Randomised controlled trials (RCTs) were eligible for inclusion if they compared short-term high-dose statins versus short-term low-dose statins or placebo. Cohort studies that compared a chronic statin pre-treatment group with a statin-naive group were eligible for inclusion. Eligible studies were required to report incidence of CIN (defined as an increase in serum creatinine level >25% or ≥0.5mg/dL).
Most of the RCTs used coronary angiography with or without percutaneous coronary intervention. Statins (simvastatin or atorvastatin) were administered at doses that ranged from 140 to more than 460mg over two to more than seven days. The mean age of patients ranged from 54 to 76 years. Some patients had chronic kidney disease or diabetes. Some patients received additional preventative agents (oral N-acetylcysteine).
Most of the cohort studies used percutaneous coronary intervention alone. Statins used included pravastatin, simvastatin, atorvastatin and rosuvastatin. Treatment duration, where reported, ranged from more than one week to more than 28 days. Where reported, all patients in some studies had chronic kidney disease. Some patients had diabetes or chronic heart failure. The mean age of patients, where reported, ranged from 63.6 to 72.7 years.
Two reviewers independently screened studies for inclusion and resolved discrepancies by consensus.