A simple pre-procedural risk score for contrast-induced nephropathy among patients with chronic total occlusion undergoing percutaneous coronary intervention

Contrast-induced nephropathy (CIN) had been demonstrated to be associated with short- and long-term adverse outcomes in patients after percutaneous coronary intervention (PCI) [1–3]. Complex PCI procedure for coronary chronic total occlusion (CTO) lesions with high risk of CIN may adversely affect the benefit of the revascularization success, because of patients with CTO–PCI administrated large contrast medium (CM), and are generally older and more likely to have reduced ventricular ejection function, and worse renal function than patients without CTO, which were risk factors of CIN [4].