Impact of Statin Pretreatment on the Incidence of Plaque Rupture in ST-elevation Acute Myocardial Infarction

Objective: Several studies in experimental animals have shown that statins stabilize atheromatous plaques by increasing fibrous-cap thickness. However, direct evidence linking the use of statins to the incidence of plaque rupture in humans is lacking. We investigated whether statin treatment before the onset of ST-elevation myocardial infarction (STEMI) influences the incidence of plaque rupture detected by intravascular ultrasound (IVUS).

Methods: The study enrolled 458 patients with STEMI who were admitted within 6h from symptom onset. IVUS interrogation was performed before percutaneous coronary intervention.

Results: Plaque ruptures were detected in 262 patients (57%). Patients with statin pretreatment (n=68) had a lower incidence of plaque rupture than those without (37% vs. 61%, p<0.001). Univariate analysis revealed that smoking (p=0.003), lower high-density lipoprotein cholesterol (p=0.001), and a lack of statin pretreatment (p<0.001) were associated with a higher incidence of plaque rupture. Multivariate logistic regression analysis identified statin pretreatment as a negative determinant of plaque rupture independent of age, gender, coronary risk factors, and all other medications (odds ratio 0.35; 95% CI 0.19-0.66, p=0.001). Positive remodeling was also associated with plaque rupture (p<0.001), and the relationship between statin pretreatment and a lower incidence of plaque rupture persisted after adjustment for positive remodeling (odds ratio 0.42; 95% CI 0.22-0.80, p=0.009).

Conclusions: Statin treatment before the onset of STEMI is associated with a lower incidence of plaque rupture, suggesting that the prevention of plaque rupture may be a crucial mechanism underlying clinical benefits associated with statins.