Compression Therapy in Acute Deep Venous Thrombosis of the Lower Limb and for the Prevention of Post-Thrombotic Syndrome.

BACKGROUND: After an acute deep venous thrombosis (DVT) of the lower limb, 20% to 63% of patients develop post-thrombotic syndrome (PTS). In this review, we address the efficacy of compression therapy in the treatment of acute DVT of the lower limb, and for the prevention of PTS. METHODS: 12 randomized controlled trials (RCTs) and one meta-analysis, with a total of 3751 patients, were identified in a structured literature search. RESULTS: Two RCTs showed that adding compression therapy to drug treatment in the first 9 days of the acute phase of lower limb DVT led to more rapid pain relief (p<0.050) and less swelling (remaining difference in circumference, 1 cm versus 3 cm, p<0.050). As for the prevention of PTS, four RCTs showed a short-term benefit or no benefit of compression therapy. In three further RCTs, medical compression stockings (MCS) brought about a 16% to 27% absolute reduction of the frequency and severity of PTS (47% vs. 20 %, p<0.001; 40% vs. 21% (95% confidence intervals [29.9; 50.1] and [12.7; 29.5], respectively; and 58% vs. 42%, relative risk [RR] 0.73 [0,55; 0.96]). The benefit of MCS was also confirmed in a recent meta-analysis (RR 0.66 [0.44; 0.99], I2 = 88%). Thigh-length MCS were not superior to knee-length MCS for the prevention of PTS (33% vs. 36%, hazard ratio [HR] 0.93 [0.62; 1.41]). Individual, symptomoriented tailoring of the duration of treatment was not inferior to a fixed treatment duration of 24 months (29% vs. 28%; odds ratio [OR] 1.06 [0.78;1.44]). CONCLUSION: Compression therapy relieves symptoms in acute DVT and lessens the frequency and severity of PTS. It is therefore recommended as standard treatment.

Principles of Optimal Antithrombotic Therapy for Iliac VEnous Stenting (POATIVES): A national expert-based Delphi consensus study.

OBJECTIVE: Management of antithrombotic therapy in patients undergoing venous stents has not yet reached consensus, and there are not any recommendations from published guidelines. We undertook a Delphi consensus from Chinese experts to develop recommendations regarding the preferred antithrombotic therapy in patients following venous stenting. METHODS: The phase 1 questionnaire was comprised of three clinical scenarios of venous stenting for non-thrombotic iliac vein lesions (NIVL), acute deep vein thrombosis (DVT), and post-thrombotic syndrome (PTS) and was sent to venous practitioners across China. In phase 2, the results of phase 1 were distributed to a panel of experts for evaluation along with a questionnaire encompassing a series of statements produced during phase 1. A modified Delphi method was used to reach consensus on recommendations through two rounds of surveys. RESULTS: The phase 1 questionnaire was completed by 283 respondents. In phase 2, an expert panel consisting of 28 vascular surgeons and interventional radiologists was assembled and voted 17 statements relating to antithrombotic management after venous stenting for NIVL (4 statements), DVT (6 statements), and PTS (7 statements). The majority of the statements about the antithrombotic agent selection received a high consensus strength. CONCLUSIONS: Based on the national Delphi consensus of Chinese experts regarding antithrombotic therapy following iliac venous stenting in three common scenarios, most of the statements could be used to guide antithrombotic management following venous stenting. Further studies are required to clarify controversial issues including the dose and duration of anticoagulants, the role of antiplatelet agents, especially in patients with NIVL.

Graduated elastic compression stockings in the prevention of post-thrombotic syndrome: A systematic review and meta-analysis.

BACKGROUND: The effect of graduated elastic compression stockings (ECS) in the prevention of post-thrombotic syndrome (PTS) has been questioned since a large randomized trial found no prophylactic effect of ECS. OBJECTIVE: To assess the effect of the wearing time of ECS on the incidence of post-thrombotic syndrome (PTS) after proximal deep venous thrombosis, we performed a meta-analysis of the incidence of PTS across randomized and observational studies. METHOD: PubMed, Embase and Cochrane databases were searched until 12 June 2023 for studies on the effect of ECS on PTS. References of eligible studies were also screened in order to identify other potential studies that might have been missed during the search. RESULTS: Four studies comprising a total of 1467 patients met our inclusion criteria for early initiation and consistent use of ECS in patients with acute proximal DVT. ECS significantly reduced the incidence of mild-moderate PTS (OR: 0.48; 95% CI: 0.36-0.63) as well as severe PTS (OR: 0.44; 95% CI: 0.28-0.58).

Coagulation-monitored, dose-adjusted catheter-directed thrombolysis or pharmaco-mechanical thrombus removal in deep vein thrombosis.

Background: Pharmaco-mechanical thrombectomy (PMT) and catheter-directed thrombolysis (CDT) are therapeutic options for selected patients with acute deep vein thrombosis (DVT) to prevent post-thrombotic syndrome (PTS). Patients and methods: We aimed to describe the clinical characteristics and outcomes of 159 patients with symptomatic iliofemoral DVT undergoing PMT alone, CDT alone, or CDT followed by PMT (bail-out) in the Swiss Venous Stent Registry. The primary outcome was the incidence of peri-interventional major and minor bleeding complications (ISTH criteria). Secondary outcomes included the incidence of PTS and stent patency after 3 years. Results: Mean age was 49±20 years and 58% were women. DVT involved the iliac veins in 99% of patients, whereas 53% had an underlying iliac vein compression. PMT alone was used in 40 patients, CDT alone in 77, and 42 received initial CDT followed by bail-out PMT due to insufficient thrombus clearance. Single-session PMT was the preferred approach in patients with iliac vein compression, patent popliteal vein, and absence of IVC thrombus. Patients treated with PMT alone received a lower r-tPA dose (median 10 mg, IQR 10-10) vs. those treated with CDT (20 mg, IQR 10-30). The rate of peri-interventional major bleeding was 0%, 1%, and 2%, whereas that of minor bleeding was 0%, 1%, and 12%, respectively, all occurring during CDT. After 3 years, PTS occurred in 6%, 9%, and 7% of patients, respectively. The primary stent patency rate was 95%, 88%, and 83%, respectively. Conclusions: The use of PMT and CDT for iliofemoral DVT was overall safe and resulted in high long-term patency and treatment success. Given the less severe presentation of DVT, single-session PMT appeared to be characterized by numerically better primary patency and lower perioperative bleeding event rates than CDT.

TILE pilot trial study protocol: Tinzaparin Lead-in to Prevent the Post-Thrombotic syndrome study protocol.

INTRODUCTION: The post-thrombotic syndrome (PTS) is a form of chronic venous insufficiency due to a prior ipsilateral deep venous thrombosis (DVT). This is a frequent complication that develops in 20%-50% of patients after a proximal DVT and is associated with significant healthcare, economic and societal consequences. In the absence of effective and well-tolerated treatment options for established PTS, effective preventative measures are needed. Anticoagulation itself reduces the risk of PTS, and low-molecular-weight heparin may reduce this further through anti-inflammatory properties targeting the initial acute inflammatory phase of DVT. METHODS AND ANALYSIS: The Tinzaparin Lead-In to Prevent the Post-Thrombotic syndrome pilot trial is an investigator-initiated, multicentre, open-label assessor-blinded trial that will randomise patients with first acute symptomatic common femoral or iliac DVT to receive either a 3-week lead-in course of tinzaparin, followed by rivaroxaban (experimental arm) or rivaroxaban alone (control arm). Its primary objectives are to assess: (1) proportion of PTS at 6 months using the Villalta scale and (2) study feasibility, which consists of (a) the proportion of screened patients eligible for the study, (2) the proportion of eligible patients recruited and (c) the proportion of recruited patients adherent to treatment (defined as at least 80% of drug taken). This study will determine the feasibility of a subsequent larger definitive trial. Secondary outcomes include change of quality of life scores, PTS severity, global improvement, patient satisfaction, bleeding, recurrent venous thromboembolism, leg pain, death and lost to follow-up. Target recruitment will be a total of 60 participants, recruited at 5-6 centres. ETHICS AND DISSEMINATION: Primary ethics approval was received from the Sunnybrook Health Sciences Center Research Ethics Board (approval ID 3315). Results of the study will be disseminated via peer-reviewed presentation at scientific conferences and open access publication. TRIAL REGISTRATION NUMBER: NCT04794569.

Current challenges in the prevention and management of post-thrombotic syndrome-towards improved prevention.

Post-thrombotic syndrome (PTS) is a common and potentially debilitating complication of deep vein thrombosis (DVT), affecting up to 50% of DVT patients. The consequence of this chronic condition includes reduced quality of life, increased use of the healthcare system and decreased productivity. The societal impact of this condition is projected to increase, given our ageing population and increased burden of thrombotic diseases. Despite significant recent advances in our understanding of PTS, many unanswered questions remain. Currently, there are few effective and proven options for established PTS; hence, the emphasis should be on instituting effective prevention to reduce the progression to PTS. Effective anticoagulation lowers the risk of PTS, with direct oral anticoagulants appearing to outperform vitamin-K antagonists. However, the evidence for elastic compression stockings and endovascular thrombolysis or thrombectomy techniques remains unclear. Accurate identification of individuals at high risk of developing PTS may also improve the targeting of preventative interventions. This review will examine the current body of evidence regarding PTS, with a focus on preventative strategies as well as novel biomarkers.

Is it necessary to wear compression stockings and how long should they be worn for preventing post thrombotic syndrome? A meta-analysis of randomized controlled trials.

BACKGROUND: Post thrombotic syndrome (PTS) is a serious complication of deep venous thrombosis (DVT). There were always debates on the efficacy of elastic compression stockings (ECS) in prevention for post thrombotic syndrome. OBJECTIVE: To assess effects of elastic compression stockings and ECS's wearing time on post thrombotic syndrome after diagnosis of deep venous thrombosis. METHODS: PubMed, Cochrane Library, Embase, Web of Science were last searched on 23 November 2022 for studies assessing effects of elastic compression stockings or theirs wearing time on post thrombotic syndrome after diagnosis of deep venous thrombosis. RESULTS: 9 randomized controlled trials were included. Wearing elastic compression stockings was associated with a statistically reduction in the overall post thrombotic syndrome rate (RR 0.73, 95 % CI 0.53 to 1.00; P = 0.05; I2 = 82 %). No significant difference in severe post thrombotic syndrome rate, recurrent deep venous thrombosis rate, and death rate was seen whether wearing elastic compression stockings or not. The pooled effect of studies comparing different wearing time of elastic compression stockings showed no significant difference in post thrombotic syndrome rate, severe and moderate post thrombotic syndrome rate, recurrent deep venous thrombosis syndrome rate and death rate. CONCLUSIONS: Wearing ECS can reduce the risk of developing PTS after DVT and a wearing time of less than or equal to 1 year is comparable to 2 years wearing. The results support ECS's role as a foundation therapy for preventing PTS.

Meta-analysis of lytic catheter-based intervention for acute proximal deep vein thrombosis in the reduction of post-thrombotic syndrome.

OBJECTIVE: Post-thrombotic syndrome (PTS) is a common complication of deep vein thrombosis (DVT) that can result in significant morbidity for the patient with detrimental impact on their quality of life. Evidence supporting lytic catheter-based interventions (LCBI) undertaken for early thrombus reduction in acute proximal DVT for the prevention of PTS is conflicting. Despite this, rates of LCBIs are increasing. To summaries the existing evidence and pool treatment effects, a meta-analysis of randomized controlled trials assessing the efficacy of LCBIs in proximal acute DVT for the prevention of PTS was undertaken. METHODS: This meta-analysis was undertaken aligning with PRISMA guidelines following a protocol pre-registered on PROSPERO. Online searches of Medline and Embase databases, as well as the gray literature, were performed up to December 2022. Included articles were randomized controlled trials that studied the use of LCBIs with additional anticoagulation vs anticoagulation alone and had determined follow-up periods. Outcomes of interest were PTS development, moderate to severe PTS, major bleeding episodes, and quality-of-life measures. Subgroup analyses were performed for DVTs involving the iliac vein and/r common femoral vein. Meta-analysis was performed using a fixed effects model. Quality assessment was performed using the Cochrane Risk of Bias and GRADE assessment tools. RESULTS: Three trials were included in the final meta-analysis, the Post-thrombotic Syndrome after Catheter-directed Thrombolysis for Deep Vein Thrombosis (CaVenT), Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis (ATTRACT), and Ultrasound-accelerated Catheter-directed Thrombolysis Versus Anticoagulation for the Prevention of Post-thrombotic Syndrome (CAVA) trials, comprising 987 patients. Patients undergoing LCBIs had a reduced risk of PTS (relative risk [RR], 0.84; 95% confidence interval [CI], 0.74-0.95; P = .006) and a lower risk of developing moderate to severe PTS (RR, 0.75; 95% CI, 0.58-0.97; P = .03). LBCIs increased the risk of having a major bleed (RR, 2.03; 95% CI, 1.08-3.82; P = .03). In the iliofemoral DVT subgroup analysis, there was a trend toward decreasing the risk of developing PTS and moderate to severe PTS (P = .12 and P = .05, respectively). There was no significant difference in quality-of-life score (as measured by the Venous Insufficiency Epidemiological and Economic Study - Quality of Life/Symptoms) between the two groups (P = .51). CONCLUSIONS: Pooling of current best evidence suggests that LCBIs in acute proximal DVT decreases the rate of PTS and moderate to severe PTS with a number needed to treat of 12 and 18, respectively. However, this is complicated by a significantly higher rate of major bleeding with a number needed to treat of 37. This evidence supports the use of LCBIs in selected patients, including those who are at low risk of major bleeding.

Systematic Review and Meta-Analysis of the Pooled Rate of Post-Thrombotic Syndrome After Isolated Distal Deep Venous Thrombosis.

OBJECTIVE: To identify the rate of post-thrombotic syndrome (PTS) after isolated distal deep venous thrombosis (IDDVT) by performing a meta-analysis of the rate of PTS across randomised and observational studies. DATA SOURCES: MEDLINE, Embase, the Cochrane Controlled Trials Register, Clinicaltrials.gov, European Union Clinical Trials, International Standard Randomised Controlled Trial Number, and the Australian and New-Zealand Trials Registries. REVIEW METHODS: This review followed PRISMA guidelines using a registered protocol (CRD42021282136). Databases were searched up to December 2021 and prospective studies reporting the development of post-thrombotic syndrome were included; these were pooled with the meta-analysis. RESULTS: The results showed a post-thrombotic rate of 17% (95% CI 11 - 26%) (seven studies, 217 cases, 1 105 participants). Heterogeneity was high (I2 = 89%). On meta-regression, the rate of post-thrombotic syndrome was not correlated with the length of follow up (p = .71). Three studies (302 participants) reported the severity of post-thrombotic syndrome: 78% were mild (Villalta score 5 - 9); 11% were moderate (Villalta score 10 - 14), and 11% were severe (Villalta score ≥ 15). CONCLUSION: The risk of post-thrombotic syndrome after IDDVT was one in five and the risk of severe clinical manifestations, including ulceration, was one in 50. There was significant clinical, methodological, and statistical heterogeneity between studies and a substantial risk of bias from pooled studies. Randomised trials to support interventions for prevention of post-thrombotic syndrome are urgently needed.

Successful Secondary Endovascular Intervention in Pediatric Patients with Venous Thromboembolic Events.

BACKGROUND: In the past, pediatric patients with venous thromboembolic events (VTE) were treated with low-molecular-weight heparin (LMWH) which was successful in around 70% of the cases. However, anticoagulation alone might not restore patency in all patients, and advanced therapeutic options to prevent postthrombotic syndrome are needed. During recent years, endovascular interventions have become a treatment option for pediatric patients with persistent thrombotic occlusion, not only in life- or limb-threatening VTE. METHODS: We evaluated 12 consecutive patients (11-17 years) with newly diagnosed VTE being treated at our department during the last 4 years (2017-2020). In case follow-up examination showed persistent venoocclusion under anticoagulation, patients received secondary interventional therapy like recanalization, percutaneous transluminal angioplasty with or without catheter-directed thrombolysis, and stenting. Patients with no clinical signs of venoocclusion or regredient thrombosis in imaging examination received anticoagulation alone. RESULTS: Six of 12 (50%) patients underwent catheter intervention. Median time from diagnosis to intervention was 4 months (0-12 months). Reintervention was necessary in one (8%) case and complete recanalization failed in one (8%) case. There were no major bleeding events or other major postinterventional complications, no acute or late local recurrence, and all patients reported clinical improvement after the procedure. CONCLUSION: If endovascular intervention is used in teenage patients with persistent symptomatic VTE, reduction of postthrombotic symptoms is possible, even if intervention is performed secondary to failure of anticoagulation. Multidisciplinary treatment decisions can be based on the clinical course and follow-up imaging.

Criteria to predict midterm outcome after stenting of chronic iliac vein obstructions (PROMISE trial).

BACKGROUND: Endovenous stent placement has become a first-line approach to prevent post-thrombotic syndrome in patients with chronic post-thrombotic obstruction (PTO) or nonthrombotic iliac vein lesions if conservative management fails. This study aims to identify factors associated with loss of patency to facilitate patient selection for endovenous stenting. METHODS: We retrospectively analyzed 108 consecutive patients after successful endovenous stenting for chronic vein obstruction performed at a single institution from January 2008 to July 2020. Using multivariable logistic regression, we explored potential predictive factors for loss of stent patency, including baseline demographics, post-thrombotic changes, and peak flow velocities measured in the common femoral vein (CFV), deep femoral vein, and femoral vein (FV) using duplex ultrasound examination. RESULTS: The mean follow-up duration was 41 ± 26 months, and participants had a mean age of 47.4 ± 15.4 years with 46.3% women. Ninety (83.3%) patients had PTO and 18 (16.7%) had nonthrombotic iliac vein lesions, predominantly due to May-Thurner syndrome. Loss of patency occurred in 20 (18.5%) patients, all treated for PTO. Comorbidities, side of intervention, and sex did not differ between patients with occluded and patent stents. Stent occlusion was more common with increasing number of stents implanted (P < .001) and with distal stent extension into and beyond the CFV (P < .001). Preinterventional predictive factors for stent occlusion were lower duplex ultrasound peak velocity in the CFV (odds ratio [OR]: 7.52, 95% confidence interval [CI]: 2.54-22.28; P < .001) and FV (OR: 10.75, 95% CI: 2.07-55.82; P < .005), and post-thrombotic changes in the deep femoral vein (OR: 4.51, 95% CI: 1.53-13.25; P = .006) and FV (OR: 3.62: 95% CI: 1.11-11.84; P = .033). Peak velocities of ≤7 cm/s (interquartile range: 0-20 cm/s) in the CVF and ≤8 cm/s (interquartile range: 5-10 cm/s) in the FV were significantly associated with loss of patency. CONCLUSIONS: Insufficient venous inflow as assessed by low peak velocities in the CFV and FV as well as post-thrombotic findings represent reliable risk predictors for stent occlusions, warranting their inclusion into the decision-making process for invasive treatment of PTO.

Restoring Venous Patency with the ClotTriever Following Deep Vein Thrombosis.

BACKGROUND: Although randomized data remain inconclusive, invasive endovenous therapy is increasingly favored in patients with extensive iliocaval or iliofemoral deep vein thrombosis (DVT) to reduce the rates of postthrombotic syndrome. Previously, pharmacomechanical thrombectomy was the therapy of choice, but the Inari ClotTriever device is an appealing, purely mechanical, alternative. It may reduce bleeding risk, intensive care unit admission, and the need for multiple procedures when compared with traditional thrombolysis. We present a series of 18 patients treated with the ClotTriever for extensive iliocaval or iliofemoral DVT. METHODS: The Inari ClotTriever is a percutaneous mechanical thrombectomy system consisting of an expandable nitinol collection bag that is dragged along the vein wall, separating and capturing thrombus for collection into the retrieval sheath. We retrospectively reviewed all patients undergoing ClotTriever thrombectomy since the device became available at our quaternary referral center in June 2019. The review of these patients' records was determined to be exempt by our institutional review board. RESULTS: Eighteen patients underwent ClotTriever thrombectomy between June 2019 and November 2021. Most patients (N = 16, 89%) presented within 2 weeks of symptom onset, and identifiable provoking factors were present in all patients. The most common provoking factor was anatomy, with May-Thurner syndrome present in 8 patients. All patients had restoration of unimpeded venous flow in the treated segments, although 3 had some residual nonflow limiting thrombus. There were no bleeding events or repeat venous procedures. The median postprocedure length of stay of 2 days. Postoperative venous imaging was performed in 15 patients and showed patency of the treated segment in 14 patients. Revised Clinical Venous Severity Scores were available in 14 patients during the course of follow-up. Of these, 9 patients' highest scores were 0, 2 patients' highest scores were 2, 2 patients' highest scores were 4, and 1 patient had a high score of 8. CONCLUSIONS: Venous flow was re-established in all 18 patients treated with the ClotTriever in this series, with no bleeding complications, and median postprocedure length of stay of 2 days. All patients with available follow-up, except 1, retained patency of the treated venous segments, and most had mild postthrombotic syndrome or none at all. These findings suggest that the ClotTriever is a safe and effective way to treat extensive iliocaval/femoral DVT.

25 mm Hg versus 35 mm Hg elastic compression stockings to prevent post-thrombotic syndrome after deep vein thrombosis (CELEST): a randomised, double-blind, non-inferiority trial.

BACKGROUND: The optimal strength of compression needed to prevent post-thrombotic syndrome (PTS) after a proximal deep vein thrombosis (DVT) is debated. We aimed to assess whether 25 mm Hg elastic compression stockings (ECS) are non-inferior to 35 mm Hg ECS in preventing PTS after a DVT. METHODS: In this multicentre, double-blind, non-inferiority, randomised controlled trial, we enrolled adults (≥18 years) with a first ipsilateral proximal DVT attending 46 French vascular medicine hospital departments or private practices. Participants were randomly allocated (1:1, stratified by centre, age, and sex; with varying block sizes of two and four) to wear 25 mm Hg or 35 mm Hg ECS for 2 years. The primary outcome was the cumulative rate of PTS 2 years after inclusion, defined by a Villalta scale (≥5). Efficacy was assessed by intention-to-treat and in eligible participants who had complete primary outcome data. A per-protocol analysis was also conducted among compliant patients as a secondary outcome measure. Safety was assessed in all participants who used ECS at least once, and for which we have at least some tolerance information during follow-up. The margin for non-inferiority was 12·5%. This study is registered with ClinicalTrials.gov, NCT01578122, and has been completed. FINDINGS: Between June 28, 2012, and July 21, 2017, we enrolled 341 eligible participants who consented to randomisation. 233 (68%) were men and median age was 59 years (IQR 45-70). Collection of ethnicity and race as a routine research variable is not authorised in France. Median follow-up was 735 days (IQR 721-760). 249 (73%) had complete data at 2 years. For the primary analysis, 40 (31%) of 129 participants with complete data in the 25 mm Hg ECS group and 40 (33%) of 120 in the 35 mm Hg group had PTS (absolute difference -2·3% [90% CI -12·1 to 7·4], pnon-inferiority=0·0062; relative risk 0·93, 95% CI 0·65 to 1·33). Results remained similar after imputation of missing data in patients we were authorised to do so: the cumulative proportion of PTS was 45 (29%) of 154 in the 25 mm Hg ECS group versus 52 (35%) of 148 in the 35 mm Hg ECS group (relative risk 0·83, 95% CI 0·60 to 1·16). Absolute difference was -5·9%, (90% CI -14·7 to 2·9), p=0·0003 for non-inferiority. Adherence was optimal (>80% and modified GIRERD score of 0-2) for 75 (51%) of 146 patients assigned to 25 mm Hg ECS and for 56 (42%) of 134 patients assigned to 35 mm Hg ECS (p=0·11). Regarding major adverse events related to ECS, there were no between-group differences in rates of deep vein thrombosis (0 vs 1 [0·6%]), ipsilateral leg ulcer (0 vs 1 [0·6%]), infection (0 vs 0), or death (0 vs 0) between the 169 patients evaluated in the 25 mm Hg ECS group and the 159 patients in the 35 mm Hg ECS group. Two (1%) of 328 patients who ever wore ESC developed ECS-related serious adverse events, one distal DVT and one leg ulcer (both in the 35 mm Hg ECS group). In the 25 mm Hg group, 6 patients died, 14 had a venous thromboembolic recurrence (proximal DVT or pulmonary embolism), and 7 had a major bleed. In the 35 mm Hg group, 5 patients died, 10 had a venous thromboembolic recurrence (proximal DVT or pulmonary embolism), and 6 had a major bleed. INTERPRETATION: Although we did not reach the prespecified sample size, our results suggest that 25 mm Hg ECS are non-inferior to 35 mm Hg ECS in preventing PTS. Larger more powerful studies are needed. FUNDING: Laboratoires Innothera, France.

How to optimize the prevention of post­thrombotic syndrome: recent advances.

Post­thrombotic syndrome (PTS) is the most frequent complication of deep vein thrombosis, and it can be detrimental to the quality of life of the affected patients. Once affected by this chronic condition, the patient's treatment options are very limited, so preventive therapies are crucial. Currently, the prevention of PTS is hampered by the lack of unequivocally effective therapies. However, improved insight into pathogenesis of this condition acquired in recent years, including the central role of residual venous obstruction, could lead to a better application of existing therapies and identification of novel therapeutic targets. Plausible therapeutic agents include flavonoids and statins, while promising future agents include those that target leukocyte­endothelial interaction. Moreover, differences in PTS risk were found to be partly explained by a tendency of patients to form clots that are less susceptible to lysis. Finally, identifying patients that are expected to benefit most from certain therapies is equally valuable for the success of future preventive strategies. This requires exploration of better risk stratification through machine learning techniques.

Prevention of post-thrombotic syndrome with rosuvastatin: A multicenter randomized controlled pilot trial (SAVER).

BACKGROUND: Post-thrombotic syndrome (PTS) is one of the most frequent complications of venous thromboembolism (VTE) leading to considerable morbidity and cost. Apart from appropriate anticoagulation, there is no drug or medical intervention that helps to prevent PTS. We conducted a multicenter randomized controlled trial to determine whether rosuvastatin can prevent PTS. METHODS: 312 patients receiving standard anticoagulation for a newly diagnosed VTE were randomly allocated to adjuvant rosuvastatin 20 mg once daily for 180 days (n = 155) or no rosuvastatin (n = 157). At the last study visit (Day 180 ± 21), an independent observer who was blinded to study treatment performed a PTS assessment using the Villalta scale. The primary clinical outcome of the trial was mean Villalta score at Day 180. We also explored the presence of PTS as defined by Villalta score > 4 at Day 180. Patients mean age was 46.7 ± 10.8 years, 55.8% were female. RESULTS: At Day 180, the Villalta score was 3.5 ± 0.3 in the rosuvastatin arm vs. 3.3 ± 0.3 in the control arm (p = 0.59), and presence of PTS (Villalta >4) was 29.7% in the rosuvastatin arm vs. 25.5% in the control arm (p = 0.41). Secondary analyses showed no difference between trial arms for presence of severe PTS at Day 180 (2.0% vs. 2.7%, p = 1) and for changes in Villalta score between baseline and Day 180 (-3.7 ± 4.4 vs. -4.0 ± 5.0, p = 0.59). CONCLUSION: This randomized controlled pilot trial did not demonstrate efficacy of rosuvastatin to reduce Villalta score. Further studies with longer duration of exposure to rosuvastatin are needed. TRIAL REGISTRATION: ClinicalTrials.gov, number NCT02679664.

Risk Factors for Post-Thrombotic Syndrome in Patients With a First Proximal Deep Venous Thrombosis Treated With Direct Oral Anticoagulants.

The incidence of post-thrombotic syndrome (PTS) in patients with deep vein thrombosis (DVT) treated with direct oral anticoagulants (DOACs) remains a matter of debate. Hence, our endeavor to investigate a large cohort of patients with a first episode of proximal DVT treated with DOACs to ascertain the incidence and predisposing risk factors for PTS. All consecutive patients referred to the Thrombotic and Haemorrhagic Diseases Unit of Padova University Hospital (Italy) between January 2014 and January 2018 for a first episode of proximal DVT were considered for enrollment. Participants received DOACs for a minimum period of 3 months. PTS was assessed using the Villalta score up to 36 months after DVT diagnosis. Among 769 enrolled patients (M/F 353/416, age range 26-87 years), 152 (19.8%) developed PTS and 30 (3.9%) developed severe PTS. The adjusted hazard ratio was significant for obesity (1.64, 95% CI 1.28-2.39) and DVT site (femoral and/or iliac veins vs popliteal vein) (1.23, 95% CI 1.15-3.00). The incidence of PTS is not negligible in patients with proximal DVT despite the use of DOACs. We identified obesity and iliofemoral DVT as possible risk factors for PTS. Larger prospective studies are needed to confirm our findings and optimize therapeutic strategies.

Treatment Strategies for Proximal Deep Vein Thrombosis: A Network Meta-analysis of Randomised Controlled Trials.

OBJECTIVE: To investigate the outcomes of treatment strategies for proximal and iliofemoral deep vein thrombosis (DVT). METHODS: Randomised controlled trials (RCTs) investigating outcomes of catheter directed thrombolysis (CDT), ultrasound assisted CDT (USCDT), percutaneous aspiration thrombectomy (PAT), and best medical therapy (BMT) for proximal DVT from 2000 onwards were considered. MEDLINE, EMBASE, and CINAHL were searched using the Healthcare Databases Advanced Search interface developed by the National Institute for Health and Care Excellence. The primary outcome was the rate of post-thrombotic syndrome (PTS), which was defined using the Villalta scoring system (score of ≥5). Secondary outcomes included vessel patency, recurrence, bleeding, and mortality. The network of evidence was summarised using network plots, and random effects network meta-analyses were performed. The certainty of evidence was assessed using the Certainty In Network Meta-Analysis (CINeMA) approach. RESULTS: Seven RCTs meeting the inclusion criteria were identified. There were direct comparisons between medical therapy, CDT, and USCDT across outcomes, except for patency. There were no direct comparisons between medical therapy and PAT (except for patency), and USCDT and PAT. There was no significant difference observed in PTS between the treatment modalities for proximal and iliofemoral DVT (low certainty). There was a significant difference in patency rates between medical therapy and USCDT (odds ratio [OR] 9.46, 95% confidence interval [CI] 3.05 - 29.35; low certainty) and CDT (OR 2.03, 95% CI 1.46 - 2.80; low certainty) in favour of USCDT and CDT, respectively, for proximal DVT. USCDT significantly improved patency rates compared with CDT (OR 4.67, 95% CI 1.58 - 13.81; very low certainty) for proximal DVT. There was no significant difference in DVT recurrence, bleeding, or mortality between treatment groups for proximal and iliofemoral DVT (low to moderate certainty for most comparisons). CONCLUSION: USCDT may improve patency rates compared with BMT and the other interventional treatment modalities used for the management of proximal DVT. However, no treatment modality showed superiority with regard to a reduction in PTS, and overall, the quality of available evidence is poor.