MRC trial of treatment of mild hypertension: principal results. Medical Research Council Working Party

Diastolic blood pressure and risk profile in renal and cardiovascular diseases. Results from the SPRINT trial

The Systolic Blood Pressure Intervention Trial (SPRINT) trial demonstrated the efficacy and safety of targeting a systolic blood pressure of <120 mmHg compared to <140 mmHg in selected hypertensive patients. Some evidence, however, suggests a J-curve for; diastolic blood pressure (DBP) particularly in subjects with cardiovascular (CV) and chronic kidney disease. We evaluated the risk of events in SPRINT with focus on these subgroups according to DBP. Mean DBP (±standard deviation) throughout follow-up time was calculated for each patient. Patients were then categorized into five groups according to mean DBP (<60 mmHg, 60-69 mmHg, 70-79 mmHg [reference], 80-89 mmHg, ≥90 mmHg); hazard ratio for outcomes was assessed overall and in the predefined subgroups. A higher risk for CV events was observed in the lower DBP range overall (hazard ratio 1.46, confidential interval 95% 1.1-1.95, P < .001), but not in the absence of pre-existing CV or renal disease. Indeed, such risk significantly increased above 80 mmHg in patients with CV disease and below 70 mmHg in those with chronic kidney disease for selected outcomes. DBP<70 mmHg particularly affected renal outcomes irrespective of renal status. Different risk profiles according to DBP appear to be related to specific clinical characteristics in SPRINT. These findings require further testing in dedicated trials with appropriate follow-up.

First-line drugs for hypertension

BACKGROUND

This is the first update of a review published in 2009. Sustained moderate to severe elevations in resting blood pressure leads to a critically important clinical question: What class of drug to use first-line? This review attempted to answer that question.

OBJECTIVES

To quantify the mortality and morbidity effects from different first-line antihypertensive drug classes: thiazides (low-dose and high-dose), beta-blockers, calcium channel blockers, ACE inhibitors, angiotensin II receptor blockers (ARB), and alpha-blockers, compared to placebo or no treatment.Secondary objectives: when different antihypertensive drug classes are used as the first-line drug, to quantify the blood pressure lowering effect and the rate of withdrawal due to adverse drug effects, compared to placebo or no treatment.

SEARCH METHODS

The Cochrane Hypertension Information Specialist searched the following databases for randomized controlled trials up to November 2017: the Cochrane Hypertension Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (from 1946), Embase (from 1974), the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov. We contacted authors of relevant papers regarding further published and unpublished work.

SELECTION CRITERIA

Randomized trials (RCT) of at least one year duration, comparing one of six major drug classes with a placebo or no treatment, in adult patients with blood pressure over 140/90 mmHg at baseline. The majority (over 70%) of the patients in the treatment group were taking the drug class of interest after one year. We included trials with both hypertensive and normotensive patients in this review if the majority (over 70%) of patients had elevated blood pressure, or the trial separately reported outcome data on patients with elevated blood pressure.

DATA COLLECTION AND ANALYSIS

The outcomes assessed were mortality, stroke, coronary heart disease (CHD), total cardiovascular events (CVS), decrease in systolic and diastolic blood pressure, and withdrawals due to adverse drug effects. We used a fixed-effect model to to combine dichotomous outcomes across trials and calculate risk ratio (RR) with 95% confidence interval (CI). We presented blood pressure data as mean difference (MD) with 99% CI.

MAIN RESULTS

The 2017 updated search failed to identify any new trials. The original review identified 24 trials with 28 active treatment arms, including 58,040 patients. We found no RCTs for ARBs or alpha-blockers. These results are mostly applicable to adult patients with moderate to severe primary hypertension. The mean age of participants was 56 years, and mean duration of follow-up was three to five years.High-quality evidence showed that first-line low-dose thiazides reduced mortality (11.0% with control versus 9.8% with treatment; RR 0.89, 95% CI 0.82 to 0.97); total CVS (12.9% with control versus 9.0% with treatment; RR 0.70, 95% CI 0.64 to 0.76), stroke (6.2% with control versus 4.2% with treatment; RR 0.68, 95% CI 0.60 to 0.77), and coronary heart disease (3.9% with control versus 2.8% with treatment; RR 0.72, 95% CI 0.61 to 0.84).Low- to moderate-quality evidence showed that first-line high-dose thiazides reduced stroke (1.9% with control versus 0.9% with treatment; RR 0.47, 95% CI 0.37 to 0.61) and total CVS (5.1% with control versus 3.7% with treatment; RR 0.72, 95% CI 0.63 to 0.82), but did not reduce mortality (3.1% with control versus 2.8% with treatment; RR 0.90, 95% CI 0.76 to 1.05), or coronary heart disease (2.7% with control versus 2.7% with treatment; RR 1.01, 95% CI 0.85 to 1.20).Low- to moderate-quality evidence showed that first-line beta-blockers did not reduce mortality (6.2% with control versus 6.0% with treatment; RR 0.96, 95% CI 0.86 to 1.07) or coronary heart disease (4.4% with control versus 3.9% with treatment; RR 0.90, 95% CI 0.78 to 1.03), but reduced stroke (3.4% with control versus 2.8% with treatment; RR 0.83, 95% CI 0.72 to 0.97) and total CVS (7.6% with control versus 6.8% with treatment; RR 0.89, 95% CI 0.81 to 0.98).Low- to moderate-quality evidence showed that first-line ACE inhibitors reduced mortality (13.6% with control versus 11.3% with treatment; RR 0.83, 95% CI 0.72 to 0.95), stroke (6.0% with control versus 3.9% with treatment; RR 0.65, 95% CI 0.52 to 0.82), coronary heart disease (13.5% with control versus 11.0% with treatment; RR 0.81, 95% CI 0.70 to 0.94), and total CVS (20.1% with control versus 15.3% with treatment; RR 0.76, 95% CI 0.67 to 0.85).Low-quality evidence showed that first-line calcium channel blockers reduced stroke (3.4% with control versus 1.9% with treatment; RR 0.58, 95% CI 0.41 to 0.84) and total CVS (8.0% with control versus 5.7% with treatment; RR 0.71, 95% CI 0.57 to 0.87), but not coronary heart disease (3.1% with control versus 2.4% with treatment; RR 0.77, 95% CI 0.55 to 1.09), or mortality (6.0% with control versus 5.1% with treatment; RR 0.86, 95% CI 0.68 to 1.09).There was low-quality evidence that withdrawals due to adverse effects were increased with first-line low-dose thiazides (5.0% with control versus 11.3% with treatment; RR 2.38, 95% CI 2.06 to 2.75), high-dose thiazides (2.2% with control versus 9.8% with treatment; RR 4.48, 95% CI 3.83 to 5.24), and beta-blockers (3.1% with control versus 14.4% with treatment; RR 4.59, 95% CI 4.11 to 5.13). No data for these outcomes were available for first-line ACE inhibitors or calcium channel blockers. The blood pressure data were not used to assess the effect of the different classes of drugs as the data were heterogeneous, and the number of drugs used in the trials differed.

AUTHORS' CONCLUSIONS

First-line low-dose thiazides reduced all morbidity and mortality outcomes in adult patients with moderate to severe primary hypertension. First-line ACE inhibitors and calcium channel blockers may be similarly effective, but the evidence was of lower quality. First-line high-dose thiazides and first-line beta-blockers were inferior to first-line low-dose thiazides.

Should we switch from bendrofluazide to chlorthalidone as the initial treatment for hypertension? A review of the available medication

INTRODUCTION Thiazide diuretics are commonly prescribed in the treatment of hypertension. However, thiazide diuretics may not all be equal in their ability to reduce cardiovascular disease outcomes. AIM To determine if bendroflumethiazide/bendrofluazide, the most commonly used diuretic for hypertension in New Zealand, is as effective as other diuretics in terms of cardiovascular disease outcomes. METHODS Using recent reviews of thiazide-like (chlorthalidone or indapamide) and thiazide-type diuretics (hydrochlorothiazide and bendrofluazide) and a separate search of bendrofluazide, data on cardiovascular disease outcomes was extracted. RESULTS Nineteen relevant papers with 21 comparisons were found. All thiazide-based diuretics have been reported in at least one trial showing them to be more effective than placebo for cardiovascular disease outcomes, with the exception of chlorothiazide. There were no comparisons of bendrofluazide alone with other medications, but there were two studies with either bendrofluazide or hydrochlorothiazide compared with β-blockers; however, the pooled relative risk (RR) was not significant (RR = 1.10 (95% CI, 0.84-1.43)). For chlorthalidone, there were four comparisons with other medications, and the summary RR was statistically significant for cardiovascular disease outcomes (RR = 0.91 (95% CI, 0.85-0.98)). Chlorthalidone was significantly more effective for some cardiovascular disease outcomes when compared with doxazosin, amlodipine and lisinopril. CONCLUSIONS All thiazide-based medicines available in New Zealand are effective in terms of cardiovascular disease outcomes compared with placebo when used for treating hypertension, with the exception of chlorothiazide. Of the diuretics available in New Zealand for hypertension, only chlorthalidone has been shown to be more effective than other blood pressure-lowering medicines. It may be time to change from using bendrofluazide and start using chlorthalidone as a treatment for hypertension.

The J-shaped Curve for Blood Pressure and Cardiovascular Disease Risk: Historical Context and Recent Updates

PURPOSE OF REVIEW

The definition and treatment of hypertension have both changed dramatically over the last century, with recent trials suggesting benefit for lower blood pressure (BP) targets than ever before considered. However, tempering the enthusiasm for more intensive BP targets are long-held concerns that BP reduction below a certain threshold may pose dangers, the so-called "J-curve." In this review, we summarize the evidence for a J-curve in the treatment of hypertension.

RECENT FINDINGS

The Systolic Blood Pressure Intervention Trial (SPRINT) reported that achieving a systolic BP target of 120 mmHg reduces cardiovascular disease in high-risk individuals, supporting more intensive BP reduction. However, contemporary observational studies consistently demonstrate a BP J-curve, the threshold of which is often close to the SPRINT target. Studies also suggest that the BP level of this J-curve may vary based on patient characteristics, including age and comorbidities. There is also more compelling evidence for the specific presence of a J-curve between diastolic BP and coronary events, in contrast to conflicting evidence of a J-curve with systolic BP and cardiovascular disease more generally. There is increased risk of coronary events below a diastolic BP of 60-70 mmHg. In comparison, the presence of a systolic J-curve is less clear and some persons at high risk may actually benefit from systolic levels down to 120 mmHg. Therefore, we suggest a personalized approach to BP management considering individual risks, benefits, and preferences when choosing therapeutic targets. Further, well-designed studies are required to support our suggestions and to define J-curve thresholds more clearly.

Association of Blood Pressure Lowering With Mortality and Cardiovascular Disease Across Blood Pressure Levels: A Systematic Review and Meta-analysis

IMPORTANCE

High blood pressure (BP) is the most important risk factor for death and cardiovascular disease (CVD) worldwide. The optimal cutoff for treatment of high BP is debated.

OBJECTIVE

To assess the association between BP lowering treatment and death and CVD at different BP levels.

DATA SOURCES

Previous systematic reviews were identified from PubMed, the Cochrane Database of Systematic Reviews, and the Database of Abstracts of Reviews of Effect. Reference lists of these reviews were searched for randomized clinical trials. Randomized clinical trials published after November 1, 2015, were also searched for in PubMed and the Cochrane Central Register for Controlled Trials during February 2017.

STUDY SELECTION

Randomized clinical trials with at least 1000 patient-years of follow-up, comparing BP-lowering drugs vs placebo or different BP goals were included.

DATA EXTRACTION AND SYNTHESIS

Data were extracted from original publications. Risk of bias was assessed using the Cochrane Collaborations assessment tool. Relative risks (RRs) were pooled in random-effects meta-analyses with Knapp-Hartung modification. Results are reported according to PRISMA guidelines.

MAIN OUTCOMES AND MEASURES

Prespecified outcomes of interest were all-cause mortality, cardiovascular mortality, major cardiovascular events, coronary heart disease (CHD), stroke, heart failure, and end-stage renal disease.

RESULTS

Seventy-four unique trials, representing 306 273 unique participants (39.9% women and 60.1% men; mean age, 63.6 years) and 1.2 million person-years, were included in the meta-analyses. In primary prevention, the association of BP-lowering treatment with major cardiovascular events was dependent on baseline systolic BP (SBP). In trials with baseline SBP 160 mm Hg or above, treatment was associated with reduced risk for death (RR, 0.93; 95% CI, 0.87-1.00) and a substantial reduction of major cardiovascular events (RR, 0.78; 95% CI, 0.70-0.87). If baseline SBP ranged from 140 to 159 mm Hg, the association of treatment with mortality was similar (RR, 0.87; 95% CI, 0.75-1.00), but the association with major cardiovascular events was less pronounced (RR, 0.88; 95% CI, 0.80-0.96). In trials with baseline SBP below 140 mm Hg, treatment was not associated with mortality (RR, 0.98; 95% CI, 0.90-1.06) and major cardiovascular events (RR, 0.97; 95% CI, 0.90-1.04). In trials including people with previous CHD and mean baseline SBP of 138 mm Hg, treatment was associated with reduced risk for major cardiovascular events (RR, 0.90; 95% CI, 0.84-0.97), but was not associated with survival (RR, 0.98; 95% CI, 0.89-1.07).

CONCLUSIONS AND RELEVANCE

Primary preventive BP lowering is associated with reduced risk for death and CVD if baseline SBP is 140 mm Hg or higher. At lower BP levels, treatment is not associated with any benefit in primary prevention but might offer additional protection in patients with CHD.

Investigation of 2-stage meta-analysis methods for joint longitudinal and time-to-event data through simulation and real data application

Background

Joint modelling of longitudinal and time‐to‐event data is often preferred over separate longitudinal or time‐to‐event analyses as it can account for study dropout, error in longitudinally measured covariates, and correlation between longitudinal and time‐to‐event outcomes. The joint modelling literature focuses mainly on the analysis of single studies with no methods currently available for the meta‐analysis of joint model estimates from multiple studies.

Methods

We propose a 2‐stage method for meta‐analysis of joint model estimates. These methods are applied to the INDANA dataset to combine joint model estimates of systolic blood pressure with time to death, time to myocardial infarction, and time to stroke. Results are compared to meta‐analyses of separate longitudinal or time‐to‐event models. A simulation study is conducted to contrast separate versus joint analyses over a range of scenarios.

Results

Using the real dataset, similar results were obtained by using the separate and joint analyses. However, the simulation study indicated a benefit of use of joint rather than separate methods in a meta‐analytic setting where association exists between the longitudinal and time‐to‐event outcomes.

Conclusions

Where evidence of association between longitudinal and time‐to‐event outcomes exists, results from joint models over standalone analyses should be pooled in 2‐stage meta‐analyses.

Nebivolol, But Not Metoprolol, Treatment Improves Endothelial Fibrinolytic Capacity in Adults With Elevated Blood Pressure

BACKGROUND

Vascular endothelial fibrinolytic function is impaired in adults with prehypertension and hypertension and plays a mechanistic role in the development of atherothrombotic events. The influence of β-blockers on endothelial fibrinolysis is unknown. This study compared the effects of chronic nebivolol and metoprolol treatment on endothelial tissue-type plasminogen activator (t-PA) release in adults with elevated blood pressure (BP).

METHODS AND RESULTS

Forty-four middle-aged adults (36% women) with elevated BP completed a 3-month, double-blind, randomized, placebo-controlled trial comparing nebivolol (5 mg/d), metoprolol succinate (100 mg/d), and placebo. Net endothelial t-PA release was determined in vivo in response to intrabrachial infusions of bradykinin and sodium nitroprusside before and after each intervention. In a subset, the dose-response curves to bradykinin and sodium nitroprusside were repeated with a coinfusion of the antioxidant vitamin C. At baseline, resting BP and endothelial t-PA release were comparable between the 3 groups. BP decreased to a similar extent (≈10 mm Hg) in the nebivolol- and metoprolol-treated groups. There was a substantial increase (≈30%; P<0.05) in the capacity of the endothelium to release t-PA following chronic treatment with nebivolol but not metoprolol or placebo. Mitigating oxidant stress with vitamin C coinfusion potentiated t-PA release (90%; P<0.05) at baseline in all groups. However, after the intervention, t-PA release was unchanged by vitamin C coinfusion in the nebivolol group only.

CONCLUSIONS

Nebivolol but not metoprolol improves endothelial t-PA release in adults with elevated BP. This may be an important vascular benefit of nebivolol.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01595516.

Impact of baseline blood pressure on the magnitude of blood pressure lowering by nifedipine gastrointestinal therapeutic system: refreshing the Wilder's principle

Background

The objective of the study was to investigate the relationship between baseline blood pressure (BP) and the magnitude of BP reduction in patients with essential hypertension treated with nifedipine gastrointestinal therapeutic system (NGTS).

Methods and patients

One hundred and thirty-eight patients with essential hypertension were enrolled in this prospective, single-arm, open-label study. NGTS was administered for 24 weeks to achieve target BP of 140/90 mmHg. The dose could be uptitrated to 60 mg/d in case of unsatisfactory BP reduction after 4-week treatment. Home blood pressure measurement was recorded through the initial 1–14 days, and office BP and heart rate were evaluated at 2, 4, 8, 12, and 24 weeks.

Results

One hundred and seventeen patients (84.8%) completed the study, and their average BP decreased by 19.0/11.3 mmHg after 24 weeks. The reduction of either systolic or diastolic BP was positively correlated with baseline BP at weeks 2, 4, or 24 after treatment (r=0.603–0.762, all p<0.05). The maximal BP reduction was observed in 83% of patients at 4 weeks of treatment even though the dose of nifedipine remained unchanged (30 mg/day).

Conclusion

These findings show that BP reduction is greatly influenced by the baseline level. Patients with high baseline BP had maximum reduction after treatment with NGTS, and the maximal antihypertensive efficacy of NGTS could appear even at 4 weeks after treatment initiation.

Time in Therapeutic Range, as a Determinant of All-Cause Mortality in Patients With Hypertension

Background

Accumulating evidence indicates that reducing systolic blood pressure (BP) to <140 mm Hg improves health outcomes; however, an optimal level has not yet been determined. Many population studies or post hoc analyses suggest a target systolic BP between 120 and 140 mm Hg with increased risk above and below that range. We tested the hypothesis that consistent control of systolic BP between 120 and 140 mm Hg—time in therapeutic range—is a strong determinant of all‐cause mortality among US veterans.

Methods and Results

A total of 689 051 individuals from 15 Veterans Administration Medical Centers were followed over a 10‐year period. Participants were classified as hypertensive, intermediate hypertensive, and normotensive according to the number of elevated BP recordings (>3, 1 or 2, and none, respectively). Time within, above, or below therapeutic range (120–140 mm Hg) was considered in quartiles and related to all‐cause mortality. The study population consisted of 54% hypertensive, 19.9% intermediate, and 26.1% normotensive participants; the corresponding mortality rates for the 3 groups were 11.5%, 8%, and 1.9%, respectively (P<0.0001 for all comparisons). Mortality rates for hypertensive participants with BP consistently within, above, or below the therapeutic range were 6.5%, 21.9%, and 33.1%, respectively (P<0.0001 for all comparisons). Mortality rates in hypertensive participants increased from 6.5% in the most consistently controlled quartile (>75%) to 8.9%, 15.6%, and 23.5% towards the less consistently controlled quartiles (50–75%, 25–50%, and <25%, respectively; P<0.0001 for all comparisons).

Conclusions

An inverse and gradual association between time in therapeutic range and all‐cause mortality was observed in this large veteran cohort. Consistency of BP control over time is a strong determinant of all‐cause mortality, and consistency of BP control should be monitored in everyday clinical practice.

Effects of blood-pressure-lowering treatment on outcome incidence in hypertension: 10 - Should blood pressure management differ in hypertensive patients with and without diabetes mellitus? Overview and meta-analyses of randomized trials

BACKGROUND

Type 2 diabetes mellitus is associated with an increased risk of hypertension, and cardiovascular and renal disease, and it has been recommended that management of hypertension should be more aggressive in presence than in absence of diabetes mellitus, but the matter is controversial at present.

OBJECTIVES

Meta-analysing all available randomized controlled trials (RCTs) to compare the effects on cardiovascular and renal outcomes of blood pressure BP lowering to different systolic BP (SBP) and diastolic BP (DBP) levels or by different drug classes in patients with and without diabetes mellitus.

METHODS

The database consisted of 72 BP-lowering RCTs (260 210 patients) and 50 head-to-head drug comparison RCTs (247 006). Among these two sets, RCTs or RCT subgroups separately reporting data from patients with and without diabetes mellitus were identified, and stratified by in-treatment achieved SBP and DBP, by drug class compared with placebo, and drug class compared with all other classes. Risk ratios and 95% confidence intervals, and absolute risk reductions of six fatal and non-fatal cardiovascular outcomes, all-cause death, and end-stage renal disease (ESRD) were calculated (random-effects model) separately for diabetes mellitus and no diabetes mellitus, and compared by interaction analysis.

RESULTS

We identified 41 RCTs providing data on 61 772 patients with diabetes mellitus and 40 RCTs providing data on 191 353 patients without diabetes mellitus. For achieved SBP at least 140 mmHg, relative and absolute reductions of most cardiovascular outcomes were significantly greater in diabetes mellitus than no diabetes mellitus, whereas for achieved SBP below 130 mmHg, the difference disappeared or reversed (greater outcome reduction in no diabetes mellitus). Significant ESRD reduction was found only in diabetes mellitus, but it was greatest when achieved SBP was at least 140 mmHg, and no further effect was found at SBP below 140 mmHg. All antihypertensive drug classes reduced cardiovascular risk vs. placebo in diabetes mellitus and no diabetes mellitus, but angiotensin-converting enzyme inhibitors were the only class more effective in diabetes mellitus than in no diabetes mellitus. When compared to other classes, renin-angiotensin system blockers were equally effective in cardiovascular prevention in no diabetes mellitus, but moderately, though significantly, more effective in diabetes mellitus.

CONCLUSION

BP-lowering treatment significantly and importantly reduces cardiovascular risk both in diabetes mellitus and no diabetes mellitus, but evidence for reduced ESRD risk is available only in diabetes. Contrary to past recommendations, in diabetes mellitus there is little or no further benefit in lowering SBP below 130 mmHg, whereas continuing benefit is seen in no diabetes mellitus also at SBP below 130 mmHg. Although all BP-lowering drugs can beneficially be prescribed in hypertensive patients with diabetes mellitus, the current recommendation to initiate or include a renin-angiotensin system blocker is supported by the evidence here presented.

Effects of blood pressure lowering treatment in hypertension: 8. Outcome reductions vs. discontinuations because of adverse drug events - meta-analyses of randomized trials

BACKGROUND

Previous meta-analyses of randomized controlled trials (RCTs) of blood pressure (BP)-lowering treatment provided overwhelming evidence that treatment markedly reduces risk of cardiovascular outcomes in hypertensive patients. However, adverse events associated with BP-lowering treatment have never been surveyed systematically.

OBJECTIVES

Identifying among BP-lowering RCTs those reporting a common and meaningful index of treatment-attributed adverse events, and describing the burden of these adverse events accompanying the benefits of mortality and morbidity reduction induced by treatment.

METHODS

The database consisted of the BP-lowering RCTs (active vs. placebo or less active treatment) we have described (70 RCTs, 255 970 participants, 1 091 964 patient-years). A common index of relevant adverse events was identified as permanent treatment discontinuation attributed to treatment adverse events. Risk ratios and 95% confidence intervals, standardized to a SBP/DBP reduction of 10/5 mmHg, of seven fatal and nonfatal outcomes and of treatment discontinuations for adverse events were calculated (random-effects model). The relationships of outcome reductions and discontinuation excess to SBP and DBP reductions were investigated by meta-regressions.

RESULTS

Forty-four RCTs provided data on treatment discontinuations for adverse events and six more on serious adverse events because of treatment (179 949 patients, 719 796 patient-years). In these 50 RCTs, a significant 24% reduction of major cardiovascular event risk was associated with a significant 89% increase in the risk of discontinuations (33 major cardiovascular effects prevented and 84 excess discontinuations/1000 patients for 5 years). Metaregression analysis indicated that both outcome reductions and treatment discontinuation excess were significantly related to the extent of SBP and DBP reduction, but absolute treatment discontinuation excess disproportionally increased with larger BP reductions than increase in outcome risk reduction. Furthermore, a standard SBP reduction was found associated with a constant relative reduction, but a smaller absolute reduction of cardiovascular events, and a greater relative excess of treatment discontinuations when the achieved SBP was below 130 mmHg rather than in higher ranges.

CONCLUSION

The burden of adverse events associated with BP-lowering treatment should be considered not to deny patients the overwhelming benefits of BP lowering, but whenever the extent of the BP lowering or the BP target to be achieved are discussed.

Pharmacotherapy for hypertension in adults aged 18 to 59 years

BACKGROUND

Hypertension is an important risk factor for adverse cardiovascular events including stroke, myocardial infarction, heart failure and renal failure. The main goal of treatment is to reduce these events. Systematic reviews have shown proven benefit of antihypertensive drug therapy in reducing cardiovascular morbidity and mortality but most of the evidence is in people 60 years of age and older. We wanted to know what the effects of therapy are in people 18 to 59 years of age.

OBJECTIVES

To quantify antihypertensive drug effects on all-cause mortality in adults aged 18 to 59 years with mild to moderate primary hypertension. To quantify effects on cardiovascular mortality plus morbidity (including cerebrovascular and coronary heart disease mortality plus morbidity), withdrawal due adverse events and estimate magnitude of systolic blood pressure (SBP) and diastolic blood pressure (DBP) lowering at one year.

SEARCH METHODS

The Cochrane Hypertension Information Specialist searched the following databases for randomized controlled trials up to January 2017: the Cochrane Hypertension Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (from 1946), Embase (from 1974), the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov. We contacted authors of relevant papers regarding further published and unpublished work.

SELECTION CRITERIA

Randomized trials of at least one year' duration comparing antihypertensive pharmacotherapy with a placebo or no treatment in adults aged 18 to 59 years with mild to moderate primary hypertension defined as SBP 140 mmHg or greater or DBP 90 mmHg or greater at baseline, or both.

DATA COLLECTION AND ANALYSIS

The outcomes assessed were all-cause mortality, total cardiovascular (CVS) mortality plus morbidity, withdrawals due to adverse events, and decrease in SBP and DBP. For dichotomous outcomes, we used risk ratio (RR) with 95% confidence interval (CI) and a fixed-effect model to combine outcomes across trials. For continuous outcomes, we used mean difference (MD) with 95% CI and a random-effects model as there was significant heterogeneity.

MAIN RESULTS

The population in the seven included studies (17,327 participants) were predominantly healthy adults with mild to moderate primary hypertension. The Medical Research Council Trial of Mild Hypertension contributed 14,541 (84%) of total randomized participants, with mean age of 50 years and mean baseline blood pressure of 160/98 mmHg and a mean duration of follow-up of five years. Treatments used in this study were bendrofluazide 10 mg daily or propranolol 80 mg to 240 mg daily with addition of methyldopa if required. The risk of bias in the studies was high or unclear for a number of domains and led us to downgrade the quality of evidence for all outcomes.Based on five studies, antihypertensive drug therapy as compared to placebo or untreated control may have little or no effect on all-cause mortality (2.4% with control vs 2.3% with treatment; low quality evidence; RR 0.94, 95% CI 0.77 to 1.13). Based on 4 studies, the effects on coronary heart disease were uncertain due to low quality evidence (RR 0.99, 95% CI 0.82 to 1.19). Low quality evidence from six studies showed that drug therapy may reduce total cardiovascular mortality and morbidity from 4.1% to 3.2% over five years (RR 0.78, 95% CI 0.67 to 0.91) due to reduction in cerebrovascular mortality and morbidity (1.3% with control vs 0.6% with treatment; RR 0.46, 95% CI 0.34 to 0.64). Very low quality evidence from three studies showed that withdrawals due to adverse events were higher with drug therapy from 0.7% to 3.0% (RR 4.82, 95% CI 1.67 to 13.92). The effects on blood pressure varied between the studies and we are uncertain as to how much of a difference treatment makes on average.

AUTHORS' CONCLUSIONS

Antihypertensive drugs used to treat predominantly healthy adults aged 18 to 59 years with mild to moderate primary hypertension have a small absolute effect to reduce cardiovascular mortality and morbidity primarily due to reduction in cerebrovascular mortality and morbidity. All-cause mortality and coronary heart disease were not reduced. There is lack of good evidence on withdrawal due to adverse events. Future trials in this age group should be at least 10 years in duration and should compare different first-line drug classes and strategies.

Optimal Systolic Blood Pressure Levels for Primary Prevention of Stroke in General Hypertensive Adults: Findings From the CSPPT (China Stroke Primary Prevention Trial)

We aimed to investigate the relationship of time-averaged on-treatment systolic blood pressure (SBP) with the risk of first stroke in the CSPPT (China Stroke Primary Prevention Trial). A post hoc analysis was conducted using data from 17 720 hypertensive adults without cardiovascular disease, diabetes mellitus, and renal function decline from the CSPPT, a randomized double-blind controlled trial. The primary outcome was first stroke. Over a median follow-up duration of 4.5 years, the association between averaged on-treatment SBP and risk for first stoke followed a U-shape curve, with increased risk above and below the reference range of 120 to 130 mm Hg. Compared with participants with time-averaged on-treatment SBP at 120 to 130 mm Hg (mean, 126.2 mm Hg), the risk of first stroke was not only increased in participants with SBP at 130 to 135 mm Hg (mean, 132.6 mm Hg; 1.5% versus 0.8%; hazard ratio, 1.63; 95% confidence interval, 1.01-2.63) or 135 to 140 mm Hg (mean, 137.5 mm Hg; 1.9% versus 0.8%; hazard ratio, 1.85; 95% confidence interval, 1.17-2.93), but also increased in participants with SBP <120 mm Hg (mean, 116.7 mm Hg; 3.1% versus 0.8%; hazard ratio, 4.37; 95% confidence interval, 2.10-9.07). Similar results were found in various subgroups stratified by age, sex, and treatment group. Furthermore, lower diastolic blood pressure was associated with lower risk of stroke, with a plateau at a time-average on-treatment diastolic blood pressure <80 mm Hg. In conclusion, among adults with hypertension and without a history of stroke or myocardial infarction, diabetes mellitus, or renal function decline, a lower SBP goal of 120 to 130 mm Hg, as compared with a target SBP of 130 to 140 mm Hg or <120 mm Hg, resulted in the lowest risk of first stroke.

Comparing six antihypertensive medication classes for preventing new-onset diabetes mellitus among hypertensive patients: a network meta-analysis

Hypertensive patients usually have a higher risk of new‐onset diabetes mellitus (NOD) which may trigger cardiovascular diseases. In this study, the effectiveness of six antihypertensive agents with respect to NOD prevention in hypertensive patients was assessed. A network meta‐analysis was conducted to compare the efficacy of specific drug classes. PubMed and Embase databases were searched for relevant articles. Results of the pairwised meta‐analysis were illustrated by odd ratios (OR) and a corresponding 95% confidence interval (CI). The probabilities and outcome of each treatment were ranked and summarized using the surface under the cumulative ranking curve (SUCRA).Twenty‐three trials were identified, including 224,832 patients with an average follow‐up period of 3.9 ± 1.0 years. The network meta‐analysis showed that patients treated by angiotensin II receptor blockers (ARBs) were associated with a lower risk of NOD compared to placebo (PCB), calcium channel blockers (CCBs) and β‐blockers, while diuretic appeared to be ineffective for NOD prevention. Network meta‐analysis results of specific drugs showed that enalapril exhibited distinct advantages and hydrochlorothiazide also exhibited a reliable performance. Our results suggested that both ARBs and angiotensin converse enzyme inhibitors (ACEIs), especially candesartan and enalapril, were preferable for NOD prevention in hypertensive patients. Hydrochlorothiazide also exhibited a reliable performance in comparison with other agents.

Beta-blockers for hypertension

BACKGROUND

Beta-blockers refer to a mixed group of drugs with diverse pharmacodynamic and pharmacokinetic properties. They have shown long-term beneficial effects on mortality and cardiovascular disease (CVD) when used in people with heart failure or acute myocardial infarction. Beta-blockers were thought to have similar beneficial effects when used as first-line therapy for hypertension. However, the benefit of beta-blockers as first-line therapy for hypertension without compelling indications is controversial. This review is an update of a Cochrane Review initially published in 2007 and updated in 2012.

OBJECTIVES

To assess the effects of beta-blockers on morbidity and mortality endpoints in adults with hypertension.

SEARCH METHODS

The Cochrane Hypertension Information Specialist searched the following databases for randomized controlled trials up to June 2016: the Cochrane Hypertension Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (2016, Issue 6), MEDLINE (from 1946), Embase (from 1974), and ClinicalTrials.gov. We checked reference lists of relevant reviews, and reference lists of studies potentially eligible for inclusion in this review, and also searched the the World Health Organization International Clinical Trials Registry Platform on 06 July 2015.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of at least one year of duration, which assessed the effects of beta-blockers compared to placebo or other drugs, as first-line therapy for hypertension, on mortality and morbidity in adults.

DATA COLLECTION AND ANALYSIS

We selected studies and extracted data in duplicate, resolving discrepancies by consensus. We expressed study results as risk ratios (RR) with 95% confidence intervals (CI) and conducted fixed-effect or random-effects meta-analyses, as appropriate. We also used GRADE to assess the certainty of the evidence. GRADE classifies the certainty of evidence as high (if we are confident that the true effect lies close to that of the estimate of effect), moderate (if the true effect is likely to be close to the estimate of effect), low (if the true effect may be substantially different from the estimate of effect), and very low (if we are very uncertain about the estimate of effect).

MAIN RESULTS

Thirteen RCTs met inclusion criteria. They compared beta-blockers to placebo (4 RCTs, 23,613 participants), diuretics (5 RCTs, 18,241 participants), calcium-channel blockers (CCBs: 4 RCTs, 44,825 participants), and renin-angiotensin system (RAS) inhibitors (3 RCTs, 10,828 participants). These RCTs were conducted between the 1970s and 2000s and most of them had a high risk of bias resulting from limitations in study design, conduct, and data analysis. There were 40,245 participants taking beta-blockers, three-quarters of them taking atenolol. We found no outcome trials involving the newer vasodilating beta-blockers (e.g. nebivolol).There was no difference in all-cause mortality between beta-blockers and placebo (RR 0.99, 95% CI 0.88 to 1.11), diuretics or RAS inhibitors, but it was higher for beta-blockers compared to CCBs (RR 1.07, 95% CI 1.00 to 1.14). The evidence on mortality was of moderate-certainty for all comparisons.Total CVD was lower for beta-blockers compared to placebo (RR 0.88, 95% CI 0.79 to 0.97; low-certainty evidence), a reflection of the decrease in stroke (RR 0.80, 95% CI 0.66 to 0.96; low-certainty evidence) since there was no difference in coronary heart disease (CHD: RR 0.93, 95% CI 0.81 to 1.07; moderate-certainty evidence). The effect of beta-blockers on CVD was worse than that of CCBs (RR 1.18, 95% CI 1.08 to 1.29; moderate-certainty evidence), but was not different from that of diuretics (moderate-certainty) or RAS inhibitors (low-certainty). In addition, there was an increase in stroke in beta-blockers compared to CCBs (RR 1.24, 95% CI 1.11 to 1.40; moderate-certainty evidence) and RAS inhibitors (RR 1.30, 95% CI 1.11 to 1.53; moderate-certainty evidence). However, there was little or no difference in CHD between beta-blockers and diuretics (low-certainty evidence), CCBs (moderate-certainty evidence) or RAS inhibitors (low-certainty evidence). In the single trial involving participants aged 65 years and older, atenolol was associated with an increased CHD incidence compared to diuretics (RR 1.63, 95% CI 1.15 to 2.32). Participants taking beta-blockers were more likely to discontinue treatment due to adverse events than participants taking RAS inhibitors (RR 1.41, 95% CI 1.29 to 1.54; moderate-certainty evidence), but there was little or no difference with placebo, diuretics or CCBs (low-certainty evidence).

AUTHORS' CONCLUSIONS

Most outcome RCTs on beta-blockers as initial therapy for hypertension have high risk of bias. Atenolol was the beta-blocker most used. Current evidence suggests that initiating treatment of hypertension with beta-blockers leads to modest CVD reductions and little or no effects on mortality. These beta-blocker effects are inferior to those of other antihypertensive drugs. Further research should be of high quality and should explore whether there are differences between different subtypes of beta-blockers or whether beta-blockers have differential effects on younger and older people.

Health Benefits and Cost-Effectiveness of Asymptomatic Screening for Hypertension and High Cholesterol and Aspirin Counseling for Primary Prevention

PURPOSE

Our aim was to update estimates of the health and economic impact of clinical services recommended for the primary prevention of cardiovascular disease (CVD) for the comparative rankings of the National Commission on Prevention Priorities, and to explore differences in outcomes by sex and race/ethnicity.

METHODS

We used a single, integrated, microsimulation model to generate comparable results for 3 services recommended by the US Preventive Services Task Force: aspirin counseling for the primary prevention of CVD and colorectal cancer, screening and treatment for lipid disorders (usually high cholesterol), and screening and treatment for hypertension. Analyses compare lifetime outcomes from the societal perspective for a US-representative birth cohort of 100,000 persons with and without access to each clinical preventive service. Primary outcomes are health impact, measured by the net difference in lifetime quality-adjusted life years (QALYs), and cost-effectiveness, measured in incremental cost per QALY or cost savings per person in 2012 dollars. Results are also presented for population subgroups defined by sex and race/ethnicity.

RESULTS

Health impact is highest for hypertension screening and treatment (15,600 QALYs), but is closely followed by cholesterol screening and treatment (14,300 QALYs). Aspirin counseling has a lower health impact (2,200 QALYs) but is found to be cost saving ($31 saved per person). Cost-effectiveness for cholesterol and hypertension screening and treatment is $33,800 per QALY and $48,500 per QALY, respectively. Findings favor hypertension over cholesterol screening and treatment for women, and opportunities to reduce disease burden across all services are greatest for the non-Hispanic black population.

CONCLUSIONS

All 3 CVD preventive services continue to rank highly among other recommended preventive services for US adults, but individual priorities can be tailored in practice by taking a patient's demographic characteristics and clinical objectives into account.

Effects of blood pressure lowering on outcome incidence in hypertension: 7. Effects of more vs. less intensive blood pressure lowering and different achieved blood pressure levels - updated overview and meta-analyses of randomized trials

BACKGROUND AND OBJECTIVES

Previous meta-analyses of our group have investigated the cardiovascular effects of more vs. less intense blood pressure (BP) treatment and the BP levels to be achieved by treatment. A few additional trials have been completed recently, particularly the large SPRINT study. Updating of the previous meta-analyses has been done with the objective of further clarifying the practical question of BP targets of antihypertensive treatment.

METHODS

Among randomized-controlled trials (RCTs) of BP lowering treatment between 1966 and 2015, 16 (52 235 patients) compared more vs. less intense treatment and fulfilled other preset criteria, and in 34 (138 127 patients) SBP in the active (vs. placebo) or the more (vs. less) intense treatment was below (vs., respectively, above) three predetermined cutoffs. For their meta-analyses risk ratios (RR) and 95% confidence intervals, standardized to -10/-5 mmHg SBP/DBP reduction, and absolute risk reductions of seven fatal and nonfatal outcomes were calculated.

RESULTS

More intense BP lowering significantly reduced risk of stroke [RR 0.71 (0.60-0.84)], coronary events [0.80 (0.68-0.95)], major cardiovascular events [0.75 (0.68-0.85)] and cardiovascular mortality [0.79 (0.63-0.97)], but not heart failure and all-cause death. When the 16 RCTs were stratified according to cardiovascular death risk, relative risk reduction did not differ between strata, but absolute risk reduction increased with cardiovascular risk, though the residual risk also increased. Stratification of the 34 RCTs according to the three different SBP cutoffs (150, 140 and 130 mmHg) showed that a SBP/DBP difference of -10/-5 mmHg across each cutoff significantly reduced risk of all outcomes to the same proportion (relative risk reduction), but absolute risk reduction of most outcomes had a significant trend to decrease at lower cutoffs.

CONCLUSION

Updating of previous meta-analyses indicates that more vs. less intense BP lowering can reduce not only stroke and coronary events, but also cardiovascular mortality. Including data from recent RCTs also shows that all major outcomes can be reduced by lowering SBP a few mmHg below vs. above 130 mmHg, but absolute risk reduction becomes smaller, suggesting patients at lower initial SBP were at a lower level of cardiovascular risk.

Diuretics in primary hypertension - Reloaded

Diuretics have long been cherished as drugs of choice for uncomplicated primary hypertension. Robust mortality and morbidity data is available for diuretics to back this strategy. Off-late the interest for diuretics has waned off perhaps due to availability of more effective drugs but more likely due to perceived lack of tolerance and side-effect profile of high-dose of diuretics required for mortality benefit. Low-dose diuretics particularly thiazide diuretics are safer but lack the mortality benefit shown by high-dose. However, indapamide and low dose chlorthalidone have fewer side-effects but continue to provide mortality benefit.

Prevalence of Eligibility Criteria for the Systolic Blood Pressure Intervention Trial in US Adults Among Excluded Groups: Age <50 Years, Diabetes Mellitus, or a History of Stroke

BACKGROUND

Adults <50 years old, with diabetes mellitus, or a history of stroke were not enrolled in the Systolic Blood Pressure Intervention Trial (SPRINT). Estimating the size and characteristics of these excluded groups who meet the other SPRINT eligibility criteria may provide information on the potential impact of providers extending the SPRINT findings to these populations.

METHODS AND RESULTS

We analyzed the National Health and Nutrition Examination Survey 2003-2012 (n=25 076) to estimate the percentage and characteristics of US adults ≥20 years in 3 populations (age <50 years, diabetes mellitus, or history of stroke) excluded from SPRINT who otherwise meet the trial eligibility criteria: age ≥50 years, systolic blood pressure (SBP) 130-180 mm Hg, high cardiovascular disease risk, and not having trial exclusion criteria. Overall, 1.0% (95% CI 0.8-1.3) of US adults age <50 years, 25.4% (95% CI 23.4-27.6) with diabetes mellitus, and 19.0% (95% CI 16.0-22.4) with history of stroke met the other SPRINT eligibility criteria. Among US adults with SBP ≥130 mm Hg, other SPRINT eligibility criteria were met by 7.5% (95% CI 6.1-9.2) of those age <50 years, 32.9% (95% CI 30.5-35.4) with diabetes mellitus, and 23.0% (95% CI 19.4-27.0) with history of stroke. Among US adults meeting the other SPRINT eligibility criteria, antihypertensive medication was being taken by 31.0% (95% CI 23.9-41.3) of those <50 years, 63.0% (95% CI 58.2-67.6) with diabetes mellitus, and 68.9% (95% CI 59.4-77.1) with a history of stroke.

CONCLUSIONS

A substantial percentage of US adults with diabetes mellitus or history of stroke and a small percentage <50 years old meet the other SPRINT eligibility criteria.

Effects of Montmorency tart cherry (Prunus Cerasus L.) consumption on vascular function in men with early hypertension

BACKGROUND

Tart cherries contain numerous polyphenolic compounds that could potentially improve endothelial function and reduce cardiovascular disease risk.

OBJECTIVE

We sought to examine the acute effects of Montmorency tart cherry (MC) juice on vascular function in subjects with early hypertension.

DESIGN

A placebo-controlled, blinded, crossover, randomized Latin square design study with a washout period of ≥14 d was conducted. Fifteen men with early hypertension [systolic blood pressure (SBP) ≥130 mm Hg, diastolic blood pressure ≥80 mm Hg, or both] received either a 60-mL dose of MC concentrate or placebo. Microvascular reactivity (laser Doppler imaging with iontophoresis), arterial stiffness (pulse wave velocity and analysis), blood pressure, and phenolic acid absorption were assessed at baseline and at 1, 2, 3, 5, and 8 h postconsumption.

RESULTS

MC consumption significantly lowered SBP (P < 0.05) over a period of 3 h, with peak reductions of mean ± SEM 7 ± 3 mm Hg 2 h after MC consumption relative to the placebo. Improvements in cardiovascular disease risk factors were closely linked to increases in circulating protocatechuic and vanillic acid at 1-2 h.

CONCLUSIONS

MC intake acutely reduces SBP in men with early hypertension. These benefits may be mechanistically linked to the actions of circulating phenolic acids. This study provides information on a new application of MCs in health maintenance, particularly in positively modulating SBP. This trial was registered at clinicaltrials.gov as NCT02234648.

Blood-Pressure Lowering in Intermediate-Risk Persons without Cardiovascular Disease

BACKGROUND

Antihypertensive therapy reduces the risk of cardiovascular events among high-risk persons and among those with a systolic blood pressure of 160 mm Hg or higher, but its role in persons at intermediate risk and with lower blood pressure is unclear.

METHODS

In one comparison from a 2-by-2 factorial trial, we randomly assigned 12,705 participants at intermediate risk who did not have cardiovascular disease to receive either candesartan at a dose of 16 mg per day plus hydrochlorothiazide at a dose of 12.5 mg per day or placebo. The first coprimary outcome was the composite of death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke; the second coprimary outcome additionally included resuscitated cardiac arrest, heart failure, and revascularization. The median follow-up was 5.6 years.

RESULTS

The mean blood pressure of the participants at baseline was 138.1/81.9 mm Hg; the decrease in blood pressure was 6.0/3.0 mm Hg greater in the active-treatment group than in the placebo group. The first coprimary outcome occurred in 260 participants (4.1%) in the active-treatment group and in 279 (4.4%) in the placebo group (hazard ratio, 0.93; 95% confidence interval [CI], 0.79 to 1.10; P=0.40); the second coprimary outcome occurred in 312 participants (4.9%) and 328 participants (5.2%), respectively (hazard ratio, 0.95; 95% CI, 0.81 to 1.11; P=0.51). In one of the three prespecified hypothesis-based subgroups, participants in the subgroup for the upper third of systolic blood pressure (>143.5 mm Hg) who were in the active-treatment group had significantly lower rates of the first and second coprimary outcomes than those in the placebo group; effects were neutral in the middle and lower thirds (P=0.02 and P=0.009, respectively, for trend in the two outcomes).

CONCLUSIONS

Therapy with candesartan at a dose of 16 mg per day plus hydrochlorothiazide at a dose of 12.5 mg per day was not associated with a lower rate of major cardiovascular events than placebo among persons at intermediate risk who did not have cardiovascular disease. (Funded by the Canadian Institutes of Health Research and AstraZeneca; ClinicalTrials.gov number, NCT00468923.).

Treatment of Hypertension in Patients with Coronary Artery Disease. A Case-Based Summary of the 2015 AHA/ACC/ASH Scientific Statement

The 2015 American Heart Association/American College of Cardiology/American Society of Hypertension Scientific Statement "Treatment of Hypertension in Patients with Coronary Artery Disease" is summarized in the context of a clinical case. The Statement deals with target blood pressures, and the optimal agents for the treatment of hypertension in patients with stable angina, in acute coronary syndromes, and in patients with ischemic heart failure. In all cases, the recommended blood pressure target is <140/90 mm Hg, but <130/80 mm Hg may be appropriate, especially in those with a history of a previous myocardial infarction or stroke, or at high risk for developing either. These numbers may need to be revised after the publication of the SPRINT data. Appropriate management should include beta-blockers, angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, and in the case of heart failure, aldosterone antagonists. Thiazide or thiazide-like (chlorthalidone) diuretics and calcium channel blockers can be used for the management of hypertension, but the evidence for improved outcomes compared with other agents in hypertension with coronary artery disease is meager. Loop diuretics should be reserved for patients with New York Heart Association Class III and IV heart failure or with a glomerular filtration rate of <30 mL/min.

Effects of blood pressure-lowering on outcome incidence in hypertension: 5. Head-to-head comparisons of various classes of antihypertensive drugs - overview and meta-analyses

BACKGROUND AND OBJECTIVES

We have recently published an overview and meta-analysis of the effects of the five major classes of blood pressure-lowering drugs on cardiovascular outcomes when compared with placebo. However, possible differences in effectiveness of the various classes can correctly be estimated only by head-to-head comparisons of different classes of agents. This has been the objective of a new survey and meta-analysis.

METHODS

A database search between 1966 and August 2014 ide ntified 50 eligible randomized controlled trials for 58 two-drug comparisons (247 006 patients for 1 029 768 patient-years). Risk ratios and their 95% confidence intervals of seven outcomes were estimated by a random-effects model.

RESULTS

The effects of all drug classes are not significantly different on most outcomes when their blood pressure effect is equivalent. However, there are also significant differences involving almost all classes of drugs. When compared to all other classes together, diuretics are superior in preventing heart failure; beta-blockers less effective in preventing stroke; calcium antagonists superior in preventing stroke and all-cause death, but inferior in preventing heart failure; angiotensin-converting enzyme inhibitors more effective in preventing coronary heart disease and less in preventing stroke; angiotensin receptor blockers inferior in preventing coronary heart disease; and renin-angiotensin system blockers more effective in preventing heart failure. When stratifying randomized controlled trials according to total cardiovascular risk, no drug class was found to change in effectiveness with the level of risk.

CONCLUSIONS

The results of all available evidence from head-to-head drug class comparisons do not allow the formulation of a fixed paradigm of drug choice valuable for all hypertensive patients, but the differences found may suggest specific choices in specific conditions, or preferable combinations of drugs.

Blood pressure lowering for prevention of cardiovascular disease and death: a systematic review and meta-analysis

BACKGROUND

The benefits of blood pressure lowering treatment for prevention of cardiovascular disease are well established. However, the extent to which these effects differ by baseline blood pressure, presence of comorbidities, or drug class is less clear. We therefore performed a systematic review and meta-analysis to clarify these differences.

METHOD

For this systematic review and meta-analysis, we searched MEDLINE for large-scale blood pressure lowering trials, published between Jan 1, 1966, and July 7, 2015, and we searched the medical literature to identify trials up to Nov 9, 2015. All randomised controlled trials of blood pressure lowering treatment were eligible for inclusion if they included a minimum of 1000 patient-years of follow-up in each study arm. No trials were excluded because of presence of baseline comorbidities, and trials of antihypertensive drugs for indications other than hypertension were eligible. We extracted summary-level data about study characteristics and the outcomes of major cardiovascular disease events, coronary heart disease, stroke, heart failure, renal failure, and all-cause mortality. We used inverse variance weighted fixed-effects meta-analyses to pool the estimates.

RESULTS

We identified 123 studies with 613,815 participants for the tabular meta-analysis. Meta-regression analyses showed relative risk reductions proportional to the magnitude of the blood pressure reductions achieved. Every 10 mm Hg reduction in systolic blood pressure significantly reduced the risk of major cardiovascular disease events (relative risk [RR] 0·80, 95% CI 0·77-0·83), coronary heart disease (0·83, 0·78-0·88), stroke (0·73, 0·68-0·77), and heart failure (0·72, 0·67-0·78), which, in the populations studied, led to a significant 13% reduction in all-cause mortality (0·87, 0·84-0·91). However, the effect on renal failure was not significant (0·95, 0·84-1·07). Similar proportional risk reductions (per 10 mm Hg lower systolic blood pressure) were noted in trials with higher mean baseline systolic blood pressure and trials with lower mean baseline systolic blood pressure (all ptrend>0·05). There was no clear evidence that proportional risk reductions in major cardiovascular disease differed by baseline disease history, except for diabetes and chronic kidney disease, for which smaller, but significant, risk reductions were detected. β blockers were inferior to other drugs for the prevention of major cardiovascular disease events, stroke, and renal failure. Calcium channel blockers were superior to other drugs for the prevention of stroke. For the prevention of heart failure, calcium channel blockers were inferior and diuretics were superior to other drug classes. Risk of bias was judged to be low for 113 trials and unclear for 10 trials. Heterogeneity for outcomes was low to moderate; the I(2) statistic for heterogeneity for major cardiovascular disease events was 41%, for coronary heart disease 25%, for stroke 26%, for heart failure 37%, for renal failure 28%, and for all-cause mortality 35%.

INTERPRETATION

Blood pressure lowering significantly reduces vascular risk across various baseline blood pressure levels and comorbidities. Our results provide strong support for lowering blood pressure to systolic blood pressures less than 130 mm Hg and providing blood pressure lowering treatment to individuals with a history of cardiovascular disease, coronary heart disease, stroke, diabetes, heart failure, and chronic kidney disease.

FUNDING

National Institute for Health Research and Oxford Martin School.

Timeline of History of Hypertension Treatment

It is surprising that only about 50 years ago hypertension was considered an essential malady and not a treatable condition. Introduction of thiazide diuretics in late 50s made some headway in successful treatment of hypertension and ambitious multicenter VA co-operative study (phase 1 and 2) started in 1964 for diastolic hypertension ranging between 90 and 129 mmHg and completed by 1971 established for the first time that treating diastolic hypertension reduced CV events such as stroke and heart failure and improved mortality. In the following decade, these results were confirmed for the wider US and non-US population, including women and goal-oriented BP treatment to diastolic 90 became the standard therapy recommendation. But isolated systolic hypertension (accounting for two-thirds of the 70 million hypertensive population in USA alone) was not considered treatable until 1991 when SHEP study (systolic hypertension in elderly program) was completed and showed tremendous benefits of treating systolic BP over 160 mmHg using only a simple regimen using small dose chlorthalidone with addition of atenolol if needed. In the next two decades, ALLHAT and other studies examined the comparability of outcomes with use of different classes and combinations of antihypertensive drugs. Although diastolic BP goal was established as 90 in the late 70s and later confirmed by HOT study, the goal BP for systolic hypertension was not settled until very recently with completion of SPRINT study. ACCORD study showed no significant difference in outcome with sys 140 vs. 120 in diabetics. But recently completed SPRINT study with somewhat similar protocol as in ACCORD but in non-diabetic showed almost one-quarter reduction in all-cause mortality and one-third reduction of CV events with systolic BP goal 120.

Blood pressure control versus atrial fibrillation management in stroke prevention

Hypertension is one of the major risk factors for atrial fibrillation which in turn is the most prevalent concomitant condition in hypertensive patients. While both these pathological conditions are independent risk factors for stroke, the association of hypertension and atrial fibrillation increases the incidence of disabling strokes. Moreover, documented or silent atrial fibrillation doubles the rate of cardiovascular death. Lowering blood pressure is strongly recommended, particularly for primary stroke prevention. However, a relatively small percentage of hypertensive patients still achieve the recommended blood pressure goals. The management of atrial fibrillation with respect to stroke prevention is changing. New oral anticoagulants represent a major advancement in long-term anticoagulation therapy in non valvular atrial fibrillation. They have several benefits over warfarin, including improved adherence to the anticoagulation therapy. This is an important issue since non-adherence to stroke prevention medications is a risk factor for first and recurrent strokes.

The Role of Beta-Blockers in the Treatment of Hypertension

IMPORTANCE

Two major guide-line committees (JNC-8 and NICE UK) have dropped beta-blockers as first-line therapy in the treatment of hypertension. Also, recent meta-analyses (that do not take age into account) have concluded that beta-blockers are inappropriate first-line agents in the treatment of hypertension. This review seeks to shed some light on the "rights and wrongs" of such actions and conclusions.

OBJECTIVES

Because the pathophysiology of primary/essential hypertension differs in elderly and younger subjects, the latter being closely linked to obesity and increased sympathetic nerve activity, the author sought to clarify the efficacy of beta-blockers in the younger/middle-aged group in reducing the risk of death, and cardiovascular end-points.

EVIDENCE ACQUISITION

Four searches were undertaken, utilising PubMed up to 31st Dec 2015. One search was under the terms "hypertension AND obesity AND sympathetic nerve activity". A second was "hypertension AND plasma noradrenaline/norepinephrine AND survival". A third was "beta-blockers or adrenergic beta-antagonists AND hypertension AND age AND stroke or myocardial infarction or death". A fourth was "meta-analysis of beta-blockers AND hypertension AND age AND death, stroke, myocardial infarction" RESULTS: Diastolic (with or without systolic) hypertension, in contrast to isolated systolic hypertension, occurs primarily in younger subjects, and is linked to overweight/obesity and increased sympathetic nerve activity. In younger/middle-aged hypertensive subjects, high plasma norepinephrine levels are linked (independent of blood pressure) to an increased risk of future cardiovascular events and death. High resting heart rates (a surrogate for high sympathetic nerve activity) likewise predict premature all-cause death, coronary heart disease and cardiovascular events in younger hypertensive subjects. In this younger/middle-aged hypertensive group, antihypertensive agents that increase sympathetic nerve activity (diuretics, dihydropyridine calcium blockers, and angiotensin receptor blockers (ARBs)) do not decrease (and may increase) the risk of myocardial infarction, and are therefore inappropriate first-line agents in this age-group. By contrast, in younger/middle-aged hypertensive subjects (less than 60 years old), meta-analysis has shown that beta-blockers are significantly superior to randomised placebo, and at least as effective as randomised comparator agents, in reducing death/stroke/myocardial infarction. In this younger/middle-aged hypertensive group beta-blockers have been shown (vs randomised placebo or diuretics) to reduce the risk of myocardial infarction by 35-50 %, and stroke by 50-55 % (vs placebo), in non-smoker men. Atenolol was at least as effective as ACE-inhibition (captopril) in reducing all 7 cardiovascular endpoints (including stroke which was reduced by 50 %), vs less tight control of blood pressure, in obese hypertensive subjects with type-2 diabetes (UKPDS study); and after 20 years follow-up, atenolol was significantly (23 %) superior to the ACE-inhibitor in reducing the risk of all-cause death (beta-blockers have anti-cancer properties, which maybe relevant).

CONCLUSIONS AND RELEVANCE

Primary/essential hypertension in younger/middle-age is underpinned by high sympathetic nerve activity. In this age-group high resting heart rates and high plasma norepinephrine levels (independent of blood pressure) are linked to premature cardiovascular events and death. Thus, anti-hypertensive agents that increase sympathetic nerve activity ie diuretics, dihydropyridine calcium blockers, and ARBs, are inappropriate first-line choices in this younger age-group. Beta-blockers perform well vs randomised placebo and other antihypertensive agents regarding reduced risk of death/stroke/myocardial infarction in younger (<60 years) hypertensive subjects, and are a reasonable first-line choice of therapy (certainly in men). These facts should be reflected in the recommendations of guideline committees around the world.

The relationship between external and internal validity of randomized controlled trials: A sample of hypertension trials from China

Objective

To explore the relationship between the external validity and the internal validity of hypertension RCTs conducted in China.

Methods

Comprehensive literature searches were performed in Medline, Embase, Cochrane Central Register of Controlled Trials (CCTR), CBMdisc (Chinese biomedical literature database), CNKI (China National Knowledge Infrastructure/China Academic Journals Full-text Database) and VIP (Chinese scientific journals database) as well as advanced search strategies were used to locate hypertension RCTs. The risk of bias in RCTs was assessed by a modified scale, Jadad scale respectively, and then studies with 3 or more grading scores were included for the purpose of evaluating of external validity. A data extract form including 4 domains and 25 items was used to explore relationship of the external validity and the internal validity. Statistic analyses were performed by using SPSS software, version 21.0 (SPSS, Chicago, IL).

Results

226 hypertension RCTs were included for final analysis. RCTs conducted in university affiliated hospitals (P < 0.001) or secondary/tertiary hospitals (P < 0.001) were scored at higher internal validity. Multi-center studies (median = 4.0, IQR = 2.0) were scored higher internal validity score than single-center studies (median = 3.0, IQR = 1.0) (P < 0.001). Funding-supported trials had better methodological quality (P < 0.001). In addition, the reporting of inclusion criteria also leads to better internal validity (P = 0.004). Multivariate regression indicated sample size, industry-funding, quality of life (QOL) taken as measure and the university affiliated hospital as trial setting had statistical significance (P < 0.001, P < 0.001, P = 0.001, P = 0.006 respectively).

Conclusion

Several components relate to the external validity of RCTs do associate with the internal validity, that do not stand in an easy relationship to each other. Regarding the poor reporting, other possible links between two variables need to trace in the future methodological researches.

Antihypertensive Drugs and Male Sexual Dysfunction

Background:

Published clinical practice guidelines have addressed antihypertensive therapy and sexual dysfunction (SD) in many different ways.

Objective:

In this systematic review, we evaluated guidelines that address antihypertensive drug-associated SD, guideline recommendations, and recent guideline trends.

Methods:

Thirty sets of guidelines for hypertension management in adults that had been published in the English language since 2000 were reviewed. The primary outcome measure was antihypertensive-associated SD potential, which was independently evaluated using specific questions by 2 authors in a nonblinded standardized manner.

Results:

Sexual dysfunctions associated with thiazide-class diuretics, β-blockers, and centrally acting sympathoplegics were addressed by half of the guidelines reviewed. There is no clarity on β-blockers and thiazide-class diuretics because one-third of the guidelines are vague about individual β-blockers and diuretics, and there is no statement on third-generation β-blockers and thiazide-like diuretics that can improve erectile function. The revised guidelines never use terms such as loss of libido, ejaculatory dysfunction, lack of orgasm, and priapism. Summary versions of guidelines are inadequate to reflect the key interpretation of the primary guidelines on SD associated with antihypertensives, even in the major guidelines that were updated recently. Therapeutic issues such as exploring SD in clinical history, assessing SD prior to and during treatment with antihypertensives, substituting the offending agents with alternatives that possess a better safety profile, intervening with phosphodiesterase-5 inhibitors, and avoiding the concomitant use of nitrovasodilators are superficially addressed by most guidelines, with the exception of 2013 European Society of Hypertension/European Society of Cardiology and Seventh Joint National Committee recommendations.

Conclusion:

Future guideline revisions, including both full and summary reports, should provide a balanced perspective on antihypertensive-related SD issues to improve the impact of hypertension treatment guidelines on patient care and quality of life.

Current and Future Treatment of Hypertension in the SPRINT Era

Based on the SPRINT trial, it is highly likely that new SPRINT-era guidelines will establish a blood pressure (BP) goal of < 130/80 mm Hg for those aged 50 or older who are at high risk for a cardiovascular event. In this group, SPRINT demonstrated that assignment to an intensive-treatment systolic BP (SBP) goal of < 120 mm Hg significantly reduced cardiovascular events and mortality compared to those assigned to a standard-treatment SPB goal of < 140 mm Hg. This review critically assesses current hypertension guidelines and presents predictions for SPRINT-era guidelines in the elderly, African Americans, and patients with uncomplicated essential hypertension, diabetes, chronic kidney disease, cardiovascular disease, and coronary artery disease. Specific attention is paid to BP goals and preferred pharmacological antihypertensive therapy in these populations, and an algorithm that incorporates the SPRINT trial results is presented. Inhibitors of the renin-angiotensin-aldosterone system as well as calcium channel blockers are universally accepted as first-line therapy in uncomplicated hypertension, but controversy exists over the role of thiazide diuretics and beta blockers. This review also discusses a physiologically and outcomes-based approach to combination therapy for treatment of hypertension.