Background:

Guidelines recommend the use of clinical scores to assess thromboembolic and bleeding risk in several clinical settings. Biomarkers might improve stroke and bleeding risk prediction.

Objective:

To determine the association of biomarkers assessed by thrombelastography with thromboembolic and bleeding risk, respectively, after transfemoral aortic valve replacement (TAVR).

Method:

Data were collected in a prospective single-center observational study in patients undergoing TAVR. Thromboembolic and bleeding risk were assessed by CHA₂DS₂VASC or HAS-BLED score, respectively and classified according to high risk (score 2-5) and very high risk (score 6-8) for CHA₂DS₂VASC and moderate risk (score 1-2) and high risk (score 3-5) for HAS-BLED. Thrombelastography was performed as specified by the manufacturer. Time to clot formation (R), clot formation time (K), maximum amplitude (MA), and lysis index (LY₃₀) were measured in citrated recalcified kaolin and tissue factor activated blood (CRT). Mann-Whitney-U-Test was used for statistical analysis.

Results:

Thrombelastography was performed in 79 patients between days 0 and 17 after TAVR. The median age was 82 years (interquartile range, IQR 79-85), and 51% were male. 36 patients (46%) had atrial fibrillation, 12 (15%) had a history of stroke or TIA, and 10 (13%) had suffered a previous myocardial infarction. The median CHA₂DS₂VASC score was 5 (IQR 4-6), and the median HAS-BLED score was 3 (IQR 2-3). Thrombelastography parameters (median [IQR]) of patients with CHA₂DS₂VASC high risk compared with very high risk group showed no significant difference (R-CRT: median 0.5 [IQR 0.4-0.7] vs 0.6 [0.5-0.7] min, p=0.32; K-CRT: 0.8 [0.8-1.0] vs 0.8 [0.7-0.9] min, p=0.32; MA-CRT: 66.6 [63.4-69.8] vs 66.6 [64.8-69.2] mm, p=0.90; LY₃₀-CRT: 0.1 [0.0-0.4] vs 0.0 [0.0-0.5] %, p=0.76). Thrombelastography parameters of patients with moderate risk HAS-BLED score compared with high risk HAS-BLED score were not significantly different (R-CRT: 0.5 [0.4-0.7] vs 0.5 [0.4-0.7] min, p=0.75; K-CRT: 0.8 [0.8-0.9] vs 0.8 [0.8-1.0] min, p=0.63; MA-CRT: 66.4 [64.4-68.8] vs 67.6 [64.6-70.3] mm, p=0.30; LY₃₀-CRT: 0.1 [0.0-0.4] vs 0.0 [0.0-0.5] %, p=0.94).

Conclusion:

In patients post TAVR with high or very high thromboembolic and bleeding risk we found no association between CHA₂DS₂VASC or HAS-BLED score and functional markers assessed by thrombelastography. Conventional risk scores do not necessarily reflect variation in functional assays potentially indicating thromboembolic or bleeding risk.