Managing ‘resistance’: is adherence a target for treatment?

Adherence to Antihypertensive Therapy and Its Determinants: A Systematic Review

Hypertension is a globally prevalent condition, and low adherence to antihypertensive therapy is considered one of the main causes of poor blood pressure (BP) control. Non-adherence to antihypertensive treatment is a complex issue that can arise from various factors; however, gaining an understanding of this provides key targets for intervention strategies. This study aimed to provide an overview of the current status and recent developments regarding our understanding of the determinants of patients' adherence to antihypertensives. A systematic review was performed using the electronic databases MEDLINE/PubMed, Web of Science, Scientific Electronic Library Online (SciELO), and "Índex das Revistas Médicas Portuguesas", which included studies published between 2017 and 2021 following the PICOS model: (P) Adult patients with the diagnosis of primary hypertension, using at least one antihypertensive agent; (I) all interventions on both pharmacological and non-pharmacological level; (C) patient's adherence against their non-adherence; (O) changes in adherence to the therapeutic plan; and (S) any study design (except review articles) written in English, French, Spanish or Portuguese. Articles were reviewed by two researchers and their quality was assessed. Subsequently, determinants were classified according to their consistent or inconsistent association with adherence or non-adherence. Only 45 of the 635 reports identified met the inclusion criteria. Adherence was consistently associated with patient satisfaction with communication, patient-provider relationship, their treatment, and use of eHealth and mHealth strategies; a patient's mental and physical health, including depression, cognitive impairment, frailty, and disability, previous hospitalization, occurrence of vital events; drug treatment type and appearance; and unwillingness due to health literacy, self-efficacy, and both implicit and explicit attitudes towards treatment. There were discrepancies regarding the association of other factors to adherence, but these inconsistent factors should also be taken into account. In conclusion, the barriers to adherence are varied and often interconnected between socioeconomic, patient, therapy, condition, and healthcare system levels. Healthcare teams should invest in studying patients' non-adherence motives and tailoring interventions to individual levels, by using a multifaceted approach to assess adherence. Further research is needed to analyze the impact of implicit attitudes, the use of new technological approaches, and the influence of factors that are inconsistently associated with non-adherence, to understand their potential in implementing adherence strategies.

Association of adherence measured by self-reported pill count with achieved blood pressure level in hypertension patients: a cross-sectional study

Background

Medication adherence plays an essential role in controlling blood pressure to reduce morbidity and mortality of hypertension disease. Thus, this study aimed to determine the association of medication adherence measured by self-reported pill count with blood pressure levels among patients at several community health centers in Surabaya.

Methods

Adherence was assessed using the pill count method by comparing the total number of antihypertension drugs taken with the prescribed drugs. The inclusion criteria involved hypertensive patients who received antihypertension drugs, specifically adults and elderly, except the pregnant woman. The patient blood pressure was measured by healthcare workers in the targeted community health centers. Descriptive and multivariable logistic regression analyses were performed to assess factors associated with medication adherence with blood pressure levels.

Results

A total of 264 hypertensive outpatients participating in this study, 77.65% of participants were adherent to antihypertensive drugs based on the pill count method, and 40.91% of participants had controlled blood pressure. Patients with uncontrolled blood pressure were about six times (adjusted odds ratio [AOR]: 6.15; 95% confidence interval [CI]: 2.694–14.039; P = 0.000) more likely to have non-adherent medication than patients with controlled blood pressure. Reciprocally, non-adherent participants (pill count < 80%) were about six times (AOR: 6.081; 95% CI: 2.672–13.838; P = 0.000) more likely to have uncontrolled blood pressure compared to adherent patients (pill count ≥ 80%). Age less than 40 years old (AOR: 5.814; 95% CI: 1.519–22.252; P = 0.01) and having middle school educational level (AOR: 0.387; 95% CI: 0.153–0.974; P = 0.045) were found to be independent factors associated with uncontrolled blood pressure.

Conclusions

The result showed that non-adherence to antihypertension drugs is associated with uncontrolled blood pressure. Then, age could be associated with uncontrolled blood pressure. Thus, pharmacists and other healthcare providers should pay attention to improving medication adherence and maintaining the controlled blood pressure.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40885-022-00195-5.

The efficacy of cognitive behavioral therapy-based interventions on patients with hypertension: A systematic review and meta-analysis

Recently, the benefits of cognitive behavioral therapy (CBT)-based interventions for patients with hypertension have been recognized, but there has been no systematic review that has comprehensively analyzed the efficacy of CBT on health outcomes in this population. We aimed to explore the therapeutic effect of CBT-based interventions on hypertension patients through a meta-analysis. Relevant randomized controlled trials (RCTs) were obtained by searching electronic databases. The primary outcomes were physiological indicators (blood pressure, blood lipid profile). Secondary outcomes were psychological indicators (anxiety, depression), and the quality of sleep. Stata version 15.0 software was used to analyze the results. A total of 15 RCTs were included. The main analysis revealed that CBT-based interventions reduced systolic pressure: -8.67 (95% CI: -10.67 to -6.67, P = 0.000); diastolic pressure: -5.82 (95% CI: -7.82 to -3.81, P = 0.000); total cholesterol levels: -0.43 (95% CI: -0.76 to -0.10, P = 0.010); depressive symptoms: -3.13 (95% CI: -4.02 to -2.24, P = 0.000); anxiety symptoms: -3.63 (95% CI: -4.40 to -2.87, P = 0.000); and improved quality of sleep: -2.93 (95% CI: -4.40 to -1.47, P = 0.000). Additionally, the results of subgroup analysis indicated that long-term group-based CBT-based interventions were particularly beneficial for blood pressure management in hypertension patients. CBT-based interventions are effective in reducing systolic pressure, diastolic pressure, total cholesterol levels, anxiety symptoms, depressive symptoms, and improving quality of sleep in hypertension patients.

Assessment of a strategy combining ambulatory blood pressure, adherence monitoring and a standardised triple therapy in resistant hypertension

PURPOSE

Poor adherence to drug therapy and inadequate drug regimens are two frequent factors responsible for the poor blood pressure (BP) control observed in patients with apparent resistant hypertension. We evaluated the efficacy of an antihypertensive management strategy combining a standardised therapy with three long acting drugs and electronic monitoring of drug adherence in patients with apparent resistant hypertension.

MATERIALS AND METHODS

In this multicentric observational study, adult patients with residual hypertension on 24 h ambulatory BP monitoring (ABMP) despite the use of three or more antihypertensive drugs could be included. Olmesartan/amlodipine (40/10 mg, single pill fixed-dose combination) and chlorthalidone (25 mg) were prescribed for 3 months in two separated electronic pills boxes (EPB). The primary outcome was 24 h ambulatory systolic BP (SBP) control at 3 months, defined as mean SBP <130 mmHg.

RESULTS

We enrolled 48 patients (36.0% women) of whom 35 had complete EPB data. After 3 months, 52.1% of patients had 24 h SBP <130 mmHg. 24 h SBP decreased by respectively -9.1 ± 15.5 mmHg, -22.8 ± 30.6 mmHg and -27.7 ± 16.6 mmHg from the tertile with the lowest adherence to the tertile with the highest adherence to the single pill combination (p = 0.024). A similar trend was observed with tertiles of adherence to chlorthalidone. Adherence superior to 90% was associated with 24 h systolic and diastolic blood pressure control in multiple logistic regression analysis (odds ratio = 14.1 (95% confidence interval 1.1-173.3, p = 0.039).

CONCLUSIONS

A simplified standardised antihypertensive therapy combined with electronic monitoring of adherence normalises SBP in about half of patients with apparent resistant hypertension. Such combined management strategy enables identifying patients who need complementary investigations and those who rather need a long-term support of their adherence.

The development and validation of the health belief model questionnaire for measuring factors affecting adherence in the elderly with hypertension

OBJECTIVES

This study aimed to validate the questionnaire on the health belief model questionnaire to assess health beliefs that could influence adherence to hypertension in the elderly.

METHODS

The questionnaire was based on a study of the literature and discussion with experts. The questionnaire was then circulated via social media. Participants who met the following criteria were asked to participate in the study: (1) aged 60-79 years of age, (2) had antihypertensive medications in the last three months, and (3) had a mobile phone with an active number. The questionnaire consists of six domains: perceived susceptibility, perceived severity, perceived threat, perceived benefits, perceived barriers, and perceived self efficacy. The findings were grouped by domain and tested for reliability and validity using SPSS ver.24.

RESULTS

Thirty participants completed the questionnaire. Each domain was tested for its reliability and validity at a value of 0.05. The result shows that each domain had a Cronbach's alpha value greater than 0.7, with a total score of 0.89 indicating that all domains in the questionnaire were reliable. Furthermore, of the 49 items in the questionnaire, only two items were invalid while the rest of the items demonstrated their validity based on the Pearson Correlation (>r table 0.361; p<0.05).

CONCLUSIONS

This self administered health belief model questionnaire was a valid and reliable instrument to assess health beliefs in elderly with hypertension.

Effects of self-management programs on blood pressure, self-efficacy, medication adherence and body mass index in older adults with hypertension: Meta-analysis of randomized controlled trials

AIM

To assess the effects of self-management interventions on systolic blood pressure, diastolic blood pressure, self-efficacy, medication adherence and body mass index in older adults with hypertension.

BACKGROUND

Effective treatment of hypertension may require the practice of self-management behaviours. However, evidence on effects of self-management interventions on blood pressure, self-efficacy, medication adherence and body mass index in older adults with hypertension is lacking.

DESIGN

A systematic review and meta-analysis.

DATA SOURCES

CINAHL, Cochrane Library, Embase, Ovid-Medline, PubMed, Scopus, Web of Science and other sources were searched to October 2020.

REVIEW METHODS

Data were analysed using Comprehensive Meta-Analysis 2.0 and quality assessment was done using ROB 2.0. The pooled effect sizes were reported as Hedges' g values with corresponding 95% confidence intervals using a random-effects model.

RESULTS

Twelve randomized controlled trials met our inclusion criteria. The results revealed that self-management interventions significantly decreased blood pressure and increased self-efficacy and medication adherence in older adult patients with hypertension, with no significant effect on body mass index.

CONCLUSIONS

Self-management interventions have considerable beneficial effects in older adults with hypertension. Health care providers should implement self-management interventions to strengthen the patient's role in managing their health.

Adherence to Antihypertensive Therapy: A Systematic Review of Russian Prospective Studies from 2000 to 2019

Russia belongs to countries with a high prevalence of arterial hypertension (AH), which is the main cause of premature death in the Russian population. The level of blood pressure (BP) is controlled in less than a third of patients, which may be due to poor adherence to medical recommendations and irregular medication. The manuscript provides a review of studies evaluating the effectiveness of measures to improve adherence to antihypertensive therapy (AHT).

Aim. To prepare a systematic review of Russian studies to assess the effectiveness of measures to increase adherence to AHT, to determine/describe the main directions of the intervention and the methodological level.

Material and methods. The search for full-text articles on adherence to AHT published in Russian in the period from 2000 to 2019 was carried out in the main Russian and international electronic databases eLIBRARY.ru, Embase, Russian Medicine, MEDLINE. Of the 563 publications found, 20 were included in the review.

Results. In 14 studies, adherence was assessed using the 4-item Morisky Medication Adherence Scale (MMAS-4), other studies used bespoke questionnaires or pill counts. Two studies examined factors associated with adherence. The observation period was up 6 weeks to 12 months, the number of participants is 30-2435 people. A higher adherence was noted in women, people over 50 years old, with higher education, working, with concomitant diabetes mellitus and a history of myocardial infarction. Patient education was effective interventions to improve adherence (in particular, in studies, improvement on the MMAS-4 from 1.8 to 3.9 points, p=0.0002 or from 2.80 to 3.79 points, p<0.0001), telephone reminders (p<0.0001), training in self-measurement of blood pressure (p<0.05) and fixed combinations of drugs (p<0.05).

Conclusion. The most effective ways to improve adherence are patient education and the use of drugs fixed combinations. In most studies, subjective methods of adherence assessing were used.

Adherence to Antihypertensive Drugs Assessed by Hyphenated High-Resolution Mass Spectrometry Analysis of Oral Fluids

Background

It is currently unknown if antihypertensive drugs can be monitored in oral fluid (OF) using liquid chromatography coupled to high‐resolution mass spectrometry.

Methods and Results

We assessed adherence using liquid chromatography coupled to high‐resolution mass spectrometry in OF, plasma, and urine of 56 consecutive patients with hypertension referred to a tertiary hypertension unit. Of these patients, 59% were completely adherent (all drugs detectable in urine), whereas 29% and 13% were partially adherent (1 drug not detectable in urine) or nonadherent (>1 drug not detectable in urine), respectively. Adherent patients were on fewer antihypertensive drugs (P=0.001), had fewer daily drug doses (P=0.012), and had lower 24‐hour ambulatory systolic (P=0.012) and diastolic (P=0.009) blood pressures than nonadherent or partially adherent patients. Most drugs were detected in urine compared with plasma and OF (181 versus 119 versus 88; P=0.001). Compared with urine and plasma, detection rates of angiotensin‐converting enzyme inhibitors, angiotensin II receptor blockers, and diuretics were lower in OF. There was no difference in the frequency of detecting β blockers (P=1.0) and calcium channel blockers (P=0.063) when comparing OF with urine. There was no difference in the number of calcium channel blockers (P=0.727), β blockers (P=1.000), thiazide diuretics (P=0.125), and α‐2 agonists (P=0.125) identified between OF and plasma.

Conclusions

This study shows the feasibility of drug adherence testing for several antihypertensive drugs, especially those without acidic components, in OF, with a similar recovery compared with plasma. Therefore, drug adherence testing in OF should be further explored as a noninvasive approach, which can easily be performed in an “out‐of‐office” setting.

Adherence in Hypertension

The global epidemic of hypertension is largely uncontrolled and hypertension remains the leading cause of noncommunicable disease deaths worldwide. Suboptimal adherence, which includes failure to initiate pharmacotherapy, to take medications as often as prescribed, and to persist on therapy long-term, is a well-recognized factor contributing to the poor control of blood pressure in hypertension. Several categories of factors including demographic, socioeconomic, concomitant medical-behavioral conditions, therapy-related, healthcare team and system-related factors, and patient factors are associated with nonadherence. Understanding the categories of factors contributing to nonadherence is useful in managing nonadherence. In patients at high risk for major adverse cardiovascular outcomes, electronic and biochemical monitoring are useful for detecting nonadherence and for improving adherence. Increasing the availability and affordability of these more precise measures of adherence represent a future opportunity to realize more of the proven benefits of evidence-based medications. In the absence of new antihypertensive drugs, it is important that healthcare providers focus their attention on how to do better with the drugs they have. This is the reason why recent guidelines have emphasize the important need to address drug adherence as a major issue in hypertension management.

Adherence to antihypertensive medication in Russia: a scoping review of studies on levels, determinants and intervention strategies published between 2000 and 2017

BACKGROUND

Arterial hypertension (HT) is common in the Russian adult population, with half of affected individuals inadequately controlled. Low adherence to medication seems likely to be a factor. We report a scoping review of studies on adherence to antihypertensive therapy (AHT) in Russia to determine the extent of research undertaken, the frequency of adherence among adults diagnosed with HT, methodologies used in the studies, and their ability to describe determinants of adherence.

METHODS

A scoping review of published studies that have assessed adherence to AHT in Russian HT patients searched the main Russian and international electronic databases eLIBRARY.ru, Russian Medicine, Embase, MEDLINE for full-text reports published in the Russian language between 2000 and 2017. The last search was on November 28, 2017. Among 520 reports identified, 31 were included in the review.

RESULTS

Eighteen studies assessed adherence using the 4-item Morisky Medication Adherence Scale (MMAS-4); others used bespoke questionnaires or pill counts. 25 studies assessed levels of adherence, 11 examined its determinants, and 18 examined intervention strategies. The proportion of "adherent" patients varied from 11 to 44% using the MMAS-4, from 23 to 74% when using bespoke questionnaires, and from 5 to 43% when using pill counts. Adherence was associated with sociodemographic factors, access to free drugs provided through the Medicine Assistance Scheme (MAS), use of home blood pressure (BP) monitoring, anxiety, and comorbidity. There was no evidence that adherence was associated with income or physical activity. Evidence of an association between MAS, grade of HT, or experience of hypertensive crisis was inconclusive. Various methods to improve adherence were studied including patient education (improved from 1.8 to 3.9 points, p = 0.0002 or 2.80 to 3.79 points, p < 0.0001 measured by the MMAS-4), telephone reminders (p < 0.0001), training in home BP monitoring (p < 0.05), and use of fixed-dose combinations (p < 0.05).

CONCLUSIONS

The main determinants of adherence to AHT are sociodemographic characteristics, the severity of HT, and presence of comorbidity. Patient education and use of fixed-dose combinations of drugs were identified as most important for improving adherence. Most studies assessing adherence use self-reported methods so there is a need for greater use of objective methods.

TRIAL REGISTRATION

This scoping review has not been registered.

2018 ESC/ESH Guidelines for the management of arterial hypertension: The Task Force for the management of arterial hypertension of the European Society of Cardiology and the European Society of Hypertension: The Task Force for the management of arterial hypertension of the European Society of Cardiology and the European Society of Hypertension

: Document reviewers: Guy De Backer (ESC Review Co-ordinator) (Belgium), Anthony M. Heagerty (ESH Review Co-ordinator) (UK), Stefan Agewall (Norway), Murielle Bochud (Switzerland), Claudio Borghi (Italy), Pierre Boutouyrie (France), Jana Brguljan (Slovenia), Héctor Bueno (Spain), Enrico G. Caiani (Italy), Bo Carlberg (Sweden), Neil Chapman (UK), Renata Cifkova (Czech Republic), John G. F. Cleland (UK), Jean-Philippe Collet (France), Ioan Mircea Coman (Romania), Peter W. de Leeuw (The Netherlands), Victoria Delgado (The Netherlands), Paul Dendale (Belgium), Hans-Christoph Diener (Germany), Maria Dorobantu (Romania), Robert Fagard (Belgium), Csaba Farsang (Hungary), Marc Ferrini (France), Ian M. Graham (Ireland), Guido Grassi (Italy), Hermann Haller (Germany), F. D. Richard Hobbs (UK), Bojan Jelakovic (Croatia), Catriona Jennings (UK), Hugo A. Katus (Germany), Abraham A. Kroon (The Netherlands), Christophe Leclercq (France), Dragan Lovic (Serbia), Empar Lurbe (Spain), Athanasios J. Manolis (Greece), Theresa A. McDonagh (UK), Franz Messerli (Switzerland), Maria Lorenza Muiesan (Italy), Uwe Nixdorff (Germany), Michael Hecht Olsen (Denmark), Gianfranco Parati (Italy), Joep Perk (Sweden), Massimo Francesco Piepoli (Italy), Jorge Polonia (Portugal), Piotr Ponikowski (Poland), Dimitrios J. Richter (Greece), Stefano F. Rimoldi (Switzerland), Marco Roffi (Switzerland), Naveed Sattar (UK), Petar M. Seferovic (Serbia), Iain A. Simpson (UK), Miguel Sousa-Uva (Portugal), Alice V. Stanton (Ireland), Philippe van de Borne (Belgium), Panos Vardas (Greece), Massimo Volpe (Italy), Sven Wassmann (Germany), Stephan Windecker (Switzerland), Jose Luis Zamorano (Spain).The disclosure forms of all experts involved in the development of these Guidelines are available on the ESC website www.escardio.org/guidelines.

Barriers to medication adherence and links to cardiovascular disease risk factor control: the Framingham Heart Study

BACKGROUND

In the elderly, impaired cognition may weaken medication adherence and compromise treatment for cardiovascular disease (CVD).

AIM

We examined risk factors for medication adherence and the relationship between adherence and levels of CVD risk factors among older participants with hypertension, dyslipidaemia and diabetes in the Framingham Heart Study.

METHODS

The four-item Morisky Medication Adherence Scale was administered to 1559 participants, median age 70 years, 53% women. We created an adherence score, ranging from 0 to 4, with low adherence defined as a score ≥2. CVD risk factors were assessed using standard protocols. Cognition was measured using the Mini-Mental State Examination (MMSE) and depressive symptoms were measured using the Center for Epidemiologic Studies of Depression (CES-D) scale.

RESULTS

Among participants who self-reported taking antihypertensive, lipid-lowering and/or hyperglycaemic medication(s), 12% (n = 191) had low medication adherence. The risk of low adherence increased by 45% (95% confidence interval (CI): 25-68%, P < 0.001) per five-unit increase in CES-D score. In participants taking antihypertensive medication (n = 1017), low adherence was associated with higher mean diastolic blood pressure (73 mmHg, 95% CI: 71-75 vs 71 mmHg, 95% CI: 70-71; P = 0.04) after adjusting for covariates. Among participants taking lipid-lowering medication (n = 937), low adherence was associated with higher mean low-density lipoprotein cholesterol (92 mg/dL, 95% CI: 87-96 vs 86 mg/dL, 95% CI: 84-88; P = 0.03). Low adherence was not associated with fasting plasma glucose (P = 0.10) or haemoglobin A1c (P = 0.68) in the subgroup of participants (n = 192) taking hypoglycaemic medication.

CONCLUSIONS

Depressive symptoms might act as a barrier for medication adherence, which exacerbates CVD risk factors in older-aged adults.

Blood pressure outcomes of medication adherence interventions: systematic review and meta-analysis

This systematic review applied meta-analytic procedures to integrate primary research that examined blood pressure outcomes of medication adherence interventions. Random-effects model analysis calculated standardized mean difference effect sizes. Exploratory dichotomous and continuous moderator analyses using meta-analytic analogues of ANOVA and regression were performed. Codable data were extracted from 156 reports with 60,876 participants. The overall weighted mean difference systolic effect size was 0.235 across 161 treatment versus control comparisons. The diastolic effect size was 0.189 from 181 comparisons. Effect sizes were significantly heterogeneous. Common risks of bias included lack of allocation concealment, unmasked data collectors, and absent intention-to-treat analyses. Exploratory moderator analyses suggested that habit-based interventions may be most effective. The largest effect sizes were for interventions delivered by pharmacists. The modest magnitude effect sizes suggest future research should explore novel higher dose interventions that might address multiple levels of influence on adherence behavior.

Interventions to Improve Medication Adherence in Hypertensive Patients: Systematic Review and Meta-analysis

This systematic review applied meta-analytic procedures to synthesize medication adherence interventions that focus on adults with hypertension. Comprehensive searching located trials with medication adherence behavior outcomes. Study sample, design, intervention characteristics, and outcomes were coded. Random-effects models were used in calculating standardized mean difference effect sizes. Moderator analyses were conducted using meta-analytic analogues of ANOVA and regression to explore associations between effect sizes and sample, design, and intervention characteristics. Effect sizes were calculated for 112 eligible treatment-vs.-control group outcome comparisons of 34,272 subjects. The overall standardized mean difference effect size between treatment and control subjects was 0.300. Exploratory moderator analyses revealed interventions were most effective among female, older, and moderate- or high-income participants. The most promising intervention components were those linking adherence behavior with habits, giving adherence feedback to patients, self-monitoring of blood pressure, using pill boxes and other special packaging, and motivational interviewing. The most effective interventions employed multiple components and were delivered over many days. Future research should strive for minimizing risks of bias common in this literature, especially avoiding self-report adherence measures.

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.