Impact of Cardiac Function Improvement on Cardiac Surgery Associated Acute Kidney Injury for Patients with Preoperative Renal Dysfunction
Background: We aim to investigate whether the postoperative cardiac function improve or not would affect the risk of cardiac surgery associated acute kidney injury (AKI) for patients with preoperative renal dysfunction. Method: Data from patients underwent cardiac surgery from April 2012 to February 2016 were collected. Renal dysfunction was defined as preoperative SCr >1.2 mg/dL (females) or >1.5 mg/dL (males). Patients were grouped as normal renal function group, renal dysfunction with
... unction with chronic kidney disease (CKD group), and non CKD group. △LVEF=postoperative LVEF - preoperative LVEF. Cardiac function improved was defined as △LVEF ≥10. Patients were further divided into non CKD & cardiac function improved (non CKD+), non CKD & cardiac function not improved (non CKD-), CKD & cardiac function improved (CKD+) and CKD & cardiac function not improved (CKD-) subgroups.Results: A total of 8,661 patients were allocated as normal renal function (n=7,903), non CKD(n = 662) and CKD (n = 136) groups. Both non CKD and CKD groups had higher AKI incidence than normal function group (39.5% vs 30.0%, P < 0.001; 61.8% vs 30.0%, P<0.001), and non CKD+ group had the similar AKI incidence with normal function group (30.9% vs 30.0%, P=0.729). Multivariate logistic regression analysis revealed that non CKD-, CKD+ and CKD- were significant risk factors, whereas non CKD+ was not a significant risk factor for postoperative AKI. The SCr at discharge in non CKD+ subgroup was significantly lower than its preoperative SCr (1.4 ± 0.8 vs 1.7 ± 0.9 mg/dL, P = 0.020).Conclusions: For renal dysfunction patients with no CKD, the risk of postoperative AKI did not exist if the cardiac function improved after surgery. For CKD patients, the risk of postoperative AKI increase regardless whether the cardiac function improved or not.