Perioperative Echocardiographic Index of Left Ventricular Filling Pressure in Cardiac Surgery.

BACKGROUND: The elevated preoperative ratio of early transmitral flow velocity to early diastolic velocity of the mitral annulus (E/e') as an echocardiographic index of left ventricular filling pressure is known to be associated with poor postoperative outcomes. We investigated the association between preoperative and postoperative E/e' elevation and clinical outcomes after cardiac operations. METHODS: The study divided 1,353 patients who underwent cardiac operations into four groups: preoperative and postoperative E/e' ≤15 (low-low), preoperative E/e' ≤15 but postoperative E/e' >15 (low-high), preoperative E/e' >15 but postoperative E/e' ≤15 (high-low), and preoperative and postoperative E/e' >15 (high-high). Cox proportional hazard analysis was performed. Kaplan-Meier curve analysis was performed before and after propensity score matching. RESULTS: The four perioperative E/e' categories were independently associated with 5-year mortality (hazard ratio, high-high vs low-low: 3.58; low-high vs low-low: 3.75; high-low vs low-low: 1.18). Kaplan-Meier curves showed that mortality was significantly different between the groups (log-rank test: high-high vs. low-low, p < 0.001; low-high vs low-low, p < 0.001). Postoperative intensive care unit and hospital lengths of stay, incidence of acute kidney injury, and 1-year mortality were significantly different. However, after propensity score matching, mortality and the incidence of postoperative acute kidney injury were significantly different only between postoperative E/e' ≤15 and E/e' >15, but not between preoperative E/e' ≤15 and E/e' >15. CONCLUSIONS: Postoperative E/e' >15 was more strongly associated with mortality and acute kidney injury than preoperative E/e' >15. Measurement of the postoperative E/e' ratio may help in assessing the risk of these patients.

Neutrophil, Lymphocyte, and Platelet Counts and Acute Kidney Injury After Cardiovascular Surgery.

OBJECTIVE: Postoperative low platelet count and perioperative high neutrophil/lymphocyte (N/L) ratio are associated with acute kidney injury (AKI) and mortality after cardiac surgery. The authors investigated whether (1) their combination neutrophil/lymphocyte × platelet (N/LP) ratio is an independent predictor of AKI and postoperative mortality and (2) whether the N/LP ratio increases predictive ability compared with the N/L ratio or platelet nadir. DESIGN: This was a retrospective and observational study. SETTING: Single large university hospital. PARTICIPANTS: The study comprised 1,099 adult patients who underwent cardiovascular surgeries with cardiopulmonary bypass. MEASUREMENTS AND MAIN RESULTS: Baseline clinical parameters including platelet counts, the N/L ratio, and the N/LP ratio measured before surgery, immediately after surgery, and on postoperative days 1 and 2 were obtained. Multivariable analysis revealed that the maximal N/LP ratio was an independent predictor of AKI and 5-year mortality. Propensity score matching was performed between the high and low preoperative N/LP ratio groups. Significant differences in the mortality rate and incidence of AKI also were found in the matched cohort. The area under the receiver operating characteristic curve (AUC) of the maximal N/LP ratio as a continuous variable was significantly higher than the AUC of the maximal N/L ratio or nadir platelet as continuous variables (maximal N/LP ratio: 0.62 v N/L ratio: 0.59; p = 0.026 v platelet nadir: 0.57; p = 0.003). The AUC of multivariable risk prediction with the maximal N/LP ratio (0.77) was significantly higher than the AUC without the N/LP ratio (0.70; p < 0.0001). CONCLUSIONS: High N/LP ratios were associated with postoperative AKI and 5-year mortality. The N/LP ratio may assist with the the prediction of AKI and mortality in high-risk cardiovascular surgery.