Effects of Dietary Nitrate Supplementation on Cardiorespiratory Control in Chronic Heart Failure

Heart Failure, Systolic Clinical Trial

Official title:

Dietary Nitrate Supplementation and Cardiorespiratory Control in Chronic Heart Failure: a Randomized, Placebo-controlled Trial

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02401126
• Other study ID #: 6012610
• Status: Completed
• Phase: Phase 4
• First received: March 24, 2015
• Last updated: April 29, 2016
• Start date: March 2015
• Est. completion date: April 2016

Study information

• Verified date: April 2016
• Source: Queen's University
• Contact: n/a
• Is FDA regulated: No
• Health authority: Canada: Health Canada
• Study type: Interventional

Clinical Trial Summary

The main purpose of this study is to determine whether dietary nitrate supplementation via concentrated beetroot juice improves central and peripheral cardiovascular control and physical capacity in patients with systolic heart failure.

Description:

Chronic heart failure (CHF) is a leading cause of morbidity and mortality worldwide. Although affecting the heart at first, it is now recognized that disability is largely due to impaired cerebral and skeletal muscle blood flow and consequently microvascular oxygenation. Reduced muscle oxygenation compromises oxidative metabolism and thus contractile performance. Impaired cerebral oxygenation not only reduces motor output (thus exacerbating muscle fatigue) but also constitutes a predictor of cerebral ischemic events and an independent prognostic risk factor.

Reduced levels of the vasodilator nitric oxide (NO) contribute to impaired blood flow and oxygenation in CHF. Development of new effective therapeutic strategies is therefore crucial given that current pharmacological treatment has failed to abrogate oxygenation deficits in CHF patients. Emerging evidence shows that nitrate serves as an alternative source for NO and improves muscle blood flow and oxygenation in health. Another striking feature of nitrate is that it can improve muscle work efficiency, a tenet of physiology that was once considered immutable.

Objective: To investigate systematically the role of dietary nitrate supplementation on central and peripheral cardiovascular function in CHF patients.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 13
• Est. completion date: April 2016
• Est. primary completion date: April 2016
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 40 Years to 80 Years

Eligibility

Inclusion Criteria:

• previous diagnosis of systolic heart failure (left ventricular ejection fraction <40%) under optimized clinical treatment as judged by the accompanying physician.

Exclusion Criteria:

• hospital admission in the previous 6 weeks;

• exercise training program in the previous 6 months;

• nitrate therapy (e.g., isosorbide dinitrate);

• tabagism;

• any condition that could interfere with the ability to exercise;

• diagnosed psychiatric or cognitive disorders;

• type I insulin-dependent diabetes mellitus;

• excessively over-weight (BMI>35kg/m²);

• other diagnosed cardiorespiratory disorders (e.g., chronic obstructive pulmonary disease, peripheral artery disease).

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Crossover Assignment, Masking: Double Blind (Subject, Investigator, Outcomes Assessor), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Heart Failure
• Heart Failure, Systolic

Intervention

Dietary Supplement:
• Nitrate supplementation
Nitrate supplementation: concentrated nitrate-rich beetroot juice (2 x 70 ml/day; approximately 10 mmol nitrate/day; Beet It, James White Drinks, Ipswich, UK) for 8 consecutive days.
• Placebo
Placebo: nitrate-depleted beetroot juice (2 x 70 ml/day; approximately 0.01 mmol nitrate/day; Beet It, James White Drinks, Ipswich, UK) for 8 consecutive days. The placebo juice is similar to the concentrated beetroot juice in appearance, texture, smell and taste and is obtained by removing nitrate ions from the latter.

Locations

Country	Name	City	State
n/a

Sponsors (1)

Lead Sponsor	Collaborator
Queen's University

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Exercise tolerance	Cycle ergometer exercise test to the limit of tolerance	8 days	No
Secondary	Plasma nitrate and nitrite concentrations	Assessed by chemiluminescence	8 days	No
Secondary	Central and peripheral fatigue	Assessed by transcutaneous femoral nerve magnetic stimulation	8 days	No
Secondary	Skeletal muscle and cerebral blood flow and oxygenation	Assessed by near-infrared spectroscopy and the rate of appearance of the optically-dense indocyanine green dye	8 days	No
Secondary	Neuromuscular activity	Assessed by electromyography	8 days	No
Secondary	Dyspnea and leg effort scores	Evaluated via a 10-point Borg scale	8 days	No
Secondary	Cognitive performance	Assessed by computer-based tests	8 days	No
Secondary	Cardiorespiratory responses to exercise	Non-invasive evaluation of cardiac (mean arterial pressure, cardiac output, stroke volume and heart rate) and pulmonary gas exchange (e.g., minute ventilation and oxygen uptake) responses during the transition from rest to exercise	8 days	No