By Katherine Kozlowski, Medical Author and Contributor to Vein News and www.VeinsVeinsVeins.com
Development of a clinical prediction model for the postthrombotic syndrome in a prospective cohort of patients with proximal deep vein thrombosis
Post-thrombotic syndrome (PTS) is a complication following a deep vein thrombosis (DVT) that can cause limb swelling, limb discomfort and pain, edema that is difficult to control, ulcers, or irreversible skin changes. It occurs in 20-50% of patients who have had a DVT.
What is the purpose of this study?
Researchers intended to develop a clinical prediction score for post-thrombotic syndrome (PTS) in patients with DVT.
Who was included in the study?
Patients were derived from the SOX trial, which was a “randomized double-blind placebo-controlled trial of elastic compressions stockings versus placebo stockings worn for 2 years after DVT to prevent PTS in patients with a first proximal DVT.”
762 patients were included.
What was the outcome studied?
The occurrence of PTS diagnosed using Ginsberg’s criteria, 6 months or later following DVT.
What is Ginsberg’s criteria?
The Ginsberg score diagnoses patients as having PTS if a patient reports typical, chronic leg pain and swelling occurring for at least 6 months following an initial DVT. (Soosainathan et al 2013)
What is a Villalta Score?
The Villalta score is a specific scale used to diagnose and categorize PTS based on symptoms (pain, cramps, heaviness, paresthesia, skin itchiness) and clinical signs (pretibial edema, skin thickening, hyperpigmentation, redness, venous insufficiency, and pain on calf compression).
The score ranges from zero (not present) to three (severe).
How is the risk of PTS predicted?
The model includes three predictors for PTS with possible scores from 0-5. The individual predictors are:
1. Extent of DVT
2. Baseline Villalta Score category
3. BMI
What are the results of the study?
Patients with a score greater than or equal to 4 have 5.9 times the risk of developing PTS compared with patients scoring 0.
Predictions were considered high-risk if the patient had an index DVT in the iliac vein, a BMI greater than or equal to 35 kg/m2, and a moderate to severe Villalta score at DVT diagnosis.
What can we conclude from the study?
This study resulted in the first known clinical prediction score for PTS risk after a first proximal DVT (a.k.a. the SOX-PTS score).
The SOX-PTS score may be useful in determining whether a patient with a DVT should be considered for close monitoring or aggressive treatment strategies.
However, the study should be replicated externally before being considered for clinical use.
References:
Rabinovich, A, Ducruet T, Kahn S.R.. Development of a clinical prediction model for the postthrombotic syndrome in a prospective cohort of patients with proximal deep vein thrombosis. J Thromb Haemost 2017; 16: 262-270.
Soosainathan A., Moore H., Manjit S et al. Scoring systems for the post-thrombotic syndrome. J Vasc Surg 2013; 57(1): 254-261.
Dr Karamanoukian has written a free ebook aboiut the post thrombotic syndrome. You can read it on the ebook section of www.VeinsVeinsVeins.com