The Relative Early Decrease in Platelet Count Is Associated With Mortality in Post-cardiotomy Patients Undergoing Venoarterial Extracorporeal Membrane Oxygenation

Predictors of mortality and transfusion requirements in venoarterial extracorporeal membrane oxygenation patients

OBJECTIVE

The aim of this study was to evaluate the prognostic impact of variables, including thrombocytopenia and the amount of platelet transfusion, for predicting survival in venoarterial extracorporeal membrane oxygenation (ECMO) recipients. Additionally, we aimed to identify the predictors of increased transfusion requirement during venoarterial ECMO support.

METHODS

All patients who received venoarterial ECMO between December 2008 and March 2020 were retrospectively analyzed. Univariate and multivariate Cox regressions were used to evaluate in-hospital mortality according to variables including thrombocytopenia and daily average of platelet concentrate transfusion. Stepwise multiple linear regression analysis was used to identify independent predictors for transfusion requirements.

RESULTS

Analysis of 218 patients demonstrated severe thrombocytopenia as an independent predictor of in-hospital mortality (hazard ratio = 2.840, 95% CI: 1.593-5.063, P < .001), along with age, pre-ECMO cardiac arrest, and pH. In contrast, the amount of platelet transfusion was not associated with in-hospital mortality. Multiple variables, including the type of indication for ECMO were associated with transfusion requirements.

CONCLUSION

Our findings identified severe thrombocytopenia as an independent prognostic factor of in-hospital mortality. However, daily average platelet transfusion was not associated with survival outcomes. Additionally, our study identified predictive variables of increased transfusion requirements.

Impact of thrombocytopenia on short-term outcomes in patients undergoing mobile extracorporeal membrane oxygenation support

INTRODUCTION

The prolonged use of extracorporeal membrane oxygenation (ECMO) support is associated with increased consumption of platelets and hemolysis. The prognostic impact of thrombocytopenia prior to and during ECMO support on patient's short-, mid- and long-term outcomes has been critically evaluated and discussed over the last years. However, only few data have been published on thrombocytopenia caused by mobile ECMO support. The aim of this study was to evaluate the impact of thrombocytopenia on short-term outcomes and predictors of in-hospital mortality in patients supported by mobile ECMO for transportation and subsequent weaning in a tertiary centre.

METHODS

This retrospective single-centre study analyzed a total of 117 patients requiring mobile veno-arterial (va) ECMO support and subsequent transportation from referral hospitals to our department from January 2015 until December 2021. A total of 15 patients had to be excluded from the analysis for missing data regarding baseline platelet count. Patients were divided into two groups: thrombocytopenia group (<130 × 109/L, n = 44) and non-thrombocytopenia group (≥130 × 109/L, n = 58). The primary outcome was in-hospital mortality. Secondary outcomes were successful ECMO-weaning, and the incidence of associated complications (bleeding, acute hepatic failure, acute renal failure, dialysis, and septic shock).

RESULTS

The dialysis rate before ECMO initiation was significantly higher (p = .041) in the thrombocytopenia group compared to the non-thrombocytopenia group. The rates of bleeding complications (p = .032) and limb ischemia (p = .003) were significantly higher in patients with low platelet count. Moreover, complication rates of acute hepatic failure (p < .001), acute renal failure (p < .001) and dialysis (p = .033) were significantly higher in the thrombocytopenia group. Also, in-hospital mortality was significantly higher (p = .002) in patients with low platelet count before initiation of ECMO support.

CONCLUSION

Based on the results of the present study, patients with thrombocytopenia prior to mobile vaECMO support may be at significantly higher risk for associated complications and short-term mortality.

PEAL Score to Predict the Mortality Risk of Cardiogenic Shock in the Emergency Department: An Observational Study

BACKGROUND

The in-hospital mortality of cardiogenic shock (CS) remains high (28% to 45%). As a result, several studies developed prediction models to assess the mortality risk and provide guidance on treatment, including CardShock and IABP-SHOCK II scores, which performed modestly in external validation studies, reflecting the heterogeneity of the CS populations. Few articles established predictive scores of CS based on Asian people with a higher burden of comorbidities than Caucasians. We aimed to describe the clinical characteristics of a contemporary Asian population with CS, identify risk factors, and develop a predictive scoring model.

METHODS

A retrospective observational study was conducted between 2014 and 2019 to collect the patients who presented with all-cause CS in the emergency department of a single medical center in Taiwan. We divided patients into subgroups of CS related to acute myocardial infarction (AMI-CS) or heart failure (HF-CS). The outcome was all-cause 30-day mortality. We built the prediction model based on the hazard ratio of significant variables, and the cutoff point of each predictor was determined using the Youden index. We also assessed the discrimination ability of the risk score using the area under a receiver operating characteristic curve.

RESULTS

We enrolled 225 patients with CS. One hundred and seven patients (47.6%) were due to AMI-CS, and ninety-eight patients among them received reperfusion therapy. Forty-nine patients (21.8%) eventually died within 30 days. Fifty-three patients (23.55%) presented with platelet counts < 155 × 103/μL, which were negatively associated with a 30-day mortality of CS in the restrictive cubic spline plot, even within the normal range of platelet counts. We identified four predictors: platelet counts < 200 × 103/μL (HR 2.574, 95% CI 1.379-4.805, p = 0.003), left ventricular ejection fraction (LVEF) < 40% (HR 2.613, 95% CI 1.020-6.692, p = 0.045), age > 71 years (HR 2.452, 95% CI 1.327-4.531, p = 0.004), and lactate > 2.7 mmol/L (HR 1.967, 95% CI 1.069-3.620, p = 0.030). The risk score ended with a maximum of 5 points and showed an AUC (95% CI) of 0.774 (0.705-0.843) for all patients, 0.781 (0.678-0.883), and 0.759 (0.662-0.855) for AMI-CS and HF-CS sub-groups, respectively, all p < 0.001.

CONCLUSIONS

Based on four parameters, platelet counts, LVEF, age, and lactate (PEAL), this model showed a good predictive performance for all-cause mortality at 30 days in the all patients, AMI-CS, and HF-CS subgroups. The restrictive cubic spline plot showed a significantly negative correlation between initial platelet counts and 30-day mortality risk in the AMI-CS and HF-CS subgroups.

External validation of the REMEMBER score

Background

The use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) after coronary artery bypass grafting (CABG) is associated with high in-hospital mortality rates. The pRedicting mortality in patients undergoing venoarterial Extracorporeal MEMBrane oxygenation after coronary artEry bypass gRafting (REMEMBER) score has been created to predict in-hospital mortality in this subgroup of patients. The aim of this study is to externally validate the REMEMBER score.

Methods

All CABG patients who received VA-ECMO during or after the operation at our center between 01/2012 and 12/2021 were included in the analysis. Discrimination was assessed using concordance statistics, visualized by ROC curve analysis. Calibration-in-the-large and Calibration slope were tested separately.

Results

A total of 107 patients (male: n = 78, 72.9%) were included in this study. The in-hospital mortality rate in our cohort was 45.8% compared with 55% in the original study. The REMEMBER score median predicted mortality rate was 52% (76.9-36%). However, the REMEMBER score showed low discriminative ability [AUC: 0.623 (p = 0.0244; 95% CI = 0.524-0.715)] and inaccurate calibration (intercept = 0.25074; p = 0.0195; slope = 0.39504; p = 0.0303), indicating poor performance.

Conclusions

The REMEMBER score did not predict in-hospital mortality and was therefore not applicable in our cohort of patients. Additional external validation studies in a multicenter setting are therefore advisable.