Interpretation of blood pressure in epidemiological studies and clinical trials

2011 ◽  
pp. 483-498
2011 ◽  
Vol 3 (1) ◽  
pp. 30
Author(s):  
Anding Xu ◽  
Zefeng Tan ◽  
◽  

Hypertension is the most important of the prevalent and modifiable risk factors for stroke. Based on evidence, blood pressure (BP) lowering is recommended in guidelines for the prevention of stroke. However, there are still some uncertainties in the guidelines for controlling BP and preventing stroke in patients with previous cerebrovascular events, such as the goal BP, who to treat and which class of BP-lowering drugs to use. This article discusses these questions by reviewing guidelines and corresponding clinical trials, with the aim of reducing the gap between guidelines and clinical practice.


2020 ◽  
Author(s):  
Lida Feyz ◽  
Yale Wang ◽  
Atul Pathak ◽  
Manish Saxena ◽  
Felix Mahfoud ◽  
...  

BACKGROUND Great and costly efforts are required to recruit potential participants into clinical trials. Using social media may make the recruitment process more efficient. Merely 20% of clinical trials are completed on time, a finding mostly linked to challenges in patient recruitment [1]. Recruitment through social media is increasingly being recognized as a tool to efficiently identify eligible subjects at lower costs [2, 3]. One of the key reasons for its success is the strong adherence of users to specific social media platforms. Facebook for instance has over 2.38 billion active monthly users of which about 75% access the network on a daily basis [4]. As such, the platform and other like it offer great potential to quickly and affordably enroll patients into clinical trials and surveys [3, 5-7]. At present, little evidence is available on the efficacy of using social media to recruit patients into cardiovascular and hypertension trials [8]. The aim of the present study was to evaluate the efficacy of social media as an approach to recruit hypertensive patients into the RADIANCE-HTN SOLO trial. OBJECTIVE The aim of the present study was to evaluate the efficacy of social media as an approach to recruit hypertensive patients into the RADIANCE-HTN SOLO trial. METHODS The RADIANCE-HTN SOLO (NCT02649426) is a multicenter, randomised study that was designed to demonstrate the efficacy and safety of endovascular ultrasound renal denervation (RDN) to reduce ambulatory blood pressure at 2 months in patients with combined systolic–diastolic hypertension in the absence of medications. Between March 28, 2016, and Dec 28, 2017, 803 patients were screened for eligibility and 146 were randomised to undergo RDN (n=74) or a sham procedure (n=72) [9]. Key entry criteria included: age 18-75 years with essential hypertension using 0-2 antihypertensive drugs. Patients were recruited from 21 hospitals in the USA and 18 hospitals in Europe. The study was approved by local ethics committees or institutional review boards and was performed in accordance with the declaration of Helsinki. All participants provided written informed consent. All recruitment materials including social media campaigns was approved by local ethics committees of the involved sites. Recruitment strategies included social media (Facebook), conventional advertisements (ads) (magazine, brochure/poster, radio, newspaper), web search (the clinical website, craigslist and web-browsing), and physician referral. Both newspaper ads and posters contained brief information about study entry criteria. Newspapers were distributed at public transport places and posters were displayed in outpatient cardiology and hypertension clinics. Radio ads were run for 30 or 60 seconds providing a short summary of the study, entry criteria and contact information. Ads were run in major metropolitan areas on radio stations with large adult listener bases during popular days and times. Facebook ads were targeted towards subjects >45 years old within a certain distance from a recruitment site (range 20-50 miles). Criteria were modified over time in order to increase response rates [i.e. distance was increased or decreased, age was increased to >55 year]. Facebook ads referred to a dedicated study website translated into country specific languages. If interested, subjects could complete an anonymous online screening questionnaire which provided direct automatic feedback on study eligibility. Eligible subjects were asked to provide contact details (name and telephone number) to receive additional information, a process coordinated via a secure online portal (Galen Gateway Patient Recruitment Portal, Galen Patient Recruitment, Inc., Cumberland, RI). Study site were only able to contact potential candidates within their area. The study sponsor was not able to access any personal data. Trained local site personnel or contracted secondary screeners contacted candidates by phone to verify eligibility and answer potential questions. A subsequent outpatient clinic visit was scheduled during which the study was explained in greater detail and the informed consent form could be signed. Statistical analysis Categorical variables were expressed as percentages and counts. Continuous variables were described as mean  standard deviation (SD) when normally distributed, data was compared using an Independent-Samples or Paired-Samples T test to analyze the difference between recruitment methods. In case of non-normal distribution, median data was presented with the interquartile range [IQR]. All statistical tests are 2-tailed. A P-value <0.05 was considered statistically significant. Statistical analysis was performed using SPSS statistical analysis (version 24.0).   RESULTS Results Facebook ads were active during a 115-day recruitment period between August and November 2017. A total of 285 potential candidates were recruited by different recruitment strategies in this specific time period, of which 184 (65%) were consented through Facebook (Table 1). The average age of the subjects consented through Facebook was 59 ± 8 years and 51% were male (Table 2). Facebook reached 5.3 million people in 168 separate campaigns run in proximity to 19 sites in the US and 14 sites in Europe. The number of candidates per site was variable with a median of 23 [17 – 26] candidates per site that passed the questionnaire (Figure 1). A total of 27/184 subjects were eventually randomised. Total cost for the Facebook ads was $152,412; costing $907/campaign and $0.83/click. This resulted in a total cost of $828/consent. During the same recruitment period, 7-day radio spots were launched with a total cost of $2,870; resulting in 9 inquiries with eventually 5 potential candidates and 2 consents ($1,435/consent).   CONCLUSIONS Conclusion Targeted social media was a successful and efficient strategy to find potential candidates for a multicenter blood pressure clinical trial. Whether this approach can be replicated across other disease states or demographics remains to be studied.


2021 ◽  
Vol 10 (3) ◽  
pp. 448
Author(s):  
Federica Piani ◽  
Arrigo F. G. Cicero ◽  
Claudio Borghi

The relationship between serum uric acid (SUA) and hypertension has been a subject of increasing interest since the 1870 discovery by Frederick Akbar Mahomed. Several epidemiological studies have shown a strong association between high SUA levels and the presence or the development of hypertension. Genetic analyses have found that xanthine oxidoreductase (XOR) genetic polymorphisms are associated with hypertension. However, genetic studies on urate transporters and Mendelian randomization studies failed to demonstrate a causal relationship between SUA and hypertension. Results from clinical trials on the role of urate-lowering therapy in the management of patients with hypertension are not uniform. Our study sought to analyze the prognostic and therapeutic role of SUA in the hypertensive disease, from uric acid (UA) biology to clinical trials on urate-lowering therapies.


2021 ◽  
pp. 0271678X2110043
Author(s):  
Thompson G Robinson ◽  
Jatinder S Minhas ◽  
Joseph Miller

Over the last two decades, there have been a number of major landmark clinical trials, classified as “major” as they sought to address clear clinical practice driven questions, in a pragmatic yet robust trial design, using a large powered sample size (n > 1000), in order to help improve patient outcome through informing guidelines. A commonality across all stroke sub-types included in these trials is the tendency to acute hypertensive crises within the acute stroke period. This phenomenon is associated with greater stroke complications and worsened overall prognosis. Multiple trials have attempted to address the issue of acute blood pressure management during the acute stroke period, with consideration for timing, magnitude of lowering, agent and relationship to other interventions. This review will consider the major clinical trials performed in ischaemic and haemorrhagic stroke that test the hypothesis that acute BP reduction improves clinical outcomes.


1986 ◽  
Vol 64 (6) ◽  
pp. 818-824 ◽  
Author(s):  
Efrain Reisin

A number of studies have established a close association between increased body mass and elevated blood pressure. The presence of obesity in hypertensive subjects is associated with some hemodynamic, metabolic, and endocrinic characteristics: an increased intravascular volume with a high intracellular body water/interstitial fluid volume ratio, increased cardiac output, stroke volume, and left ventricular work while peripheral resistance was reduced or normal. Weight loss of at least 10 kg can reduce blood pressure independently of changes in sodium intake in obese persons of both sexes with mild, moderate, or severe high blood pressure. The fall in arterial pressure in obese hypertensives after weight loss may reverse many of the previously mentioned altered findings and underscore previous epidemiological studies that have shown that weight control could be an important measure in the treatment of hypertension.


2011 ◽  
Vol 37 (5) ◽  
pp. 1030-1041 ◽  
Author(s):  
Katarina Paunović ◽  
Stephen Stansfeld ◽  
Charlotte Clark ◽  
Goran Belojević

Author(s):  
Mahdieh Hosseinzadeh ◽  
Fatemeh Pakravanfar ◽  
Elham Hosseinzadeh ◽  
Maryam Khosravi

Background: Hypertension is a major risk factor for the development of coronary, cerebrovascular, and peripheral vascular diseases, which lead to myocardial infarction, stroke, and vascular death. Green coffee extract is particularly producer a great deal of chlorogenic acids (CGA) that may reduce the risk of high blood pressure. Therefore, the target of the study was to summarize the available publications on the effect of green coffee consumption on high blood pressure. Methods: The systematic review was done with a search in PubMed-Medline and Scopus. The search strategy included keywords related to blood pressure and green coffee. Inclusion criteria were randomized controlled clinical trials conducted on people aged between 18 and 70 years. The publication date of articles  was from 2004 to 2018. Exclusion criteria were articles not published in English. Results: We discussed five articles that included  our criteria. Green coffee had moderate effects on high blood pressure.  It sounds that the effect of green coffee on reducing blood pressure is because of its phenolic compounds, as well as caffeine and chlorogenic acids, coffee’s roasting status, participants’ ethnicity, and even gender. Conclusion: Green coffee intake for a long time might moderately decrease blood pressure. However, there is still a need for further clinical trials.


Author(s):  
Zeinab Yazdanpanah ◽  
Mandana Amiri ◽  
Azadeh Nadjarzadeh ◽  
Hadis Hooshmandi ◽  
Maryam Azadi-Yazdi

Introduction: Hypertension is a chronic condition that might lead to renal and cardiovascular diseases. The previous trials examining the effect of cinnamon supplementation on blood pressure have led to conflicting results. The present systematic review aimed to summarize the effect of cinnamon supplementation on blood pressure using a meta-analysis of published randomized controlled clinical trials. Methods: To identify the eligible articles, MEDLINE, SCOPUS, ISI Web of Science, and Google Scholar were searched from inception until September 2019 for relevant articles. The risk of bias assessment was performed using the Cochrane collaboration tool. A Random-effects model was applied to calculate the summary effects. Results: Totally, 11 trials with 686 participants were included in this systematic review and meta-analysis. The dose of cinnamon supplement consumption varied from 500 to 10000 mg/d. The meta-analysis revealed that cinnamon supplementation significantly decreases systolic blood pressure (SBP) [WMD (weighted mean difference)= -5.72 mmHg, 95% confidence interval (CI): -8.63 to -2.80; P<0.001, I2= 81.1)] and diastolic blood pressure (DBP) (WMD= -4.06 mmHg, 95% CI: -6.68 to -1.44; P= 0.002, I2 = 88.6). Subgroup analysis suggested no significant reduction of DBP in subjects with diabetes (WMD= -2.015 mmHg, 95% CI: -4.55 to 0.52; P= 0.12, I2 = 72.3) and prediabetes or metabolic syndrome (WMD= -4.8 mmHg, 95% CI: -10.06 to 0.44; P= 0.073, I2= 92.5). Conclusions: Cinnamon supplementation could be beneficial in lowering SBP and DBP in adults. Further studies with different doses are recommended to confirm the present findings.


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