Enhanced Detection of Cardiac Surgery-Associated Acute Kidney Injury by a Composite Biomarker Panel in Patients with Normal Preoperative Kidney Function.

We have recently shown that minor subclinical creatinine dynamic changes enable the excellent detection of acute kidney injury (AKI) within 6-12 h after cardiac surgery. The aim of the present study was to examine a combination of neutrophil gelatinase-associated lipocalin (NGAL), cystatin C (CysC) and creatinine for enhanced AKI detection early after cardiac surgery. Elective patients with normal renal function undergoing cardiac surgery using cardiopulmonary bypass were enrolled. Concentrations of plasma NGAL, serum CysC and serum creatinine were determined after the induction of general anesthesia, at the termination of the cardiopulmonary bypass and 2 h thereafter. Out of 119 enrolled patients, 51 (43%) developed AKI. A model utilizing an NGAL, CysC and creatinine triple biomarker panel including sequential relative changes provides a better prediction of cardiac surgery-associated acute kidney injury than any biomarker alone already 2 h after the termination of the cardiopulmonary bypass. The area under the receiver-operator curve was 0.77, sensitivity 77% and specificity 68%.

Creatinine, Neutrophil Gelatinase-Associated Lipocalin, and Cystatin C in Determining Acute Kidney Injury After Heart Operations Using Cardiopulmonary Bypass.

Acute kidney injury (AKI) represents frequent complication after cardiac surgery using cardiopulmonary bypass (CPB). In the hope to enhance earlier more reliable characterization of AKI, we tested the utility of neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C (CysC) in addition to standard creatinine for early determination of AKI after cardiac surgery using CPB. Forty-one patients met the inclusion criteria. Arterial blood samples collected after induction of general anesthesia were used as baseline, further sampling occurred at CPB termination, 2 h after CPB, on the first and second day after surgery. According to AKIN classification 18 patients (44%) developed AKI (AKI1-2 groups) and 23 (56%) did not (non-AKI group). Groups were similar regarding demographics and operative characteristics. CysC levels differed already preoperatively (non-AKI vs. AKI2; P = 0.045; AKI1 vs. AKI2; P = 0.011), while postoperatively AKI2 group differed on the first day and AKI1 on the second regarding non-AKI group (P = 0.004; P = 0.021, respectively). NGAL and creatinine showed significant difference already 2 h after CPB between groups AKI2 and non-AKI and later on the first postoperative day between groups AKI1 and AKI2 (P = 0.028; P = 0.014, respectively). This study shows similar performance of early plasma creatinine and NGAL in patients with preserved preoperative renal function. It demonstrates that creatinine, as well as NGAL, differentiate subsets of patients developing AKI of clinically more advanced grade early after 2 h, also when used single and uncombined.

Severe Cardiac Autonomic Derangement and Altered Ventricular Repolarization Pave the Way to Postoperative Atrial Fibrillation.

OBJECTIVE: Postoperative atrial fibrillation (POAF) is a frequent complication after heart surgery. It has been shown that cardiac autonomic derangement plays a significant role in the genesis of atrial fibrillation (AF) and that AF might also be promoted by altered repolarization. Thus, the aim of our study was to determine the levels of cardiac autonomic modulation and repolarization properties in patients developing POAF. METHODS: Seventy-nine patients scheduled for aortic and/or coronary artery bypass grafting surgery with cardiopulmonary bypass were enrolled prospectively. High-resolution 20-minute electrocardiogram recordings were obtained day before surgery to determine P, PR, QT, and QTc intervals, as well as linear (time and frequency domain) and nonlinear heart rate variability parameters (fractal dimension and detrended fluctuation analysis). QTc interval was calculated using Framingham correction. RESULTS: Twenty-nine patients developed POAF (AF group), and 50 did not (non-AF group). Groups were similar regarding demographics, surgery type, and perioperative characteristics, except for older age in the AF group. QT and QTc intervals (Framingham) were longer in the AF group [442 (44) vs 422 (28) milliseconds, P = 0.018; and 448 (44) vs 431 (24) milliseconds, P = 0.031 and P = 0.019, respectively]. Time domain heart rate variability parameter PNN50 (percentage of pairs of adjacent NN intervals differing >50 milliseconds) was higher [14% (21%) vs 8% (16%), P = 0.015], and nonlinear parameter detrended fluctuation analysis α2 was lower in the AF group [0.81 (0.21) vs 0.91 (0.20), P = 0.031]. CONCLUSIONS: Profound cardiac autonomic derangement, suggestive of parasympathetic excessive modulation, exists preoperatively in patients inclined to POAF after cardiac surgery, whereby parameters PNN50 and α2 differentiated the AF from the non-AF group. Prolonged QTc intervals are associated with an increased risk of POAF.

The effects of levosimendan on renal function early after heart transplantation: results from a pilot randomized trial.

BACKGROUND: We evaluated the effects of a levosimendan (LS)-based strategy compared with standard inotropic therapy on renal function in heart transplantation. METHODS AND RESULTS: Using a randomized study design, 94 patients were assigned to LS-based therapy or standard inotropic support. At the time of transplantation, the groups did not differ in age, gender, heart failure etiology, hemodynamic profile, LVEF, or comorbidities. While there were no differences in serum creatinine (sCr) or eGFR between groups at baseline, patients in the LS group had a greater increase in their relative eGFR (62% vs. 12%, p = 0.002) and a lower incidence of acute kidney injury (AKI) (28% vs. 6%, p = 0.01) during the first post-transplant week. On logistic regression analysis, correlates of AKI were randomization to LS therapy (OR = 0.21 [0.09-0.62], p = 0.01), baseline renal dysfunction (OR = 3.9 [1.1-13.6], p = 0.032), and diabetes mellitus (OR = 4.2 [1.1-16.5], p = 0.038). However, LS was associated with a greater need for additional norepinephrine therapy (40 [85%] vs. 15 [31%], p < 0.001) and a trend toward longer intensive care unit stay (9.5 ± 9.0 d vs. 7.0 ± 6.0 d, p = 0.13). CONCLUSIONS: In patients undergoing heart transplantation, levosimendan-based strategy may be associated with better renal function when compared to standard therapy.