title: Association between baseline lipoprotein (a) levels and restenosis after coronary stenting: meta-analysis of 9 cohort studies.
abstract: BACKGROUND
  Previous studies have shown inconsistent results on the association between baseline plasma Lipoprotein (a) [Lp(a)] levels and in-stent restenosis (ISR) after coronary stenting.
  
  
  OBJECTIVE
  We conducted a meta-analysis of observational studies to assess the association between baseline Lp(a) levels and the restenosis after successful coronary stenting.
  
  
  METHODS
  We searched for studies without language restriction in PubMed, Embase, Cochrane library, Ovid library database prior to October 2012. Random-effects method was applied to estimate the pooled standard mean difference (SMD). Heterogeneity, sensitivity and subgroup analysis were used to evaluate the results. Meta-regression analysis was employed to investigate sources of heterogeneity.
  
  
  RESULTS
  9 cohort studies including 1834 patients (600 ISR and 1234 no-ISR patients) were eligible for our analysis. Overall, we found significantly elevated baseline Lp(a) levels in ISR (in-stent restenosis) patients (SMD = 0.42, 95% CI: 0.14-0.71, P = 0.003). High heterogeneity existed between the individual studies (P < 0.001, I(2) = 86.9%). The association was stronger in the Asian population than the overall association found. Further, similar observations were made in the subgroup with drug-eluting stent and the group in which Lp(a) was assayed by immunoturbidimetry. Multivariable regression analysis suggested that ethnicity was the major source of heterogeneity in the data (P = 0.036).
  
  
  CONCLUSIONS
  Our meta-analysis suggests that significantly elevated baseline plasma Lp(a) level is associated with ISR. The Lp(a) level appears to be a good predictor of ISR, especially in the Asian population or patients who received drug-eluting stent implantation. Further research is warranted to evaluate the association by taking the ethnicity and type of stent into account.
authors: First Affiliated Hospital of Guangxi Medical University, Nanning 530021, China.
authors: Shan-yu
authors: SY
authors: Qin
authors: Jie
authors: J
authors: Liu
authors: Hai-xing
authors: HX
authors: Jiang
authors: Bang-li
authors: BL
authors: Hu
authors: You
authors: Y
authors: Zhou
authors: Vesa M
authors: VM
authors: Olkkonen
mesh_terms: D015906:Angioplasty, Balloon, Coronary / Q000379:methods*; D044466:Asian People; D002986:Clinical Trials as Topic; D015331:Cohort Studies; D017023:Coronary Angiography / Q000379:methods; D023903:Coronary Restenosis / Q000097:blood*; D054855:Drug-Eluting Stents; D006801:Humans; D017270:Lipoprotein(a) / Q000097:blood*; D008875:Middle Aged; D015999:Multivariate Analysis
chemical_list: D017270:Lipoprotein(a)