Abstract
The intravascular administration of iodine-based contrast media remains a common cause of acute kidney injury and a leading cause of iatrogenic renal disease. Past research has elucidated the principal risk factors for contrast-induced acute kidney injury (CIAKI) and helped to establish the efficacy of various interventions for the prevention of this condition. The importance of preventing CIAKI has been underscored by a growing number of studies showing strong associations of CIAKI with serious adverse short- and long-term outcomes. However, it remains unclear whether these associations are causal. This is important because considerable health care resources are used to prevent CIAKI. If CIAKI is a marker, but not a mediator, of serious adverse downstream outcomes, more judicious and selective use of preventive care may be appropriate. Moreover, with an increasing number of studies reporting the underuse of coronary angiography in patients with acute coronary syndrome and underlying chronic kidney disease, presumably in part because of a fear of CIAKI, a clear understanding of whether this condition directly results in adverse downstream outcomes is essential. Careful inspection of past studies that investigated the association of CIAKI with adverse short- and long-term events sheds light on their strengths and weaknesses and provides insight into how future research may be better able to characterize the short- and long-term implications of this iatrogenic condition.