Hyperhomocysteinemia and the risk of restenosis after coronary artery stenting: fact or fiction?

The incidence of restenosis after coronary artery stent placement is approximately 38%. An interesting view has been stipulated: that hyperhomocysteinemia may be partly responsible for in-stent restenosis. Epidemiologic evidence exists that is persuasive in suggesting that individuals with occlusive vascular disease have a higher blood homocysteine concentration than control subjects. Thus, elevated plasma levels of homocysteine have been implicated as a risk factor for coronary artery disease. The composition of the current clinical knowledge on the question of whether hyperhomocysteinemia is a significant factor for restenosis of coronary artery stents consists of several trials with different approaches, objectives and outcomes. However, the current studies that have been published in the peer-reviewed medical literature have not reached a consensus as to whether an elevated plasma level of homocysteine is an independent risk factor responsible for restenosis following stent implantation. Our current knowledge as to the place of plasma homocysteine levels in the development of in-stent restenosis seems incomplete, and in the realm of homocysteine and restenosis of stents, there are plenty of questions that still remain to be answered.