Combination drug treatment of hypertension: Have we come full circle?

Pioglitazone Improves Mitochondrial Organization and Bioenergetics in Down Syndrome Cells

Mitochondrial dysfunction plays a primary role in neurodevelopmental anomalies and neurodegeneration of Down syndrome (DS) subjects. For this reason, targeting mitochondrial key genes, such as PGC-1α/PPARGC1A, is emerging as a good therapeutic approach to attenuate cognitive disability in DS. After demonstrating the efficacy of the biguanide metformin (a PGC-1α activator) in a cell model of DS, we extended the study to other molecules that regulate the PGC-1α pathway acting on PPAR genes. We, therefore, treated trisomic fetal fibroblasts with different doses of pioglitazone (PGZ) and evaluated the effects on mitochondrial dynamics and function. Treatment with PGZ significantly increased mRNA and protein levels of PGC-1α. Mitochondrial network was fully restored by PGZ administration affecting the fission-fusion mitochondrial machinery. Specifically, optic atrophy 1 (OPA1) and mitofusin 1 (MFN1) were upregulated while dynamin-related protein 1 (DRP1) was downregulated. These effects, together with a significant increase of basal ATP content and oxygen consumption rate, and a significant decrease of reactive oxygen species (ROS) production, provide strong evidence of an overall improvement of mitochondria bioenergetics in trisomic cells. In conclusion, we demonstrate that PGZ is able to improve mitochondrial phenotype even at low concentrations (0.5 μM). We also speculate that a combination of drugs that target mitochondrial function might be advantageous, offering potentially higher efficacy and lower individual drug dosage.

Current status of stroke in Qatar: Including data from the BRAINS study

BACKGROUND

Qatar is located on the north-eastern coast of the Arabian Peninsula. Qatari natives account for less than 15% of the population while the largest migrant group comprising 60% derives from South Asia. Despite projections that stroke burden in Qatar will increase with population ageing, epidemiological studies focusing on stroke in Qatar are relatively scarce.

METHOD

We reviewed the available epidemiological publications relating to Qatar. In addition, we have added to this knowledge by incorporating Qatari data from the on-going Bio-Repository of DNA in Stroke, an independent multinational database of stroke patients.

RESULTS

Qatar has low reported incidence and mortality rates of 58 and 9.17 per 100,000 per year, respectively, which may be explained by its middle-aged migrant worker majority population. Correspondingly, South Asian migrants in Qatar suffered younger strokes than Qatari natives (48.7 vs 63.4 years, P < 0.001). Among the most common risk factors identified in stroke patients were hypertension (77.9%), diabetes (43.8%) and hypercholesterolemia (28.5%). Ischaemic stroke was the most frequent subtype amongst migrant South Asians (71.1%). The majority of stroke cases had computed tomography and/or magnetic resonance imaging scans, but only 11.1% of ischaemic strokes were thrombolysed. Qataris on one-year follow up were more often found to have died (6.5% vs 0.3%) and had further stroke/transient ischaemic attack events (17.4% vs 6.4%, P = 0.009) compared to South Asians.

CONCLUSION

The burden of stroke is increasing in Qatar, and considerable disparities are observed between the native and migrant populations which likely will require different approaches to management by its healthcare system.

Combination therapy with lercanidipine and enalapril in the management of the hypertensive patient: an update of the evidence

Hypertension is an important risk factor for premature death as it increases the probability of stroke, myocardial infarction, and heart failure. Antihypertensive drugs can decrease cardiovascular (CV) morbidity and mortality. The majority of hypertensive patients need more than one antihypertensive agent to attain blood pressure (BP) targets. Monotherapy can effectively reduce BP only in 20%–40% of patients. Multiple mechanisms including increased peripheral vascular resistance, increased cardiac work, and hypervolemia are involved in the pathogenesis of hypertension. Targeting multiple pathways may more potently reduce BP. Increasing the dose of a single agent in many cases does not provide the expected BP-lowering effect because the underlying mechanism of the BP increase is either different or already corrected with the lower dose. Moreover, drugs acting on different pathways may have synergistic effects and thus better control hypertension. It is well known that diuretics enhance the actions of renin–angiotensin aldosterone system and activate it as a feedback to the reduced circulated blood volume. The addition of a renin–angiotensin aldosterone system blocker to a diuretic may more effectively reduce BP because the system is upregulated. Reducing the maximal dose of an agent may also reduce possible side effects if they are dose dependent. The increased prevalence of peripheral edema with higher doses of calcium channel blockers (CCBs) is reduced when renin–angiotensin aldosterone system blockers are added to CCBs through vein dilation. The effectiveness of the combination of enalapril with lercanidipine in reducing BP, the safety profile, and the use of the combination of angiotensin-converting enzyme inhibitors with CCBs in clinical trials with excellent CV hard end point outcomes make this combination a promising therapy in the treatment of hypertension.

Real-life Effectiveness and Safety of Amlodipine/Valsartan Single-pill Combination in Patients with Hypertension in Egypt: Results from the EXCITE Study

BACKGROUND

EXCITE (clinical experience of amlodipine and valsartan in hypertension) evaluated the real-world effectiveness and safety of single-pill combinations (SPCs) of amlodipine/valsartan (Aml/Val) and amlodipine/valsartan/hydrochlorothiazide (Aml/Val/HCTZ) in patients with hypertension from the Middle East and Asia.

OBJECTIVE

The objective of this study was to report the results of EXCITE study from Egypt, where all patients were prescribed Aml/Val.

METHODS

This was a 26-week, observational, multicenter, prospective, non-interventional, open-label study. Effectiveness was assessed as change in the mean sitting systolic/diastolic blood pressure (msSBP/msDBP) from baseline and the proportion of patients achieving the therapeutic blood pressure (BP) goal (<140/90; <130/80 mmHg in patients with diabetes mellitus) and BP response (SBP <140 mmHg or reduction of ≥20 mmHg; DBP <90 mmHg or reduction of ≥10 mmHg). Safety was monitored by recording the incidence of adverse events (AEs) and serious AEs (SAEs).

RESULTS

A total of 2566 patients (mean age, 52.6 years; mean duration of hypertension, 7.9 years) were prescribed Aml/Val, of whom 2439 (95.1 %) completed the study. At week 26, Aml/Val SPC significantly (p < 0.0001) reduced msSBP/msDBP by -34.5/-19.4 mmHg from baseline (BP: 164.3/100.5 mmHg). Therapeutic goal, SBP response, and DBP response was achieved by 49.3, 91.1, and 91.4 % of patients, respectively. AEs were reported in 12.5 % of patients, with the most common including peripheral edema (1.8 %), bronchitis (1.1 %), and gastritis (0.8 %), and SAEs in 0.5 % of patients. Two deaths were reported during the study, none of which were considered to be study drug related by the investigators.

CONCLUSION

Aml/Val SPC provided clinically significant BP reductions and was generally well tolerated in patients with hypertension from Egypt.

Use of combination antihypertensive therapy initiation in older Americans without prevalent cardiovascular disease

OBJECTIVES

To describe new users of antihypertensive medications and identify predictors of combination therapy initiation in older Americans.

DESIGN

Retrospective observational cohort study.

SETTING

Population-based study using U.S. Medicare fee-for-service healthcare claims (2007-2010).

PARTICIPANTS

Medicare beneficiaries aged 65 and older with no recent diagnoses, procedures, or medications for cardiovascular disease who newly initiated an antihypertensive therapy (n = 275,493; 210,605 initiated monotherapy, 64,888 initiated combination therapy).

MEASUREMENTS

Multivariable Poisson regression was used to assess factors associated with initiation of combination therapy versus monotherapy, including participant characteristics, prescriber characteristics, and participant encounters with the healthcare system.

RESULTS

Initiation of combination therapy increased from 21.9% in 2007 to 24.7% in 2010. The most frequently initiated combinations were angiotensin-converting enzyme inhibitors with thiazide (29.7%) and angiotensin II receptor antagonists with thiazide (18.7%). Blacks (prevalence ratio (PR) = 1.48, 95% confidence interval (CI) = 1.45-1.51 vs. whites), individuals seeing a generalist (PR = 1.10, 95% CI = 1.07-1.14), individuals seeing more than one doctor (PR = 3.38, 95% CI = 3.33-3.44), and participants with no pharmacy claims in the previous 6 months (PR = 1.34, 95% CI = 1.30-1.37 vs. ≥3 unique drug classes) were more likely to initiate combination therapy, whereas those who had more outpatient visits in the previous 12 months were less likely to initiate combination therapy (per five visits, PR = 0.82, 95% CI = 0.80-0.83).

CONCLUSION

Nearly one in four new users of antihypertensive medications aged 65 and older started treatment with combination therapy. Blacks, individuals living in the south, and those with fewer outpatient physician office visits were more likely to initiate combination therapy. Further research is needed to determine whether this approach to managing hypertension is being well targeted to individuals who will require combination treatment.

Can we reduce the cost of illness with more compliant patients? An estimation of the effect of 100% compliance with hypertension treatment

INTRODUCTION

The current study was designed to calculate the direct cost of noncompliance of hypertensive patients to the US health system. Understanding these expenses can inform screening and education budget policy regarding expenditure levels that can be calculated to be cost-beneficial.

METHOD

The study was conducted in 3 parts. First, a computer search of National Institutes of Health Web sites and professional society Web sites for organizations with members that treat hypertension, and a PubMed search were performed to obtain the numbers required for calculations. Second, formulas were developed to estimate the risk of noncompliance and undiagnosed hypertension. Third, risk calculations were performed using the information obtained in part 1 and the formulas developed in part 2.

RESULTS

Direct risk reduction for stroke caused by hypertension, heart attack, kidney disease, and heart disease was calculated for a 100% compliant strategy. Risk, case, and cost reduction for a 100% compliant strategy for hypertension were 32%, 8.5 million and US$ 72 billion, respectively.

DISCUSSION

Our analysis means that the society can spend up to the cost of noncompliance in screening, education, and prevention efforts in an attempt to reduce these costly and traumatic sequelae of poorly controlled hypertension in the light of published analysis.

Valsartan combination therapy in the management of hypertension - patient perspectives and clinical utility

The morbidity and mortality benefits of lowering blood pressure (BP) in hypertensive patients are well established, with most individuals requiring multiple agents to achieve BP control. Considering the important role of the renin-angiotensin-aldosterone system (RAAS) in the pathophysiology of hypertension, a key component of combination therapy should include a RAAS inhibitor. Angiotensin receptor blockers (ARBs) lower BP, reduce cardiovascular risk, provide organ protection, and are among the best tolerated class of antihypertensive therapy. In this article, we discuss two ARB combinations (valsartan/hydrochlorothiazide [HCTZ] and amlodipine/valsartan), both of which are indicated for the treatment of hypertension in patients not adequately controlled on monotherapy and as initial therapy in patients likely to need multiple drugs to achieve BP goals. Randomized, double-blind studies that have assessed the antihypertensive efficacy and safety of these combinations in the first-line treatment of hypertensive patients are reviewed. Both valsartan/HCTZ and amlodipine/valsartan effectively lower BP and are well tolerated in a broad range of patients with hypertension, including difficult-to-treat populations such as those with severe BP elevations, prediabetes and diabetes, patients with the cardiometabolic syndrome, and individuals who are obese, elderly, or black. Also discussed herein are patient-focused perspectives related to the use of valsartan/HCTZ and amlodipine/valsartan, and the rationale for use of single-pill combinations as one approach to enhance patient compliance with antihypertensive therapy.

Choice of ACE inhibitor combinations in hypertensive patients with type 2 diabetes: update after recent clinical trials

The diabetes epidemic continues to grow unabated, with a staggering toll in micro- and macrovascular complications, disability, and death. Diabetes causes a two- to fourfold increase in the risk of cardiovascular disease, and represents the first cause of dialysis treatment both in the UK and the US. Concomitant hypertension doubles total mortality and stroke risk, triples the risk of coronary heart disease and significantly hastens the progression of microvascular complications, including diabetic nephropathy. Therefore, blood pressure reduction is of particular importance in preventing cardiovascular and renal outcomes. Successful antihypertensive treatment will often require a combination therapy, either with separate drugs or with fixed-dose combinations. Angiotensin converting enzyme (ACE) inhibitor plus diuretic combination therapy improves blood pressure control, counterbalances renin-angiotensin system activation due to diuretic therapy and reduces the risk of electrolyte alterations, obtaining at the same time synergistic antiproteinuric effects. ACE inhibitor plus calcium channel blocker provides a significant additive effect on blood pressure reduction, may have favorable metabolic effects and synergistically reduce proteinuria and the rate of decline in glomerular filtration rate, as evidenced by the GUARD trial. Finally, the recently published ACCOMPLISH trial showed that an ACE inhibitor/calcium channel blocker combination may be particularly useful in reducing cardiovascular outcomes in high-risk patients. The present review will focus on different ACE inhibitor combinations in the treatment of patients with type 2 diabetes mellitus and hypertension, in the light of recent clinical trials, including GUARD and ACCOMPLISH.

Improving microvascular outcomes in patients with diabetes through management of hypertension

Diabetes mellitus is an independent risk factor for cardiovascular disease (CVD) and current opinion holds that hyperglycemia directly damages smaller blood vessels, resulting in microvascular complications of nephropathy, retinopathy, and neuropathy. In a patient with diabetes, hypertension compounds and greatly increases the risk of microvascular complications, and thus the risk of end-stage kidney disease, vision loss, and nontraumatic limb amputations. Hypertension and hyperglycemia directly damage the microvasculature, leading to small vessel dysfunction that manifests as the clinical disease states of diabetic retinopathy and nephropathy. Early recognition and treatment of both hyperglycemia and hypertension may prevent vision loss and chronic kidney disease, the devastating outcomes of these microvascular complications. One of the pathogenic mechanisms for microvascular dysfunction is upregulation of the angiotensin II type 1 receptor, the most physiologically common receptor for the vasoconstrictor properties of angiotensin II. In patients with diabetic retinopathy and nephropathy, tight control of blood pressure (BP) (< 130/80 mm Hg) delays the progression of retinopathy and nephropathy in addition to reducing cardiovascular morbidity and mortality. Aggressive treatment with 2 or more antihypertensive agents, selected from different drug classes, is often needed to reach the optimal BP target level. A PubMed search was conducted to identify randomized controlled trials that evaluated hypertension control and microvascular outcomes in patients with diabetes. Several clinical trials have yielded promising data with renin-angiotensin-aldosterone system (RAAS) inhibitors (the direct renin inhibitor aliskiren, angiotensin-converting enzyme inhibitors, and angiotensin receptor blockers). Attainment of BP control with RAAS inhibitors reduces the risk for CVD, nephropathy, and retinopathy. In addition, RAAS inhibitors have demonstrated renoprotective effectiveness independent of the BP reduction achieved. This review will examine the results of clinical trials in the context of BP control, diabetes, and the microvascular complications of retinopathy and nephropathy.

Assessment of adherence, persistence, and costs among valsartan and hydrochlorothiazide retrospective cohorts in free-and fixed-dose combinations

OBJECTIVES

To assess medication adherence, persistence, and costs between cohorts of patients in managed care settings using a fixed-dose combination (FDC) or individual components (IC) of valsartan and hydrochlorothiazide in an insurance claims database.

METHODS

Medical and prescription claims for hypertensive patients using a combination of valsartan and HCTZ were identified from the IHCIS National Managed Care Benchmark Database via a retrospective cohort analysis. Study subjects had at least 110 days prior to start of study medications during which no other antihypertensive medications were prescribed, and were followed for 12 months. Claims for 8711 adult patients were analyzed for adherence, persistence and costs. General linear regression was conducted to detect differences in adherence among groups. Covariates included age, gender, persistence, number on concomitant cardiovascular drugs, and number of cardiovascular diagnoses.

RESULTS

Most subjects used an FDC product (N=8150, 93.6%) vs. the IC (N=561, 6.4%). The FDC group had a larger portion of males and less concomitant cardiovascular medications or disease. A random sample of 1628 of the FDC subjects had improved values for medication adherence compared to the IC group (62.1 vs. 53.0%, p<0.001) and persistence values were improved at both 180 days (73 vs. 28%, p<0.001) and 365 days (54 vs. 19%, p<0.001). Both prescription drug costs ($1587 vs. $2050, p<0.001) and medical costs ($3343 vs. $3817, p<0.001) were lower in the FDC cohorts.

CONCLUSIONS

The use of fixed-dose therapy in hypertension may lead to increased adherence and persistence with a positive financial impact on both prescription and total medical costs. As with any retrospective claims database analysis, unobserved systematic differences between the two medication groups may exist.

Efficacy and safety of fixed combinations of irbesartan/hydrochlorothiazide in older vs younger patients with hypertension uncontrolled with monotherapy

Subgroup analysis of the Irbesartan/Hydrochlorothiazide Blood Pressure Reductions in Diverse Patient Populations (INCLUSIVE) trial evaluated the efficacy and safety of irbesartan/hydrochlorothiazide (HCTZ) fixed combinations in patients aged 65 years or older with uncontrolled systolic blood pressure (SBP) after >or= 4 weeks of antihypertensive monotherapy. The INCLUSIVE trial was a prospective, open-label, single-arm trial carried out in 119 sites. Of 844 patients completing placebo treatment, 212 were aged 65 years or older. Participants received treatment with placebo (4-5 weeks), HCTZ 12.5 mg (2 weeks), irbesartan/HCTZ 150/12.5 mg (8 weeks), and then irbesartan/HCTZ 300/25 mg (8 weeks). From baseline to week 18 (n=184, intent-to-treat population), mean change in SBP was -23.0+/-13.3 mm Hg (P<.001) and diastolic BP (DBP) was -10.9+/-7.7 mm Hg (P<.001). Mean SBP/DBP at study end was 134.0+/-14.7/75.1+/-8.4 mm Hg, and SBP, DBP, and SBP/DBP goal was achieved in 73%, 96%, and 72% of patients, respectively. Irbesartan/HCTZ combination therapy allowed SBP goal attainment in 73% of patients aged 65 years or older whose hypertension was previously uncontrolled with antihypertensive monotherapy.

What factors contribute to the inadequate control of elevated blood pressure?

Inadequate control of blood pressure may be attributed to both provider-related and patient-related factors. Health care provider-related factors may include an excessive reliance on monotherapy and reluctance to increase drug doses or add additional antihypertensive agents to the treatment regimen. The primary patient-related factor is nonadherence with the prescribed antihypertensive medication. Although the high cost of therapy is sometimes a reason for poor adherence, drug side effects or dosing considerations may be more important factors. Better adherence with antihypertensive medication is associated with a significantly greater likelihood of achieving blood pressure control and, consequently, with lower costs and reduced utilization of health care resources. Therefore, strategies that improve long-term adherence should be adopted. Single-pill, or fixed-dose, combination therapy is one approach that improves adherence, while also providing the antihypertensive efficacy needed to help patients achieve their blood pressure goals.

Combination pharmacotherapy in hypertension

Combination pharmacotherapy with two or more drugs is required in order to reach the currently recommended blood pressure goals in the majority of hypertensive patients, particularly those with a goal of <130/80 mm Hg. Further to the potentiation of the antihypertensive effects, benefits of combination therapy include the potential of fewer adverse affects and of improvement of patients' compliance. Current guidelines recommend that combination pharmacotherapy might also be considered as initial treatment in patients with significant elevation of blood pressure and evidence of complications. Several effective and well-tolerated antihypertensive drug classes available today offer multiple options for combination therapy. The choice of antihypertensive agents should be made on the basis of current recommendations regarding first line drugs and compelling indications. Specific drug combinations might have additional beneficial or detrimental long-term metabolic effects, beyond their effects on blood pressure. However, more outcome data comparing antihypertensive drug combinations are required. The implementation of an intensive up-titration treatment strategy, together with a systematic use of full doses of multiple drug combinations, is expected to achieve optimal blood pressure control in the vast majority of hypertensive patients.

Optimizing hypertension management in clinical practice

A clear relationship exists between elevated blood pressure (BP) and various manifestations of cardiovascular disease. Despite the availability of numerous treatment guidelines, hypertension remains inadequately controlled, with only a small proportion of patients achieving target BP levels. Many factors, both patient and physician related, contribute to this poor level of hypertension control. Major determinants include the implementation of inappropriate treatment regimens that do not enable patients to achieve goal and poor patient compliance. For example, it is widely acknowledged that most patients require two or more antihypertensive drugs to achieve BP goal; however, physicians may be reluctant to employ such treatment strategies. The aim of this review is to explore factors that contribute to poor hypertension control rates and how to overcome these, including the rationale for selecting combination therapy, with particular reference to angiotensin II receptor blocker combinations.