Cardiac surgery-associated acute kidney injury (CSA-AKI) is a common and serious postoperative complication of cardiac surgery requiring cardiopulmonary bypass (CPB), and it is the second most common cause of AKI in the intensive care unit. Although the complication has been associated with the use of CPB, the etiology is likely multifactorial and related to intraoperative and early postoperative management including pharmacologic therapy. To date, very little evidence from randomized trials supporting specific interventions to protect from or prevent AKI in broad cardiac surgery populations has been found. The definition of AKI employed by investigators influences not only the incidence of CSA-AKI, but also the identification of risk variables. The advent of novel biomarkers of kidney injury has the potential to facilitate the subclinical diagnosis of CSA-AKI, the assessment of its severity and prognosis, and the early institution of interventions to prevent or reduce kidney damage. Further studies are needed to determine how to optimize cardiac surgical procedures, CPB parameters, and intraoperative and early postoperative blood pressure and renal blood flow to reduce the risk of CSA-AKI. No pharmacologic strategy has demonstrated clear efficacy in the prevention of CSA-AKI; however, some agents, such as the natriuretic peptide nesiritide and the dopamine agonist fenoldopam, have shown promising results in renoprotection. It remains unclear whether CSA-AKI patients can benefit from the early institution of such pharmacologic agents or the early initiation of renal replacement therapy.

Among elective cardiac surgical patients with normal resting glomerular filtration rates, preoperative RFR was highly predictive of AKI. A reduced RFR appears to be a novel risk factor for AKI, and measurement of RFR preoperatively can identify patients who are likely to benefit from preventive measures or to select for use of biomarkers for early detection. Larger prospective studies to validate the use of RFR in strategies to prevent AKI are warranted. ClinicalTrials.gov identifier: NCT03092947, ISRCTN Registry: ISRCTN16109759.

Cardiac surgery-associated acute kidney injury (CSA-AKI) is a common and serious postoperative complication of cardiac surgery requiring cardiopulmonary bypass (CPB), and it is the second most common cause of AKI in the intensive care unit. Although the complication has been associated with the use of CPB, the etiology is likely multifactorial and related to intraoperative and early postoperative management including pharmacologic therapy. To date, very little evidence from randomized trials supporting specific interventions to protect from or prevent AKI in broad cardiac surgery populations has been found. The definition of AKI employed by investigators influences not only the incidence of CSA-AKI, but also the identification of risk variables. The advent of novel biomarkers of kidney injury has the potential to facilitate the subclinical diagnosis of CSA-AKI, the assessment of its severity and prognosis, and the early institution of interventions to prevent or reduce kidney damage. Further studies are needed to determine how to optimize cardiac surgical procedures, CPB parameters, and intraoperative and early postoperative blood pressure and renal blood flow to reduce the risk of CSA-AKI. No pharmacologic strategy has demonstrated clear efficacy in the prevention of CSA-AKI; however, some agents, such as the natriuretic peptide nesiritide and the dopamine agonist fenoldopam, have shown promising results in renoprotection. It remains unclear whether CSA-AKI patients can benefit from the early institution of such pharmacologic agents or the early initiation of renal replacement therapy.

Among elective cardiac surgery patients, AKI or elevated post-operative CCA biomarkers were associated with decreased RFR at 3 months despite normalization of serum creatinine. Larger prospective studies to validate the use of RFR to assess renal recovery in combination with biochemical biomarkers are warranted.

The optimal use of prophylactic intra-aortic balloon pump (IABP) to prevent postcardiotomy low cardiac output syndrome (LCOS) is still debated and poorly defined. The aim of this study was to evaluate whether prophylactic IABP reduces the rate of postcardiotomy LCOS and improves the early outcome in hemodynamically stable, high-risk patients undergoing coronary artery bypass grafting (CABG). From May 2004 to August 2007, 141 consecutive risk patients underwent CABG. Of these 38 (27%) received prophylactic IABP. The remaining 103 patients underwent operation without preoperative insertion of the device. Prophylactic IABP patients were more likely to be younger (P<0.0001), had a recent myocardial infarction (P<0.0001), lower ejection fraction (P=0.006), and higher New York Heart Association (NYHA) functional class (P=0.05). After risk-adjusting for propensity score, prophylactic IABP patients had a lower incidence of postcardiotomy LCOS (adjusted OR 0.07, P=0.006), postoperative myocardial infarction (adjusted OR 0.04, P=0.04), a shorter length of hospital stay (10.4+/-0.8 vs. 12.2+/-0.6 days, P<0.0001) than those who did not receive IABP. This study shows that prophylactic IABP treatment for hemodynamically stable high-risk patients undergoing CABG may improve postoperative course reducing postcardiotomy LCOS, postoperative myocardial infarction and length of hospital stay.