Long‐term risk of postthrombotic syndrome after symptomatic distal deep vein thrombosis: The CACTUS‐PTS study

Abstract

Background After a proximal lower limb deep vein thrombosis (DVT; involving popliteal veins or above), up to 40% of patients develop postthrombotic syndrome (PTS) as assessed by the Villalta scale (VS). Poor initial anticoagulant treatment is a known risk factor for PTS. The risk of developing PTS after isolated distal DVT (infra‐popliteal DVT without pulmonary embolism), and the impact of anticoagulant treatment on this risk, are uncertain. Methods Long‐term follow‐up of CACTUS double‐blind trial comparing 6 weeks of s.c. nadroparin (171 IU/kg/d) versus s.c. placebo for a first symptomatic isolated distal DVT. At least 1 year after randomization, patients had a PTS assessment in clinic or by phone using the VS. Results After a median follow‐up of 6 years, PTS was present in 30% (n = 54) of the 178 patients who had a PTS assessment. PTS was moderate or severe in 24% (n = 13) of cases. There was no statistically significant difference in prevalence of PTS in the nadroparin versus placebo groups (29% versus 32%, P = .6), except in patients without evidence of primary chronic venous insufficiency (9% versus 24%, P = .04). Rates of venous thromboembolism recurrence during follow‐up in the nadroparin and placebo groups were, respectively, 8% (n = 7) and 14% (n = 13; P = .2). Conclusion After a first isolated distal DVT, the risk of PTS is substantial but much lower than that reported after proximal DVT. Anticoagulation with nadroparin doesn't provide any clear benefit to prevent PTS, except in patients without preexisting chronic venous insufficiency. Anticoagulation might be associated with a lower risk of venous thromboembolism recurrence.

Management of isolated distal deep vein thrombosis. A persistent conundrum?

“…The CACTUS-PTS study (2020) studied the long-term effects, after 6 years since the first episode of IDDVT. The results showed an overall PTS incidence of 30%, still considerably less than the reported values for patients after PDVT [27].…”

Venous Thromboembolism Prophylaxis and Thrombotic Risk Stratification in the Varicose Veins Surgery—Prospective Observational Study

“…However, it should also be emphasized that distal DVT cannot be free from early and late complications, including pulmonary embolism or post-thrombotic syndrome. In the Contention Alone Versus Anticoagulation for Symptomatic Calf Vein Thrombosis Diagnosed by Ultrasonography (CACTUS PTS) study, the postthombotic syndrome prevalence in patients with isolated calf DVT after median follow-up of 6 years was 30% [39].…”

Prevention of the Postthrombotic Syndrome with Anticoagulation: A Narrative Review

“…16 Although we would no longer be able to randomize anticoagulation against placebo in an acute proximal DVT treatment trial, a recent randomized controlled trial (RCT) included 178 patients with distal DVT and randomized them to either therapeutic LMWH (nadroparin) or placebo for 6 weeks. 17 It showed that in the subgroup of patients without evidence of primary CVI, the rate of PTS at 6 years might be lower when treated with LMWH (9% vs. 24%, p = 0.04); however, this was a subgroup analysis. Current guidelines endorse good-quality anticoagulation as an effective tool for prevention of PTS but do not suggest a specific anticoagulant agent.…”