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Study of High Dosage of Losartan in Comparison to Low Dose of Losartan in Heart Failure Patients

NCT02238457 · Status: WITHDRAWN · Phase: PHASE4 · Type: INTERVENTIONAL

Last updated 2018-11-02

No results posted yet for this study

Summary

The sympathetic nervous system, a part of the nervous system that stimulates the heart via release of substances, noradrenaline and adrenaline (combined called catecholamines), becomes activated in people with heart failure. As these people become sicker, the nervous system becomes more active, causing further damage to the heart.

Large trials have shown that Angiotensin-converting enzyme (ACE) inhibitors reduce morbidity and mortality in patients with heart failure. Higher doses of these drugs are more effective than lower doses. Studies show that ACE-inhibitors decrease catecholamine levels. This could be why congestive heart failure (CHF) patients taking this class of drugs show improvement in heart function.

There are several ways of measuring the activity of the sympathetic nervous system. The most common measurement is to test the blood for catecholamine levels. This is not very reliable or reproducible. Microneurography is a new technique used to measure sympathetic nerve activity. A small electrode (comparable to an acupuncture needle) is placed in a muscle nerve and hooked up to a stimulator and a recorder. It produces direct recordings of skeletal muscle nerve traffic. Both the rate and amplitude of the burst can be measured. The results in this technique are highly reproducible. By using this technique we get a more accurate picture of how the nervous system responds to medications given to treat heart failure.

Losartan (Cozaar) is an angiotensin II type 1 (AT1) receptor blocker. It blocks the binding of angiotensin II, a hormone that constricts blood vessels. As a result the blood vessels remain relaxed, leading to a reduction in the workload of the heart. Minor decreases in blood catecholamine levels have been reported with a low dose of this drug. The purpose of this study is to see whether a high dose of losartan (200 mg) has a greater effect on the sympathetic nervous system than a low dose of losartan (50 mg) does.

A total of 30 participants will be recruited. Participants will be assigned to one of two groups: high-dose, in which subjects will receive treatment of 200 mg/day of losartan, and low-dose, in which subjects will receive treatment of 50 mg/day of losartan. Via microneurography the investigators will measure the difference in sympathetic activity in subjects in high-dose vs low-dose losartan. The investigators expect to see further decrease in sympathetic activity in high-dose group than in low-dose group.

Conditions

Interventions

DRUG

Low dose losartan

25 mg losartan bid for 10 weeks

DRUG

High dose losartan

50 mg, 75 mg, or 100 mg bid for 10 weeks. Dose will be determined by the medical doctor depending on patients' tolerability

Sponsors & Collaborators

  • Baker Heart and Diabetes Institute

    lead OTHER

Principal Investigators

  • Markus P Schlaich · Baker IDI Heart & Diabetes Institute

Study Design

Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Model
SINGLE_GROUP

Eligibility

Min Age
21 Years
Max Age
75 Years
Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

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Entities

Diseases

Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT02238457 on ClinicalTrials.gov