title: Pregnancy-associated plasma protein A predicts adverse vascular events in patients with coronary heart disease: a systematic review and meta-analysis.
abstract: BACKGROUND
  Prospective studies about the association between elevated circulating pregnancy-associated plasma protein A (PAPP-A) and adverse vascular events in patients with coronary heart diseases (CHD) are inconsistent. We performed a meta-analysis to clarify this issue.
  
  
  METHODS
  We identified prospective studies by searching MEDLINE. The vascular outcomes included all-cause mortality, combination of all-cause mortality and non-fatal myocardial infarction (MI), and combined cardiovascular events. Prospective studies providing multivariable adjusted relative risks (RRs) and their 95% confidence intervals (CIs) of pre-mentioned outcomes were included. A random-effects model was used to calculate the pooled RRs. Subgroup and sensitivity analyses were used to explore the potential sources of heterogeneity or modifiable factors.
  
  
  RESULTS
  Fourteen studies with a total of 12 830 participants were included. Elevated PAPP-A level was associated with all-cause mortality (pooled RR 1.74, 95% CI: 1.45 to 2.09, p < 0.001), combined all-cause mortality and non-fatal MI (RR 1.59, 95% CI: 1.37 to 1.85, p < 0.001) and combined cardiovascular events (RR 1.50, 95% CI: 1.22 to 1.85, p < 0.001). There was no significant heterogeneity. Subgroup and sensitivity analyses showed that the positive association was not affected by follow-up term, CHD type, different assay methods of PAPP-A, or studies with less than 5 adjusted variables.
  
  
  CONCLUSIONS
  Elevated serum PAPP-A level is associated with adverse vascular outcomes in patients with CHD.
authors.affiliation: State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China ; Hypertension Division, Fuwai Hospital, National Center for Cardiovascular Diseases, Beijing, China ; Sino-German Laboratory for Molecular Medicine, Fuwai Hospital, National Center for Cardiovascular Diseases, Beijing, China.
authors.forename: Yuehua
authors.initials: Y
authors.lastname: Li
authors.forename: Chenghui
authors.initials: C
authors.lastname: Zhou
authors.forename: Xianliang
authors.initials: X
authors.lastname: Zhou
authors.forename: Lihuan
authors.initials: L
authors.lastname: Li
authors.forename: Rutai
authors.initials: R
authors.lastname: Hui
keywords: coronary heart disease; meta-analysis; mortality; myocardial infarction; pregnancy-associated plasma protein A; revascularization