Progression of coronary artery calcium and risk of first myocardial infarction in patients receiving cholesterol-lowering therapy.
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.
Raggi
Paolo
P
Tulane University School of Medicine, New Orleans, La, USA. praggi@tulane.edu
Callister
Tracy Q
TQ
Shaw
Leslee J
LJ
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
D000924:Anticholesteremic Agents; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D008077:Lipoproteins, LDL