Quality of anticoagulant therapy and the incidence of in‐stent thrombosis after venous stenting

Abstract

Background In patients with a venous outflow obstruction following iliofemoral deep vein thrombosis stenting of the venous tract to prevent or alleviate postthrombotic syndrome is applied with increasing frequency. The impact of the quality of anticoagulant therapy with vitamin K antagonists (VKAs) on the development of in‐stent thrombosis is currently unknown. Objectives To determine the association between the quality of postinterventional VKA treatment and the occurrence of in‐stent thrombosis. Methods Seventy‐nine patients with iliofemoral and/or caval venous stent placement for obstruction of the venous outflow were included in this study. All patients received postinterventional VKA. The quality of VKA anticoagulant therapy was expressed as the time within therapeutic range (TTR) calculated using the linear interpolation method and as the proportion of International Normalized Ratio (INR) values < 2.0. In‐stent thrombosis was assessed by the use of duplex ultrasound. Survival analysis (Kaplan‐Meier curves, Cox regression) was used to analyze the data. Results In‐stent thrombosis developed in 16 patients (20.3%). The total population had a mean TTR of 64.0% (±19.0) and a mean proportion of INR values < 2.0 of 11.6% (±12.0). Overall, a TTR < 49.9% was associated with an increased risk of in‐stent thrombosis. The multivariable adjusted analysis showed a hazard ratio (HR) of 0.96 (95% confidence interval [CI], 0.92‐0.99; P = .02) per 1% increase in TTR. The proportion of INR values < 2.0 had no significant association with the occurrence of in‐stent thrombosis: HR 0.98 (95% CI, 0.91‐1.06; P = .66). Conclusions We conclude that the quality of anticoagulant treatment reflected in the TTR following a venous stenting procedure is an important independent determinant for the risk of in‐stent thrombosis. The role of anticoagulant treatment for the prevention of in‐stent thrombosis following stenting procedures therefore merits further research.

Postinterventional antithrombotic management after venous stenting of the iliofemoral tract in acute and chronic thrombosis: A systematic review

“…All studies performed treatment of acute or chronic thrombotic iliofemoral venous obstructions using venous stent placement (including adjunctive procedures) and all studies provided information on the postinterventional antithrombotic therapy prescribed (Table 1). Details on preinterventional and peri‐interventional antithrombotic treatment were provided in 28 (50%) 2,3,10‐19,26,31,35‐37,43,45,51,54,55,57,59,60,62,64‐71 and 46 (82%) 2,3,10‐28,30‐32,34‐36,41‐47,50‐61,63‐65,67,69‐71 studies, respectively. Information about eventual (dis)continuation of existing antithrombotic therapy during the intervention was provided in 19 studies (34%) 2,3,10‐16,18,19,24,26,27,30,43,51,63‐65,67‐70 …”

“…In 13 studies incidences could be specified for patients with (a history of) DVT who underwent venous stent placement 16,26,28,45,54,57,58,63,66,70 ; reDVT was only seen in studies that included patients treated during the acute phase of DVT: Sebastian et al (1%), 26 Park et al (2.0%), 45 and Kölbel et al (2.8%) 28 . ReDVT was absent in the other seven studies (including three case reports) 16,54,57,58,63,66,70 with an acute indication for intervention as well as in the other three studies with mixed treatment indications including both acute and chronic pathology 3,27,60 …”

“…If study populations also included patients receiving interventions for chronic pathology, 3,25,31,34,38,40‐42,46,47,55,60 the occurrence of IST in patients with (post)thrombotic stenting ranged from 0.0% 60,62 to 43.8% 40 next to the multiple recurrences resulting from nonresponsiveness to antithrombotic treatment in one 68 of the two case reports 62,68 . Early occurrences ranged from 5.4% 3 to 18.8% 40 and late occurrences from 3.8% 31 to 34.4% 38 . In studies that did not allow specification of outcomes for patients with thrombotic or nonthrombotic chronic pathology, 23,27,30,39,44,49,50,53 the overall risk of IST ranged from 3.2% 30 to 27.4% 53 .…”

“…Our up‐to‐date search showed that in the year 2020, there still is no or little attention for antithrombotic treatment surrounding venous stent placement given that only two studies directly assessed this issue when reporting on study outcomes. Only one of these studies addressed the direct impact of antithrombotic treatment on IST following stenting procedures 3 . This study suggested that the risk of IST decreases with increased quality of antithrombotic treatment with VKA, expressed as TTR.…”

“…Although a meta‐analysis could not be performed, an indication for a protective effect of postinterventional antithrombotic treatment was suspected. This is in particular based on the study by Notten et al 3 showing that a more adequately executed antithrombotic treatment could protect against the development of IST.…”