title: Progression of coronary artery calcium and risk of first myocardial infarction in patients receiving cholesterol-lowering therapy.
abstract: OBJECTIVE
  Statins reduce cardiovascular risk and slow progression of coronary artery calcium (CAC). We investigated whether CAC progression and low-density lipoprotein (LDL) reduction have a complementary prognostic impact.
  
  
  RESULTS
  We measured the change in CAC in 495 asymptomatic subjects submitted to sequential electron-beam tomography (EBT) scanning. Statins were started after the initial EBT scan. Myocardial infarction (MI) was recorded in 41 subjects during a follow-up of 3.2+/-0.7 years. Mean LDL level did not differ between groups (118+/-25 mg/dL versus 122+/-30 mg/dL, MI versus no MI). On average, MI subjects demonstrated a CAC change of 42%+/-23% yearly; event-free subjects showed a 17%+/-25% yearly change (P=0.0001). Relative risk of having an MI in the presence of CAC progression was 17.2-fold (95% CI: 4.1 to 71.2) higher than without CAC progression (P<0.0001). In a Cox proportional hazard model, the follow-up score (P=0.034) as well as a score change >15% per year (P<0.001) were independent predictors of time to MI.
  
  
  CONCLUSIONS
  Progression of CAC was significantly greater in patients receiving statins who had an MI compared with event-free subjects despite similar LDL control. Continued expansion of CAC may indicate failure of some patients to benefit from statin therapy and an increased risk of having cardiovascular events.
authors.affiliation: Tulane University School of Medicine, New Orleans, La, USA. praggi@tulane.edu
authors.forename: Paolo
authors.initials: P
authors.lastname: Raggi
authors.forename: Tracy Q
authors.initials: TQ
authors.lastname: Callister
authors.forename: Leslee J
authors.initials: LJ
authors.lastname: Shaw
mesh_terms: D000328:Adult; D000368:Aged; D000924:Anticholesteremic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D002114:Calcinosis / Q000097:blood / Q000000981:diagnostic imaging / Q000453:epidemiology*; D003324:Coronary Artery Disease / Q000097:blood / Q000000981:diagnostic imaging / Q000453:epidemiology*; D018450:Disease Progression; D018572:Disease-Free Survival; D004351:Drug Resistance; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D006937:Hypercholesterolemia / Q000150:complications / Q000188:drug therapy*; D008077:Lipoproteins, LDL / Q000097:blood; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology* / Q000209:etiology; D016016:Proportional Hazards Models; D012306:Risk; D014057:Tomography, X-Ray Computed
chemical_list: D000924:Anticholesteremic Agents; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D008077:Lipoproteins, LDL