Validation of a predictive risk score for radiocontrast-induced nephropathy following percutaneous coronary intervention

OBJECTIVE: We sought to externally validate the William Beaumont Hospital (WBH) risk score for radiocontrastinduced nephropathy (RCIN) following percutaneous coronary intervention (PCI). Background. RCIN is associated with increased mortality and morbidity following PCI and accounts for increased hospital costs and length of stay. METHODS: A total of 4,814 PCI procedures were used for validation of the WBH risk score, using a >1.0 mg/dl increase in serum creatinine (Cr) as the definition of RCIN. Clinical and procedural details were identified within the Mayo Clinic PCI registry. Multiple imputation was used to impute values where missing. Five imputation sets were created and averaged to compute the final estimate. RESULTS: Follow-up Cr was available in 3,213 (67%) of procedures and RCIN occurred in 1.9% of cases. Baseline Cr clearance was missing in 13%. All other risk factors used to calculate the risk score were missing in 25% of the procedures. The risk score has the ability to discriminate well between patients at low and high risk of post-PCI RCIN; c-statistic ≤ 0.86. In-hospital mortality occurred in 6.6% (4/61) with RCIN vs. 1.2% (37/3152) without RCIN. The odds ratio for in-hospital mortality is 5.3 (95% CI, 1.9, 15.0; p ≤ 0.002) for those with RCIN vs. those without. CONCLUSIONS: The WBH risk score can identify patients at high and low risk of RCIN following PCI. Use of this risk score can identify patients at high risk of RCIN development and direct the use of preventative measures to the highest-risk population, improving patient outcome and prognosis.