compared with the atorvastatin group (n = 471) (79.5 vs. 69.4%, respectively; p < 0.0001). Similar results were observed for 1998 European goals for total cholesterol (TC), and the 2003 European goals for LDL-C and TC. LDL-C and TC levels were reduced significantly more with rosuvastatin compared with atorvastatin. Both drugs were well-tolerated and the incidence and type of adverse events were similar in each group.

TRIALS REGISTRATION

The trial registry summary is available at http://www.clinicaltrials.gov/; ClinicalTrials.gov Identifier: NCT00241488

CONCLUSIONS

This 12-week study showed that the starting dose of rosuvastatin 10 mg o.d. was significantly more effective than the starting dose of natorvastatin 10 mg o.d. at enabling patients with primary hypercholesterolaemia to achieve European goals for LDL-C and TC in a largely Asian population in real-life clinical practice. The safety profile of rosuvastatin 10 mg is similar to that of atorvastatin 10 mg in the Asian population studied here, and is consistent with the known safety profile of rosuvastatin in the white population.