Background: The prognostic impact of contrast-associated acute kidney injury (CA-AKI) in patients undergoing chronic total occlusion (CTO) percutaneous coronary intervention (PCI) remains underestimated.

Methods: We examined 2707 consecutive procedures performed in a referral CTO center between 2015 and 2019. CA-AKI was defined as an increase in serum creatinine ≥0.3 mg/dl or ≥50% within 48 h post-PCI. Primary endpoints were in-hospital major adverse cardiac and cerebrovascular events (MACCE, composite of all-cause death, myocardial infarction, target vessel revascularization, stroke) and at 1-year of follow-up.

Results: The overall incidence of CA-AKI was 11.5%, respectively. Technical success was comparable (87.2% vs. 90.5%, p=0.056), whereas procedural success was lower in the CA-AKI group (84.3% vs. 89.7%, p=0.004). Overall in-hospital MACCE was 1.3%, and were similar in patients with and without CA-AKI (1.6% vs. 1.3%, p=0.655), however, pericardial tamponade requiring pericardiocentesis were significantly higher in patients with CA-AKI (2.2% vs. 0.5%, p=0.001). In multivariate analysis, CA-AKI was not independently associated with higher risk for in-hospital MACCE (adjusted odds ratio [OR] 1.34, confidence intervals 95% [CI] 0.45-3.19, p=0.563). At median follow-up time of 14 months (interquartile range [IQR], 11 to 35 months), 1-year MACCE was significantly higher in patients with versus without CA-AKI (20.8% vs. 12.8%, p<0.001), and CA-AKI has increased the risk for 1-year MACCE (adjusted hazard ratio [HR] 1.46, CI 95% 1.07-1.95, p=0.017) following CTO PCI.

Conclusions: CA-AKI in patients undergoing CTO PCI occurs approximately in one out of ten patients. Our study highlights that patients developing CA-AKI are at increased risk for long-term MACCE.

Keywords: percutaneous coronary intervention, contrast-associated acute kidney injury, outcomes

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