Evaluation of Systemic Microvascular Reactivity in Patients With Resistant Hypertension

Systemic arterial hypertension is a serious health problem worldwide. In some cases, it can phenotypically present as resistant arterial hypertension, which consists of blood pressure levels outside the treatment goals in patients using three or more classes of antihypertensive drugs, one of which is preferably a thiazide diuretic. Resistant hypertension contributes to a 47% higher risk of developing cardiovascular events when compared to patients with non-resistant hypertension. It is known that the microcirculation plays a relevant role in the pathophysiology of arterial hypertension. Furthermore, it is known that the cutaneous microvascular network is an adequate model and that it reflects the systemic microcirculation. In this sense, the present research proposes the study of cutaneous capillary density - through high resolution intravital microscopy - and of the endothelium-dependent and independent microvascular vasodilator response - by the speckle laser flowmetry method coupled to a pharmacological system of micro- iontophoresis - in patients diagnosed with resistant hypertension, with the aim of identifying changes in comparison with patients with non-resistant hypertension and normotensive individuals. Additionally, the evaluation of the association between systemic microvascular function and the presence of target organ lesions in this population may indicate that this is a new non-invasive way of stratifying cardiovascular risk in these individuals.

Study Overview

• Status: Completed
• Conditions: Endothelial Dysfunction; Arterial Hypertension; Resistant Hypertension; Microvascular Rarefaction
• Intervention / Treatment: Diagnostic test: Evaluation of systemic skin microvascular endothelial function

• Study Type: Observational
• Enrollment (Actual): 111

Contacts and Locations

Study Locations

• Brazil
  • Rio de Janeiro, Brazil, 22240006
    • Eduardo Tibiriçá

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: N/A

• Sampling Method: Probability Sample

Study Population

Resistant hypertension: Blood pressure levels outside the treatment goals in patients using three or more classes of antihypertensive drugs, one of which is preferably a thiazide diuretic.

Description

Inclusion Criteria:

• Resistant hypertension

Exclusion Criteria:

• Pregnancy or lactation for all groups.
• For the control group: endocrine and metabolic diseases, including diabetes mellitus, cardiovascular diseases, including hypertension, autoimmune diseases and cancer.
• For the resistant arterial hypertension and non-resistant arterial hypertension groups: endocrine diseases, except diabetes mellitus, autoimmune diseases and cancer .

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Cross-Sectional

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Resistant hypertension; Patients presenting with resistant hypertension	Diagnostic test: Evaluation of systemic skin microvascular endothelial function; Laser-based method for evaluating non-invasive, operator-independent systemic microvascular function that detects microvascular flow in the skin for the evaluation of systemic vascular endothelial function.
non-resistant hypertension; Patients presenting with non-resistant hypertension	Diagnostic test: Evaluation of systemic skin microvascular endothelial function; Laser-based method for evaluating non-invasive, operator-independent systemic microvascular function that detects microvascular flow in the skin for the evaluation of systemic vascular endothelial function.
normotensive subjects; control group including normotensive volunteers	Diagnostic test: Evaluation of systemic skin microvascular endothelial function; Laser-based method for evaluating non-invasive, operator-independent systemic microvascular function that detects microvascular flow in the skin for the evaluation of systemic vascular endothelial function.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Systemic microvascular reactivity	evaluation of endothelium-dependent and -independent microvascular function	two years - during one visit to the microcirculation laboratory

Collaborators and Investigators

• Sponsor: National Institute of Cardiology, Laranjeiras, Brazil

Publications and helpful links

General Publications

• Crahim V, Verri V, De Lorenzo A, Tibirica E. Reduced systemic microvascular function in patients with resistant hypertension and microalbuminuria: an observational study. J Hum Hypertens. 2024 Dec;38(12):806-813. doi: 10.1038/s41371-024-00958-7. Epub 2024 Sep 17.

Study record dates

Study Major Dates

• Study Start (Actual): December 20, 2021
• Primary Completion (Actual): December 30, 2025
• Study Completion (Actual): December 30, 2025

Study Registration Dates

• First Submitted: July 12, 2022
• First Submitted That Met QC Criteria: July 14, 2022
• First Posted (Actual): July 19, 2022

Study Record Updates

• Last Update Posted (Actual): April 13, 2026
• Last Update Submitted That Met QC Criteria: April 7, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Pathological Conditions, Anatomical; Pathological Conditions, Signs and Symptoms; Microvascular Rarefaction; Hypertension
• Other Study ID Numbers: CAAE 53946021.8.0000.5272

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No