Statins may act rapidly to reverse abnormalities of the arterial wall that may predispose to recurrent ischemic events after acute coronary syndromes. Such abnormalities are endothelial dysfunction, a local inflammatory response. and an exaggerated thrombogenic tendency. In one study almost 20,000 patients with first myocardial infarction were studied with regard to statin treatment (28%) or not. Baseline characteristics were adjusted using multivariate regression analysis including propensity analysis. One year mortality was 3.7/5.0% in statin/not statin groups, respectively, P = 0.001, relative risk 0.75. In another study of more than 20,000 patients, 18% were prescribed statin after an acute coronary syndrome and followed for six months. Propensity analysis was performed in this study as well. Deaths in statin/not statin groups were 1.7/3.5%, P<0.0001, relative risk 0.48. In the Myocardial Ischemia Reduction with Aggressive Cholesterol Lowering (MIRACL), a double-blind randomized, placebo-controlled intervention study, 3086 patient with acute non-Q-wave coronary syndromes were allocated immediately in hospital to receive atorvastatin 80 mg daily or placebo for four months. No lower limit for plasma LDL cholesterol was used. Primary endpoint was time to first occurrence of death, non-fatal myocardial infarction, cardiac arrest, and worsening angina with objective evidence of ischemia. This was significantly reduced compared to the placebo group by 2.4% (14.8 versus 17.2%, relative risk 0.84, P= 0.048). Atorvastatin also reduced significantly fatal or non-fatal strokes. Possible mechanisms behind these acute beneficial effects are discussed. The studies highlight the importance of treatment with a statin in the early management of acute coronary syndromes and the need to incorporate this therapeutic strategy in national guidelines and treatment recommendations.