Association between statin treatment and outcome in relation to renal function in survivors of myocardial infarction

Abstract

As statins are recommended at discharge to all patients following myocardial infarction (MI), we studied their use and efficacy in renal disease by analyzing the data, in the nationwide SWEDEHEART registry, of 42,814 consecutive survivors of MI with available creatinine/dialysis data but without statin therapy on admission. The estimated glomerular filtration rate (eGFR) was determined by the Modification of Diet in Renal Disease Study formula and the patients classified into the five traditional stages of kidney disease. The 1-year survival in relation to prescription of statin at discharge was assessed in a Cox regression analysis adjusted by a propensity score that described each individual's likelihood of being treated with a statin, established by 36 baseline characteristics and in-hospital therapies. Statin use at discharge decreased with increased renal impairment from 81% in eGFR stage 1 to 31% in eGFR stage 5. After adjusting for the propensity score and discharge medication, statin use was associated with a significant reduction in overall risk of death (hazard ratio 0.63), with a statistically significant interaction between statin therapy and the stage of renal function. Thus, statin use at discharge was associated with improved 1-year survival of patients in stages 2-4 (mild-to-severe) of renal insufficiency. This effect appears attenuated in those with stage 5 renal failure.