Diabetes Mellitus and Cardiovascular Events in Older Patients With Myocardial Infarction Prescribed Intensive-Dose and Moderate-Dose Statins

BACKGROUND: Practice guidelines recommend intensive-dose statins for patients with acute coronary syndrome, but recent data about the risk of new-onset diabetes mellitus have raised concerns about its use. Our main objective was to evaluate the association between intensive statin therapy and new-onset diabetes mellitus in patients with myocardial infarction and to evaluate the association of intensive statin therapy with long-term adverse clinical outcomes. METHODS AND RESULTS: A propensity score-matched cohort was created consisting of 17 080 patients with myocardial infarction aged >65 years old, hospitalized in Ontario, Canada, from 2004 to 2010. Clinical outcomes were compared in patients prescribed intensive-dose versus moderate-dose statins at hospital discharge. At 5 years, 13.6% of patients receiving intensive-dose statins and 13.0% of patients receiving moderate-dose statins had new-onset diabetes, which was not significantly different (P=0.19). By contrast, the 5-year rate of death or acute coronary syndrome was significantly lower at 44.8% in the intensive-dose statin group compared with 46.5% in the moderate-dose group (P=0.044). The reduction in combined clinical outcome was driven mainly by a significantly lower rate of acute coronary syndrome (P=0.039) associated with intensive-dose statins. No significant difference in mortality rates (34.8% in both groups) was observed between the treatment groups during the study period (P=0.89). CONCLUSIONS: In older patients with myocardial infarction, we found intensive-dose statin therapy to be effective in reducing repeat hospitalization for acute coronary syndrome. The rate of new-onset diabetes mellitus at long term was not significantly different between intensive-dose and moderate-dose statins.