Remote ischaemic preconditioning protects against cardiopulmonary bypass-induced tissue injury: a preclinical study.
OBJECTIVE
To test the hypothesis that remote ischaemic preconditioning (rIPC) reduces injury after cardiopulmonary bypass (CPB).


METHODS
Randomised study with an experimental model of CPB (3 h CPB with 2 h of cardioplegic arrest). Twelve 15 kg pigs were randomly assigned to control or rIPC before CPB and followed up for 6 h.


METHODS
rIPC was induced by four 5 min cycles of lower limb ischaemia before CPB.


METHODS
Troponin I, glial protein S-100B, lactate concentrations, load-independent indices (conductance catheter) of systolic and diastolic function, and pulmonary resistance and compliance were measured before and for 6 h after CPB.


RESULTS
Troponin I increased after CPB in both groups but during reperfusion the rIPC group had lower concentrations than controls (mean area under the curve -57.3 (SEM 7.3) v 89.0 (11.6) ng.h/ml, p = 0.02). Lactate increased after CPB in both groups but during reperfusion the control group had significantly more prolonged hyperlactataemia (p = 0.04). S-100B did not differ between groups. Indices of ventricular function did not differ. There was a tendency to improved lung compliance (p = 0.07), and pulmonary resistance changed less in the rIPC than in the control group during reperfusion (p = 0.02). Subsequently, peak inspiratory pressure was lower (p = 0.001).


CONCLUSIONS
rIPC significantly attenuated clinically relevant markers of myocardial and pulmonary injury after CPB. Transient limb ischaemia as an rIPC stimulus has potentially important clinical applications.
Kharbanda
R K
RK
University of Cambridge, Cambridge, UK. r.kharbanda@rbht.nhs.uk
Li
J
J
Konstantinov
I E
IE
Cheung
M M H
MM
White
P A
PA
Frndova
H
H
Stokoe
J
J
Cox
P
P
Vogel
M
M
Van Arsdell
G
G
MacAllister
R
R
Redington
A N
AN
D000818:Animals; D002302:Cardiac Output / Q000502:physiology; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D019157:Ischemic Preconditioning, Myocardial / Q000379:methods*; D019344:Lactic Acid / Q000378:metabolism; D008168:Lung / Q000502:physiology; D017202:Myocardial Ischemia / Q000378:metabolism / Q000503:physiopathology / Q000601:surgery*; D015428:Myocardial Reperfusion Injury / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control*; D009414:Nerve Growth Factors / Q000378:metabolism; D011897:Random Allocation; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000378:metabolism; D013552:Swine; D019210:Troponin I / Q000378:metabolism; D014655:Vascular Resistance
D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; D019210:Troponin I; D019344:Lactic Acid