Endothelial biomarkers of thrombosis in critically ill patients with acquired coagulopathy: a prospective cohort study.

Background: It remains largely unknown whether endothelial biomarkers can be used to predict thromboembolism in critically ill patients with an acquired coagulopathy. Materials & methods: The ability of syndecan-1, P-selectin and microRNA expressions to predict thromboembolism were assessed in 40 critically ill coagulopathic patients. Results: The area under the receiver operating characteristic curves for syndecan-1, P-selectin and the four differentially expressed microRNAs - determined by real-time qPCR analysis - to predict thromboembolism (n = 10, 25%) were 0.71 (95% CI: 0.52-0.89), 0.73 (95% CI: 0.52-0.95) and >0.80, respectively. Syndecan-1 and P-selectin concentrations were also significantly correlated with one another (R = 0.41, p = 0.008). Conclusion: Endothelial function biomarkers, including endothelial microRNA expressions, were associated with subsequent thromboembolism in critically ill patients who had a deranged coagulation profile.

Thromboelastography Predicts Thromboembolism in Critically Ill Coagulopathic Patients.

OBJECTIVES: Critically ill patients with deranged conventional coagulation tests are often perceived to have an increased bleeding risk. Whether anticoagulant prophylaxis for these patients should be withheld is contentious. This study assessed the ability of using in vitro clot strength, as measured by thromboelastography, to predict thromboembolism in patients with abnormal coagulation profiles. DESIGN: Prospective cohort study. SETTING: A tertiary ICU. PATIENTS: Two-hundred and fifteen critically ill coagulopathic patients with thrombocytopenia and/or a derangement in at least one conventional coagulation test (international normalized ratio or activated partial thromboplastin time) within 48 hours of ICU admission. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Thromboelastography was performed for all study patients, and plasma thrombotic biomarkers were measured in a nested cohort (n = 40). Of the 215 patients included, 34 patients (16%) developed subsequent thromboembolism-predominantly among those with a normal (maximum amplitude, 54-72 mm) or increased (maximum amplitude, > 72 mm) in vitro clot strength on thromboelastography (91%; area under the receiver-operating characteristic curve, 0.74; 95% CI, 0.64-0.83). The ability of the maximum amplitude to predict thromboembolism was comparable to plasma P-selectin concentrations (thromboembolism, 78.3 ng/mL vs no thromboembolism, 59.5 ng/mL; p = 0.031; area under the receiver-operating characteristic curve, 0.73; 95% CI, 0.52-0.95). In addition, patients with an increased maximum amplitude were also less likely to receive blood product transfusions within 24 hours of testing compared with those with a subnormal maximum amplitude (12.8% vs 69.2%, respectively; area under the receiver-operating characteristic curve, 0.74; 95% CI, 0.67-0.80). CONCLUSIONS: In patients with abnormal coagulation profiles, an increased in vitro clot strength on thromboelastography was associated with an increased risk of thromboembolism, and a reduced risk of requiring transfusion compared with those with a normal or reduced in vitro clot strength.

Predicting contrast-induced nephropathy after CT pulmonary angiography in the critically ill: a retrospective cohort study.

BACKGROUND: It is uncertain whether we can predict contrast-induced nephropathy (CIN) after CT pulmonary angiography (CTPA). This study compared the ability of a validated CIN prediction score with the Pulmonary Embolism Severity Index (PESI) in predicting CIN after CTPA. METHODS: This cohort study involved critically ill adult patients who required a CTPA to exclude acute pulmonary embolism (PE). Patients with end-stage renal failure requiring dialysis were excluded. CIN was defined as an elevation in plasma creatinine concentrations > 44.2µmol/l (or 0.5 mg/dl) within 48 h after CTPA. RESULTS: Of the 137 patients included, 77 (51%) were hypotensive, 54 (39%) required inotropic support, and 68 (50%) were mechanically ventilated prior to the CTPA. Acute PE was confirmed in 21 patients (15%) with 14 (10%) being bilateral. CIN occurred in 56 patients (41%) with 35 (26%) required dialysis subsequent to CTPA. The CIN prediction score had a good ability to discriminate between patients with and without developing CIN (Area under the receiver-operating-characteristic (AUROC) curve 0.864, 95% confidence interval [CI] 0.795-0.916) and requiring subsequent dialysis (AUROC 0.897, 95% CI 0.833-0.942) and was better than the PESI in predicting both outcomes (AUROC 0.731, 95% CI 0.649-0.804 and 0.775, 95% CI 0.696-0.842, respectively). A CIN risk score > 10 and 12 had an 82.1 and 85.7% sensitivity and 81.5 and 78.4% specificity to predict subsequent CIN and dialysis, respectively. The CIN prediction model tended to underestimate the observed risks of dialysis, but this was improved after recalibrating the slope and intercept of the original prediction equation. CONCLUSIONS: The CIN prediction score had a good ability to discriminate between critically ill patients with and without developing CIN after CTPA. Used together for critically ill patients with suspected acute PE, the CIN prediction score and PESI may be useful to inform clinicians when the benefits of a CTPA scan will outweigh its potential harms.

Use of viscoelastic tests to predict clinical thromboembolic events: A systematic review and meta-analysis.

We aimed to assess whether whole-blood viscoelastic tests are useful to identify patients who are hypercoagulable and at increased risk of thromboembolism. Two investigators independently analyzed studies in the MEDLINE, EMBASE, and Cochrane controlled trial register databases to determine the ability of viscoelastic tests to identify a hypercoagulable state that is predictive of objectively proven thromboembolic events. Forty-one eligible studies, including 10,818 patients, were identified and subject to meta-analysis. The majority of the studies (n = 36, 88%) used the maximum clot strength to identify a hypercoagulable state which had a moderate ability to differentiate between patients who developed thromboembolic events and those who did not (area under the summary receiver operating characteristic [sROC] curve = 0.70, 95% confidence interval [CI]: 0.65-0.75). The pooled sensitivity, specificity, and diagnostic odds ratio to predict thromboembolism were 56% (95%CI: 44-67), 76% (95%CI: 67-83), and 3.6 (95%CI: 2.6-4.9), respectively. The predictive performance did not vary substantially between patient populations, and publication bias was not observed. Current evidence suggests that whole-blood viscoelastic tests have a moderate ability to identify a variety of patient populations with an increased risk of thromboembolic events and can be considered as a useful adjunct to clinical judgment to stratify a patient's risk of developing thromboembolism.