| Description: |
A decreased cardiac output is a frequently occuring complication after cardiac surgery. The aim of this study is to investigate the relationship between decreased cardiac index (CI) level and negative outcome after elective cardiac surgery ; and compare its predictive value to cardiac output (CO), and cardiac index adjusted by ideal weight. This single-center, observational study included all patients over 18 years old, completing an elective cardiac surgery monitored by a pulmonary artery catheter (Swan Ganz). Primary endpoint was a composite criterion combining : 30 day mortality, low cardiac output syndrome (defined by the need for dobutamine or mechanical circulatory support), the need for dialysis, or doubling of creatinemia. Comparaison of area under the ROC curves (AUC-ROC) was performed to assess the predictive efficacy for negative outcome of cardiac output and its derivative. Youden’s index calculation was used to provide the optimal cut-off for each variable. 567 patients were included between 2016 and 2019. The mean age was 68 years old. 18 patients (3,2%) died. Low cardiac output syndrom occured in 160 patients (28%). 33 patients (6,4%) experienced doubling of their creatinemia, while 10 patients needed dialysis. AUC-ROC for CI to predict death was 0,624 (IC95% 0,582 - 0,664) with a threshold value of 1,8L/min/m² (sensitivity 77,8%, specificity 46,3%). AUC-ROC for CI to predict the primary composite criterion was 0,505 (IC95% 0,463 - 0,547). There was no statistically significant difference of AUC-ROC when taking CO or adjusted CI into consideration for predicting death : AUCCO at 0,656 (IC95% 0,615-0,695), AUCCIadjusted at0,643 (IC95% 0,602-0,682). Use of dobutamine didn’t alter AUC-ROC to predict death, at 0,693 (IC95% 0.631 - 0.747). In this study, we found that a decreased cardiac index after cardiac surgery cannot reliably predict mortality or morbidity in the first 30 post operative days. The predictive value of cardiac index adjusted by ideal weight or cardiac output wasn’t significantly ... |