Prevalence of treatment-resistant hypertension and important associated factors—results from the Swedish Primary Care Cardiovascular Database

Characterizing apparent treatment resistant hypertension in the United States: insights from the All of Us Research Program

BACKGROUND

Hypertension (HTN) remains a significant public health concern and the primary modifiable risk factor for cardiovascular disease, which is the leading cause of death in the United States. We applied our validated HTN computable phenotypes within the All of Us Research Program to uncover prevalence and characteristics of HTN and apparent treatment-resistant hypertension (aTRH) in United States.

METHODS

Within the All of Us Researcher Workbench, we built a retrospective cohort (January 1, 2008-July 1, 2023), identifying all adults with available age data, at least one blood pressure (BP) measurement, prescribed at least one antihypertensive medication, and with at least one SNOMED "Essential hypertension" diagnosis code.

RESULTS

We identified 99 461 participants with HTN who met the eligibility criteria. Following the application of our computable phenotypes, an overall population of 81 462 were further categorized to aTRH (14.4%), stable-controlled HTN (SCH) (39.5%), and Other HTN (46.1%). Compared to participants with SCH, participants with aTRH were older, more likely to be of Black or African American race, had higher levels of social deprivation, and a heightened prevalence of comorbidities such as hyperlipidemia and diabetes. Heart failure, chronic kidney disease, and diabetes were the comorbidities most strongly associated with aTRH. β-blockers were the most prescribed antihypertensive medication. At index date, the overall BP control rate was 62%.

DISCUSSION AND CONCLUSION

All of Us provides a unique opportunity to characterize HTN in the United States. Consistent findings from this study with our prior research highlight the interoperability of our computable phenotypes.

Effects of baroreflex activation therapy on cardiac function and morphology

AIMS

Arterial hypertension (aHTN) plays a fundamental role in the pathogenesis and prognosis of heart failure with preserved ejection fraction (HFpEF). The risk of heart failure increases with therapy-resistant arterial hypertension (trHTN), defined as inadequate blood pressure (BP) control ≥140/90 mmHg despite taking ≥3 antihypertensive medications including a diuretic. This study investigates the effects of the BP lowering baroreflex activation therapy (BAT) on cardiac function and morphology in patients with trHTN with and without HFpEF.

METHODS

Sixty-four consecutive patients who had been diagnosed with trHTN and received BAT implantation between 2012 and 2016 were prospectively observed. Office BP, electrocardiographic and echocardiographic data were collected before and after BAT implantation.

RESULTS

Mean patients' age was 59.1 years, 46.9% were male, and mean body mass index (BMI) was 33.2 kg/m2. The prevalence of diabetes mellitus was 38.8%, atrial fibrillation was 12.2%, and chronic kidney disease (CKD) stage ≥3 was 40.8%. Twenty-eight patients had trHTN with HFpEF, and 21 patients had trHTN without HFpEF. Patients with HFpEF were significantly older (64.7 vs. 51.6 years, P < 0.0001), had a lower BMI (30.0 vs. 37.2 kg/m2, P < 0.0001), and suffered more often from CKD-stage ≥3 (64 vs. 20%, P = 0.0032). After BAT implantation, mean office BP dropped in patients with and without HFpEF (from 169 ± 5/86 ± 4 to 143 ± 4/77 ± 3 mmHg [P = 0.0019 for systolic BP and 0.0403 for diastolic BP] and from 170 ± 5/95 ± 4 to 149 ± 6/88 ± 5 mmHg [P = 0.0019 for systolic BP and 0.0763 for diastolic BP]), while a significant reduction of the intake of calcium-antagonists, α2-agonists and direct vasodilators, as well as a decrease in average dosage of ACE-inhibitors and α2-agonists could be seen. Within the study population, a decrease in heart rate from 74 ± 2 to 67 ± 2 min-1 (P = 0.0062) and lengthening of QRS-time from 96 ± 3 to 106 ± 4 ms (P = 0.0027) and QTc-duration from 422 ± 5 to 432 ± 5 ms (P = 0.0184) were detectable. The PQ duration was virtually unchanged. In patients without HF, no significant changes of echocardiographic parameters could be seen. In patients with HFpEF, posterior wall diameter decreased significantly from 14.0 ± 0.5 to 12.7 ± 0.3 mm (P = 0.0125), left ventricular mass (LVM) declined from 278.1 ± 15.8 to 243.9 ± 13.4 g (P = 0.0203), and e' lateral increased from 8.2 ± 0.4 to 9.0 ± 0.4 cm/s (P = 0.0471).

CONCLUSIONS

BAT reduced systolic and diastolic BP and was associated with morphological and functional improvement of HFpEF.

Prevalence and associated risk factors of resistant hypertension among Chinese hypertensive patients in primary care setting

INTRODUCTION

Hypertension (HT) is a major public health problem globally, and it is the commonest chronic disease with a prevalence of 27% among people aged 15 years or above in Hong Kong. There is emerging literature confirmed that patients with resistant hypertension (RHT) give its increased risk for adverse clinical outcomes and higher rate of documented target organ damage. This study aims to identify the prevalence of RHT among Chinese hypertensive patients managed in public primary care setting of Hong Kong and exploring its associated risk factors.

METHODOLOGY

This is a cross-sectional descriptive study. Chinese hypertensive patients aged 30 or above with regular follow-up between 1st July 2019 and 30th June 2020 in 10 public primary care clinics under the Hospital Authority of Hong Kong were included. Demographic data, clinical parameters and drug profile of patients were retrieved from its computerized record system. The prevalence of RHT was identified and the associated risk factors of RHT were explored by multivariate logistic regression analysis.

RESULTS

Among the 538 sampled Chinese hypertensive patients, the mean age was 67.4 ± 11.5 years old, and 51.9% were female. The mean duration of hypertension was 10.1 ± 6.4 years, with a mean systolic and diastolic blood pressure of 128.8 ± 12.3 and 72.9 ± 10.8 mmHg respectively. 40 out of 538 patients were found to have RHT, giving an overall prevalence of 7.43%. Four factors were found to be associated with increased risk of RHT, in ascending order of odds ratio: duration of hypertension (OR 1.08), male gender (OR 2.72), comorbid with type 2 diabetes mellitus (T2DM, OR 2.99), and congestive heart failure (CHF, OR 5.39).

CONCLUSION

The prevalence of RHT among Chinese hypertensive patients in primary care setting of Hong Kong is 7.43%. RHT is more common in male patients, patients with longer duration of hypertension, concomitant T2DM and CHF. Clinicians should be vigilant when managing these groups of patients and provide aggressive treatment and close monitoring.

Characteristics and Predictors of Apparent Treatment-Resistant Hypertension in Real-World Populations Using Electronic Health Record-Based Data

BACKGROUND

Apparent treatment-resistant hypertension (aTRH) is defined as uncontrolled blood pressure (BP) despite using ≥3 antihypertensive classes or controlled BP while using ≥4 antihypertensive classes. Patients with aTRH have a higher risk for adverse cardiovascular outcomes compared with patients with controlled hypertension (HTN). Although there have been prior reports on the prevalence, characteristics, and predictors of aTRH, these have been broadly derived from smaller datasets, randomized controlled trials, or closed healthcare systems.

METHODS

We extracted patients with HTN defined by ICD-9 and ICD-10 codes during 1/1/2015-12/31/2018, from 2 large electronic health record databases: the OneFlorida Data Trust (n = 223,384) and Research Action for Health Network (REACHnet) (n = 175,229). We applied our previously validated aTRH and stable controlled HTN computable phenotype algorithms and performed univariate and multivariate analyses to identify the prevalence, characteristics, and predictors of aTRH in these populations.

RESULTS

The prevalence of aTRH among patients with HTN in OneFlorida (16.7%) and REACHnet (11.3%) was similar to prior reports. Both populations had a significantly higher proportion of Black patients with aTRH compared with those with stable controlled HTN. aTRH in both populations shared similar significant predictors, including Black race, diabetes, heart failure, chronic kidney disease, cardiomegaly, and higher body mass index. In both populations, aTRH was significantly associated with similar comorbidities, when compared with stable controlled HTN.

CONCLUSIONS

In 2 large, diverse real-world populations, we observed similar comorbidities and predictors of aTRH as prior studies. In the future, these results may be used to improve healthcare professionals' understanding of aTRH predictors and associated comorbidities.

Hypertension management in primary health care: a survey in eight regions of Sweden

PURPOSE

To explore hypertension management in primary healthcare (PHC).

DESIGN

Structured interviews of randomly selected PHC centres (PHCCs) from December 2019 to January 2021.

SETTING

Seventy-six PHCCs in eight regions of Sweden.

MAIN OUTCOME MEASURES

Staffing and organization of hypertension care. Methods of measuring blood pressure (BP), laboratory tests, registration of co-morbidities and lifestyle advice at diagnosis and follow-up.

RESULTS

The management of hypertension varied among PHCCs. At diagnosis, most PHCCs (75%) used the sitting position at measurements, and only 13% routinely measured standing BP. One in three (33%) PHCCs never used home BP measurements and 25% only used manual measurements. The frequencies of laboratory analyses at diagnosis were similar in the PHCCs. At follow-up, fewer analyses were performed and the tests of lipids and microalbuminuria decreased from 95% to 45% (p < 0.001) and 61% to 43% (p = 0.001), respectively. Only one out of 76 PHCCs did not measure kidney function at routine follow-ups. Lifestyle, physical activity, food habits, smoking and alcohol use were assessed in ≥96% of patients at diagnosis. At follow-up, however, there were fewer assessments. Half of the PHCCs reported dedicated teams for hypertension, 82% of which were managed by nurses. There was a great inequality in the number of patients per tenured GP in the PHCCs (median 2500; range 1300-11300) patients.

CONCLUSIONS

The management of hypertension varies in many respects between PHCCs in Sweden. This might lead to inequity in the care of patients with hypertension.

Characteristics and Predictors of Apparent Treatment Resistant Hypertension in Real-World Populations Using Electronic Health Record-Based Data

Background

Apparent treatment-resistant hypertension (aTRH) is defined as uncontrolled blood pressure (BP) despite using ≥3 antihypertensive classes or controlled BP while using ≥4 antihypertensive classes. Patients with aTRH have a higher risk for adverse cardiovascular outcomes compared to patients with controlled hypertension. Although there have been prior reports on the prevalence, characteristics, and predictors of aTRH, these have been broadly derived from smaller datasets, randomized controlled trials, or closed healthcare systems.

Methods

We extracted patients with hypertension defined by ICD 9 and 10 codes during 1/1/2015-12/31/2018, from two large electronic health record databases: the OneFlorida Data Trust (n=223,384) and Research Action for Health Network (REACHnet) (n=175,229). We applied our previously validated aTRH and stable controlled hypertension (HTN) computable phenotype algorithms and performed univariate and multivariate analyses to identify the prevalence, characteristics, and predictors of aTRH in these real-world populations.

Results

The prevalence of aTRH in OneFlorida (16.7%) and REACHnet (11.3%) was similar to prior reports. Both populations had a significantly higher proportion of black patients with aTRH compared to those with stable controlled HTN. aTRH in both populations shared similar significant predictors, including black race, diabetes, heart failure, chronic kidney disease, cardiomegaly, and higher body mass index. In both populations, aTRH was significantly associated with similar comorbidities, when compared with stable controlled HTN.

Conclusion

In two large, diverse real-world populations, we observed similar comorbidities and predictors of aTRH as prior studies. In the future, these results may be used to improve healthcare professionals' understanding of aTRH predictors and associated comorbidities.

Clinical Perspective

What Is New?: Prior studies of apparent treatment resistant hypertension have focused on cohorts from smaller datasets, randomized controlled trials, or closed healthcare systems.We used validated computable phenotype algorithms for apparent treatment resistant hypertension and stable controlled hypertension to identify the prevalence, characteristics, and predictors of apparent treatment resistant hypertension in two large, diverse real-world populations.What Are the Clinical Implications?: Large, diverse real-world populations showed a similar prevalence of aTRH, 16.7% in OneFlorida and 11.3% in REACHnet, compared to those observed from other cohorts.Patients classified as apparent treatment resistant hypertension were significantly older and had a higher prevalence of comorbid conditions such as diabetes, dyslipidemia, coronary artery disease, heart failure with preserved ejection fraction, and chronic kidney disease stages 1-3.Within diverse, real-world populations, the strongest predictors for apparent treatment resistant hypertension were black race, higher body mass index, heart failure, chronic kidney disease, and diabetes.

The Burden of Resistant Hypertension Across the World

PURPOSE OF REVIEW

Resistant hypertension (R-HTN) is related to worse cardiovascular, renal outcomes, and death compared to non R-HTN. We aimed to review the burden of R-HTN across the world, focusing on its prevalence, associated factors and outcomes, and the impact of treatment.

RECENT FINDINGS

R-HTN prevalence among hypertensive individuals varies around 10-20%, depending on the population and definition applied. R-HTN consistently relates to older age, chronic kidney disease, obesity, and obstructive sleep apnea - which are increasing in prevalence with global population aging. As such, R-HTN prevalence is also expected to rise. Infrequent use of ambulatory blood pressure monitoring to identify at higher risk individuals and poor adherence to treatment are still barriers in the approach of R-HTN. Available evidence suggests that 10-20% of patients with hypertension have R-HTN. However, the prevalence of true R-HTN using contemporaneous standardized definitions is still unknown. Novel strategies to address clinicians, patients and health system barriers to treatment inertia and adherence are fundamental to reduce the burden of R-HTN.

Resistance to antihypertensive treatment and long-term risk: The Atherosclerosis Risk in Communities study

More stringent blood pressure (BP) goals have led to greater prevalence of apparent resistant hypertension (ARH), yet the long‐term prognostic impact of ARH diagnosed according to these goals in the general population remains unknown. We assessed the prognostic impact of ARH according to contemporary BP goals in 9612 participants of the Atherosclerosis Risk in Communities (ARIC) study without previous cardiovascular disease. ARH, defined as BP above goal (traditional goal <140/90 mmHg, more stringent goal <130/80 mmHg) despite the use of ≥3 antihypertensive drug classes or any BP with ≥4 antihypertensive drug classes (one of which was required to be a diuretic) was compared with controlled hypertension (BP at goal with 1‐3 antihypertensive drug classes). Cox regression models were adjusted for age, sex, race, study center, BMI, heart rate, smoking, eGFR, LDL, HDL, triglycerides, and diabetes. Using the traditional BP goal, 133 participants (3.8% of the treated) had ARH. If the more stringent BP goal was instead applied, 785 participants (22.6% of the treated) were reclassified from controlled hypertension to uncontrolled hypertension (n = 725) or to ARH (n = 60). Over a median follow‐up time of 19 years, ARH was associated with increased risk for a composite end point (all‐cause mortality, hospitalization for myocardial infarction, stroke, or heart failure) regardless of whether traditional (adjusted HR 1.50, 95% CI: 1.23‐1.82) or more stringent (adjusted HR 1.43, 95% CI: 1.20‐1.70) blood pressure goals were applied. We conclude that in patients free from cardiovascular disease, ARH predicted long‐term risk regardless of whether traditional or more stringent BP criteria were applied.

Clinical Characteristics of Resistant vs. Refractory Hypertension in a Population of Hypertensive Afrodescendants

Background Afrodescendants have been associated with a greater severity of arterial hypertension and a higher incidence of cardiovascular complications. Characteristics in the presentation of resistant hypertension (RH) or refractory hypertension (RfH), specifically in this ethnic group, have not been properly studied. Objectives The study compares clinical and epidemiological characteristics and prevalence of cardiovascular events in people of African descent diagnosed with RH or RfH. Methods Cross-sectional study carried out in a referral clinic for patients with severe hypertension. The level of significance was 5%. Results 146 consecutive patients were evaluated, of which 68.7% were female. The average age was 61.8 years, with 88.4% of Afrodescendants (mixed race or black). 51% had RfH. There was a high prevalence of cardiovascular risk factors: 34.2% of subjects had diabetes, 69.4% dyslipidemia, 36.1% obesity, and 38.3% history of smoking. Reduced renal function was seen in 34.2%. Previous cardiovascular events occurred in 21.8% for myocardial infarction and in 19.9% for stroke. The Framingham's risk score was moderate/high at 61%. RfH patients were younger (mean age 59.38±11.69 years versus 64.10±12.23 years, p=0.02), had more dyslipidemia (83.8 versus 66.7%, p=0.021), and stroke (30.4 versus 12.3%, p=0.011) when compared to those with RH. The use of a combination of ACEi/ARB+CCB+Diuretic, chlortalidone and spironolactone was also more frequent in individuals with RfH. Conclusion Africandescendant people with RH had a high cardiovascular risk, a high prevalence of RfH, a higher frequency of dyslipidemia and stroke, compatible with a high incidence of injury to target organs. (Arq Bras Cardiol.2020; 115(1):31-39).

Does Compassion Predict Blood Pressure and Hypertension? The Modifying Role of Familial Risk for Hypertension

Background

This study investigated (i) whether compassion is associated with blood pressure or hypertension in adulthood and (ii) whether familial risk for hypertension modifies these associations.

Method

The participants (N = 1112–1293) came from the prospective Young Finns Study. Parental hypertension was assessed in 1983–2007; participants’ blood pressure in 2001, 2007, and 2011; hypertension in 2007 and 2011 (participants were aged 30–49 years in 2007–2011); and compassion in 2001.

Results

High compassion predicted lower levels of diastolic and systolic blood pressure in adulthood. Additionally, high compassion was related to lower risk for hypertension in adulthood among individuals with no familial risk for hypertension (independently of age, sex, participants’ and their parents’ socioeconomic factors, and participants’ health behaviors). Compassion was not related to hypertension in adulthood among individuals with familial risk for hypertension.

Conclusion

High compassion predicts lower diastolic and systolic blood pressure in adulthood. Moreover, high compassion may protect against hypertension among individuals without familial risk for hypertension. As our sample consisted of comparatively young participants, our findings provide novel implications for especially early-onset hypertension.

Electronic supplementary material

The online version of this article (10.1007/s12529-020-09886-5) contains supplementary material, which is available to authorized users.

Increased Incidence of Resistant Hypertension in Patients With Systemic Lupus Erythematosus: A Retrospective Cohort Study

OBJECTIVE

To compare the risk of resistant hypertension (RHTN) in patients with systemic lupus erythematosus (SLE) and in controls without SLE, and to define factors associated with RHTN in patients with SLE.

METHODS

We studied 1,044 patients with SLE and 5,241 control subjects using de-identified electronic health records from a tertiary care center. SLE was defined as ≥4 International Classification of Diseases, Ninth Revision codes for SLE and antinuclear antibody titer ≥1:160. RHTN was defined as uncontrolled blood pressure on 3 antihypertensive medications or requiring 4 or more antihypertensives to attain control. First, we compared the risk of RHTN between groups. Second, we examined the association between RHTN and all-cause mortality in patients with SLE.

RESULTS

RHTN was nearly twice as prevalent in patients with SLE compared to control subjects (10.2% and 5.3%, respectively), with an incidence rate of 10.2 versus 6.1 cases per 1,000 person-years of observation (hazard ratio [HR] 1.72 [95% confidence interval 1.28-2.30]; P < 0.001, adjusted for age, sex, race, baseline end-stage renal disease [ESRD], creatinine, and calendar year). In patients with SLE, we found associations between RHTN and black race, lower renal function, hypercholesterolemia, and increased inflammatory markers. RHTN was associated with a significantly higher mortality risk (HR 2.91, P = 0.0005) after adjustment for age, sex, race, calendar year, creatinine, baseline ESRD, and number of visits.

CONCLUSION

Patients with SLE have a higher risk of RHTN compared to frequency-matched controls, independent of multiple covariates. RHTN is an important comorbidity for clinicians to recognize in SLE, because it is associated with a higher risk of mortality.

Apparent therapy-resistant hypertension as risk factor for the development of type 2 diabetes mellitus

OBJECTIVE

To evaluate whether the relationship between hypertension and type 2 diabetes mellitus (T2DM) is different for patients with uncontrolled hypertension, controlled hypertension or patients with apparent therapy-resistant hypertension (aTRH), compared with patients without hypertension.

METHODS

Using Cox proportional hazard models we evaluated the risk of new-onset T2DM in 8756 patients, at high risk for vascular disease. Hypertensive patients were subdivided according to blood pressure (BP) and use of BP-lowering drugs. BP ≥ 140/90 mmHg was defined as uncontrolled BP. aTRH was defined as uncontrolled BP despite being treated with at least three BP-lowering drugs including a diuretic, or the use at least four BP-lowering drugs irrespective of BP levels. Further analysis evaluated the risk of new-onset T2DM for patients with uncontrolled hypertension and for patients with aTRH, compared with patients with controlled hypertension and without hypertension, respectively.

RESULTS

Forty-five percent had controlled hypertension, 20% had uncontrolled hypertension, 5.7% had aTRH, and 29% were nonhypertensive. During a follow-up of 7.0 (interquartile range: 0-14) years there were 705 new cases of T2DM. Patients with hypertension had a 1.48 (95% confidence interval 1.22-1.80) times higher risk of new-onset T2DM than nonhypertensive patients. There was no significant difference in risk among different hypertension groups.

CONCLUSION

Patients at high risk for cardiovascular disease with hypertension have a 1.48 times higher risk of new-onset T2DM than nonhypertensive counterparts. The risk did not differ between patients with controlled hypertension, uncontrolled hypertension, or aTRH.

The prevalence and predictors of resistant hypertension in high-risk overweight and obese patients: A cross-sectional study based on the 2017 ACC/AHA guidelines

Obesity is significantly associated with uncontrolled blood pressure and resistant hypertension (RH). There are limited studies on the prevalence and determinants of RH in patients with higher body mass index (BMI) values. Since the hypertension guidelines changed in 2017, the prevalence of RH has become unknown and now is subject to be estimated by further studies. We conducted a cross-sectional study in an urban Federally Qualified Health Center in New York City aiming to estimate the prevalence of RH in high-risk overweight and obese patients based on the new hypertension definition, BP threshold ≥130/80 mm Hg, and also to describe the associated comorbid conditions in these patients. We identified 761 eligible high-risk overweight and obese subjects with hypertension between October 2017 and October 2018. Apparent treatment-RH was found in 13.6% among the entire study population. This represented 15.4% of those treated with BP-lowering agents. True RH confirmed with out-of-office elevated BP was found in 6.7% of the study population and 7.4% among patients treated with BP-lowering agents. Prevalence was higher with higher BMI values. Those with true RH were more likely to be black, to have diabetes mellitus requiring insulin, chronic kidney disease stage 3 or above and diastolic heart failure. In conclusion, obesity is significantly associated with RH and other significant metabolic comorbid conditions.

Prevalence of treatment-resistant hypertension after considering pseudo-resistance and morbidity: a cross-sectional study in Irish primary care

BACKGROUND

To confirm treatment-resistant hypertension (TRH), ambulatory blood pressure measurement (ABPM) must exclude white-coat hypertension (WCH), three or more medications should be prescribed at the optimal doses tolerated, and non-adherence and lifestyle should be examined. Most previous studies have not adequately considered pseudo-resistance and merely provide an apparent TRH (aTRH) prevalence figure.

AIM

To conduct a cross-sectional study of the prevalence of aTRH in general practice, and then consider pseudo-resistance and morbidity.

DESIGN AND SETTING

With support, 16 practices ran an anatomical therapeutic chemical (ATC) drug search, identifying patients on any possible hypertensive medications, and then a search of individual patients' electronic records took place.

METHOD

ABPM was used to rule out WCH. The World Health Organization-defined daily dosing guidelines determined adequate dosing. Adherence was defined as whether patients requested nine or more repeat monthly prescriptions within the past year.

RESULTS

Sixteen practices participated (n = 50 172), and 646 patients had aTRH. Dosing was adequate in 19% of patients, 84% were adherent to medications, as defined by prescription refill, and 43% had ever had an ABPM. Using a BP cut-off of 140/90 mmHg, the prevalence of aTRH was 9% (95% confidence interval [CI] = 9.0 to 10.0). Consideration of pseudo-resistance further reduced prevalence rates to 3% (95% CI = 3.0 to 4.0).

CONCLUSION

Reviewing individual patient records results in a lower estimate of prevalence of TRH than has been previously reported. Further consideration for individual patients of pseudo-resistance additionally lowers these estimates, and may be all that is required for management in the vast majority of cases.

Trends for prevalence and incidence of resistant hypertension: population based cohort study in the UK 1995-2015

Objective To estimate the incidence and prevalence of resistant hypertension among a UK population treated for hypertension from 1995 to 2015.Design Cohort study.Setting Electronic health records from the UK Clinical Practice Research Datalink in primary care.Participants 1 317 290 users of antihypertensive drugs with a diagnosis of hypertension.Main outcome measures Resistant hypertension was defined as concurrent use of three antihypertensive drugs inclusive of a diuretic, uncontrolled hypertension (≥140/90 mm Hg), and adherence to the prescribed drug regimen, or concurrent use of four antihypertensive drugs inclusive of a diuretic and adherence to the prescribed drug regimen. To determine incidence, the numerator was new cases of resistant hypertension and the denominator was person years of those with treated hypertension and at risk of developing resistant hypertension. To determine prevalence, the numerator was total number of cases with resistant hypertension and the denominator was those with treated hypertension. Prevalence and incidence were age standardised to the 2015 hypertensive population.Results The age standardised incidence of resistant hypertension increased from 0.93 cases per 100 person years (95% confidence interval 0.87 to 1.00) in 1996 to a peak level of 2.07 cases per 100 person years (2.03 to 2.12) in 2004. Incidence then decreased to 0.42 cases per 100 person years (0.40 to 0.44) in 2015. Age standardised prevalence increased from 1.75% (95% confidence interval 1.66% to 1.83%) in 1995 to a peak of 7.76% (7.70% to 7.83%) in 2007. Prevalence then plateaued and subsequently declined to 6.46% (6.38% to 6.54%) in 2015. Compared with patients aged 65-69 years, those aged 80 or more years were more likely to have prevalent resistant hypertension throughout the study period.Conclusions Prevalent resistant hypertension has plateaued and decreased in recent years, consistent with a decrease in incidence from 2004 onwards. Despite this, resistant hypertension is common in the UK hypertensive population. Given the importance of hypertension as a modifiable risk factor for cardiovascular disease, reducing uncontrolled hypertension should remain a population health focus.

The effects of baroreflex activation therapy on blood pressure and sympathetic function in patients with refractory hypertension: the rationale and design of the Nordic BAT study

OBJECTIVE

To explore the effects of baroreflex activation therapy (BAT) on hypertension in patients with treatment resistant or refractory hypertension.

METHODS

This investigator-initiated randomized, double-blind, 1:1 parallel-design clinical trial will include 100 patients with refractory hypertension from 6 tertiary referral hypertension centers in the Nordic countries. A Barostim Neo System will be implanted and after 1 month patients will be randomized to either BAT for 16 months or continuous pharmacotherapy (BAT off) for 8 months followed by BAT for 8 months. A second randomization will take place after 16 months to BAT or BAT off for 3 months. Eligible patients have a daytime systolic ambulatory blood pressure (ABPM) of  ≥145 mm Hg, and/or a daytime diastolic ABPM of  ≥95 mm Hg after witnessed drug intake (including  ≥3 antihypertensive drugs, preferably including a diuretic).

RESULTS

The primary end point is the reduction in 24-hour systolic ABPM by BAT at 8 months, as compared to pharmacotherapy. Secondary and tertiary endpoints are effects of BAT on home and office blood pressures, measures of indices of cardiac and vascular structure and function during follow-up, and safety.

CONCLUSIONS

This academic initiative will increase the understanding of mechanisms and role of BAT in the refractory hypertension.

Guest Editorial Challenges in Resistant Hypertension

Hypertension is the major risk factor for disease and premature death. Although the efficacy of antihypertensive therapy is undisputed, few patients reach target blood pressure. Steps to improve treatment and control include assessment of global cardiovascular risk for the individual patient, improving caregiver support, education and organisation, increasing treatment persistence, using out of office blood pressure monitoring more often, detecting secondary hypertension forms, and referring patients with remaining uncontrolled hypertension to a specialist hypertension centre. In conclusion, there is room for improvement of blood pressure control in hypertensive patients. The clinical benefit of improved blood pressure control may be considerable. This may be particularly true for patients with resistant hypertension.