Cardiac Biomarkers and Prediction of Early Outcome After Heart Valve Surgery: A Prospective Observational Study.

OBJECTIVES: Circulating cardiac biomarkers may improve the prediction of long-term outcomes after cardiac surgery. The authors sought to assess if cardiac biomarkers also help better predict short-term morbidity. DESIGN: Prospective observational study. SETTING: Single academic hospital. PARTICIPANTS: A total of 250 patients undergoing aortic or mitral valve surgery with or without associated coronary artery bypass grafts. INTERVENTION: None MEASUREMENT AND MAIN RESULTS: Relationships between preoperative plasma concentrations of four cardiac biomarkers (sST2, Galectin-3, GDF-15, and NT-proBNP) and postoperative outcome were assessed using logistic regressions and Cox proportional hazards models. The primary outcome was a composite of 30-day mortality, an inotropic support longer than 48 hours and an initial length of stay in the intensive care >five days. Secondary outcome measures were postoperative acute kidney injury, inotropic support duration, lengths of intensive care unit and hospital stays, and 30-day and one-year mortality. No association was observed between any of the four cardiac biomarkers and the primary outcome. The preoperative levels of Galectin-3 (hazard ratio = 1.2; p < 0.001) and sST2 (hazard ratio = 1.01, p < 0.001) were significantly associated with one-year survival, and their addition to the EuroSCORE II significantly improved the prediction of one-year mortality (p < 0.001). Similarly, Galectin-3 was associated with postoperative acute kidney injury (odds ratio = 1.15, p = 0.001) and improved the prediction of this complication when added to the EuroSCORE II (p = 0.002). CONCLUSIONS: These results suggested that the ability of cardiac biomarkers to predict short-term outcome after cardiac surgery, though of interest, appears limited. Conversely, cardiac biomarkers may have the potential to refine the prediction of long-term outcome. Admittedly, all positive results were obtained on secondary outcomes and must be regarded with caution.

The Edmonton Frail Scale Improves the Prediction of 30-Day Mortality in Elderly Patients Undergoing Cardiac Surgery: A Prospective Observational Study.

OBJECTIVES: To investigate whether the Edmonton Frail Scale (EFS), a multidimensional frailty assessment tool, improves the prediction of 30-day or in-hospital mortality over the use of the European System for Cardiac Outcome Risk Evaluation (EuroSCORE) II alone. DESIGN: Single-center prospective observational study. SETTING: University hospital. PARTICIPANTS: Patients aged 75 years or older undergoing cardiac surgery between February 2014 and May 2017. INTERVENTION: No intervention was performed. The EFS was administered the day before surgery. MEASUREMENTS AND MAIN RESULTS: The primary endpoint was 30-day or in-hospital mortality. Secondary endpoints were times to discharge from the intensive care unit (ICU) and from the hospital, discharge to a health care facility, and ability to return home by postoperative day 30. The EFS had a good discriminative ability for 30-day mortality (area under the receiver operating characteristic curve = 0.69; 95% confidence interval [CI], 0.56-0.82). Adding frailty, defined by an EFS ≥8, to the EuroSCORE II significantly improved the prediction of 30-day (p = 0.04) mortality. The integrated discrimination index was 0.03 (95% CI, 0.01-0.06, p = 0.01), meaning that the difference in predicted risk between patients who died and those who survived increased by 3% due to the addition of frailty determined by the EFS to the EuroSCORE II. Frailty also was associated significantly with a decreased cumulative probability of discharge from the ICU (p = 0.02) and an increased incidence of discharge to a health care facility (p = 0.01). CONCLUSION: The EFS has a good predictive ability for 30-day mortality after cardiac surgery in elderly patients and improves the prediction of 30-day mortality over the use of the EuroSCORE II.

Low Cardiac Output Syndrome After Adult Cardiac Surgery: Predictive Value of Peak Systolic Global Longitudinal Strain.

BACKGROUND: Peak systolic global longitudinal strain (GLS) is increasingly used to quantify left ventricular systolic function. The primary objective of this study was to assess whether GLS obtained during intraoperative transesophageal echocardiogram, performed before cardiopulmonary bypass, improves the prediction of postoperative low cardiac output syndrome (LCOS) after adult cardiac surgery. METHODS: GLS from 275 patients undergoing on-pump cardiac surgery was calculated retrospectively using two-dimensional- speckle tracking echocardiography (aCMQ module from Qlab software version 10.5, Philips Medical, Brussels, Belgium). LCOS was defined as the need for inotropic or mechanical circulatory support for >24 hours postoperatively. Patient and procedure characteristics associated with LCOS at the univariable level (P ≤ .05) were entered into a forward stepwise logistic regression to create a first predictive model. A second model was created by adding GLS. The 2 models were compared using the likelihood-ratio test, the area under the receiver operating characteristic (ROC) curve, and the integrated discrimination index. The optimal cutoff value of GLS associated with LCOS was determined by maximizing the Youden index of the ROC curve. Secondary outcomes included time until complete weaning from inotropes, discharge from the intensive care unit and from the hospital, and 30-day mortality. RESULTS: GLS was significantly associated with LCOS (P < .001) at the univariable level. Predictors of LCOS retained in the first model were cardiopulmonary bypass duration, decreased left ventricular ejection fraction, mitral valve surgery, and New York Heart Association functional class III or IV. Adding the GLS value improved the prediction of LCOS (P = .02). However, the area under the ROC curve did not differ between the 2 models (0.83; 95% confidence interval [CI], 0.77-0.99 vs 0.84; 95% CI, 0.79-0.90; P = .15). The integrated discrimination index associated with addition of GLS was 0.02 (P = .046), meaning that the difference in predicted risk between patients with and without LCOS increased by 2% after adding GLS. A GLS cutoff value of -17% (95% CI, -18.8% to -15.3%) was found to best identify LCOS. After adjusting for covariates included in model 1, a lower GLS value was significantly associated with a lower cumulative probability of weaning from inotropes postoperatively (hazard ratio, 0.90; 95% CI, 0.82-0.97; P = .01). No association was found between GLS and other secondary outcome measures. CONCLUSIONS: GLS is an independent predictor of LCOS after on-pump cardiac surgery. Its incremental value over other established risk factors for postoperative LCOS is, however, limited.

Hydroxyethyl Starch 130/0.4 and the Risk of Acute Kidney Injury After Cardiopulmonary Bypass: A Single-Center Retrospective Study.

OBJECTIVES: To investigate whether using hydroxyethyl starch (HES) 130/0.4 as a pump prime and for intraoperative fluid therapy is associated with postoperative acute kidney injury (AKI) after adult cardiac surgery. DESIGN: Retrospective observational study. SETTING: University hospital, single center. PARTICIPANTS: Six hundred six adult patients who underwent on-pump cardiac surgery between April 2013 and June 2014 were included. INTERVENTIONS: Until July 2013, balanced HES 130/0.4 (Volulyte(®), Fresenius Kabi AG, Bad Homburg, Germany) was used both as a pump prime (1,500 mL) and for intraoperative fluid therapy (1,000 mL). From August 2013, HES was replaced entirely by a balanced crystalloid solution (Plasma-Lyte A, Baxter, Lessines, Belgium). MEASUREMENTS AND MAIN RESULTS: The primary endpoint was the incidence of postoperative AKI during the first 48 postoperative hours, determined using the Acute Kidney Injury Network classification. Secondary outcomes included kidney function at postoperative day 7, postoperative dialysis or hemofiltration, postoperative pulmonary complications, lengths of intensive care unit and hospital stays, postoperative fluid balance and urinary output, surgical revision for bleeding, and 30-day mortality. Multivariable logistic regression was used to adjust for confounders. AKI occurred in 9.5% of crystalloid patients and in 21.5% of HES patients. Patients who received HES were about twice as likely to develop postoperative AKI as those treated with crystalloids (adjusted OR 2.26; 95% CI, 1.40-3.80; p = 0.02). HES patients also had a significantly more positive fluid balance and a lower urinary output during the first 48 postoperative hours. The incidence of surgical revision for bleeding was greater in the HES group (4.6% v 1.4%, p = 0.02). CONCLUSION: This study suggested that using balanced HES 130/0.4 as a pump prime and for intraoperative fluid therapy in adult patients undergoing on-pump cardiac surgery was associated with a greater incidence of AKI during the early postoperative period.

The effect of intraoperative 6% balanced hydroxyethyl starch (130/0.4) during cardiac surgery on transfusion requirements.

OBJECTIVES: To compare transfusion requirements in adult cardiac surgery patients when balanced hydroxyethyl starches (HES) (130/0.4) or balanced crystalloids is used for pump prime and intraoperative fluid therapy. DESIGN: Data were obtained retrospectively from medical records and perfusion charts. Matching based on propensity scores was used to adjust for potential confounders. SETTING: A university hospital. PARTICIPANTS: Adult patients undergoing cardiac surgery with the use of cardiopulmonary bypass. INTERVENTIONS: Allocation to one of the study groups according to whether balanced HES or balanced crystalloids was used for pump prime and intraoperative fluid therapy. MEASUREMENTS AND MAIN RESULTS: 240 propensity-matched patients were retained for final analyses. Forty-eight patients (40%) of the colloid group and 28 patients (23.3%) of the crystalloid group received blood products, with an odd ratio (95% CI) of 2.1(1.2-3.8 (P=0.009). After bypass HES patients had lower hemoglobin levels (8.4 [1.3] gr/dL vs 9.6 [2] gr/dL; P<0.001) and a higher cumulative chest drain output after 3 hours (180 [210] mL vs 140 [100] mL, P<0.001]. Heparinase thromboelastogram (TEG®) showed longer K times (2.5[1.1] vs 1.6[0.8], P<0.001) and lower maximal amplitudes (55.1[12.5] vs 63.4[9.8], P=0.008). CONCLUSIONS: HES patients required more transfusions, owing to greater hemodilution, HES-induced clotting disturbances, and bleeding.