“Despite greater initial treatment costs, intervention in acute and subacute lower extremity deep vein thrombosis (DVT) with mechanical thrombectomy is cost effective in the UK.” This is according to an article in press in the European Journal of Vascular and Endovascular Surgery (EJVES).
Authors Stephen Black (King’s College London, London, UK) and colleagues write that interventional methods—such as mechanical thrombectomy and catheter-directed thrombolysis—offer an alternative strategy for managing DVT that may reduce the incidence of subsequent complications, such as post-thrombotic syndrome (PTS). However, the authors note that such methods incur higher initial treatment costs compared with the standard of care, namely anticoagulation, and it is unclear whether those higher costs are mitigated by the reduction in PTS. It was the aim of the present study, therefore, to evaluate the lifetime health utility of mechanical thrombectomy plus anticoagulation compared with anticoagulation alone in the UK.
The researchers implemented a combined decision tree and Markov model to evaluate complications from a healthcare payer’s perspective over a lifetime horizon in patients with acute and subacute iliofemoral DVT treated with either mechanical thrombectomy or anticoagulation.
Black and colleagues specify that resource utilisation and cost estimates were sourced from published literature and were evaluated in terms of inflation-adjusted 2021 British pound sterling. They add that complication rates, PTS health state transition probabilities, and health utilities were established from a published cohort of 164 pairs of propensity-score matched patients treated with mechanical thrombectomy or anticoagulation from the CLOUT registry and ATTRACT trial, respectively.
In EJVES, the authors report that mechanical thrombectomy resulted in lower lifetime costs (£20,889 vs. £26,193) and greater mean lifetime quality-adjusted life years (QALYs; 15.4 vs. 14.3) compared with anticoagulation. “Thus, mechanical thrombectomy was dominant compared with the standard of care, with a net monetary benefit of £27,904 at a willingness-to-pay threshold of £20,000,” they write. In addition, the authors note that results of univariate and probabilistic sensitivity analyses were consistent with the deterministic result, “suggesting robustness of the model results”.
Based on their findings, Black and colleagues conclude that mechanical thrombectomy is cost effective in the UK, regardless of higher initial treatment costs. Their results “suggest that patient benefit is realised over a lifetime horizon by reducing PTS incidence and associated costs,” they state, going on to stress that randomised controlled trials will validate these potential clinical and economic benefits.
Black presented these findings at the 39th European Society for Vascular Surgery (ESVS) annual meeting (23–26 September, Istanbul, Türkiye), closing his talk with the remark: “I think we can quite confidently now say […] that intervention does not cost you money.”
During discussion time following Black’s presentation, one audience member asked about mean follow-up time in the study. Black shared that, for the modelling, the team had two-year follow-up data from the ATTRACT trial available. “There are some data points that we included that give us out to five years of follow-up on post-thrombotic syndrome,” he added, before noting that the data “start to become weaker” at that stage.
“But what we see is that patients will probably progress to severe [PTS], and unless you account for that long-term progression in the untreated arm, you lose the QALY gained, particularly in a young cohort of patients who have 30 years to live,” he added. “So we do need better long-term data”.
