Table 2. Activated partial thromboplastin time, aPTT ratio and clot waveform analysis parameters.
| Results |
VTE (N = 45) |
Control (N = 111) |
P |
|---|---|---|---|
| aPTT, s | 28 ± 7 | 28 ± 3 | 0.830 |
| aPTT ratio | 1.0 ± 0.2 | 1.0 ± 0.1 | 0.830 |
| aPTT ratio ≤ 0.9, N (proportion) | 11 (0.24) | 17 (0.15) | 0.178 |
| CWA parameters | |||
| Min1, %/s | 6.95 ± 3.02 | 5.54 ± 2.32 | < 0.001 |
| Min2, %/s2 | 1.09 ± 0.50 | 0.89 ± 0.38 | 0.001* |
| Max2, %/s2 | 0.89 ± 0.42 | 0.74 ± 0.32 | 0.002* |
| Delta change, % | 68.44 ± 32.86 | 51.42 ± 23.40 | < 0.001 |
| CWA > ULRR, N (proportion) | |||
| Min1 > 6.87%/s | 25 (0.56) | 15 (0.14) | < 0.001 |
| Min2 > 1.05%/s2 | 26 (0.58) | 23 (0.21) | < 0.001 |
| Max2 > 0.91%/s2 | 20 (0.44) | 16 (0.14) | < 0.001 |
| Delta change > 71.63% | 21 (0.47) | 5 (0.5) | < 0.001 |
| aPTT - activated partial thromboplastin time. aPTT and CWA parameters results are given as mean ± 2 standard deviations. VTE – venous thromboembolism. CWA – clot waveform analysis. ULRR - upper limit of reference interval. Proportions of cases within the venous thromboembolism (VTE) and control groups expressing aPTT ratio ≤ 0.9 and CWA parameters above the upper limit of the respective reference intervals are shown. aPTT ratio was established using the subjects’ aPTT over the mean aPTT of healthy volunteers. Reference intervals were established locally based on 191 healthy controls in accordance with the Clinical and Laboratory Standards Institute guidelines. *P-values < 0.001 after adjustment for age, gender and ethnicity. P<0.05 was considered statistically significant. | |||