Acute Dietary Nitrate in Dilated Cardiomyopathy

Study Overview
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Brief Summary
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Acute consumption of dietary nitrate (as beetroot juice) has been shown to improve exercise capacity in athletes, healthy adults and subjects with both peripheral vascular disease or COPD. Many patients with dilated cardiomyopathy have reduced exercise capacity, The investigators hypothesized that acute nitrate consumption might increase incremental shuttle walk test (ISWT) distance in dilated cardiomyopathy subjects compared to a placebo beetroot juice.

Detailed Description
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Acute consumption of dietary nitrate (as beetroot juice) has been shown to improve exercise capacity in athletes, healthy adults and subjects with both peripheral vascular disease or COPD. Many patients with dilated cardiomyopathy have reduced exercise capacity, The investigators hypothesized that acute nitrate consumption might increase incremental shuttle walk test (ISWT) distance in dilated cardiomyopathy subjects compared to a placebo beetroot juice. This study is a randomized, double-blind placebo-controlled, crossover trial. Resting blood pressure, phlebotomy and ISWT will be performed. Following completion, each subject is randomized to consume beetroot juice or placebo. 3 hours later, the same assessments are repeated by the same people. After a 7d washout, the entire protocol is repeated with the crossover beverage.

Official Title
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Dietary Nitrate Supplementation in Dilated Cardiomyopathy: An Acute, Double-blind, Randomized, Placebo-controlled, Crossover Trial.

Conditions
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Cardiomyopathy

Intervention / Treatment
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* Dietary Supplement: Dietary nitrate
* Dietary Supplement: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Clinically stable, Confirmed non-ischemic, dilated cardiomyopathy Exclusion Criteria: Active musculo-skeletal conditions Ischemic heart disease Pulmonary hypertension COPD Taking vasodilators Diabetes mellitus

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Supportive Care
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Nitrate rich beetroot juice<br>Concentrated, beetroot juice is a rich source of dietary nitrate. | Dietary Supplement: Dietary nitrate<br>* 140ml of nitrate rich beetroot juice provides 12.9mmol nitrate and will be on a single occasion by the study subjects.<br>* Other names: Beetroot juice;|
| Placebo Comparator: Nitrate depleted placebo beetroot juice<br>Placebo beetroot juice is identical to active beetroot juice in every way except nitrate content. | Dietary Supplement: Placebo<br>* 140ml of nitrate depleted beetroot juice provides 0.5mmol nitrate and will be on a single occasion by the study subjects.<br>* Other names: Nitrate depleted beetroot juice;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change between incremental shuttle walk test distance pre and post juice |  | Day 1 and day 8 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Clinic blood pressure |  | Day 1 and day 8 | 
| Plasma nitrate |  | Day 1 and day 8 | 
| Dyspnoea using self report, validated Borg scale |  | Day 1 and day 8 | 
| Oxygen saturation using pulse oximetry |  | Day 1 and day 8 | 
| Plasma nitrite |  | Day 1 and day 8 |