Ischemic preconditioning may provide a systemic organ protection,evident as the phenomenon known as remote preconditioning. Unstable angina may be a clinical analogue to ischemic preconditioning. Veingraft harvesting induces inflammation of the graft wall. We hypothesized that preoperative unstable angina preconditions vein grafts and reduces the inflammatory response to graft harvesting. Consecutive patients with stable or unstable angina undergoing open heart surgery (n = 12 in each group) were studied. Saphenous vein biopsies were collected at the start of graft harvesting, and when the last proximalanastomosis to the aorta was finished (average 112 minutes later). Gene expression of inflammatory mediators (tumor necrosis factor alpha, interleukin-1β (IL-1β), E-selectin (CD62E), intercellular leukocyte adhesion molecule1, inducible nitric oxide synthase, endothelin-1) increased after surgical handling (semiquantitative RT-PCR). In vein grafts from unstable patients the increase was attenuated for Il-1β (p < 0.004) and CD62E(p < 0.001). In stable patients the protein expression of IκBα and heat shock protein72 was reduced by surgical handling (p < 0.04), but was not influenced in unstable patients (immunoblotting). In vitro relaxation to acetylcholine was enhanced, and contractions to phenylephrine and endothelin-1 were attenuatedin veins rings from unstable patients (p < 0.003). In conclusion, surgical handling of vein grafts induces inflammation of the vessel wall. This response was reduced in grafts from patients with unstable angina, indicating a possible systemic preconditioning-like effect of acute coronary syndromes.
All Science Journal Classification (ASJC) codes
- Cardiology and Cardiovascular Medicine
- Physiology (medical)