Clinical trial NCT01348906: Intermittent Normoxia Reduces Myocardial Reperfusion Injury
Official title: Effect of Intermittent Normoxic Cardiopulmonary Bypass on Myocardial Reperfusion Injury in Adult Valve Replacement
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: Hyperoxia
Keywords: cardiopulmonary bypass
Lead sponsor: Central South University
Sponsor class: OTHER
First posted: 2011-05-06
Enrollment: 70
Sex: ALL
Minimum age (years): 25
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: This study aims to determine the effect of intermittent normoxic cardiopulmonary bypass (CPB) on inflammatory response, oxidative stress and myocardial reperfusion injury in adult patients undergoing valve replacement. The investigators hypothesized that nuclear factor kappa B (NFkB) was involved in regulating gene expression of myocardial inflammatory factor.

Detailed description: Methods:Patients meeting the requirement will be randomized into 2 groups: the control group received hyperoxic reperfusion (PaO2 180-250 mmHg) throughout CPB as routine; the treatment group underwent 3 cycles of 5/5 min normal/high oxygenation (PaO2 80-150/180-250 mmHg) during cardioplegia arrest, and maintained the same hyperoxia as the control group in the rest time of CPB. The clinical data of inotropes requirement, drainage, ventilation and intensive care time will be recorded. Venous blood samples will be taken perioperatively for detecting concentration of troponin I (cTnI), tumor necrosis factor-α , interleukin-6, 10, and malondialdehyde (MDA). Atrial biopsies will be removed before cardioplegia arrest and 30min after aortic de-clamping to determine the extent of neutrophil infiltration (myeloperoxidase activity), NFkB binding DNA activity, and gene expression of inflammatory factors (TNF-α, IL-6, 10).

Statistical analysis:A sample size of at least 32 patients in each group was needed to have a power of 90%, significance at the two-side 5% level, on the basis that a SD of 0.2 ng/ml and a difference in peak serum cTnI release of about 0.15 ng/ml between control and conditioned patients was determined.

Expected Results: The treatment group will have significantly lower release of cTnI, inflammatory factors, and MDA during CPB and afterwards. Intermittent normoxia may be related to less myocardial inflammation characterized by decreased myeloperoxidase activity, gene expression of inflammatory factors, the later may result from reduced activity of NFkB binding to DNA after reperfusion.

Eligibility criteria: Inclusion Criteria:

* rheumatic heart valve disease requiring selective aortic or double valve(aortic and mitral valve) replacement

Exclusion Criteria:

* infective endocarditis congenital valve disease previous cardiac surgery complicated with diabetes, coronary artery disease, hypertension or peripheral vascular disease.

receiving aspirin, corticosteroids, angiotensin-converting enzyme inhibitors or statin perioperatively

Primary outcomes:
measure: plasma concentration of troponin I
timeFrame: within the first 24h after cardiac surgery
Secondary outcomes:
measure: gene expression of TNFa, IL-6, and IL-10 in myocardium
timeFrame: 30 min after aotic de-clamping
Other outcomes:
Locations:
city: Changsha City
country: China
facility: Department of Cardiothoracic Surgery, Xiangya Hospital, Central South University
state: Hunan
Study officials:
References: