Homocysteine and malondialdehyde as predictors of restenosis following percutaneous coronary intervention
Restenosis is one of the major adverse outcomes of Percutaneous Coronary Intervention (PCI). Previous studies have shown conflicting reports for homocysteine as a predictor of restenosis following PCI. The conflicting reports may be due to oxidative factors (stimulation of polymorphonuclear leukocyte [PMNL]-induced reactive oxygen species generation, xanthine- xanthine oxidase, and arachidonic acid metabolism) other than homocysteine which could cause endothelial cell dysfunction leading to restenosis. Malondialdehyde (MDA), a lipid peroxidation product, is a marker for oxidative stress and is related to all oxidative factors. Therefore, it is possible that serum MDA may be a better predictor of restenosis than plasma homocysteine. The purpose of this study is to determine whether or not the pre-procedural serum MDA and plasma homocysteine levels are elevated in patients who develop restenosis post PCI. The study included fifty-one patients undergoing elective PCI who consented to participate in a protocol that was approved by the Ethics Committee of the University of Saskatchewan. Homocysteine and malondialdehyde were measured in the plasma and serum respectively. Blood samples were collected pre-procedural, 0 time, 8 hours, 24 hours, and 6 months post-procedure. Exercise tolerance tests were performed at two weeks, and six months post-procedure to determine if there was any evidence of restenosis. The results of the study showed that pre-procedural values of plasma homocysteine in the restenosis and non-restenosis groups were 10.37 ± 0.46 and 10.73 ± 0.49 respectively. These values were not significantly different (p=0.60) between the groups. The pre-procedural levels of plasma homocysteine were not significantly different (p=0.08) from the post-PCI values of those patients who did not develop restenosis at the 6-month time interval. However, the pre-procedural levels of plasma homocysteine were significantly different from the post-PCI values of those patients in the restenosis group at the 24hr (p=0.04) and 6-month (p=0.002) time intervals. In the restenosis group there was a significant increase (24%) after six months in the values of homocysteine from the pre-procedural levels. Thus, this indicates that restenosis is associated with higher post-PCI levels of homocysteine. The pre-procedural levels of serum MDA in the restenosis and non-restenosis groups were 0.124± 0.16 and 0.147± 0.02 respectively. There was no significant difference (p=0.60) between the two groups. There was also no significant difference (p=0.053) between the pre-procedural values and the 6-month post-PCI values in those patients who did not develop restenosis. However, there was a significant difference (p=0.001) between the pre-procedural values and the 6-month post-PCI values in those patients who developed restenosis. The levels of serum MDA in patients with restenosis at 6-months increased by 109% and were significantly different (p=0.001) in the restenosis group. The results suggest that pre-procedural levels of plasma homocysteine and serum MDA were not predictors of restenosis following PCI. However, the post-PCI six-month levels of both homocysteine and MDA are predictors of restenosis. Moreover, the post-PCI levels of MDA were better predictors of restenosis than the post-PCI levels of homocysteine because the increase in MDA levels were greater at six months than the rise in homocysteine levels at the same time interval.
DegreeMaster of Science (M.Sc.)
SupervisorQureshi, Mabood; Prasad, Kailash
Copyright DateApril 2006
Coronary Artery Disease