Homocysteine, lipoprotein(a), and restenosis after percutaneous transluminal coronary angioplasty: A prospective study

Background Restenosis complicates 30% to 40% of angioplasty procedures and may be unrelated to traditional coronary risk factors. Homocysteine, lipopr otein(a), and methylenetetrahydrofolate reductase (MTHFR 677T) (a genetic d eterminant of plasma homocysteine concentrations) are novel risk factors fo r coronary artery disease. Their roles in restenosis are unclear, and the p otential synergism between homocysteine and lipoprotein(a) has not previous ly been studied. The objective of this study was to determine the relations among homocysteine, lipoprotein (a), MTHFR 677T, and restenosis after perc utaneous transluminal coronary angioplasty, Methods This prospective study enrolled patients with successful elective p ercutaneous transluminal coronary angioplasty or stenting of a single, de n ovo, native coronary lesion. Fasting blood was drawn the morning of the pro cedure for homocysteine, lipoprotein(a), and MTHFR 677T. Follow-vp angiogra phy was performed 6 months after the procedure or earlier if clinically ind icated. All cineangiograms were analyzed quantitatively. Results A total of 144 (92%) of 156 eligible patients underwent follow-up c oronary angiography. The overall angiographic restenosis rate (residual ste nosis >50%) was 31%. Mean homocysteine concentration was 10.1 +/- 3.7 mu mo l/L. Plasma homocysteine concentrations were not significantly different in patients with or without angiographic restenosis (9.6 +/- 3.3 vs 10.3 +/- 3.8 mu mol/L; P =.31). Mean lipoprotein(a) concentration was 21.2 +/- 20.1 mg/dl. Plasma lipoprotein(a) concentrations were not significantly differen t in patients with or without restenosis (21.9 +/- 21.8 vs 20.9 +/- 19.5 mg /dl), Homozygosity for MTHFR 677T was present in 6.5% and was not associate d with increased restenosis, No interaction between homocysteine and lipopr otein(a) was detected. Conclusions Homocysteine, lipoprotein(a), and MTHFR 677T are not associated with restenosis after percutaneous transluminal coronary angioplasty.