Total plasma homocysteine and restenosis after percutaneous coronary angioplasty: current evidence

BACKGROUND. Restenosis after percutaneous coronary angioplasty (PTCA) remains an important limitation of this procedure. AIM. To assess the relationship between homocysteine levels and restenosis after PTCA, and discuss the potential benefit of homocysteine-lowering therapy. METHOD. MEDLINE-based literature review. RESULTS. The conflicting literature on the association between homocysteine levels and restenosis after PTCA can partially be explained by differences in methodology. Depending on the type of studies considered, a pooling of data resulted in a 22%-36% risk reduction of restenosis in lesions exposed to low homocysteine levels. The strongest reduction was found in balloon-only treated lesions (42%), while only a trend (14%) was seen in stented lesions. Based on the only available trial, homocysteine-lowering therapy yielded a 54% restenosis rate reduction, 76% in balloon-only treated lesions and 31% in stented lesions. Furthermore, homocysteine-lowering therapy provided a significant clinical benefit with a 40% relative reduction in major adverse events at 6 months' follow-up. CONCLUSIONS. This review suggests that plasma homocysteine is a modifiable risk factor for restenosis, which when lowered improves outcome after PTCA. This inexpensive treatment with virtually no side-effects could therefore be considered as adjunctive therapy for patients undergoing PTCA, while awaiting results from further studies.