Statin treatment intensity, discontinuation and long-term outcome in patients with acute myocardial infarction and impaired kidney function.

Statin dosage in patients with acute myocardial infarction (AMI) and concomitant kidney dysfunction is a clinical dilemma. We studied discontinuation during the first year after an AMI and long-term outcome in patients receiving high versus low-moderate intensity statin treatment, in relation to kidney function. For the intention-to-treat analysis (ITT-A) we included all patients admitted to Swedish coronary care units for a first AMI between 2005-16 that survived in-hospital, had known creatinine and initiated statin therapy (N=112,727). High-intensity was initiated in 38.7%, low-moderate in 61.3%. In patients with eGFR<60 mL/min/1.73 m2, 25% discontinued treatment the first year, however discontinuation rate was similar regardless of statin intensity. After excluding patients that died, changed therapy or were non-adherent during the first year, 84,705 remained for the on-treatment analysis (OT-A). Patients were followed for 12.6 (median 5.6) years. In patients with eGFR 30-59 mL/min, high-intensity statin was associated with lower risk for the composite death, reinfarction or stroke both in ITT-A (HR 0.93; 95% CI, 0.87-0.99) and OT-A (HR 0.90; 0.83-0.99); the interaction test for OT-A indicated no heterogeneity for the eGFR<60 mL/min group (p=0.46). Similar associations were seen for all-cause mortality. We confirm that high-intensity statin treatment is associated with improved long-term outcome after AMI in patients with reduced kidney function. Most patients with reduced kidney function initiated on high-intensity statins are persistent after one year, and equally persistent as patients initiated on low-moderate intensity.