Reversible preoperative renal dysfunction does not add to the risk of postoperative acute kidney injury after cardiac valve surgery

Abstract

ObjectiveTo evaluate the impact of the renal dysfunction (RD) type and change of postoperative cardiac function on the risk of developing acute kidney injury (AKI) in patients who underwent cardiac valve surgery.MethodReversible renal dysfunction (RRD) was defined as preoperative RD in patients who had not been initially diagnosed with chronic kidney disease (CKD). Cardiac function improvement (CFI) was defined as postoperative left ventricular ejection function – preoperative left ventricular ejection function (ΔEF) >0%, and cardiac function not improved (CFNI) as ΔEF ≤0%.ResultsOf the 4,805 (94%) cardiac valve surgery patients, 301 (6%) were RD cases. The AKI incidence in the RRD group (n=252) was significantly lower than in the CKD group (n=49) (36.5% vs 63.3%, P=0.018). The AKI and renal replacement therapy incidences in the CFI group (n=174) were significantly lower than in the CFNI group (n=127) (33.9% vs 50.4%, P=0.004; 6.3% vs 13.4%, P=0.037). After adjustment for age, gender, and other confounding factors, CKD and CKD + CFNI were identified as independent risk factors for AKI in all patients after cardiac valve surgery. Multivariate logistic regression analysis showed that the risk factors for postoperative AKI in preoperative RD patients were age, gender (male), hypertension, diabetes, chronic heart failure, cardiopulmonary bypass time (every 1 min added), and intraoperative hypotension, while CFI after surgery could reduce the risk.ConclusionFor cardiac valve surgery patients, preoperative CKD was an independent risk factor for postoperative AKI, but RRD did not add to the risk. Improved postoperative cardiac function can significantly reduce the risk of postoperative AKI.

Renal Injury in All-Comers After Transcatheter Aortic Valve Replacement: A Systematic Review and Meta-Analysis

“…One study showed that improvement in stroke volume and cardiac output after SAVR or TAVR increases the level of renal perfusion, which itself favors the improved renal function and supports our study's results. However, the study further claims that patients with baseline chronic kidney disease (CKD) are at increased risk of persistent renal injury and need RRT after aortic valve replacement [17]. One retrospective study concluded that as the estimated glomerular filtration rate drops below 30 ml/min/m2, the need for RRT is increased to one in six patients with mortality increasing to one in three in CKD-4 patients at one year [18].…”