High rates of non-adherence to antihypertensive treatment revealed by high-performance liquid chromatography-tandem mass spectrometry (HP LC-MS/MS) urine analysis

Adherence to Antihypertensive Treatment and the Blood Pressure–Lowering Effects of Renal Denervation in the Renal Denervation for Hypertension (DENERHTN) Trial

Background:

The DENERHTN trial (Renal Denervation for Hypertension) confirmed the blood pressure–lowering efficacy of renal denervation added to a standardized stepped-care antihypertensive treatment for resistant hypertension at 6 months. We report the influence of adherence to antihypertensive treatment on blood pressure control.

Methods:

One hundred six patients with hypertension resistant to 4 weeks of treatment with indapamide 1.5 mg/d, ramipril 10 mg/d (or irbesartan 300 mg/d), and amlodipine 10 mg/d were randomly assigned to renal denervation plus standardized stepped-care antihypertensive treatment, or the same antihypertensive treatment alone. For standardized stepped-care antihypertensive treatment, spironolactone 25 mg/d, bisoprolol 10 mg/d, prazosin 5 mg/d, and rilmenidine 1 mg/d were sequentially added at monthly visits if home blood pressure was ≥135/85 mm Hg after randomization. We assessed adherence to antihypertensive treatment at 6 months by drug screening in urine/plasma samples from 85 patients.

Results:

The numbers of fully adherent (20/40 versus 21/45), partially nonadherent (13/40 versus 20/45), or completely nonadherent patients (7/40 versus 4/45) to antihypertensive treatment were not different in the renal denervation and the control groups, respectively ( P =0.3605). The difference in the change in daytime ambulatory systolic blood pressure from baseline to 6 months between the 2 groups was –6.7 mm Hg ( P =0.0461) in fully adherent and –7.8 mm Hg ( P =0.0996) in nonadherent (partially nonadherent plus completely nonadherent) patients. The between-patient variability of daytime ambulatory systolic blood pressure was greater for nonadherent than for fully adherent patients.

Conclusions:

In the DENERHTN trial, the prevalence of nonadherence to antihypertensive drugs at 6 months was high (≈50%) but not different in the renal denervation and control groups. Regardless of adherence to treatment, renal denervation plus standardized stepped-care antihypertensive treatment resulted in a greater decrease in blood pressure than standardized stepped-care antihypertensive treatment alone.

Clinical Trial Registration:

URL: http://www.clinicaltrials.gov . Unique identifier: NCT01570777.

Detecting non-adherence by urine analysis in patients with uncontrolled hypertension: rates, reasons and reactions

Poor adherence with pharmacotherapy is well recognised as one of the main barriers to achieving satisfactory blood pressure control, although accurately measuring patient adherence has historically been very challenging. Urine analysis by high-performance liquid chromatography-tandem mass spectrometry has recently become routinely available as a method of screening for non-adherence. In addition to measuring rates of adherence in hypertensive patients, this study aimed to investigate the reasons for non-adherence given by patients and how patients react when they are informed of their results. This was a retrospective observational study looking at results from the routine use of this assay in a specialist hypertension clinic in Birmingham, UK, in patients with uncontrolled hypertension and those under consideration for renal denervation. Out of the 131 patients analysed, only 67 (51%) were taking all their medications as prescribed. Forty-three patients (33%) were taking some of their medications, whilst 21 patients (16%) were completely non-adherent. The most common reasons cited for non-adherence were adverse effects of medication and forgetfulness. Adherence rates for thiazide/thiazide-like diuretics and spironolactone were lower than for other classes of antihypertensive drug. Despite the objective nature and high sensitivity of the test, 36% of non-adherent patients disputed the results. A minority of patients did not attend follow-up. Further research investigating the implications of a 'non-adherence' result on the patient-clinician relationship is required.

Clinical Diagnosis and Management of Resistant Hypertension

Resistant hypertension (RHT) is variably defined as insufficient blood pressure (BP) response to multiple drug treatment. Prevalence of RHT has been thoroughly studied in the recent years, ranging from about 5 to 30 % in various cohorts. Initial management of patients with apparent RHT requires identification of true treatment resistance by out-of-office BP measurements, assessment of adherence and screening for treatable causes of uncontrolled BP. Endorsement of lifestyle modifications and maximisation of the doses of a suitable regimen, preferably with the further addition of an aldosterone antagonist, are the mainstay of treatment. An invasive approach to RHT, mainly represented by renal nerve ablation, should be kept for persistently severe cases managed in a specialised hypertension centre.

Resistant Hypertension: A Real Entity Requiring Special Treatment?

Resistant hypertension (RH) was defined many years ago as a clinical situation in which blood pressure remains uncontrolled despite concomitant intake of at least three antihypertensive drugs (one of them preferably being a diuretic) at full doses. This operative definition was aimed at identifying a subset of hypertensive patients requiring a more extensive clinical workup in order to achieve an adequate blood pressure control. An oversimplification of this picture led to consider RH as a separate clinical entity requiring special, expensive treatments, such as renal denervation and baroreceptor activating therapy. In this review we will discuss the utility and the shortcomings of the definition of RH and the possible consequences for treatment.

Resistant Hypertension and the Pivotal Role for Mineralocorticoid Receptor Antagonists: A Clinical Update 2016

True resistant hypertension must be distinguished from apparent resistant hypertension, of which important causes include medication nonadherence, illicit drug use, and alcoholism. Ambulatory blood pressure monitoring should be considered to rule out white coat hypertension. The pathogenesis is multifactorial, but the 2 pivotal factors include volume excess and the myriad effects of aldosterone. Aldosterone increases vascular tone because of endothelial dysfunction and enhances the pressor response to catecholamines. It also plays a crucial role in vascular remodeling of small and large arteries. Aldosterone also promotes collagen synthesis, which leads to increased arterial stiffness and elevation of blood pressure. Because aldosterone has been demonstrated to modulate baroreflex resetting, in cases of severe hypertension, there would be fewer compensatory mechanisms available to offset the blood pressure elevation.

Serum drug levels to diagnose non-adherence in acute decompensated heart failure

BACKGROUND

The aim of this study was to analyze medication non-adherence by measuring serum drug levels (SDL) in patients presenting with acute decompensated heart failure (ADHF).

METHODS

Included in the study were chronic heart failure patients presenting with signs of acute decompensation. Blood sampling for the measurement of SDL was performed shortly after presentation. SDL were measured using liquid chromatography coupled with mass spectrometry. The estimation of SDL was calculated from the recommended chronic cardiac medications with the exception of drugs administered as part of the acute treatment prior to blood sampling. The patients were labeled as non-adherent when any one of the evaluated medications was not found in the serum.

RESULTS

Fifty patients with ADHF were prospectively enrolled. All of the evaluated drugs were detected in the sera of 28 (56%) patients. Non-adherence was diagnosed in the remaining 22 (44%) patients. None of the evaluated medications was detected in the sera of 5 (10%) patients.

CONCLUSION

The estimation of SDL indicates that non-adherence to the recommended chronic therapy is a common problem among patients presenting with ADHF. This method should be an essential aspect of routine clinical evaluation in these patients.

Renal denervation in the era of HTN-3. Comprehensive review and glimpse into the future

The pathophysiological role of sympathetic overactivity in conditions such as hypertension has been well documented. Catheter-based renal denervation (RDN) is a minimally invasive percutaneous procedure which aims to disrupt sympathetic nerve afferent and efferent activity through the application of radiofrequency energy directly within the renal artery wall. This technique has emerged as a very promising treatment with dramatic effects on refractory hypertension but also in other conditions in which a sympathetic influence is present. Several studies have evaluated the safety and efficacy of this procedure, presently surrounded by controversy since the recent outcome of Symplicity HTN-3, the first randomized, sham-control trial, which failed to confirm RDN previous reported benefits on BP and cardiovascular risk lowering. Consequently, although some centers halted their RDN programs, research continues and both the concept of denervation and treatment strategies are being redefined to identify patients who can drive the most benefit from this technology. In the United States, the Food and Drug Administration (FDA) has appropriately mandated that RDN remains an investigative procedure and a new generation of sham-controlled trials are ongoing and aimed to assess not only its efficacy against pharmacotherapy but also trials in drug free patients with the objective of demonstrating once and for all whether the procedure actually does lower BP in comparison to a placebo arm. In this article, we present an overview of the sympathetic nervous system and its role in hypertension, examine the current data on RDN, and share some insights and future expectations.

Renal denervation for resistant hypertension: no

In recent years, catheter-based radiofrequency denervation of the renal arteries (RDN) has emerged as a potential treatment for resistant hypertension. Though initial non-randomized and randomized small studies demonstrate large reductions in office blood pressure, RDN superiority to conventional treatment is not confirmed either by randomized controlled trials or by large international registries. Increasing evidence supports the hypothesis that a rational pharmacological therapeutic scheme is equally or more effective; this approach, together with an intervention aimed at increasing patient's compliance with treatment, might solve most of the cases of refractory hypertension. Thus, based on current evidence, renal denervation should not be routinely used to treat resistant hypertension. Though the possibility that RDN might be useful in other subsets of hypertensive patients exists, it has never been proven. Thus, its use should be limited to extreme situations, when all other possible treatments have failed.

Impact of number of prescribed medications on visit-to-visit variability of blood pressure: implications for design of future trials of renal denervation

BACKGROUND

Visit-to-visit blood pressure (BP) variability limits the ability to detect therapeutic effects in hypertension trials.

METHODS

To enable future renal denervation trials to detect smaller effect sizes and reliably identify technical improvements, we examined within-patient visit-to-visit BP variability, quantified as SD of change from baseline to final BP (SDΔ), in renal denervation (RDN) trials, trials of BP-lowering tablets, and the VOLTAGE study including 4151 patients.

RESULTS

The control arms of RDN trials had more visit-to-visit BP variability than tablet trials (SDΔ 23.6 versus 13.5 mmHg; P < 0.001). This might be explained by more prescribed antihypertensive patients in the RDN trials (5.19 ± 0.13 versus 0.11 ± 0.11; P < 0.001). In the VOLTAGE study, as the number of medications prescribed rose from 0 to 4, SDΔ rose: 11.9, 11.2, 12.9, 14.4 and 18.0 mmHg (P < 0.001 for trend). Neither baseline BP, nor demographics, nor diabetes independently affected variability. The sample size required for a trial rises proportionally to the square of the number of medications prescribed (rather than just linearly). The relationship between the number of background medications prescribed in a cohort and the excess test-retest variance closely fitted this quadratic formula (R = 0.98, P = 0.001).

CONCLUSION

Visit-to-visit variability in BP is dramatically larger in patients with more background medications prescribed. If this is due to variable adherence, then future RDN trials, needing to detect smaller effect sizes, would benefit from measures to guarantee adherence. Conceivable measures include enrolling patients on no background medication, preceding each BP measurement with a period off medication, or directly supervising medication intake.

The Association Between Antihypertensive Medication Nonadherence and Visit-to-Visit Variability of Blood Pressure: Findings From the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial

Low adherence to antihypertensive medication has been hypothesized to increase visit-to-visit variability (VVV) of blood pressure (BP). We assessed the association between antihypertensive medication adherence and VVV of BP in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). VVV of BP was calculated using SD independent of mean, SD, and average real variability across study visits conducted 6 to 28 months after randomization. Participants who reported taking <80% of their antihypertensive medication at ≥1 study visits were categorized as nonadherent. Participants were followed up for cardiovascular events and mortality after the assessment of adherence and VVV of BP. SD independent of mean of BP was higher for nonadherent (n=2912) versus adherent (n=16 878) participants; 11.4±4.9 versus 10.5±4.5 for systolic BP; 6.8±2.8 versus 6.2±2.6 for diastolic BP (each P<0.001). SD independent of mean of BP remained higher among nonadherent than among adherent participants after multivariable adjustment (0.8 [95% confidence interval, 0.7-1.0] higher for systolic BP and 0.4 [95% confidence interval, 0.3-0.5] higher for diastolic BP]. SD and average real variability of systolic BP and diastolic BP were also higher among nonadherent than among adherent participants. Adjustment for nonadherence did not explain the association of VVV of BP with higher fatal coronary heart disease or nonfatal myocardial infarction, stroke, heart failure, or mortality risk. In conclusion, improving medication adherence may lower VVV of BP. However, VVV of BP is associated with cardiovascular outcomes independent of medication adherence.

Resistant Hypertension: An Incurable Disease or Just a Challenge For Our Medical Skill?

Resistant hypertension is classically defined as a clinical condition in which target blood pressure values of 140/90 mmHg are not achieved despite an optimal pharmacological therapy of at least three antihypertensive drugs, including a diuretic. The aim of this review is to give an outline of the nosography of this disorder, highlighting the differences between true and apparent resistant hypertension. Since the proportions of patients who can be defined as resistant to antihypertensive treatment is elevated, this distinction is mandatory in order to identify only those who need special clinical attention and, possibly, newer non-traditional techniques. While at first glance resistant hypertension may appear as an insuperable problem, an accurate clinical work-up of these patients, aimed at excluding reversible causes and optimizing pharmacological treatment, represents an effective solution in most cases.

Adherence to antihypertensive therapy and therapeutic dosage of antihypertensive drugs

Adherence to antihypertensive therapy is critical to achieving adequate blood pressure control. About half of hypertensive patients do not take their drugs as directed and the physicians often underestimate this issue. Non-adherence has important public health economic implications (numbers of visits, diagnostic procedures, prescribed drugs) and, moreover, it results in increased morbidity and mortality rates. Poor adherence can have several patients and therapy related causes. Currently, multiple different direct and indirect methods to measure therapeutic adherence are available, but, in clinical practice, there is no cost-effective and simple one. Therapeutic drug monitoring (TDM), characterized by drug (or metabolites) concentration measurement in body fluids (blood or urine), is a cost-effective direct method to assess therapeutic adherence. Despite some limitations, TDM may decrease health costs, by reducing the number of visits and by identifying those patients who would undergo unnecessary invasive procedures. Moreover, TDM can be a new alternative method to identify patients with true resistant hypertension, improving the achievement of blood pressure control In this minor revision, we would assess poor therapeutic adherence in hypertensive population, analyzing the different direct and direct available methods, with emphasis on TDM.

Personalized medicine and treatment approaches in hypertension: current perspectives

In the US, hypertension affects one in three adults. Current guideline-based treatment of hypertension involves little diagnostic testing. A more personalized approach to the treatment of hypertension might be of use. Several methods of personalized treatment have been proposed and vetted to varying degrees. The purpose of this narrative review is to discuss the rationale for personalized therapy in hypertension, barriers to its development and implementation, some influential examples of proposed personalization measures, and a view of future efforts.

A practical approach for measurement of antihypertensive medication adherence in patients with resistant hypertension

Confirmation of medication adherence is a challenge in clinical practice and essential for the accurate diagnosis of resistant hypertension. Although it is well established that drug adherence is critical for controlling blood pressure, there are still difficulties applying a simple, inexpensive, and reliable assessment of adherence in the clinical setting. We aimed to test a simple method to assess adherence in resistant hypertensive (RH) patients. A pilot study with normotensives or mild/moderate hypertensive subjects was performed to provide a fluorescence cutoff point for adherence. After that, 21 patients referred to the Resistant Hypertension Clinic had triamterene prescribed and were monitored for a 30-day period. We conducted two unannounced randomly selected home visits for urine collection to test drug intake that day. Office, home and 24-hour ambulatory blood pressure, biochemical data, and the 8-item Morisky Medication Adherence Scale (MMAS-8) were systematically acquired. According to adherence indicated by urine fluorescence, subjects were divided into adherent and nonadherent groups. We found 57% of nonadherence. No differences were found between groups regarding baseline characteristics or prescribed medications; Kappa's test showed concordance between adherence through MMAS-8 items and fluorescence (kappa = 0.61; 95% confidence interval: 0.28-0.94; P = .005). Nonadherent patients had higher office (81 ± 11 vs. 73 ± 6 mm Hg, P = .03), 24-hour ambulatory blood pressure monitoring (75 ± 9 vs. 66 ± 7 mm Hg, P = .01), and home blood pressure measurement (77 ± 9 vs. 67 ± 8 mm Hg, P = .01) diastolic blood pressure than their counterparts. Nonadherence to antihypertensive therapy is high in patients with RH, even when assessed in clinics specialized in this condition. Fluorometry to detect a drug in the urine of RH patients is safe, easy, and reliable method to assess adherence.

Emerging applications of metabolomics in drug discovery and precision medicine

Metabolomics is an emerging 'omics' science involving the comprehensive characterization of metabolites and metabolism in biological systems. Recent advances in metabolomics technologies are leading to a growing number of mainstream biomedical applications. In particular, metabolomics is increasingly being used to diagnose disease, understand disease mechanisms, identify novel drug targets, customize drug treatments and monitor therapeutic outcomes. This Review discusses some of the latest technological advances in metabolomics, focusing on the application of metabolomics towards uncovering the underlying causes of complex diseases (such as atherosclerosis, cancer and diabetes), the growing role of metabolomics in drug discovery and its potential effect on precision medicine.

Adherence to Antihypertensive Medication in Treatment-Resistant Hypertension Undergoing Renal Denervation

BACKGROUND

Adherence to medication has been repeatedly proposed to represent a major cause of treatment-resistant hypertension (TRH); however, treatment decisions such as treating TRH with renal denervation depend on accurate judgment of adherence. We carefully analyzed adherence rates to medication before and after renal denervation and its effect on blood pressure (BP) control.

METHODS AND RESULTS

Eighty patients with TRH were included in 2 prospective observational studies that assessed the difference of potential antihypertensive and nephroprotective effects of renal denervation. To compare prescribed with actual medication intake (representing a measure of adherence), we analyzed urine samples collected at baseline and at 6 months after renal denervation for antihypertensive compounds or metabolites (by liquid chromatography-mass spectrometry). In addition to office BP, 24-hour ambulatory BP and central hemodynamics (central systolic pressure, central pulse pressure) were assessed. Informed consent for analyses of urine metabolites was obtained from 79 of 80 patients. Actual intake of all antihypertensive drugs was detected at baseline and at 6 months after renal denervation in 44 (56%) and 52 (66%) patients, respectively; 1 drug was missing in 22 (28%) and 17 (22%) patients, respectively, and ≥2 drugs were missing in 13 (16%) and 10 (13%) patients, respectively. At baseline, 24-hour ambulatory BP (P=0.049) and central systolic BP (P=0.012) were higher in nonadherent patients. Adherence did not significantly change overall (McNemar-Bowker test, P=0.362). An increase in adherence was observed in 21 patients, and a decrease was observed in 11 patients. The decrease in 24-hour ambulatory BP was not different in those with stable adherence 6 months after renal denervation (n=41, -7±13 mm Hg) compared with those with increased adherence (n=21, -10±13 mm Hg) and decreased adherence (n=11, -7±14 mm Hg) (P>0.20). Our study is limited by the relatively small sample size and potentially by the specific health environment of our university center (Northern Bavaria, Germany).

CONCLUSIONS

Nonadherence to medication among patients with TRH was relatively low: ≈1 of 6 patients with TRH did not take ≥2 of the prescribed drugs. Adherence pattern did not change significantly after renal denervation and had no impact on the overall observed BP changes, supporting the concept that renal denervation is an effective treatment in patients with TRH.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifiers: NCT00888433, NCT01442883 and NCT01687725.

Translation and cultural adaptation of the Hill-Bone Compliance to High Blood Pressure Therapy Scale to Portuguese

INTRODUCTION

Hypertension is an extremely prevalent disease worldwide and hypertension control rates remain low. Lack of adherence contributes to poor control and to cardiovascular events. No questionnaire in Portuguese is readily available for the assessment of adherence to antihypertensive drugs. We aimed to perform a translation and cultural adaptation to Portuguese of the Hill-Bone Compliance to High Blood Pressure Therapy Scale, a validated instrument to measure adherence in hypertensive patients.

METHODS

A formal process was employed, consisting of a forward translation by two independent translators and a back translation by a third translator. Discrepancies were resolved after each step. Hypertensive patients were involved to identify and resolve phrasing and wording difficulties and misunderstandings.

RESULTS

The forward and back translation did not produce significant discrepancies. However, important issues were identified when the questionnaire was presented to patients, which led to changes in the wording of the questions and in the format of the questionnaire.

CONCLUSION

Questionnaires are important instruments to assess adherence to therapy, particularly in hypertension. A formal translation and cultural adaptation process ensures that the new version maintains the same concepts as the original. After translation, several changes were necessary to ensure that the questionnaire was understandable by elderly, low literacy patients, such as the majority of hypertensive patients. We propose a Portuguese version of the Hill-Bone Compliance Scale, which will require validation in further studies.

The rise, fall, and possible resurrection of renal denervation

Renal denervation has a chequered history. Dramatic reductions in blood pressure after denervation of the renal arteries were observed in early trials, but later trials in which denervation was tested against a sham procedure produced neutral results. Although a sound pathophysiological basis exists for interruption of the renal sympathetic nervous system as a treatment for hypertension, trial data to date are insufficient to support renal denervation as an established clinical therapy. In this Perspectives article, we summarize the currently available trial data, device development, and trials in progress, and provide recommendations for future trial design.

Plasma membrane calcium ATPases (PMCAs) as potential targets for the treatment of essential hypertension

The incidence of hypertension, the major modifiable risk factor for cardiovascular disease, is increasing. Thus, there is a pressing need for the development of new and more effective strategies to prevent and treat hypertension. Development of these relies on a continued evolution of our understanding of the mechanisms which control blood pressure (BP). Resistance arteries are important in the regulation of total peripheral resistance and BP; changes in their structure and function are strongly associated with hypertension. Anti-hypertensives which both reduce BP and reverse changes in resistance arterial structure reduce cardiovascular risk more than therapies which reduce BP alone. Hence, identification of novel potential vascular targets which modify BP is important. Hypertension is a multifactorial disorder which may include a genetic component. Genome wide association studies have identified ATP2B1, encoding the calcium pump plasma membrane calcium ATPase 1 (PMCA1), as having a strong association with BP and hypertension. Knockdown or reduced PMCA1 expression in mice has confirmed a physiological role for PMCA1 in BP and resistance arterial regulation. Altered expression or inhibition of PMCA4 has also been shown to modulate these parameters. The mechanisms whereby PMCA1 and 4 can modulate vascular function remain to be fully elucidated but may involve regulation of intracellular calcium homeostasis and/or comprise a structural role. However, clear physiological links between PMCA and BP, coupled with experimental studies directly linking PMCA1 and 4 to changes in BP and arterial function, suggest that they may be important targets for the development of new pharmacological modulators of BP.

Quantifying the 3 Biases That Lead to Unintentional Overestimation of the Blood Pressure-Lowering Effect of Renal Denervation

BACKGROUND

Studies of renal denervation report disparate results. Meta-analysis by trial design may allow quantitative estimation of sources and magnitude of biases in denervation studies.

METHODS AND RESULTS

One hundred forty nonrandomized, 6 randomized open-label, and 2 randomized blinded studies were analyzed for 2 outcomes: (1) blood pressure changes for nonrandomized, open-label randomized, and blinded studies; and (2) quantification of 3 biases potentially contributing to apparent antihypertensive effects: (a) regression to the mean, (b) asymmetrical data handling, and (c) true blood pressure drops caused by something other than the tested therapy (confounding). Nonrandomized studies and open-label randomized trials reported large reductions in office blood pressure of 23.6 mm Hg (95% confidence interval [CI], 22.0 to 25.3) and 29.1 mm Hg (95% CI, 25.2 to 33.1 mm Hg), respectively. They reported smaller reductions in ambulatory blood pressures (11.2 mm Hg; 95% CI, 10.0 to 12.4). The blinded trials found no significant reduction in blood pressure (2.9 mm Hg; 95% CI, -0.4 to 6.3). Analyses of these data indicate the magnitude of the 3 potential sources of bias to be regression to the mean, -1.01 mm Hg (95% CI, 4.24 to -6.27); asymmetrical data handling, -10.8 mm Hg (95% CI, -8.77 to -12.87); and confounding, -8.3 mm Hg (95% CI, -4.73 to -11.83).

CONCLUSIONS

Increasingly bias-resistant trial designs report effect sizes of decreasing magnitude. This disparity may be caused by asymmetrical data handling and confounding (eg, increased drug adherence). If these differences are caused by trial design and not by some other differences in patients or procedures, which happen to match the trial design, then randomization alone is not enough: blinding is also needed. This has broad implications across trials of medications and devices.

Adherence to medication and drug monitoring in apparent treatment-resistant hypertension

Poor drug adherence is one of the main reasons for the failure to achieve treatment targets in hypertensive patients. In patients who receive pharmacological treatment, assessment of drug adherence is of the utmost importance. The aim of this review is to present an update of the methods available to reveal and monitor non-adherence in patients with apparent treatment-resistant hypertension. Methods for monitoring adherence are divided into indirect and direct methods. The indirect methods are mainly based on self-reported adherence and can easily be manipulated by the patient. Directly observed therapy and therapeutic drug monitoring are examples of direct methods. There are limitations and advantages to all of the methods, and because of the patient's ability to manipulate the outcome of indirect methods, direct methods should be preferred. Therapeutic drug monitoring and directly observed therapy with subsequent ambulatory blood pressure measurement are considered to be reliable methods and should be used more in the routine assessment of patients with apparent treatment-resistant hypertension.

Adherence to Treatment in Hypertension

The lack of adherence to treatment in hypertension affects approximately 30 % of patients. The elderly, those with several co-morbidities, social isolation, low incomes or depressive symptoms are the most vulnerable to this problem. There is no ideal method to quantify the adherence to the treatment. Indirect methods are recommended in clinical practice. Any intervention strategy should not blame the patient and try a collaborative approach. It is recommended to involve the patient in decision-making. The clinical interview style must be patient-centered including motivational techniques. The improvement strategies that showed greater effectiveness in the compliance of hypertension treatment were: treatment simplification, appointment reminders systems, blood pressure self-monitoring, organizational improvements and nurse and pharmacists care. The combination of different interventions are recommended against isolated interventions.

Spironolactone versus placebo, bisoprolol, and doxazosin to determine the optimal treatment for drug-resistant hypertension (PATHWAY-2): a randomised, double-blind, crossover trial

BACKGROUND

Optimal drug treatment for patients with resistant hypertension is undefined. We aimed to test the hypotheses that resistant hypertension is most often caused by excessive sodium retention, and that spironolactone would therefore be superior to non-diuretic add-on drugs at lowering blood pressure.

METHODS

In this double-blind, placebo-controlled, crossover trial, we enrolled patients aged 18-79 years with seated clinic systolic blood pressure 140 mm Hg or greater (or ≥135 mm Hg for patients with diabetes) and home systolic blood pressure (18 readings over 4 days) 130 mm Hg or greater, despite treatment for at least 3 months with maximally tolerated doses of three drugs, from 12 secondary and two primary care sites in the UK. Patients rotated, in a preassigned, randomised order, through 12 weeks of once daily treatment with each of spironolactone (25-50 mg), bisoprolol (5-10 mg), doxazosin modified release (4-8 mg), and placebo, in addition to their baseline blood pressure drugs. Random assignment was done via a central computer system. Investigators and patients were masked to the identity of drugs, and to their sequence allocation. The dose was doubled after 6 weeks of each cycle. The hierarchical primary endpoints were the difference in averaged home systolic blood pressure between spironolactone and placebo, followed (if significant) by the difference in home systolic blood pressure between spironolactone and the average of the other two active drugs, followed by the difference in home systolic blood pressure between spironolactone and each of the other two drugs. Analysis was by intention to treat. The trial is registered with EudraCT number 2008-007149-30, and ClinicalTrials.gov number, NCT02369081.

FINDINGS

Between May 15, 2009, and July 8, 2014, we screened 436 patients, of whom 335 were randomly assigned. After 21 were excluded, 285 patients received spironolactone, 282 doxazosin, 285 bisoprolol, and 274 placebo; 230 patients completed all treatment cycles. The average reduction in home systolic blood pressure by spironolactone was superior to placebo (-8·70 mm Hg [95% CI -9·72 to -7·69]; p<0·0001), superior to the mean of the other two active treatments (doxazosin and bisoprolol; -4·26 [-5·13 to -3·38]; p<0·0001), and superior when compared with the individual treatments; versus doxazosin (-4·03 [-5·04 to -3·02]; p<0·0001) and versus bisoprolol (-4·48 [-5·50 to -3·46]; p<0·0001). Spironolactone was the most effective blood pressure-lowering treatment, throughout the distribution of baseline plasma renin; but its margin of superiority and likelihood of being the best drug for the individual patient were many-fold greater in the lower than higher ends of the distribution. All treatments were well tolerated. In six of the 285 patients who received spironolactone, serum potassium exceeded 6·0 mmol/L on one occasion.

INTERPRETATION

Spironolactone was the most effective add-on drug for the treatment of resistant hypertension. The superiority of spironolactone supports a primary role of sodium retention in this condition.

FUNDING

The British Heart Foundation and National Institute for Health Research.

Assessment of hypertension control and clinical course of patients excluded from the SYMPLICITY HTN-3 trial

The screening of patients referred for the Symplicity Renal-Denervation Catheter Therapy on Resistant Hypertension (SYMPLICITY HTN-3) trial was rigorous, with many found not eligible to participate. We investigate patients who were not included in the trial and evaluate their current hypertensive (HTN) therapy, control and clinical status. A retrospective review and telephone interview was performed 8-10 months postscreening on 45 patients and their referring providers who were ultimately not included. Patients were grouped into 4 categories: (1) noninterest; (2) excluded (not meeting inclusion criteria); (3) screen failure (excluded during screening visits due to adequate blood pressure control guided by HTN specialist); or (4) referred after enrollment closure. Primary outcomes evaluated included current anti-HTN management and clinical outcomes. This population consisted of 42% males, mean age 65 ± 5 years, 78% African American, 64% diabetic, and 21% chronic kidney disease. Primary referral basis included cardiology (44%), nephrology (30%), and primary care (26%). At time of follow-up, 20% had continued resistant HTN while most of the patients had controlled HTN (60%); with highest success rates among the screen failure group (88%) who also had the lowest average systolic blood pressure (137 ± 11 mm of Hg) when compared to other groups (P = .04). Average number of medications was lowest in the screen failure group (2.8 ± 1.6, P = .07). Resistant and/or uncontrolled HTN was most prevalent in the noninterest or excluded groups, as were hospitalization for cardiovascular and HTN urgency/emergency. This study highlights the disparity of HTN control and treatment in daily practice compared with clinical trials, and confirms a need for vigilant screening of those considered candidates for renal denervation.

The double challenge of resistant hypertension and chronic kidney disease

Resistant hypertension is defined as blood pressure above goal despite adherence to a combination of at least three optimally dosed antihypertensive medications, one of which is a diuretic. Chronic kidney disease is the most frequent of several patient factors or comorbidities associated with resistant hypertension. The prevalence of resistant hypertension is increased in patients with chronic kidney disease, while chronic kidney disease is associated with an impaired prognosis in patients with resistant hypertension. Recommended low-salt diet and triple antihypertensive drug regimens that include a diuretic, should be complemented by the sequential addition of other antihypertensive drugs. New therapeutic innovations for resistant hypertension, such as renal denervation and carotid barostimulation, are under investigation especially in patients with advanced chronic kidney disease. We discuss resistant hypertension in chronic kidney disease stages 3-5 (ie, patients with an estimated glomerular filtration rate below 60 mL/min per 1·73 m(2) and not on dialysis), in terms of worldwide epidemiology, outcomes, causes and pathophysiology, evidence-based treatment, and a call for action.

Screening for non-adherence to antihypertensive treatment as a part of the diagnostic pathway to renal denervation

Renal denervation is a potential therapeutic option for resistant hypertension. A thorough clinical assessment to exclude reversible/spurious causes of resistance to antihypertensive therapy is required prior to this procedure. The extent to which non-adherence to antihypertensive treatment contributes to apparent resistance to antihypertensive therapy in patients considered for renal denervation is not known. Patients (n=34) referred for renal denervation entered the evaluation pathway that included screening for adherence to antihypertensive treatment by high-performance liquid chromatography-tandem mass spectrometry-based urine analysis. Biochemical non-adherence to antihypertensive treatment was the most common cause of non-eligibility for renal denervation-23.5% of patients were either partially or completely non-adherent to prescribed antihypertensive treatment. About 5.9% of those referred for renal denervation had admitted non-adherence prior to performing the screening test. Suboptimal pharmacological treatment of hypertension and 'white-coat effect' accounted for apparently resistant hypertension in a further 17.7 and 5.9% of patients, respectively. Taken together, these three causes of pseudo-resistant hypertension accounted for 52.9% of patients referred for renal denervation. Only 14.7% of referred patients were ultimately deemed eligible for renal denervation. Without biochemical screening for therapeutic non-adherence, the eligibility rate for renal denervation would have been 38.2%. Non-adherence to antihypertensive treatment and other forms of therapeutic pseudo-resistance are by far the most common reason of 'resistant hypertension' in patients referred for renal denervation. We suggest that inclusion of biochemical screening for non-adherence to antihypertensive treatment may be helpful in evaluation of patients with 'resistant hypertension' prior to consideration of renal denervation.

Renal Denervation in Patients With Uncontrolled Hypertension and Confirmed Adherence to Antihypertensive Medications

Renal denervation (RDN) has emerged as a potential device-based treatment for resistant hypertension. The authors present their experience of the use of catheter-based RDN as part of routine clinical care in two specialist hypertension clinics. Thirty-four patients with uncontrolled hypertension underwent RDN. All patients had ambulatory blood pressure (BP) monitoring and directly observed medication administration prior to the procedure to exclude white-coat hypertension and nonadherence, respectively. Overall, there was a significant change in clinic systolic BP of -15.1 mm Hg (95% confidence interval, -23.4 to -6.8; P=.001) and clinic diastolic BP of -6.2 mm Hg (95% confidence interval, -11.5 to -0.9; P=.02) 6 months postprocedure, and a nonsignificant change in daytime ambulatory BP of -5.4/-2.9 mm Hg. Eighteen patients (51.4%) showed a significant reduction in their clinic systolic BP (≥10 mm Hg) and 16 (47%) had a significant reduction in their daytime ambulatory systolic BP (≥5 mm Hg) at 6 months.

Cost-Effectiveness of Therapeutic Drug Monitoring in Diagnosing Primary Aldosteronism in Patients With Resistant Hypertension

Primary aldosteronism (PA) is present in up to 20% of patients with treatment-resistant hypertension (TRH). Investigation for PA in patients with TRH is recommended by current guidelines after medication nonadherence is excluded. Studies using therapeutic drug monitoring (TDM) have shown that >50% of patients with TRH are nonadherent to their prescribed antihypertensive medications. However, the relationship between the prevalence of PA and medication adherence as confirmed by TDM has not been previously assessed. A retrospective analysis from a hypertension referral clinic showed that prevalence of PA in adherent patients with TRH by TDM was significantly higher than in nonadherent patients (28% vs 8%, P<.05). Furthermore, cost analysis showed that TDM-guided PA screening was $590.69 less expensive per patient, with minimal impact on the diagnostic accuracy. These data support a TDM-guided PA screening approach as a cost-saving strategy compared with routine PA screening for TRH.

A Novel 'Dilute-and-Shoot' Liquid Chromatography-Tandem Mass Spectrometry Method for the Screening of Antihypertensive Drugs in Urine

Arterial hypertension is one of the most preventable causes of premature morbidity and mortality with resistant hypertension reported to be present in 5-30% of the total hypertensive population. Despite the poor prognosis, as many as 53% of those with resistant hypertension are reported to be nonadherent to their prescribed medication. An objective test of adherence, which is easy to administer, quick, inexpensive and reliable, is therefore needed to identify patients with true resistance to antihypertensive drugs to optimize their treatment. We have developed a novel LC-MS-MS method for the detection of 23 commonly prescribed antihypertensive medications in urine. The validated method was subsequently applied to the analysis of urine from a cohort of 49 individuals who were taking at least one antihypertensive agent in the screening profile to determine their adherence. The screening method was found to be reproducible, sensitive and specific with the limit of detection ranging from 0.1 to 1.0 µg/L. Sample preparation is rapid (30 s) and simple, with a total analysis time of 11 min. The assay successfully identified the majority of drugs our cohort had admitted to taking (88%) with drugs not detected in urine, potentially indicating nonadherence to prescribed medication. The performance of this simple, robust LC-MS-MS procedure is suitable for screening urine for the presence of commonly prescribed antihypertensive medications. The assay, which can easily be implemented in other laboratories, has the potential to significantly improve investigation and management of resistant hypertension.

Hypertension

Raised blood pressure is the biggest single contributor to the global burden of disease and to global mortality. The numbers of people affected and the prevalence of high blood pressure worldwide are expected to increase over the next decade. Preventive strategies are therefore urgently needed, especially in less developed countries, and management of hypertension must be optimised. Genetic advances in some rare causes of hypertension have been made lately, but the aggregate effect on blood pressure of all the genetic loci identified to date is small. Hence, intervention on key environmental determinants and effective implementation of trial-based therapies are needed. Three-drug combinations can control hypertension in about 90% of patients but only if resources allow identification of patients and drug delivery is affordable. Furthermore, assessment of optimal drug therapy for each ethnic group is needed.

The future of renal denervation in resistant hypertension

Resistant hypertension, defined as inadequate blood pressure control despite three or more antihypertensive medications at maximally tolerated doses, is strongly linked to increased cardiovascular morbidity and mortality. Increased renal afferent and efferent sympathetic activity carried by nerves which arborize the adventitia of the renal arteries, appears to be central to the pathobiology of resistant hypertension. Historical experience indicates that surgical denervation and/or sympathectomy often dramatically reduced blood pressure in patients with malignant hypertension. Catheter-based radio-frequency renal denervation was developed in the past decade as a percutaneous adaptation of surgical denervation. Percutaneous renal denervation using a variety of systems has demonstrated to date, in non-randomized and unblinded studies, dramatic reductions in office-based blood pressure, but more modest impact on ambulatory blood pressure. The only single, appropriately powered, blinded, sham-controlled study of renal denervation conducted to date, however, failed to meet its primary endpoint, casting doubt on the value of the therapy. Ancillary benefits of renal denervation have been described in such conditions as diabetes mellitus, heart failure, and sleep apnea but require further study. While renal denervation is already widely available outside of the USA for commercial use, its utility in resistant hypertension must be vetted by further rigorous investigation before its use can be routinely recommended.

Prevention And Treatment of Hypertension With Algorithm-based therapy (PATHWAY) number 2: protocol for a randomised crossover trial to determine optimal treatment for drug-resistant hypertension

INTRODUCTION

Resistant hypertension is inadequately controlled blood pressure (BP) despite treatment with at least three BP-lowering drugs. A popular hypothesis is that resistant hypertension is due to excessive Na(+)-retention, and that 'further diuretic therapy' will be superior to alternative add-on drugs.

METHODS AND ANALYSIS

Placebo-controlled, random crossover study of fourth-line treatment when added to standard (A+C+D) triple drug therapy: ACE inhibitor or Angiotensin receptor blocker (A) +Calcium channel blocker (C)+Diuretic (D). Patients (aged 18-79 years) with clinical systolic BP ≥ 140 mm Hg (135 mm Hg in diabetics) and Home BP Monitoring (HBPM) systolic BP average ≥ 130 mm Hg on treatment for at least 3 months with maximum tolerated doses of A+C+D are randomised to four consecutive randomly allocated 12-week treatment cycles with an α-blocker, β-blocker, spironolactone and placebo. The hierarchical coprimary end point is the difference in HBPM average systolic BP between (in order) spironolactone and placebo, spironolactone and the average of the other two active drugs, spironolactone and each of the other two drugs. A key secondary outcome is to determine whether plasma renin predicts the BP response to the different drugs. A sample size of 346 (allowing 15% dropouts) will confer 90% power to detect a 3 mm Hg HBPM average systolic BP difference between any two drugs. The study can also detect a 6 mm Hg difference in HBPM average systolic BP between each patient's best and second-best drug predicted by tertile of plasma renin.

ETHICS AND DISSEMINATION

The study was initiated in May 2009 and results are expected in 2015. These will provide RCT evidence to support future guideline recommendations for optimal drug treatment of resistant hypertension.

TRIAL REGISTRATION NUMBER

Clinicaltrials.gov NCT02369081, EUDract number: 2008-007149-30.

Uncontrolled blood pressure and risk of sleep apnea among blacks: findings from the Metabolic Syndrome Outcome (MetSO) study

Uncontrolled blood pressure (BP) is linked to increased risk of obstructive sleep apnea (OSA). However, few studies have assessed the impact of this relationship among blacks with metabolic syndrome (MetS). Data for this study were collected from 1035 blacks (mean age=62±13 years) enrolled in the Metabolic Syndrome Outcome study. Patients with a score ⩾6 on the Apnea Risk Evaluation System were considered at risk for OSA. Of the sample, 77.1% were low-to-high OSA risk and 92.3% were hypertensive, of which 16.8% had uncontrolled BP levels. Analysis also showed that 60.4% were diabetic, 8.9% had a stroke history, 74.3% had dyslipidemia, 69.8% were obese and 30.9% had a history of heart disease. Logistic regression analyses were employed to investigate associations between uncontrolled BP and OSA risk, while adjusting for known covariates. Findings showed that uncontrolled BP independently increased the odds of OSA risk twofold (odds ratio=2.02, 95% confidence interval=1.18-3.48, P<0.05). In conclusion, our findings show that uncontrolled BP was associated with a twofold greater risk of OSA among blacks, suggesting that those with MetS and who have uncontrolled BP should be screened for the presence of OSA.

Nocebo and the potential harm of 'high risk' labelling: a scoping review

AIMS

A discussion of the existence, prevalence and characteristics of the nocebo effect in health care.

BACKGROUND

There is increasing but inconsistent evidence for nocebo effects (the opposite of placebo). Causal mechanisms are believed to be similar to placebo (negative effects result from suggestions of negative clinical outcomes). Risk screening in health care may produce this unintended effect through labelling some patients as high risk. Given health care's almost universal coverage this potentially affects many people.

DESIGN

Discussion paper following a scoping review of the existence and frequency of nocebo.

DATA SOURCES

Literature databases (PsycINFO, MEDLINE, CCTR, CINAHL and EMBASE) searched from inception dates to 2013.

IMPLICATIONS FOR NURSING

Significant empirical evidence indicates that negative beliefs may impact on health outcomes (incidence estimates range from 3-27%). The nocebo effect, rooted in the complex interplay between physiological functioning and social factors, appears significantly more common among women and where prior negative knowledge or expectations exist. Pre-existing psychological characteristics (anxiety, neuroses, panic disorder or pessimism) exacerbate it.

CONCLUSION

While the placebo effect is well documented, there has been no systematic attempt to synthesize primary empirical research on the role of nocebo. It is possible that nocebo outcomes may be preventable through careful consideration of information provision and the prior identification of potentially high risk individuals. This paper summarizes the scale and importance of the nocebo effect, its distribution according to a range of social and clinical variables and its known relation to psychological precursors. It identifies important gaps in the research literature.