OBJECTIVES: Contrast-induced nephropathy (CIN) is a common and morbid complication of percutaneous coronary intervention (PCI), occurring in up to 5% of patients. CIN after PCI not only increases the morbidity/mortality risk, but is also associated with a large potential impact on costs, particularly in elderly Medicare patients. Our objective was to estimate the short- and long-term economic impact of CIN in Medicare patients undergoing PCI.

METHODS: Patients undergoing inpatient PCI between 1/1/2017 and 6/30/2020 were identified from Medicare 100% administrative and claims data. PCI, and CIN within the PCI admission, were identified using diagnosis and procedure codes. Patients diagnosed with CIN during their index admission were propensity-score matched (PSM) 1:1 to non-CIN patients. We identified total payer costs (Medicare paid amount inflated to 2020) from 6 months before, up to 12 months after PCI. After PSM matching confirmed no cost differences during 6 months before index PCI, doubly robust, generalized linear modelling was used to estimate the expected cumulative cost difference in those with CIN (vs. without) during the index admission and during 12 months of follow-up.

RESULTS: Among 8,930 propensity-matched patients (4,465 each group), the mean age was 77, 56% were male, 85% were white, and 47% had an Elixhauser score ≥5. After PSM, standardized differences among demographic, clinical, and procedural variables were <0.1. The average cost of the index admission was $35,181 for CIN compared with $29,995 for no CIN (Δ $5,186: P<0.001). The average cumulative cost during 12 months follow-up was $69,425 and $59,105, respectively (Δ $10,320: P<0.001).

CONCLUSIONS: CIN after PCI has a large economic impact on the US health system. CIN is associated with increased costs during the index hospitalization, which increase further at 12 months. Additional research is warranted to assess the economic and clinical impact of the adoption of contrast-sparing strategies and protocols.