Lessons in Uncertainty and Humility - Clinical Trials Involving Hypertension

Guidelines-based therapeutic strategies for controlling hypertension in non-controlled hypertensive patients followed by family physicians in primary health care in Portugal: the GPHT-PT study

PURPOSE

In a prospective open study, with intervention, conducted in Primary Health Care Units by General Practitioners (GPs) in Portugal, the effectiveness of a single pill of candesartan/amlodipine (ARB/amlodipine), as the only anti-hypertension (anti-HTN) medication, in adult patients with uncontrolled HTN (BP > 140/or > 90 mm Hg), either previously being treated with anti-HTN monotherapies (Group I), or combinations with hydrochlorothiazide (HCTZ) (Group II), or not receiving medication at all (Group III), was evaluated across 12-weeks after implementation of the new therapeutic measure.

MATERIALS AND METHODS

A total of 118 GPs recruited patients with uncontrolled HTN who met inclusion/exclusion criteria. Participants were assigned, according to severity, one of 3 (morning) fixed combination candesartan/amlodipine dosage (8/5 or 16/5 or 16/10 mg/day) and longitudinally evaluated in 3 visits (v0, v6 and v12 weeks). Office blood pressure was measured in each visit, and control of HTN was defined per guidelines (BP< 140/90 mmHg).

RESULTS

Of the 1234 patients approached, 752 (age 61 ± 10 years, 52% women) participated in the study and were assigned to groups according to previous treatment conditions. The 3 groups exhibited a statistically significant increased control of blood pressure after receiving the fixed combination candesartan/amlodipine dosage. The overall proportion of controlled HTN participants increased from 0,8% at v0 to 82% at v12. The mean arterial blood pressure values decreased from SBP= 159.0 (± 13.0) and DBP= 91.1 (± 9.6) at baseline to SBP= 132,1 (± 11.3) and DBP= 77,5 (± 8.8) at 12 weeks (p < 0.01). Results remained consistent when controlling for age and sex.

CONCLUSION

In patients with uncontrolled HTN, therapeutic measures in accordance with guidelines, with a fixed combination candesartan/amlodipine, allowed to overall achieve HTN control at 12 weeks in 82% of previously uncontrolled HTN patients, reinforcing the advantages of these strategies in primary clinical practice.

Causal role of immune cells in hypertension: a bidirectional Mendelian randomization study

Background

Although Hypertension (HTN) is considered to be a cardiovascular disease caused by multiple factors, the cause of it is still unknown. In this study, we aim to find out whether circulating immune cell characteristics have an impact on susceptibility to HTN.

Methods

This study employed a comprehensive two-sample Mendelian randomization (MR) analysis to investigate the causal association between immune cell characteristics and HTN. Utilizing publicly accessible genetic data, we examined the causal relationship between HTN and the susceptibility to 731 immune cell signatures. To ensure the reliability and validity of the findings, a comprehensive sensitivity analysis was conducted to assess heterogeneity, confirm the robustness of the results and evaluate the presence of horizontal pleiotropy.

Results

After FDR correction, immune phenotype had an effect on HTN. In our study, one immunophenotype was identified as being positively associated with HTN risk significance: HLA DR on CD33- HLA DR+. In addition, we examined 8 immune phenotype with no statistically significant effect of HTN, but it is worth mentioning that they had an unadjusted low P-value phenotype.

Conclusions

Our MR study by genetic means demonstrated the close relationship between HTN and immune cells, thus providing guidance for future clinical prediction and subsequent treatment of HTN.

Temporal trends in evidence supporting therapeutic interventions in heart failure and other European Society of Cardiology guidelines

AIMS

This study aimed to determine whether any change occurred over time in level of evidence (LoE) of therapeutic interventions supporting heart failure (HF) and other European Society of Cardiology guideline recommendations.

METHODS AND RESULTS

We selected topics with at least three documents released between 2008 and April 2022. Classes of recommendations (CoR) and supporting LoE related to therapeutic interventions within each document were collected and compared over time. A total of 1822 recommendations from 18 documents on 6 topics [median number per document = 112, 867 (48%) CoR I] were included in the analysis. There was a trend towards a reduction over time in the percentage of CoR I in HF (46-36-34%), non-ST elevation myocardial infarction (NSTEMI; 78-58-54%), and pulmonary embolism (PE; 65-50-39%) guidelines, with a decrease in the total number of recommendations for HF only. Percentage of CoR I was stable over time around 40% for valvular heart disease (VHD) and atrial fibrillation (AF), and around 60% for cardiovascular prevention (CVP), with an increase in the total number of recommendations for VHD and CVP and a decrease for AF. Among CoR I, 319 (37%) were supported by LoE A, with a decrease over time for HF (56-46-42%), an increase for NSTEMI (29-38-48%) and AF (28-31-36%), a bimodal distribution for PE and CVP, and a lack for VHD.

CONCLUSIONS

LoE supporting therapeutic recommendations in contemporary European guidelines is generally low. Physicians should be aware of these limitations, and scientific societies promote a greater understanding of their significance and drive future research directions.

Machine learning integration of multimodal data identifies key features of blood pressure regulation

BACKGROUND

Association studies have identified several biomarkers for blood pressure and hypertension, but a thorough understanding of their mutual dependencies is lacking. By integrating two different high-throughput datasets, biochemical and dietary data, we aim to understand the multifactorial contributors of blood pressure (BP).

METHODS

We included 4,863 participants from TwinsUK with concurrent BP, metabolomics, genomics, biochemical measures, and dietary data. We used 5-fold cross-validation with the machine learning XGBoost algorithm to identify features of importance in context of one another in TwinsUK (80% training, 20% test). The features tested in TwinsUK were then probed using the same algorithm in an independent dataset of 2,807 individuals from the Qatari Biobank (QBB).

FINDINGS

Our model explained 39·2% [4·5%, MAE:11·32 mmHg (95%CI, +/- 0·65)] of the variance in systolic BP (SBP) in TwinsUK. Of the top 50 features, the most influential non-demographic variables were dihomo-linolenate, cis-4-decenoyl carnitine, lactate, chloride, urate, and creatinine along with dietary intakes of total, trans and saturated fat. We also highlight the incremental value of each included dimension. Furthermore, we replicated our model in the QBB [SBP variance explained = 45·2% (13·39%)] cohort and 30 of the top 50 features overlapped between cohorts.

INTERPRETATION

We show that an integrated analysis of omics, biochemical and dietary data improves our understanding of their in-between relationships and expands the range of potential biomarkers for blood pressure. Our results point to potentially key biological pathways to be prioritised for mechanistic studies.

FUNDING

Chronic Disease Research Foundation, Medical Research Council, Wellcome Trust, Qatar Foundation.

Long-term evolution of ambulatory blood pressure and cardiovascular events in hypertensive patients

Ambulatory blood pressure monitoring (ABPM) is now considered the gold standard to evaluate BP, and predicts related cardiovascular risk. However, no study has reported the association of long-term changes in ABPM with the incidence of cardiovascular events, therefore the objective of this work. We included patients from the Bordeaux cohort of hypertensive patients, who had undergone at least two ABPM; the first was performed before or after antihypertensive treatment was started, and the second was the last recording available before any cardiovascular event. We included 591 patients (mean age, 54 years) with a 7-year average interval between the first and last ABPM, a 10-year average follow-up, and a total of 111 cardiovascular events. The patients were divided into four groups: G0, first and last 24 h systolic blood pressure (SBP) < 130; G1, first 24 h SBP ≥ 130, last 24 h SBP < 130; G2, first 24 h SBP < 130, last 24 h SBP ≥ 130; and G3, first 24 h SBP ≥ 130, last 24 h SBP ≥ 130 mmHg. Baseline ABPM better predicted future events than the last ABPM. G0 and G2 had similar survival. G1 and G3 had a worse prognosis than G0 and G2, while G1 had an intermediate risk between G0 and G3, indicating some benefit of treatment. In conclusion, our study showed the prognostic value of the first ABPM recorded in hypertensive patients and the persistence of risk when 24 h BP is controlled by antihypertensive treatment.

Editing of the myosin phosphatase regulatory subunit suppresses angiotensin II induced hypertension via sensitization to nitric oxide mediated vasodilation

Alternative splicing of exon 24 (E24) of the myosin phosphatase regulatory subunit (Mypt1) tunes smooth muscle sensitivity to NO/cGMP-mediated vasorelaxation and thereby controls blood pressure (BP) in otherwise normal mice. This occurs via the toggling in or out of a C-terminal leucine zipper (LZ) motif required for hetero-dimerization with and activation by cGMP-dependent protein kinase cGK1α. Here we tested the hypothesis that editing (deletion) of E24, by shifting to the LZ positive isoform of Mypt1, would suppress the hypertensive response to angiotensin II (AngII). To test this, mice underwent tamoxifen-inducible and smooth muscle-specific deletion of E24 (E24 cKO) at age 6 weeks followed by a chronic slow-pressor dose of AngII (400 ng/kg/min) plus additional stressors. E24 cKO suppressed the hypertensive response to AngII alone or with the addition of a high salt diet. This effect was not a function of altered salt balance as there were no differences in intake or renal excretion of sodium. This effect was NO dependent as L-NAME in the drinking water caused an exaggerated hypertensive response in the E24cKO mice. E24cKO mouse mesenteric arteries were more sensitive to DEA/NO-induced vasorelaxation and less responsive to AngII- and α-adrenergic-induced vasoconstriction at baseline. Only the latter two effects were still present after 2 weeks of chronic AngII treatment. We conclude that editing of Mypt1 E24, by shifting the expression of naturally occurring isoforms and sensitizing to NO-mediated vasodilation, could be a novel approach to the treatment of human hypertension.

Impact of cumulative SBP and serious adverse events on efficacy of intensive blood pressure treatment: a randomized clinical trial

BACKGROUND

Intensive blood pressure lowering is increasingly gaining attention. In addition to higher baseline blood pressure, cumulative SBP, visit-to-visit variability, and treatment-induced serious adverse events (SAEs) could impact treatment efficacy over time. Our aim was to assess the impact of cumulative SBP and SAEs on intensive hypertension treatment efficacy in the Systolic Blood Pressure Intervention Trial (SPRINT) population during follow-up.

METHODS

Secondary analysis of the SPRINT study: a randomized, controlled, open-label trial including 102 clinical sites in the United States. We included 9068 SPRINT participants with 128 139 repeated SBP measurements. Participants were randomly assigned to intensive (target SBP < 120 mmHg) versus standard treatment (target SBP between 135 and 139 mmHg). We used cumulative joint models for longitudinal and survival data analysis. Primary outcome was a composite outcome of myocardial infarction, other acute coronary syndromes, acute decompensated heart failure, stroke, and cardiovascular mortality.

RESULTS

Although intensive treatment decreased the risk for the primary SPRINT outcome at the start of follow-up, its effect lost significance after 3.4 years of follow-up in the total SPRINT population and after 1.3, 1.3, 1.1, 1.8, 2.1, 1.8, and 3.4 years among participants with prevalent chronic kidney disease, prevalent cardiovascular disease, women, black individuals, participants less than 75 years, those with baseline SBP more than 132 mmHg, and individuals who suffered SAEs during follow-up, respectively.

CONCLUSION

The initial beneficial impact of intensive hypertension treatment might be offset by cumulative SBP and development of SAEs during follow-up.

Benefits and harms of lower blood pressure treatment targets: systematic review and meta-analysis of randomised placebo-controlled trials

OBJECTIVES

To assess the effect of antihypertensive treatment in the 130-140 mm Hg systolic blood pressure range.

DESIGN

Systematic review and meta-analysis.

INFORMATION SOURCES

PubMed, CDSR and DARE were searched for the systematic reviews, which were manually browsed for clinical trials. PubMed and Cochrane Central Register of Controlled Trials were searched for trials directly in February 2018.

ELIGIBILITY CRITERIA

Randomised double-blind trials with ≥1000 patient-years of follow-up, comparing any antihypertensive agent against placebo.

DATA EXTRACTION AND RISK OF BIAS

Two reviewers extracted study-level data, and assessed risk of bias using Cochrane Collaborations risk of bias assessment tool, independently.

MAIN OUTCOMES AND MEASURES

Primary outcomes were all-cause mortality, major cardiovascular events and discontinuation due to adverse events. Secondary outcomes were cardiovascular mortality, myocardial infarction, stroke, heart failure, hypotension-related adverse events and renal impairment.

RESULTS

Eighteen trials, including 92 567 participants (34% women, mean age 63 years), fulfilled the inclusion criteria. Primary preventive antihypertensive treatment was associated with a neutral effect on all-cause mortality (relative risk 1.00, 95% CI 0.95 to 1.06) and major cardiovascular events (1.01, 0.96 to 1.06), but an increased risk of discontinuation due to adverse events (1.23, 1.03 to 1.47). None of the secondary efficacy outcomes were significantly reduced, but the risk of hypotension-related adverse events increased with treatment (1.71, 1.32 to 2.22). In coronary artery disease secondary prevention, antihypertensive treatment was associated with reduced risk of all-cause mortality (0.91, 0.83 to 0.99) and major cardiovascular events (0.85, 0.77 to 0.94), but doubled the risk of adverse events leading to discontinuation (2.05, 1.62 to 2.61).

CONCLUSION

Primary preventive blood pressure lowering in the 130-140 mm Hg systolic blood pressure range adds no cardiovascular benefit, but increases the risk of adverse events. In the secondary prevention, benefits should be weighed against harms.

PROSPERO REGISTRATION NUMBER

CRD42018088642.

Standardizing hypertension management in a primary care setting in India through a protocol based model

Hypertension is a leading cause of death in India. Control rates of hypertension are abysmal, even for people on treatment. There are a number of barriers to adequate control of hypertension in India, including therapeutic inertia and the lack of a systematic, simplified approach. Standardizing hypertension management through an evidence based model that sets thresholds for diagnosis, treatment goals, follow up intervals and choice of drugs can lead to improved management of hypertension in an individual hospital or health system. In this paper, we summarize the evidence for such a model, and adapt it to the Indian context, focusing on maximizing effectiveness, safety and ease of use by a non-expert. This model can be utilized by individual practitioners, hospitals, primary health centers (PHCs) and the Health and Wellness Centers (HWCs) under the Ayushman Bharat initiative.

Dangers of Overly Aggressive Blood Pressure Control

PURPOSE OF REVIEW

Recent US guidelines have changed the definition of hypertension to ≥ 130/80 mmHg and recommended more intense blood pressure (BP) targets. We summarize the evidence for intense BP treatment and discuss risks that must be considered when choosing treatment goals for individual patients.

RECENT FINDINGS

The SPRINT study reported that treating to a systolic BP target of 120 mmHg reduces cardiovascular outcomes in high-risk individuals, supporting more intensive BP reduction than previously recommended. However, recent observational studies have placed emphasis on the BP J-curve phenomenon, where low BPs are associated with adverse cardiovascular outcomes, suggesting that overly aggressive BP targets may sometimes be harmful. We attempt to reconcile these apparent contradictions for the clinician. We also review other potential dangers of aggressive BP targets, including syncope, renal impairment, polypharmacy, drug interactions, subjective drug side-effects, and non-adherence. We suggest a personalized approach to BP drug management considering individual risks, benefits, and preferences when choosing therapeutic targets, recognizing that a goal of 130/80 mmHg should always be considered. Additionally, we recommend an intense focus on lifestyle changes and medication adherence.

Why all randomised controlled trials produce biased results

BACKGROUND

Randomised controlled trials (RCTs) are commonly viewed as the best research method to inform public health and social policy. Usually they are thought of as providing the most rigorous evidence of a treatment's effectiveness without strong assumptions, biases and limitations.

OBJECTIVE

This is the first study to examine that hypothesis by assessing the 10 most cited RCT studies worldwide.

DATA SOURCES

These 10 RCT studies with the highest number of citations in any journal (up to June 2016) were identified by searching Scopus (the largest database of peer-reviewed journals).

RESULTS

This study shows that these world-leading RCTs that have influenced policy produce biased results by illustrating that participants' background traits that affect outcomes are often poorly distributed between trial groups, that the trials often neglect alternative factors contributing to their main reported outcome and, among many other issues, that the trials are often only partially blinded or unblinded. The study here also identifies a number of novel and important assumptions, biases and limitations not yet thoroughly discussed in existing studies that arise when designing, implementing and analysing trials.

CONCLUSIONS

Researchers and policymakers need to become better aware of the broader set of assumptions, biases and limitations in trials. Journals need to also begin requiring researchers to outline them in their studies. We need to furthermore better use RCTs together with other research methods. Key messages RCTs face a range of strong assumptions, biases and limitations that have not yet all been thoroughly discussed in the literature. This study assesses the 10 most cited RCTs worldwide and shows that trials inevitably produce bias. Trials involve complex processes - from randomising, blinding and controlling, to implementing treatments, monitoring participants etc. - that require many decisions and steps at different levels that bring their own assumptions and degree of bias to results.

Blood Pressure-Related Risk Among Users Versus Nonusers of Antihypertensives: A Population-Based Cohort in Korea

There have been few studies comparing blood pressure (BP)-related outcomes between users and nonusers of antihypertensive drugs. We constructed a population-based cohort of 492 540 Koreans aged 40 to 79 years, who had no preexisting cardiorenal diseases, from the National Health Insurance Service-Health Screening database. The primary composite outcome was death (or critical care unit admission) from cardiorenal causes, revascularization for myocardial infarction or stroke, and new-onset end-stage renal disease. Using time-dependent Cox models, we estimated hazard ratios according to BP and antihypertensive use, which were determined in each year of follow-up. Over 10 years of follow-up, the primary outcome occurred in 26 122 subjects, and 33 550 deaths were noted. Among nonusers of antihypertensives, the risk for the primary outcome increased linearly from a BP of 105/65 mm Hg, and the risk for all-cause mortality increased from a BP of 115/75 mm Hg. Among irregular users, the risk for the primary outcome increased as the BP increased >115/75 mm Hg. Among active users, the risk for the primary outcome increased in systolic BP <115 mm Hg and >135 mm Hg, and in diastolic BP <65 mm Hg and >85 mm Hg, and the risk for all-cause mortality increased in systolic BP <125 mm Hg and >135 or 145 mm Hg. In conclusion, this population-based study demonstrated that the associations between BP and adverse outcomes were J-shaped among active antihypertensive users, but linear or flat and then increasing among nonusers or irregular users.

Burden of cardiovascular disease across 29 countries and GPs' decision to treat hypertension in oldest-old

OBJECTIVES

We previously found large variations in general practitioner (GP) hypertension treatment probability in oldest-old (>80 years) between countries. We wanted to explore whether differences in country-specific cardiovascular disease (CVD) burden and life expectancy could explain the differences.

DESIGN

This is a survey study using case-vignettes of oldest-old patients with different comorbidities and blood pressure levels. An ecological multilevel model analysis was performed.

SETTING

GP respondents from European General Practice Research Network (EGPRN) countries, Brazil and New Zeeland.

SUBJECTS

This study included 2543 GPs from 29 countries.

MAIN OUTCOME MEASURES

GP treatment probability to start or not start antihypertensive treatment based on responses to case-vignettes; either low (<50% started treatment) or high (≥50% started treatment). CVD burden is defined as ratio of disability-adjusted life years (DALYs) lost due to ischemic heart disease and/or stroke and total DALYs lost per country; life expectancy at age 60 and prevalence of oldest-old per country.

RESULTS

Of 1947 GPs (76%) responding to all vignettes, 787 (40%) scored high treatment probability and 1160 (60%) scored low. GPs in high CVD burden countries had higher odds of treatment probability (OR 3.70; 95% confidence interval (CI) 3.00-4.57); in countries with low life expectancy at 60, CVD was associated with high treatment probability (OR 2.18, 95% CI 1.12-4.25); but not in countries with high life expectancy (OR 1.06, 95% CI 0.56-1.98).

CONCLUSIONS

GPs' choice to treat/not treat hypertension in oldest-old was explained by differences in country-specific health characteristics. GPs in countries with high CVD burden and low life expectancy at age 60 were most likely to treat hypertension in oldest-old. Key Points  • General practitioners (GPs) are in a clinical dilemma when deciding whether (or not) to treat hypertension in the oldest-old (>80 years of age).  • In this study including 1947 GPs from 29 countries, we found that a high country-specific cardiovascular disease (CVD) burden (i.e. myocardial infarction and/or stroke) was associated with a higher GP treatment probability in patients aged >80 years.  • However, the association was modified by country-specific life expectancy at age 60. While there was a positive association for GPs in countries with a low life expectancy at age 60, there was no association in countries with a high life expectancy at age 60.  • These findings help explaining some of the large variation seen in the decision as to whether or not to treat hypertension in the oldest-old.

Variation in GP decisions on antihypertensive treatment in oldest-old and frail individuals across 29 countries

Background

In oldest-old patients (>80), few trials showed efficacy of treating hypertension and they included mostly the healthiest elderly. The resulting lack of knowledge has led to inconsistent guidelines, mainly based on systolic blood pressure (SBP), cardiovascular disease (CVD) but not on frailty despite the high prevalence in oldest-old. This may lead to variation how General Practitioners (GPs) treat hypertension. Our aim was to investigate treatment variation of GPs in oldest-olds across countries and to identify the role of frailty in that decision.

Methods

Using a survey, we compared treatment decisions in cases of oldest-old varying in SBP, CVD, and frailty. GPs were asked if they would start antihypertensive treatment in each case. In 2016, we invited GPs in Europe, Brazil, Israel, and New Zealand. We compared the percentage of cases that would be treated per countries. A logistic mixed-effects model was used to derive odds ratio (OR) for frailty with 95% confidence intervals (CI), adjusted for SBP, CVD, and GP characteristics (sex, location and prevalence of oldest-old per GP office, and years of experience). The mixed-effects model was used to account for the multiple assessments per GP.

Results

The 29 countries yielded 2543 participating GPs: 52% were female, 51% located in a city, 71% reported a high prevalence of oldest-old in their offices, 38% and had >20 years of experience. Across countries, considerable variation was found in the decision to start antihypertensive treatment in the oldest-old ranging from 34 to 88%. In 24/29 (83%) countries, frailty was associated with GPs’ decision not to start treatment even after adjustment for SBP, CVD, and GP characteristics (OR 0.53, 95%CI 0.48–0.59; ORs per country 0.11–1.78).

Conclusions

Across countries, we found considerable variation in starting antihypertensive medication in oldest-old. The frail oldest-old had an odds ratio of 0.53 of receiving antihypertensive treatment. Future hypertension trials should also include frail patients to acquire evidence on the efficacy of antihypertensive treatment in oldest-old patients with frailty, with the aim to get evidence-based data for clinical decision-making.

Electronic supplementary material

The online version of this article (doi:10.1186/s12877-017-0486-4) contains supplementary material, which is available to authorized users.

Heart Failure and Hypertension: Importance of Prevention

This article discusses the role of hypertension in heart failure. Elevated blood pressure has the greatest population attributable risk for the development of heart failure. The mortality rates following the clinical recognition of heart failure is increased multifold. The treatment of hypertension with antihypertensive agents is particularly effective in preventing heart failure, which makes it the most effective therapy for heart failure.