Safety margin of minimized contrast volume during percutaneous coronary intervention in patients with chronic kidney disease

Maximum allowable contrast dose (MACD) calculated as body weight × 5/serum creatinine has been a standard contrast dye volume (CV) used to decrease contrast-induced acute kidney injury. Recent advances in intravascular ultrasound-guided percutaneous coronary intervention (PCI) can dramatically minimize CV. The safe threshold when using an extremely low-dose CV is unknown. This study was designed as a multicenter, retrospective study of chronic kidney disease (CKD) patients with estimated glomerular filtration rate (eGFR) <30 ml/min/1.73 m² undergoing elective PCI. We divided the patients into three groups according to following criteria: (1) low dose, CV/eGFR ratio <1.0; (2) medium dose, CV/eGFR ratio ≥1 and <MACD; and (3) high dose, CV ≥MACD. A total of 100 patients were enrolled. Average age was 74 ± 8 years, 64 % were male and 48 % were diabetic. Mean baseline eGFR was 22.8 ± 6.0 ml/min/1.73 m². CV in the three groups was 15 ± 6 ml (n = 18), 69 ± 39 ml (n = 47) and 224 ± 99 ml (n = 35), respectively. The incidences of CI-AKI were 0, 11 and 23 %, respectively (p = 0.02). All-cause death or introduction of maintenance hemodialysis at 1 year was 0, 13.8 and 31 %, respectively (p = 0.01). Extreme reduction of CV to a CV/eGFR ratio <1.0 may reduce CI-AKI and achieve better clinical outcomes following PCI in patients with severe CKD.