Large, sustained cardiac lipid peroxidation and reduced antioxidant capacity in the coronary circulation after brief episodes of myocardial ischemia

Objective. We sought to investigate whether a brief episode of myocardial i schemia produces a detectable cardiac oxidative stress in patients undergoi ng elective coronary angioplasty (PTCA). Background. Although cardiac oxidative stress has been dearly demonstrated in experimental models of ischemia-reperfusion, its presence in patients af ter transient myocardial ischemia is still unclear. Methods. In order to evaluate oxidative stress in ischemic cardiac regions, plasma conjugated dienes (CD), lipid hydroperoxides (ROOHs) and total anti oxidant capacity (TRAP), independent indexes of oxidative stress, were meas ured in the aorta and great cardiac vein (GCV) before (t(0)), 1, (t(1)), 5 (t(5)) and 15 min (t(15)) after first balloon inflation in 15 patients unde rgoing PTCA on left anterior descending coronary artery (Group 1); six pati ents with right coronary artery stenosis (Group 2), which is not drained by the GCV, were studied as controls. Results. In Group 1 at baseline, CD and ROOHs levels were higher in GCV tha n in aorta (p < 0.01 for both), and TRAP levels were lower (p < 0.01). Aort ic levels of CD, ROOHs and TRAP did not change at any time after t(0); veno us levels of CD and ROOHs levels markedly increased at t(1), at t(5) and re mained elevated ar t(15) (P < 0.01 for all comparisons vs. t(0)); venous le vels of TRAP decreased at t(1) and t(5) (p < 0.01 vs. t(0)) and returned to normal at t(15). In Group 2, CD, ROOHs and TRAP levels were similar in the aorta and GCV and did not change throughout the study. Conclusions. Short episodes of myocardial ischemia duringPTCA induce a sust ained oxidative stress, which is detectable in the venous eifluent oireperf used myocardium. (C) 2000 by the American College of Cardiology.