Statin use after acute myocardial infarction by patient complexity: Are the rates right?

Abstract

Background: Guidelines suggest statin use after acute myocardial infarction (AMI) should be close to universal in patients without safety concerns yet rates are much lower than recommended, decline with patient complexity, and display substantial geographic variation. Trial exclusions have resulted in little evidence to guide statin prescribing for complex patients. Objective: Assess the benefits and risks associated with higher rates of statin use after AMI by baseline patient complexity. Research Design: Sample includes Medicare fee-for-service patients with AMIs in 2008-2009. Instrumental variable estimators using variation in local area prescribing patterns by statin-intensity as instruments were used to assess the association of higher statin prescribing rates by statin-intensity on 1-year survival, adverse events, and cost by patient complexity. Results: Providers appear to have individualized statin use across patients based on potential risks. Higher statin rates for non-complex AMI patients were associated with increased survival rates with little added adverse event risk. Higher statin rates for complex AMI patients were associated with tradeoffs between higher survival rates and higher rates of adverse events. Conclusions: Higher rates of statin use for non-complex AMI patients are associated with outcome rate changes similar to existing evidence. For the complex patients in our study, who were least represented in existing trials, higher statin-use rates were associated with survival gains and higher adverse event risks not previously documented. Policy interventions promoting higher statin-use rates for complex patients may need to be re-evaluated taking careful consideration of these tradeoffs.