Coronary Artery Bypass and Nitrate Oral Supplementation (CABANOS)

Karolinska Institute

Status and phase: Completed; Phase 2

Conditions: Coronary Artery Disease

Treatments: Dietary Supplement: Sodium nitrate; Other: Sodium chloride

Study type: Interventional

Funder types: Other

Identifiers

NCT01348971

KI-101

Details and patient eligibility

About

The purpose of this study is to determine whether oral sodium nitrate administration prior to coronary artery bypass surgery can reduce perioperative levels of troponin T. In addition, plasma and urine surrogate markers of renal, hepatic and brain injury will be monitored.

Full description

Nitric oxide (NO) is an important mediator in the cardiovascular system and has been shown to have protective properties in ischemia-reperfusion injury. Inorganic nitrate, an oxidation product from endogenous NO production and also a constituent in green leafy vegetables, can be recycled, via nitrite, back to bioactive NO in the body. Recent research has shown beneficial effects of nitrate and nitrite in animal models of myocardial ischemia-reperfusion injury. Moreover, dietary nitrate reduces blood pressure and oxygen cost during exercise in humans.

During coronary bypass surgery the heart undergoes ischemia-reperfusion injury and troponin T is most often released from the myocardium. The aim of the present study is to investigate if preoperative inorganic nitrate, in doses easily achievable from the diet, can affect troponin T release as well as other surrogate markers of injury to the liver, kidneys and the brain. In addition, plasma and urine samples will be collected for markers of oxidative stress and inflammation (sCRP and cytokines). Patients planned for bypass surgery who give their written informed consent will, the night before surgery, get a standardized, low-nitrate meal where after they receive sodium nitrate on two occasions preoperatively; the night before and in the morning before surgery. Plasma and urine samples will be collected at various time points up to 72 hours after surgery.

Enrollment: 100 estimated patients

Sex: All

Ages: 18 to 80 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Patients undergoing coronary artery bypass surgery
• Over 18 years of age

Exclusion criteria

• Over 80 years of age
• Pregnancy
• Reoperation
• Intended heart valve or additional surgery
• Angina or troponin release above 45 nmol/L < 48 hours before surgery
• Medication with organic nitrates/nitrites < 24 hours before surgery
• Medication with glibenclamide or corticosteroids
• Significant renal, pulmonary or hepatic disease

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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100 participants in 2 patient groups, including a placebo group

Sodium nitrate

Experimental group

Description:

Preoperative oral administration of sodium nitrate. 700 mg the night before surgery and 700 mg three hours before surgery

Treatment:

Dietary Supplement: Sodium nitrate

Placebo

Placebo Comparator group

Description:

Preoperative oral administration of sodium chloride the night before surgery and three hours before surgery

Treatment:

Other: Sodium chloride