Myocardial injury in major aortic surgery

Purpose: The purpose of this study was to examine the effects of major aort ic surgery and its associated oxidative stress and injury on the myocardium . Methods: Plasma from 27 patients who underwent thoracoabdominal aortic aneu rysm (TAAA) repair and 17 patients who underwent infrarenal aortic aneurysm (AAA) repair was collected at incision, aortic crossclamping, and reperfus ion and 1, 8, and 24 hours thereafter. Samples were assayed for the myocard ial specific protein troponin-T, total antioxidant status, and lipid hydrop eroxides. Results: Ten patients experienced cardiac dysfunction in the fu-st 24 hours after surgery (eight patients in the TAAA group and two patients in the AA A group). Immediately after reperfusion, total antioxidant status levels dr opped in all patients with TAAA and with AAA; this was more marked in patie nts with TAAA, leading to a significant difference between the two groups a t this time point and for up to 1 hour thereafter (P < .01). Patients with TAAA showed a sharp rise in lipid hydroperoxide levels immediately after re perfusion, and levels were significantly higher than in patients with AAA ( P = .0007). In patients with AAA, no significant change in troponin-T was o bserved throughout the study period; whereas in patients with TAAA, levels were significantly elevated at 8 and 24 hours after reperfusion (P < .01). Troponin-T levels significantly correlated with total antioxidant status (r = -0.5) and lipid hydroperoxides (r = 0.78) but not with systolic blood pr essure. Conclusion: Supracoeliac aortic crossclamping is associated with a signific ant release of the myocardial injury marker troponin-T. This seems to corre late with the severity of oxidative rather than hemodynamic stresses. Ameli orating oxidative injury during TAAA surgery may therefore have a cardiopro tective effect.