Is there a true beneficial effect of statin therapy in the acute phase of unstable angina or myocardial infarction?

It has been claimed that early use of statins in acute coronary syndromes (ACS) protects patients against recurrent ischemic events. This protective effect takes place as early as 4 months after treatment initiation in non-ST elevation ACS, as reported in the MIRACL trial. Mechanisms such as improvement in endothelial function and inflammation are possible explanations for this early effect. These findings have been used to propose statins as part of the acute phase therapy. However, the use of statins during hospitalization is an unresolved issue, because there is a lack of evidence regarding the benefit of initiating therapy in the acute phase. Most randomized trials included patients after several days of the index event and did not report in-hospital outcome. This review critically discusses the use of statins in ACS and the level of evidence regarding their beneficial effect in acute phase treatment.