Risk of Recurrent Venous Thromboembolism After an Initial Episode: Risk Stratification and Implications for Long-term Treatment

Unsupervised clustering of venous thromboembolism patients by clinical features at presentation identifies novel endotypes that improve prognostic stratification

BACKGROUND

Individuals with acute venous thromboembolism (VTE) constitute a heterogeneous group of patients with diverse clinical characteristics and outcome.

OBJECTIVES

To identify endotypes of individuals with acute VTE based on clinical characteristics at presentation through unsupervised cluster analysis and to evaluate their molecular proteomic profile and clinical outcome.

METHODS

Data from 591 individuals from the Genotyping and Molecular phenotyping of Venous thromboembolism (GMP-VTE) project were explored. Hierarchical clustering was applied to 58 variables to define VTE endotypes. Clinical characteristics, three-year incidence of thromboembolic events or death, and acute-phase plasma proteomics were assessed.

RESULTS

Four endotypes were identified, exhibiting different patterns of clinical characteristics and clinical course. Endotype 1 (n = 300), comprising older individuals with comorbidities, had the highest incidence of thromboembolic events or death (HR [95 % CI]: 3.76 [1.96-7.19]), followed by endotype 4 (n = 127) (HR [95 % CI]: 2.55 [1.26-5.16]), characterised by men with history of VTE and provoking risk factors, and endotype 3 (n = 57) (HR [95 % CI]: 1.57 [0.63-3.87]), composed of young women with provoking risk factors, vs. reference endotype 2 (n = 107). The reference endotype was constituted by individuals diagnosed with PE without comorbidities, who had the lowest incidence of the investigated endpoint. Differentially expressed proteins associated with the endotypes were related to distinct biological processes, supporting differences in molecular pathophysiology. The endotypes had superior prognostic ability compared to existing risk stratifications such as provoked vs unprovoked VTE and D-dimer levels.

CONCLUSION

Four endotypes of VTE were identified by unsupervised phenotype-based clustering that diverge in clinical outcome and plasmatic protein signature. This approach might support the future development of individualized treatment in VTE.

The incidence, risk factors, characteristics, and prognosis of recurrent deep venous thrombosis in the contralateral lower extremity

BACKGROUND

Recurrent events after a first symptomatic deep venous thrombosis (DVT) are relatively frequent, but little is known about contralateral recurrent DVT (RDVT).

METHODS

We retrospectively reviewed the medical records of patients with a first symptomatic lower extremity DVT between January 2017 and April 2021. The incidence, demographics, risk factors, and prognosis of RDVT were analyzed, with differences compared between patients with contralateral RDVT and those with ipsilateral RDVT.

RESULTS

In 570 consecutive patients with DVT, 28 patients (4.91%) developed contralateral RDVT, and 49 patients (8.60%) developed ipsilateral RDVT during a mean follow-up of 27.62 ± 14.84 months. Contralateral RDVT was more frequently found in the right lower extremity, whereas ipsilateral RDVT had more left lower extremity involvement. The median follow-up was 12 months until ipsilateral RDVT and 26.5 months until contralateral RDVT. In multivariate Cox analysis, inherited thrombophilia, stent extension with 50% to 100% coverage, autoimmune disease and anticoagulation noncompliance were identified as risk factors for contralateral RDVT. During follow-up, 5 patients (17.86%) with contralateral RDVT and 10 patients (20.41%) with ipsilateral RDVT died (P > .05), with 12 of 15 dying of an underlying malignancy.

CONCLUSIONS

The incidence of contralateral RDVT after a first symptomatic DVT is relatively low, and contralateral DVT is strongly associated with stent extension with 50% to 100% coverage, autoimmune disease, anticoagulation noncompliance, and inherited thrombophilia. Compared with ipsilateral RDVT, contralateral RDVT occurs later and is more often in the right lower extremity. Survival following contralateral RDVT is similar to survival following ipsilateral RDVT, with underlying malignancy being the leading cause of death.

The Use of Rivaroxaban for Unprovoked Pulmonary Embolism in the Setting of Antithrombin Deficiency

A 24-year-old woman with antithrombin (AT) deficiency presented with right-sided pleuritic chest pain of five days duration with diagnosis of pulmonary embolism (PE) made at an outside hospital. After discussion of treatment options with the patient, her treatment was changed to rivaroxaban protocol. The case illustrates an appropriate treatment plan for patients with AT deficiency presenting with unprovoked PE, especially when prioritizing ease of use.

Venous Thromboembolism Recurrence in Latvian Population: Single University Hospital Data

Background and objectives: Recurrence of venous thromboembolism (VTE) after a primary event is common; however, no sufficient risk scores have been widely introduced in clinical practice. The aim of this study was to assess the risk factors for VTE recurrences, as well as the effect of treatment strategies on the recurrence rate in a single-center patient cohort. Materials and Methods: The prospective cohort study included consecutive patients in a single center from June 2014 till June 2018 presenting with acute VTE confirmed by imaging tests. All patients were followed up for at least one year or till death. Statistical analyses were conducted using IBM SPSS Statistics 23 and Stata 13. Competing risk of death was considered. Results: A total of 219 eligible patients were identified during the study period. Pulmonary embolism with or without deep vein thrombosis (DVT) was present in 95.9% (n = 210), isolated DVT was present in 4.1% (n = 9) of patients. The total number of documented recurrences was 13 (5.9%). Incidence rate was 5.6 per 100 person-years. Recurrent VTE predicted significantly higher mortality rate (hazard ratio (HR) 6.64 [95% CI 2.61–16.93]). In univariate analysis, active cancer was associated with higher recurrence rate (p = 0.036). In competing-risks regression model (with death as the competing risk), active cancer (subdistribution hazard ratio (SHR) 2.11 (95% CI 0.58–7.76)) did not retain statistical significance for VTE recurrence. Discontinuation and duration of anticoagulant treatment (≤6 or >6 months), and drug class in acute or long-term therapy (parenteral, vitamin K antagonist (VKA), direct oral anticoagulant (DOAC)) were not associated with recurrences (p > 0.05). Conclusions: Patients who experienced recurrent VTE had 6.6-fold higher mortality rate than patients with no recurrences. The presence of active cancer was not a statistically significant risk factor for recurrence when taking into account the competing risk of death. Duration and drug class of anticoagulation did not seem to impact recurrence rate.