Association Between Non-Recovered Contrast-Associated Acute Kidney Injury and Poor Prognosis in Patients Undergoing Coronary Angiography

Background: Previous studies have shown that renal function recovery after acute kidney injury (AKI) was associated with decreased risk of all-cause mortality. However, little is known about the correlation between renal function recovery and long-term prognosis in patients with contrast-associated acute kidney injury (CA-AKI) undergoing coronary angiography (CAG).

Methods: We retrospectively enrolled 5,865 patients who underwent CAG. CA-AKI was defined as an increase in serum creatinine (SCr) ≥ 50% or ≥ 0.3 mg/dl from baseline within 72 h post procedure. Recovered CA-AKI was defined as a decrease in SCr to baseline or no CA-AKI level. The first endpoint was long-term all-cause mortality. Kaplan-Meier analysis and Cox regression analysis were used to investigate the association between kidney function recovery and long-term mortality.

Results: During the median follow-up period of 5.25 years, the overall long-term mortality was 20.07%, and the long-term mortality in patients with recovered CA-AKI and non-recovered CA-AKI was 17.46 and 27.44%, respectively. After multivariate Cox hazard regression, non-recovered CA-AKI was significantly associated with long-term mortality, while recovered CA-AKI was not [recovered CA-AKI vs. no CA-AKI, hazard ratio (HR) = 1.06, 95% confidence interval (CI): 0.81-1.39, p = 0.661; non-recovered CA-AKI vs. no CA-AKI, HR = 1.39, 95% CI: 1.21-1.60, p < 0.001]. In the subgroup of CAD, both recovered CA-AKI and non-recovered CA-AKI were associated with increased risk of long-term all-cause mortality. However, in other subgroup analyses, only non-recovered CA-AKI was associated with increased risk of long-term all-cause mortality.

Conclusion: Our results found that non-recovered CA-AKI is significantly associated with long-term mortality. In patients with CAD, recovered CA-AKI can still increase the risk of all-cause mortality. Clinicians need to pay more attention to patients suffering from CA-AKI, whose kidney function has not recovered. In addition, active prevention treatments should be taken by patients with CAD.