Amlodipine and angiotensin-converting enzyme inhibitor combination versus amlodipine monotherapy in hypertension: a meta-analysis of randomized controlled trials

The Rationale for Using Fixed-Dose Combination Therapy in the Management of Hypertension in Colombia: A Narrative Review

Hypertension is a major risk factor for cardiovascular disease and the leading cause of death in Colombia. While the rate of hypertension awareness in Colombia is generally high, rates of treatment initiation, adherence, and blood pressure (BP) control are suboptimal. Major international hypertension guidelines recommend starting treatment with a combination of antihypertensive agents, and the use of a single-pill combination (SPC) to maximize adherence. In contrast, Colombian hypertension guidelines recommend starting treatment with diuretic monotherapy in most patients, and only initiating combination therapy in those with BP > 160/100 mmHg. Therefore, the aim of the current narrative review is to examine the rationale for using SPCs to treat hypertension in Colombia, in the context of the major issues for BP control there. There is evidence of widespread therapeutic inertia in hypertension management, particularly in primary care, in Colombia. Moreover, combination therapy, angiotensin-converting enzyme inhibitors, and long-acting calcium channel blockers, which are internationally recommended as first-line drug therapies, are underutilized there. Adherence to antihypertensive therapy is low in Colombia and may be enhanced by use of SPCs as well as better patient education and follow-up. While there are promising national initiatives to improve BP management, more needs to be done by individual physicians. Antihypertensive SPCs are available on the national essential medicines list and may help to overcome some of the problems with suboptimal adherence, therapeutic inertia, and low rates of BP control that contribute to the high cardiovascular death rate in Colombia.

Effects of renin-angiotensin system blockers on renal and cardiovascular outcomes in patients with diabetic nephropathy: a meta-analysis of randomized controlled trials

PURPOSE

This study aimed to evaluate the effect f angiotensin-converting enzyme inhibitors (ACEI) and angiotensin receptor blockers (ARB) on renal or cardiovascular outcomes in patients with diabetic nephropathy (DN).

METHODS

PubMed, Embase, and Cochrane Library were searched for randomized controlled trials (RCTs) evaluating the treatment effects of ACEI and ARB on renal or cardiovascular outcomes in patients with DN until August 2017. The outcomes included end-stage renal disease (ESRD), doubling of serum creatinine levels, all-cause mortality, major cardiovascular events (MACEs), myocardial infarction (MI), stroke, and cardiac death. Relative risks (RR) with 95% confidence intervals (CIs) were used for calculating the summary results using a random-effects model.

RESULTS

Twenty-four RCTs including 57,818 patients with DN and 891 events of ESRD, 1050 doubling of serum creatinine concentration, 4352 all-cause mortality, 6342 MACEs, 1073 MI, 2900 stroke, and 1674 cardiac deaths were reported. Overall, the summary results suggested that in patients with DN, receiving ACEI did not have a significant effect on ESRD, doubling of serum creatinine levels, all-cause mortality, MI, stroke, and cardiac death, while ACEI significantly reduced the risk of total MACEs. Furthermore, ARB therapy was associated with a low risk of ESRD and doubling of serum creatinine levels, while it did not differ significantly on all-cause mortality, MACEs, MI, stroke, and cardiac death in patients with DN.

CONCLUSIONS

Patients with DN receiving ACEI had significantly reduced the risk of total MACEs, and ARB could reduce the incidence of ESRD and the doubling of serum creatinine levels.

First-line combination therapy versus first-line monotherapy for primary hypertension

BACKGROUND

This is the first update of a review originally published in 2017. Starting with one drug and starting with a combination of two drugs are strategies suggested in clinical guidelines as initial treatment of hypertension. The recommendations are not based on evidence about clinically relevant outcomes. Some antihypertensive combinations have been shown to be harmful. The actual harm-to-benefit balance of each strategy is unknown.

OBJECTIVES

To determine if there are differences in clinical outcomes between monotherapy and combination therapy as initial treatment for primary hypertension.

SEARCH METHODS

The Cochrane Hypertension Information Specialist searched the following databases for randomised controlled trials up to April 2019: the Cochrane Hypertension Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (from 2005), Embase (from 1974), the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov. We used no language restrictions. We also searched clinical studies repositories of pharmaceutical companies, reviews of combination drugs on the US Food and Drug Administration and European Medicines Agency websites, and lists of references in reviews and clinical practice guidelines.

SELECTION CRITERIA

We included randomised, double-blind trials with at least 12 months' follow-up in adults with primary hypertension (systolic blood pressure/diastolic blood pressure 140/90 mmHg or higher, or 130/80 mmHg or higher if participants had diabetes), which compared combination of two first-line antihypertensive drugs with monotherapy as initial treatment. Trials had to include at least 50 participants per group and report mortality, cardiovascular mortality, cardiovascular events, or serious adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, evaluated the risk of bias, and performed data entry. The primary outcomes were mortality, serious adverse events, cardiovascular events, and cardiovascular mortality. Secondary outcomes were withdrawals due to drug-related adverse effects, reaching blood pressure control (as defined in each trial), and blood pressure change from baseline. Analyses were based on the intention-to-treat principle. We summarised data on dichotomous outcomes as risk ratios (RR) with 95% confidence intervals (CI).

MAIN RESULTS

This update included one new study in which a subgroup of participants met our inclusion criteria. As none of the four included studies focused solely on people initiating antihypertensive treatment, we asked investigators for data for this subgroup. One study (PREVER-treatment 2016) used a combination of thiazide-type diuretic/potassium-sparing diuretic; as the former is not indicated in monotherapy, we analysed this study separately. The three original trials in the main comparison (monotherapy: 335 participants; combination therapy: 233 participants) included outpatients, mostly European and white people. Two trials only included people with type 2 diabetes; the remaining trial excluded people treated with diabetes, hypocholesterolaemia, or cardiovascular drugs. The follow-up was 12 months in two trials and 36 months in one trial. It is very uncertain whether combination therapy versus monotherapy reduces total mortality (RR 1.35, 95% CI 0.08 to 21.72), cardiovascular mortality (zero events reported), cardiovascular events (RR 0.98, 95% CI 0.22 to 4.41), serious adverse events (RR 0.77, 95% CI 0.31 to 1.92), or withdrawals due to adverse effects (RR 0.85, 95% CI 0.53 to 1.35); all outcomes had 568 participants, and the evidence was rated as of very low certainty due to serious imprecision and for using a subgroup that was not defined in advance. The confidence intervals were extremely wide for all important outcomes and included both appreciable harm and benefit. The PREVER-treatment 2016 trial, which used a combination therapy with potassium-sparing diuretic (monotherapy: 84 participants; combination therapy: 116 participants), included outpatients. This trial was conducted in Brazil and had a follow-up of 18 months. The number of events was very low and confidence intervals very wide, with zero events reported for cardiovascular mortality and withdrawals due to adverse events. It is very uncertain if there are differences in clinical outcomes between monotherapy and combination therapy in this trial.

AUTHORS' CONCLUSIONS

The numbers of included participants, and hence the number of events, were too small to draw any conclusion about the relative efficacy of monotherapy versus combination therapy as initial treatment for primary hypertension. There is a need for large clinical trials that address the review question and report clinically relevant endpoints.

First-line combination therapy versus first-line monotherapy for primary hypertension

BACKGROUND

Starting with one drug and starting with a combination of two drugs are strategies suggested in clinical guidelines as initial treatment of hypertension. The recommendations are not based on evidence about clinically relevant outcomes. Some antihypertensive combinations have been shown to be harmful. The actual harm-to-benefit balance of each strategy is unknown.

OBJECTIVES

To determine if there are differences in clinical outcomes between monotherapy and combination therapy as initial treatment for primary hypertension.

SEARCH METHODS

We searched the Hypertension Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL, 2016, Issue 2), Ovid MEDLINE, Ovid Embase, LILACS, ClinicalTrials.gov, Current Controlled Trials, and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) up to February 2016. We searched in clinical studies repositories of pharmaceutical companies, reviews of combination drugs in Food and Drug Administration and European Medicines Agency, and lists of references in reviews and clinical practice guidelines.

SELECTION CRITERIA

Randomized, double-blind trials with at least 12 months' follow-up in adults with primary hypertension (systolic blood pressure/diastolic blood pressure 140/90 mmHg or higher, or 130/80 mmHg or higher if participants had diabetes), which compared combination of two first-line antihypertensive drug with monotherapy as initial treatment. Trials had to include at least 50 participants per group and report mortality, cardiovascular mortality, cardiovascular events or serious adverse events.

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials for inclusion, evaluated the risk of bias and entered the data. Primary outcomes were mortality, serious adverse events, cardiovascular events and cardiovascular mortality. Secondary outcomes were withdrawals due to drug-related adverse effects, reaching blood pressure control (as defined in each trial) and blood pressure change from baseline. Analyses were based on the intention-to-treat principle. We summarized data on dichotomous outcomes as risk ratios with 95% confidence intervals.

MAIN RESULTS

We found three studies in which a subgroup of participants met our inclusion criteria. None of the studies focused solely on people initiating antihypertensive treatment so we asked investigators for data for this subgroup (monotherapy: 335 participants; combination therapy: 233 participants). They included outpatients, and mostly European and white people. Two trials included only people with type 2 diabetes, whereas the other trial excluded people treated with diabetes, hypocholesterolaemia or cardiovascular drugs. The follow-up was 12 months in two trials and 36 months in one trial. Certainty of evidence was very low due to the serious imprecision, and for using a subgroup not defined in advance. Confidence intervals were extremely wide for all important outcomes and included both appreciable harm and benefit.

AUTHORS' CONCLUSIONS

The numbers of included participants and, hence the number of events, were too small to draw any conclusion about the relative efficacy of monotherapy versus combination therapy as initial treatment for primary hypertension. There is a need for large clinical trials that address the question and report clinically relevant endpoints.

High-dose calcium channel blocker (CCB) monotherapy vs combination therapy of standard-dose CCBs and angiotensin receptor blockers for hypertension: a meta-analysis

In this study, we evaluated the efficacy and safety of high-dose calcium channel blocker (CCB) monotherapy and standard-dose CCBs combined with angiotensin receptor blockers (ARBs) for patients with hypertension. A comprehensive search of PubMed, Embase and the Cochrane Central Register of Controlled Trials was performed in December 2015. Randomized controlled trials designed to identify the above goal were included. Thirteen trials including 2371 patients were identified. The standard-dose CCB/ARB combination resulted in a greater reduction of systolic blood pressure (WMD -2.52, 95% confidence interval (CI): -3.76 to -1.28) and diastolic blood pressure (weighted mean difference (WMD) -2.07, 95% CI: -3.73 to -0.42) compared to high-dose CCB monotherapy. The overall hypertension control rate for the CCB/ARB combination was higher than that for CCB monotherapy (relative risk (RR): 1.17, 95% CI: 1.08-1.26). Furthermore, the CCB/ARB combination treatment yielded significantly fewer overall adverse events (RR: 0.84, 95% CI: 0.74-0.95), oedema (RR: 0.31; 95% CI: 0.18-0.52) and rash (RR: 0.27, 95% CI: 0.08-0.96, P=0.04) than did CCB monotherapy. The standard-dose CCB/ARB combination is superior to high-dose CCB monotherapy for lowering blood pressure and reducing adverse events in hypertensive patients. Future research should focus on the cost-effectiveness and long-term effects of these two treatment strategies for patients with hypertension.

Perindopril arginine + amlodipine for the treatment of hypertension in the USA

INTRODUCTION

Controlling blood pressure is a global health priority; single-pill combinations of antihypertensive agents are often prescribed to improve adherence, persistence, and outcomes.

AREAS COVERED

A novel preparation of perindopril arginine and amlodipine besylate was approved by the US Food and Drug Administration on 21 Jan 2015, based primarily on a 837-subject, 6-week, randomized, multicenter, prospective, clinical trial. The maximal marketed dose of the combination (14/10 mg daily) lowered both systolic and diastolic blood pressure significantly more than either monotherapy, with a reduction in adverse effects (especially ankle edema), compared to amlodipine alone.

EXPERT OPINION

Substantial clinical trial experience with amlodipine or perindopril suggests that these two agents effectively lower blood pressure, and may reduce the risk of major adverse cardiovascular events. In the Anglo-Scandinavian Cardiac Outcomes Trial, hypertensive subjects randomized to receive these two drugs (in sequence) had a significantly lower incidence of several types of clinical events, compared to those who received atenolol ± bendroflumethiazide. The new formulation of perindopril arginine protects its ethyl ester, without requiring physical separation from amlodipine in a single pill, and is less hydroscopic than perindopril erbumine. These and other attributes may make this combination an attractive addition to the antihypertensive armamentarium.

Comparative effectiveness of renin-angiotensin system blockers and other antihypertensive drugs in patients with diabetes: systematic review and bayesian network meta-analysis

OBJECTIVE

To assess the effects of different classes of antihypertensive treatments, including monotherapy and combination therapy, on survival and major renal outcomes in patients with diabetes.

DESIGN

Systematic review and bayesian network meta-analysis of randomised clinical trials.

DATA SOURCES

Electronic literature search of PubMed, Medline, Scopus, and the Cochrane Library for studies published up to December 2011.

STUDY SELECTION

Randomised clinical trials of antihypertensive therapy (angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), α blockers, β blockers, calcium channel blockers, diuretics, and their combinations) in patients with diabetes with a follow-up of at least 12 months, reporting all cause mortality, requirement for dialysis, or doubling of serum creatinine levels.

DATA EXTRACTION

Bayesian network meta-analysis combined direct and indirect evidence to estimate the relative effects between treatments as well as the probabilities of ranking for treatments based on their protective effects.

RESULTS

63 trials with 36,917 participants were identified, including 2400 deaths, 766 patients who required dialysis, and 1099 patients whose serum creatinine level had doubled. Compared with placebo, only ACE inhibitors significantly reduced the doubling of serum creatinine levels (odds ratio 0.58, 95% credible interval 0.32 to 0.90), and only β blockers showed a significant difference in mortality (odds ratio 7.13, 95% credible interval 1.37 to 41.39). Comparisons among all treatments showed no statistical significance in the outcome of dialysis. Although the beneficial effects of ACE inhibitors compared with ARBs did not reach statistical significance, ACE inhibitors consistently showed higher probabilities of being in the superior ranking positions among all three outcomes. Although the protective effect of an ACE inhibitor plus calcium channel blocker compared with placebo was not statistically significant, the treatment ranking identified this combination therapy to have the greatest probability (73.9%) for being the best treatment on reducing mortality, followed by ACE inhibitor plus diuretic (12.5%), ACE inhibitors (2.0%), calcium channel blockers (1.2%), and ARBs (0.4%).

CONCLUSIONS

Our analyses show the renoprotective effects and superiority of using ACE inhibitors in patients with diabetes, and available evidence is not able to show a better effect for ARBs compared with ACE inhibitors. Considering the cost of drugs, our findings support the use of ACE inhibitors as the first line antihypertensive agent in patients with diabetes. Calcium channel blockers might be the preferred treatment in combination with ACE inhibitors if adequate blood pressure control cannot be achieved by ACE inhibitors alone.

Antihypertensive effects of olmesartan compared with other angiotensin receptor blockers: a meta-analysis

OBJECTIVES

Angiotensin II type 1 receptor antagonists (angiotensin receptor blockers [ARBs]) have been shown to be effective and well tolerated in hypertensive patients. Olmesartan is the seventh angiotensin receptor blocker licensed by the US Food and Drug Administration. The aim of this meta-analysis was to determine the efficacy and tolerability of olmesartan medoxomil in comparison with other ARBs.

DATA SOURCES

Reports of randomized controlled trials (RCTs) of olmesartan versus other ARBs were identified through a systematic search of PubMed (up to July 2010), EMBASE (1980 to July 2010), SinoMed (up to July 2010), and the Cochrane Central Register of Controlled Trials (Cochrane Library Issue 7, 2010).

REVIEW METHODS

Pertinent studies were selected through extensive searches of PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and SinoMed. Two of the authors abstracted data from the identified studies independently. Criteria for inclusion in our meta-analyses were randomized clinical trials in which patients were receiving an ARB and outcome data for blood pressure reduction or the incidence of adverse events were available. Quantitative and qualitative analyses of data from all RCTs meeting the criteria were performed. Our meta-analysis was undertaken according to the Quality of Reporting Meta-analyses (QUOROM) statement.

RESULTS

Twenty-two studies with data from 4892 patients were considered for analyses. Olmesartan provided greater diastolic blood pressure (DBP) and systolic blood pressure (SBP) reductions compared with losartan (DBP: 95% confidence interval [CI] 0.59, 2.62; SBP: 95% CI 0.46, 5.92). Olmesartan provided greater SBP reductions compared with valsartan (95% CI 0.29, 3.16). Similar blood pressure response rates and incidence of adverse events were found with losartan, valsartan, candesartan, and irbesartan.

CONCLUSION

Olmesartan provides better antihypertensive efficacy than losartan and valsartan and has no association with an increased risk of adverse events in comparison with losartan, valsartan, candesartan, and irbesartan.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Hypertension management 2011: optimal combination therapy

Raised levels of blood pressure result from the complex interplay of environmental and genetic factors. The complexity of blood pressure control mechanisms has major implications for individual responsiveness to antihypertensive drugs. The underlying haemodynamic disorder in the majority of cases is a rise in peripheral vascular resistance. This observation led to the discovery and development of increasingly sophisticated and targeted vasodilators, although many of the earlier antihypertensive drugs, by virtue of their actions blocking the sympathetic nervous system, had a vasodilator component to their mode of action. A recent meta-analysis of placebo controlled trials of monotherapy in unselected hypertensives, reports average (placebo-corrected) blood pressure responses to single agents of 9.1 mmHg systolic and 5.5 mmHg diastolic pressure. These average values disguise the extremely wide ranging responses in individuals across a fall of 20-30 mmHg systolic at one extreme, to no effect at all, or even a small rise in blood pressure at the other. The second factor determining individual responses to monotherapy is the extent to which initial falls in pressure are opposed by reflex responses in counter regulatory mechanisms that are activated following the blood pressure reduction. Thus, a satisfactory blood pressure response is rarely reached with monotherapy alone. What then is the next step if blood pressure is not a goal after the patient has been treated with monotherapy for a few weeks? Should you uptitrate, substitute or combine?

Twenty-four-hour ambulatory blood pressure measurement in clinical practice and research: a critical review of a technique in need of implementation

This review presents evidence that ambulatory blood pressure measurement (ABPM) should be used more widely in clinical practice and hypertension research. The technique, which should be mandatory in trials of antihypertensive drugs, is not being used in all studies of antihypertensive drug efficacy. ABPM is also being under-used in outcome studies. The failure to implement ABPM in primary care and hypertension research is impeding patient management and scientific advancement. ABPM offers so many advantages in assessing the efficacy of blood pressure (BP)-lowering drugs that it should be mandatory in pharmacological trials. Likewise, the technique provides a means of achieving BP control in clinical practice, which is essential if we are to halt the epidemic of the cardiovascular consequences of hypertension. However, if ABPM is to be implemented for these purposes, certain requirements will need to be fulfilled. These include the availability of accurate, patient-friendly and inexpensive devices; standardization of the presentation and plotting of data with summary statistics for day-to-day practice; provision of comprehensive data analysis for research; an interpretative report to facilitate use in busy clinical practice; a trend report to demonstrate efficacy or otherwise of treatment in clinical practice and online transmission of data to provide immediate real-time data analysis. The reasons why ABPM is not being implemented are reviewed, and proposals are made to make the technique more acceptable.