Heart Rate Variability and Medication Adherence in Resistant Hypertension (HRV-HYP-1)

July 13, 2026 updated by: Matej Pekar, MD, PhD, Nemocnice AGEL Trinec-Podlesi a.s.

Eart Rate Variability, Medication Adherence, and Blood Pressure Control in Resistant Hypertension: A Cross-Sectional Study

This single-center, cross-sectional observational study examines the relationship between adherence to antihypertensive therapy - verified objectively by therapeutic drug monitoring (TDM) - and heart rate variability (HRV) in patients with resistant hypertension. Patients are recruited opportunistically, in a nurse-led manner, in a one-day-care cardiology unit, and undergo a single examination: a short-term HRV recording (Polar H10), a single blood draw for antihypertensive drug levels, office blood pressure, and self-completed questionnaires. There is no follow-up.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Non-adherence to antihypertensive medication is a major cause of apparently resistant hypertension and confounds interpretation of autonomic measures. HRV is a non-invasive index of autonomic cardiac regulation and is systematically influenced by antihypertensive drugs. The study tests whether TDM-verified intake of antihypertensives is reflected in HRV parameters, and whether HRV can serve as a complementary marker of adherence. Adherence is determined by TDM (the objective gold standard); a self-report questionnaire (MARS-CZ) is collected as a secondary, descriptive measure. HRV is recorded for 10-15 minutes seated, before sedation and before heparin/contrast; the blood sample is drawn before heparin/contrast, with the time of last dose recorded. Time-domain (SDNN, RMSSD, pNN50) and frequency-domain (LF, HF, LF/HF) HRV parameters are analysed. Approximately 100-200 patients are planned for enrolment. It does not interfere with the patient's planned cardiac procedure; the one-day-care unit is the recruitment venue only.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
150

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Czechia
    • Moravian-Silesian Region
      • Třinec, Moravian-Silesian Region, Czechia, 739 61
        • Nemocnice AGEL Třinec-Podlesí a.s.
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Adults (18-75 years) with essential hypertension treated with at least three antihypertensive drugs of different classes, including at least one diuretic (resistant hypertension), and in sinus rhythm. Participants are identified and recruited opportunistically, in a nurse-led manner, among patients attending a one-day-care cardiology unit at a single center.

Description

Inclusion Criteria:

  • Age 18-75 years with diagnosed essential hypertension
  • Treated with ≥3 antihypertensive drugs of different classes, including ≥1 diuretic (resistant hypertension)
  • Sinus rhythm
  • Able to give informed consent and understand Czech

Exclusion Criteria:

  • Absence of sinus rhythm: atrial fibrillation/flutter, ventricular arrhythmias, higher-degree AV block, pacemaker/ICD with sustained pacing, sustained SVT, or significant ectopy
  • Secondary hypertension
  • Pregnancy or breastfeeding
  • Cognitive impairment precluding informed consent

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Resistant hypertension (≥3 antihypertensives incl. diuretic, sinus rhythm)
Single cohort analysed by adherence status defined by TDM: adherent vs non-adherent.
Diagnostic test: Heart rate variability recording (Polar H10) ·
Short-term (10-15 min) seated HRV; time-domain (SDNN, RMSSD, pNN50) and frequency-domain (LF, HF, LF/HF) parameters.
Diagnostic test: Therapeutic drug monitoring (antihypertensive drug levels)
Single blood draw measuring antihypertensive drug levels; defines adherent vs non-adherent status.
Other: Questionnaires (MARS-CZ, PHQ-9, SF-36, IPAQ)
Self-completed instruments assessing medication adherence, mood, quality of life, and physical activity.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Heart rate variability parameters by TDM-defined adherence
Time Frame: At the single study visit (Day 1)
Time-domain (SDNN, RMSSD, pNN50) and frequency-domain (LF, HF, LF/HF ratio) HRV parameters from a short-term seated recording, compared between TDM-adherent and TDM-non-adherent patients.
At the single study visit (Day 1)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Heart rate variability in relation to office blood-pressure control
Time Frame: At the single study visit (Day 1)
Association between HRV parameters and office blood pressure measured seated immediately before the HRV recording.
At the single study visit (Day 1)
Questionnaire scores in relation to adherence and HRV
Time Frame: At the single study visit (Day 1)
Scores of MARS-CZ (adherence), PHQ-9 (mood), SF-36 (quality of life), and IPAQ (physical activity) examined against TDM-defined adherence and HRV parameters.
At the single study visit (Day 1)
Prevalence of non-adherence by therapeutic drug monitoring
Time Frame: At the single study visit (Day 1)
Proportion of patients classified as non-adherent to antihypertensive therapy based on TDM (absent or subtherapeutic drug levels).
At the single study visit (Day 1)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Nemocnice AGEL Trinec-Podlesi a.s.

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Masaryk University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Jan Alexander Mohr, MD, Nemocnice AGEL Třinec-Podlesí a.s.
  • Study Director: Matej Pekar, MD, PhD, Nemocnice AGEL Třinec-Podlesí a.s.

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 20, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 20, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 13, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 13, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 16, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 16, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 13, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • HRV-HYP-1
  • EK 29/25 (Other Identifier: Ethics Committee, AGEL Třinec-Podlesí Hospital)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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