Predictors of contrast-induced nephropathy in chronic total occlusion percutaneous coronary intervention

Contrast-induced nephropathy (CIN) is a leading cause of morbidity and mortality in patients undergoing percutaneous coronary intervention (PCI). Limited data, however, are available on predictors of CIN in PCI for chronic total occlusion (CTO) lesions. The aim of the study was to determine the risk of developing CIN in patients undergoing CTO PCI by studying the effects of clinical variables, interventional techniques, and CTO lesion characteristics on renal function.

This retrospective analysis included consecutive patients referred for CTO PCI between January 2002 and December 2009. CIN was defined as an elevated serum creatinine level ≥25% of baseline serum creatinine level at 48-72 hours after procedure. Patient characteristics, Mehran score, lesion characteristics, interventional procedure, and devices used were compared between CIN and non-CIN groups. For the 516 patients eligible for analysis, the incidence of CIN was 5.4% (28/516). Two patients needed transient haemodialysis (0.4%, 2/516). Analysis of risk using Mehran scoring found that the incidence of CIN was 0.5% (1/207) among low-risk patients, 3.4% (7/205) among moderate-risk patients, 15.9% (14/88) among high-risk patients and 37.5% (6/16) among very high-risk patients. The Mehran score high-risk group (11-15) and the very high-risk group (≥16) were definitely predictors of CIN after CTO PCI (OR: 27.022 [95% CI: 2.787-262.028, p=0.004]; OR: 32.512 [95% CI: 2.149-491.978, p=0.012]). Severe tortuosity was the only predictor of CIN after CTO PCI in angiographic and procedural findings (OR: 6.621 [95% CI: 1.090-40.227, p=0.040]).

Being in the Mehran score high-risk group (11-15) or the very high-risk group (≥16) and severe tortuosity were predictors of CIN after CTO PCI.