Impact of adherence to elastic compression stockings on efficacy to prevent postthrombotic syndrome: a prespecified analysis of the Compression Elastique Evaluation du Syndrome post Thrombotique study.

BACKGROUND

Elastic compression stockings (ECS) are commonly used to prevent postthrombotic syndrome (PTS) after deep vein thrombosis (DVT). However, their efficacy is controversial. This could be due to suboptimal adherence in the negative study. Additional data on the impact of adherence on ECS efficacy are needed.

OBJECTIVES

To assess the impact of adherence on ECS efficacy to prevent PTS.

METHODS

We conducted a prespecified analysis of the double-blind "Compression Elastique Evaluation du Syndrome post Thrombotique" trial comparing 25 mm Hg ECS with 35 mm Hg ECS to prevent PTS after DVT. The objectives were to 1) assess the proportion of patients with PTS at 2 years according to adherence to ECS; 2) assess predictors of PTS; and 3) build a decision tree algorithm to measure the impact of each independent predictor of PTS.

RESULTS

The proportion of patients with PTS at 2 years who whore the study ECS <50%, 50% to 79%, and ≥ 80% of the time were 38.4% (95% CI, 28.8%-48.7%), 24.5% (95% CI, 13.3%-38.9%), and 27.5% (95% CI, 20.0%-36.0%), respectively. Obesity (adjusted odds ratio [aOR], 4.73 [95% CI, 2.13-10.51]), patient height (aOR, 1.07 [95% CI, 1.02-1.11]), and DVT involving 2 to 3 and ≥4 venous segments (aOR, 5.23 [95% CI, 1.11- 24.74] and aOR, 15.59 [95% CI, 3.22-75.43], respectively) increased PTS risk; male sex (aOR, 0.37 [95% CI, 0.16-0.83]), hypertension (aOR, 0.46 [95% CI, 0.21-0.99]), and wearing ECS ≥ 50% of the study time (aOR, 0.51 [95% CI, 0.28-0.92]) decreased this risk. Wearing ECS ≥ 50% of the study time was most beneficial among nonobese patients with extensive DVT; the proportion with PTS at 2 years was 29.8% vs 54.3% among nonadherent patients.

CONCLUSION

Adherence to ECS is an independent predictor of PTS that becomes apparent when ECS are worn ≥ 50% of the time. Adherence to ECS appears particularly advantageous in nonobese patients with extensive DVT.