BACKGROUND AND AIMS:
Bleeding complications are frequent and independently impact mortality after TAVI. Thromboelastography (TEG) measures viscoelastic properties of clot formation and is currently best known for perioperative management to reduce blood transfusion in cardiac surgery. We sought to determine whether TEG may be predictive of bleeding in patients treated with TAVI.
METHODS AND RESULTS:
Overall, 54 consecutive patients with severe aortic stenosis treated with TAVI were prospectively included. In all patients, 2 blood samples were obtained for TEG measurement (1st – 12h prior to procedure tested with Citrated Kaolin [CK] TEG assay, and the 2nd – immediately after prosthesis deployment tested with CK and Citrated Kaolin Heparinised assay [CKH]). Major or life-threatening bleeding (MLTB) was diagnosed in 13 (24%) patients. In receiver-operating characteristic (ROC) curve analysis the only TEG parameters showing significant sensitivity and specificity for predicting MLTB were those obtained in the CK sample at the end of the procedure: R value (reaction time, time to initiation of clot formation) AUC 0.69, 95% confidence intervals (CI) 0.49-0.88, P=0.04; Angle (the rate of clot formation), AUC 0.75, 95%CI 0.59-0.92, P=0.007 and MA (maximum amplitude, ultimate strength of fibrin clot), AUC 0.77, 95%CI 0.62-0.93, P=0.003. After controlling for confounding factors in multivariate logistic regression, MA remained as the only TEG parameter which significantly correlated with bleeding after TAVI, both as a continuous variable (P=0.004; 95%CI 0.92-0.98; OR 0.95 per 1mm increment) and after using the cut-off value derived from ROC analysis; MA <46.6 mm (P=0.004; OR 10.4; 95%CI 2.1-51.8).
CONCLUSIONS:
Low strength of fibrin clot measured by TEG immediately after TAVI may serve as an independent predictor of short-term major and life-threatening bleeding complications.
