Association of dialysis-requiring acute kidney injury with 90-day prognosis in patients with coronary artery disease and advanced kidney disease after coronary angiography

BACKGROUND: Dialysis-requiring acute kidney injury (AKI-D) is a potentially serious complication associated with high in-hospital mortality among patients with coronary artery disease (CAD) after coronary angiography (CAG). Patients with existing advanced kidney disease (AKD) have an increased risk of developing AKI-D. However, few studies have investigated the prognosis of AKI-D in patients with both CAD and AKD. METHODS: In this observational study, 603 CAD patients with AKD (estimated glomerular filtration rate, eGFR <30 mL/min/1.73 m(2)) were enrolled. AKI-D was defined as acute or worsening renal failure requiring the initiation of renal dialysis. The primary endpoint was 90-day all-cause mortality. Kaplan-Meier and Cox regression analyses were used to assess the association of AKI-D and 90-day all-cause mortality among CAD patients complicated with AKD. RESULTS: Overall, among 603 CAD patients complicated with AKD, 83 patients (13.8%) required AKI-D. Patients underwent AKI-D had a significantly higher rate of 90-day mortality than those who did not (13.3% vs. 6.5%, log rank P=0.028), with an unadjusted hazard ratio (HR) of 1.28 [95% confidence interval (CI): 1.02–1.61, P=0.032]. After adjustment for cardiac and renal impairment, however, AKI-D was no longer associated with 90-day mortality (HR: 1.08, 95% CI: 0.84–1.39, P=0.559). The attenuation analysis showed that after adjustment for cardiac and renal function, the residual effect of 90-day mortality was as low as 30% of the unadjusted effect. CONCLUSIONS: The incidence of AKI-D is high among patients with CAD complicated by AKD. The high 90-day mortality rate of patients undergoing AKI-D is mainly attributable to cardio-renal impairment.