Clinical trial NCT02401126: Effects of Dietary Nitrate Supplementation on Cardiorespiratory Control in Chronic Heart Failure
Official title: Dietary Nitrate Supplementation and Cardiorespiratory Control in Chronic Heart Failure: a Randomized, Placebo-controlled Trial
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Heart Failure, Systolic
Lead sponsor: Queen's University
Sponsor class: OTHER
First posted: 2015-03-27
Enrollment: 13
Sex: ALL
Minimum age (years): 40
Maximum age (years): 80
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: TREATMENT

Brief 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.

Detailed 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.

Eligibility criteria: 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).

Primary outcomes:
measure: Exercise tolerance
timeFrame: 8 days
Secondary outcomes:
measure: Plasma nitrate and nitrite concentrations
timeFrame: 8 days
measure: Central and peripheral fatigue
timeFrame: 8 days
measure: Skeletal muscle and cerebral blood flow and oxygenation
timeFrame: 8 days
measure: Neuromuscular activity
timeFrame: 8 days
measure: Dyspnea and leg effort scores
timeFrame: 8 days
measure: Cognitive performance
timeFrame: 8 days
measure: Cardiorespiratory responses to exercise
timeFrame: 8 days
Other outcomes:
Locations:
Study officials:
affiliation: Queen's University
name: J. Alberto Neder, MD, PhD
role: PRINCIPAL_INVESTIGATOR
References: