AngioJet Pharmacomechanical Thrombectomy and Catheter Directed Thrombolysis vs. Catheter Directed Thrombolysis Alone for the Treatment of Iliofemoral Deep Vein Thrombosis: A Single Centre Retrospective Cohort Study.

OBJECTIVE: Percutaneous thrombus removal is used for the treatment of iliofemoral deep vein thrombosis (DVT), but the efficacy of different treatment modalities has not yet been determined. The aim of this study was to compare the outcomes of patients treated with additional AngioJet pharmacomechanical thrombectomy (PCDT) vs. catheter directed lysis (CDT) alone. METHODS: A retrospective review of all patients who received thrombolysis for the treatment of symptomatic acute iliofemoral DVT between 2011 and 2017 was carried out. Outcome measures included the incidence of post-thrombotic syndrome (PTS), procedural outcomes (lytic exposure), the incidence of complications, and vessel patency. All patients were followed up for a minimum of one year. RESULTS: A total of 151 limbs were treated, 70 limbs with PCDT and 81 limbs with CDT alone. Demographic data and prevalence of risk factors were comparable. Incidence of PTS (Villalta score at one year) showed no significant difference (22.2% PCDT vs. 24.7% CDT alone, p = .74). Use of PCDT resulted in a non-statistically significant trend for fewer bleeds (n = 4/63 [6.3%] vs. 13/76 [17.1%]; relative risk 0.37, 95% confidence interval [CI] 0.13-1.08; p = .07), a statistically significant reduction in lysis duration (40 h [95% CI 34-46] vs. 53 h [95% CI 49-58]; p < .001) and a reduction in lytic dose (49 mg [95% CI 42-55] vs. 57 mg [95% CI 52-61]; p = .011) compared with CDT. This reduction was accentuated in 24 cases primarily treated with AngioJet PowerPulse mode (27 h, 95% CI 20-34 [p < .001] and 42 mg, 95% CI 34-50 [p = .009]). Incidences of complications were comparable between groups, with one death due to an intracranial haemorrhage following CDT. Although the incidence of haemoglobinuria was increased following PCDT (12/63 [19.0%] vs. 3/76 [3.9%]; p = .006), no significant difference in acute kidney injury was observed (3/63 [4.8%] vs. 1/76 [1.3%]; p = .33). No significant difference in vessel patency over two years was observed (p = .73). CONCLUSION: The use of PCDT for the treatment of iliofemoral DVT was observed to provide comparable patient outcomes, comparable vessel patency, an acceptable safety profile, and reduced overall lytic dose.

Machine learning to predict venous thrombosis in acutely ill medical patients.

BACKGROUND: The identification of acutely ill patients at high risk for venous thromboembolism (VTE) may be determined clinically or by use of integer-based scoring systems. These scores demonstrated modest performance in external data sets. OBJECTIVES: To evaluate the performance of machine learning models compared to the IMPROVE score. METHODS: The APEX trial randomized 7513 acutely medically ill patients to extended duration betrixaban vs. enoxaparin. Including 68 variables, a super learner model (ML) was built to predict VTE by combining estimates from 5 families of candidate models. A "reduced" model (rML) was also developed using 16 variables that were thought, a priori, to be associated with VTE. The IMPROVE score was calculated for each patient. Model performance was assessed by discrimination and calibration to predict a composite VTE end point. The frequency of predicted risks of VTE were plotted and divided into tertiles. VTE risks were compared across tertiles. RESULTS: The ML and rML algorithms outperformed the IMPROVE score in predicting VTE (c-statistic: 0.69, 0.68 and 0.59, respectively). The Hosmer-Lemeshow goodness-of-fit P-value was 0.06 for ML, 0.44 for rML, and <0.001 for the IMPROVE score. The observed event rate in the lowest tertile was 2.5%, 4.8% in tertile 2, and 11.4% in the highest tertile. Patients in the highest tertile of VTE risk had a 5-fold increase in odds of VTE compared to the lowest tertile. CONCLUSION: The super learner algorithms improved discrimination and calibration compared to the IMPROVE score for predicting VTE in acute medically ill patients.

Idraparinux versus standard therapy for venous thromboembolic disease.

BACKGROUND: Venous thromboembolism is treated with unfractionated heparin or low-molecular-weight heparin, followed by a vitamin K antagonist. We investigated the potential use of idraparinux, a long-acting inhibitor of activated factor X, as a substitute for standard therapy. METHODS: We conducted two randomized, open-label noninferiority trials involving 2904 patients with deep-vein thrombosis and 2215 patients with pulmonary embolism to compare the efficacy and safety of idraparinux versus standard therapy. Patients received either subcutaneous idraparinux (2.5 mg once weekly) or a heparin followed by an adjusted-dose vitamin K antagonist for either 3 or 6 months. The primary efficacy outcome was the 3-month incidence of symptomatic recurrent venous thromboembolism (nonfatal or fatal). RESULTS: In the study of patients with deep venous thrombosis, the incidence of recurrence at day 92 was 2.9% in the idraparinux group as compared with 3.0% in the standard-therapy group (odds ratio, 0.98; 95% confidence interval [CI], 0.63 to 1.50), a result that satisfied the prespecified noninferiority requirement. At 6 months, the hazard ratio for idraparinux was 1.01. The rates of clinically relevant bleeding at day 92 were 4.5% in the idraparinux group and 7.0% in the standard-therapy group (P=0.004). At 6 months, bleeding rates were similar. In the study of patients with pulmonary embolism, the incidence of recurrence at day 92 was 3.4% in the idraparinux group and 1.6% in the standard-therapy group (odds ratio, 2.14; 95% CI, 1.21 to 3.78), a finding that did not meet the noninferiority requirement. CONCLUSIONS: In patients with deep venous thrombosis, once-weekly subcutaneous idraparinux for 3 or 6 months had an efficacy similar to that of heparin plus a vitamin K antagonist. However, in patients with pulmonary embolism, idraparinux was less efficacious than standard therapy. (ClinicalTrials.gov numbers, NCT00067093 [ClinicalTrials.gov] and NCT00062803 [ClinicalTrials.gov].).

Extended prophylaxis of venous thromboembolism with idraparinux.

BACKGROUND: The extended use of vitamin K antagonists for prophylaxis against venous thromboembolism is often constrained by risk-benefit limitations and inconvenience. We evaluated the efficacy and safety of a 6-month extension of prophylaxis against recurrent venous thromboembolism with idraparinux in patients who had initially received 6 months of prophylaxis with an anticoagulant. METHODS: We randomly assigned patients who had completed 6 months of prophylaxis with idraparinux or a vitamin K antagonist and in whom extended anticoagulation was warranted to receive once-weekly injections of 2.5 mg of idraparinux or placebo for 6 months without monitoring. The primary efficacy and safety outcomes were recurrent venous thromboembolism and major bleeding. RESULTS: Of 1215 patients, 6 of 594 (1.0%) in the idraparinux group and 23 of 621 (3.7%) in the placebo group had recurrent venous thromboembolism (P=0.002). Major bleeding occurred in 11 patients (1.9%) in the idraparinux group and in none in the placebo group (P<0.001). Of these 11 episodes, 3 were fatal intracranial hemorrhages. As compared with patients whose initial treatment was a vitamin K antagonist, patients whose initial treatment was idraparinux who were assigned to 6 months in the placebo group had a lower incidence of recurrent thromboembolism (0.7% vs. 5.9%); patients who received 6 additional months of idraparinux therapy had a higher incidence of major bleeding (3.1% vs. 0.9%). CONCLUSIONS: During a 6-month extension of thromboprophylaxis, idraparinux was effective in preventing recurrent thromboembolism but was associated with an increased risk of a major hemorrhage. (ClinicalTrials.gov number, NCT00071279 [ClinicalTrials.gov].).