Mehran R, Owen R, Chiarito M, et al. - This study provides a contemporary simple risk score that enables an accurate discrimination of the risk of contrast-associated acute kidney injury following percutaneous coronary intervention (PCI). This risk score is based on easily accessible variables from patients undergoing PCI. The occurrence of contrast-associated acute kidney injury is strongly linked with subsequent death.

• This study involved patients undergoing PCI with available creatinine measurements both before and within 48 h after the procedure; 14 616 patients comprised the derivation cohort (treated between 2012 and 2017; mean age 66·2 years, 29·2% female) and 5606 comprised the validation cohort (treated between 2018 and 2020; mean age 67·0 years, 26·4% female).

• Only pre-procedural variables were incorporated in Model 1, whereas Model 2 also included procedural variables.

• In 4·3% of participants, contrast-associated acute kidney injury occurred, and following were independent predictors of such injury in Model 1: clinical presentation, estimated glomerular filtration rate, left ventricular ejection fraction, diabetes, haemoglobin, basal glucose, congestive heart failure, and age.

• Additional independent predictors in Model 2 were also noted, and a gradual increase in contrast-associated acute kidney injury occurrence was observed, in the derivation cohort, from the lowest to the highest of the four risk score groups in both models (2·3% to 34·9% in Model 1, and 2·0% to 38·8% in Model 2).

• Slight improvement in discrimination of the risk score was achieved by including procedural variables (C-statistic in the derivation cohort: 0·72 for Model 1 and 0·74 for model 2; in the validation cohort: 0·84 for Model 1 and 0·86 for Model 2).

• Patients with contrast-associated acute kidney injury had a significantly elevated risk of 1-year deaths (adjusted hazard ratio 1·76) which was mainly because of excess 30-day deaths.