title: Genetic risk prediction and a 2-stage risk screening strategy for coronary heart disease.
abstract: OBJECTIVE
  Genome-wide association studies have identified several genetic variants associated with coronary heart disease (CHD). The aim of this study was to evaluate the genetic risk discrimination and reclassification and apply the results for a 2-stage population risk screening strategy for CHD.
  
  
  RESULTS
  We genotyped 28 genetic variants in 24 124 participants in 4 Finnish population-based, prospective cohorts (recruitment years 1992-2002). We constructed a multilocus genetic risk score and evaluated its association with incident cardiovascular disease events. During the median follow-up time of 12 years (interquartile range 8.75-15.25 years), we observed 1093 CHD, 1552 cardiovascular disease, and 731 acute coronary syndrome events. Adding genetic information to conventional risk factors and family history improved risk discrimination of CHD (C-index 0.856 versus 0.851; P=0.0002) and other end points (cardiovascular disease: C-index 0.840 versus 0.837, P=0.0004; acute coronary syndrome: C-index 0.859 versus 0.855, P=0.001). In a standard population of 100 000 individuals, additional genetic screening of subjects at intermediate risk for CHD would reclassify 2144 subjects (12%) into high-risk category. Statin allocation for these subjects is estimated to prevent 135 CHD cases over 14 years. Similar results were obtained by external validation, where the effects were estimated from a training data set and applied for a test data set.
  
  
  CONCLUSIONS
  Genetic risk score improves risk prediction of CHD and helps to identify individuals at high risk for the first CHD event. Genetic screening for individuals at intermediate cardiovascular risk could help to prevent future cases through better targeting of statins.
authors.affiliation: Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland.
authors.forename: Emmi
authors.initials: E
authors.lastname: Tikkanen
authors.forename: Aki S
authors.initials: AS
authors.lastname: Havulinna
authors.forename: Aarno
authors.initials: A
authors.lastname: Palotie
authors.forename: Veikko
authors.initials: V
authors.lastname: Salomaa
authors.forename: Samuli
authors.initials: S
authors.lastname: Ripatti
mesh_terms: D000328:Adult; D003327:Coronary Disease / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics* / Q000517:prevention & control; D018450:Disease Progression; D005260:Female; D005387:Finland / Q000453:epidemiology; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005820:Genetic Testing; D055106:Genome-Wide Association Study; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use; D016014:Linear Models; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D017720:Molecular Epidemiology; D018579:Patient Selection; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D011237:Predictive Value of Tests; D015995:Prevalence; D011314:Preventive Health Services; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors
keywords: cardiovascular genomics; genetic association; genetic epidemiology; risk factor; risk prediction