Impact of contrast volume on medium- to long-term renal function in patients undergoing repeated percutaneous coronary interventions

Background Contrast-associated nephropathy is a complication of cardiovascular procedures. Although contrast volume is a risk factor for acute kidney injury, its impact on medium- to long-term renal function remains unknown. This study aimed to investigate this association in patients undergoing repeated percutaneous coronary interventions (PCI). Methods This retrospective single-centre study included patients undergoing repeated PCIs between 2003 and 2023, with intervals of ≥7 and ≤ 365 days between procedures. Renal function was classified by “Kidney Disease: Improving Global Outcomes” (KDIGO) staging system. The maximum allowable contrast dose (MACD) was retrospectively calculated as individual threshold. Primary endpoint was progression to a higher KDIGO stage at readmission. Secondary endpoints included changes in estimated glomerular filtration rate (eGFR). Results In total 6714 patients were included (mean age 67.2 years; 80.2% male; KDIGO stage analysis available for 6611; median interval between procedures 127 days). Baseline mean eGFR was 74.4 mL/min/1.73 m 2 . Median contrast volume was 220 mL, and median MACD 300 mL. At readmission, mean eGFR was 72.2 mL/min/1.73 m 2 , 1700 Patients (25.7%) showed KDIGO stage progression. Neither contrast volume nor MACD exceedance was associated with renal deterioration. However, predispositions (diabetes mellitus, arterial hypertension, age), clinical presentation (STEMI, NSTEMI) and the vascular access route were significantly associated with adverse renal outcomes. Conclusions Contrast volume and MACD exceedance during PCI was not associated with deterioration of medium- to long-term renal function. Abbreviations PCI: Percutaneous coronary intervention eGFR: Estimated glomerular filtration rate KDIGO: Kidney Disease: Improving Global Outcomes MACD: Maximum allowable contrast dose CA-AKI: Contrast-associated acute kidney injury BMI: Body mass index HR: Hazard ratio CI: Confidence interval NSTEMI: Non-ST-segment elevation myocardial infarction STEMI: ST-segment elevation myocardial infarction