Role of Hematological Parameters in Predicting Severity of Acute Venous Thromboembolism

Background- Many studies have shown that inflammation and clotting mechanisms are closely related. Hence, inflammatory markers such as Neutrophil-Lymphocyte ratio(NLR) and Platelet-Lymphocyte ratio (PLR) can be elevated in patients with acute venous thromboembolism (VTE) including deep vein thrombosis(DVT) and pulmonary embolism(PE) In this retrospective study, we evaluated the significance of NLR & PLR in predicting the severity of VTE.

Methods -We retrospectively analyzed data of all patients who were diagnosed with first episode of DVT and PE from 01/2005 to 06/2015. Clinical data for 212 patients with DVT and PE and 58 random healthy controls (outpatient well visit) were collected from the electronic medical record system database of our 850 bed tertiary care center hospital.

Results: The number of patients with VTE and healthy controls (C) were (DVT-115(54%), PE 97(46%)) and 58 respectively. The mean age DVT was 61.3 ± 16.3, PE 61.6 ± 16.2 & C 55.2 ± 16.6 years. The mean NLR VTE and C was 6.6±7.24 & 5.89±8.8 respectively. Mean PLR VTE and C was 17.15±17.18 & 17.49±17.5. Increased age was significantly associated with DVT (p=0.012) and PE (p=0.001). Odd for DVT in females were 1.7 (1.04-2.78; p=0.03) compared to males. Though there were no differences in odds of PE between sexes. In patients with DVT, PLR was higher in proximal v/s distal (p=0.014). Also, platelet counts were significantly lower in extensive DVT compared with either distal or proximal DVT (p=0.039). NLR was significantly higher in patients with central v/s distal PE (p=0.042). No significant differences were noticed in NLR, PLR or platelet counts between PE, DVT and C.

Conclusion: In this study, inflammatory markers like NLR , PLR were increased with acute thrombosis. Moreover, the ratios were higher with proximal thrombosis both in central and peripheral venous system.Platelet counts were lower in extensive DVT probably from increased consumption. Thus the inflammatory markers when combined with traditional risk factors for DVT and PE can increase the probability of its diagnosis and predict the severity of thrombosis.