Ruling out deep vein thrombosis in patients with superficial vein thrombosis: external validation of the ICARO score

Predictive factors of clot propagation in patients with superficial venous thrombosis towards deep venous thrombosis and pulmonary embolism: a systematic review and meta-analysis

OBJECTIVE

A subset of patients with superficial venous thrombosis (SVT) experiences clot propagation towards deep venous thrombosis (DVT) and/or pulmonary embolism (PE). The aim of this systematic review is to identify all clinically relevant cross-sectional and prognostic factors for predicting thrombotic complications in patients with SVT.

DESIGN

Systematic review.

DATA SOURCES

PubMed/MEDLINE and Embase were systematically searched until 3 March 2023.

ELIGIBILITY CRITERIA

Original research studies with patients with SVT, DVT and/or PE as the outcome and presenting cross-sectional or prognostic predictive factors.

DATA EXTRACTION AND SYNTHESIS OF RESULTS

The CHecklist for critical Appraisal and data extraction for systematic Reviews of prediction Modelling (CHARMS) checklist for prognostic factor studies was used for systematic extraction of study characteristics. Per identified predictive factor, relevant estimates of univariable and multivariable predictor-outcome associations were extracted, such as ORs and HRs. Estimates of association for the most frequently reported predictors were summarised in forest plots, and meta-analyses with heterogeneity were presented. The Quality in Prognosis Studies (QUIPS) tool was used for risk of bias assessment and Grading of Recommendations, Assessment, Development and Evaluations (GRADE) for assessing the certainty of evidence.

RESULTS

Twenty-two studies were included (n=10 111 patients). The most reported predictive factors were high age, male sex, history of venous thromboembolism (VTE), absence of varicose veins and cancer. Pooled effect estimates were heterogenous and ranged from OR 3.12 (95% CI 1.75 to 5.59) for the cross-sectional predictor cancer to OR 0.92 (95% CI 0.56 to 1.53) for the prognostic predictor high age. The level of evidence was rated very low to low. Most studies were scored high or moderate risk of bias.

CONCLUSIONS

Although the pooled estimates of the predictors high age, male sex, history of VTE, cancer and absence of varicose veins showed predictive potential in isolation, variability in study designs, lack of multivariable adjustment and high risk of bias prevent firm conclusions. High-quality, multivariable studies are necessary to be able to identify individual SVT risk profiles.

PROSPERO REGISTRATION NUMBER

CRD42021262819.

Superficial Venous Thrombosis: A Comprehensive Review

Superficial venous thrombosis (SVT), an inflammatory-thrombotic process of a superficial vein, is a relatively common event that may have several different underlying causes. This phenomenon has been generally considered benign, and its prevalence has been historically underestimated; the estimated incidence ranges from about 0.3 to 1.5 event per 1000 person-years, while the prevalence is approximately 3 to 11%, with different reports depending on the population studied. However, such pathology is not free of complications; indeed, it could extend to the deep circulation and embolize to pulmonary circulation. For this reason, an ultrasound examination is recommended to evaluate the extension of SVT and to exclude the involvement of deep circulation. Also, SVT may be costly, especially in the case of recurrence. Therefore, accurate management is necessary to prevent sequelae and costs related to the disease. This review aims to analyse the epidemiology of SVT, its complications, optimal medical treatment, and open questions with future perspectives.

Management of superficial venous thrombosis based on individual risk profiles: protocol for the development and validation of three prognostic prediction models in large primary care cohorts

BACKGROUND

Superficial venous thrombosis (SVT) is considered a benign thrombotic condition in most patients. However, it also can cause serious complications, such as clot progression to deep venous thrombosis (DVT) and pulmonary embolism (PE). Although most SVT patients are encountered in primary healthcare, studies on SVT nearly all were focused on patients seen in the hospital setting. This paper describes the protocol of the development and external validation of three prognostic prediction models for relevant clinical outcomes in SVT patients seen in primary care: (i) prolonged (painful) symptoms within 14 days since SVT diagnosis, (ii) for clot progression to DVT or PE within 45 days and (iii) for clot recurrence within 12 months.

METHODS

Data will be used from four primary care routine healthcare registries from both the Netherlands and the UK; one UK registry will be used for the development of the prediction models and the remaining three will be used as external validation cohorts. The study population will consist of patients ≥18 years with a diagnosis of SVT. Selection of SVT cases will be based on a combination of ICPC/READ/Snowmed coding and free text clinical symptoms. Predictors considered are sex, age, body mass index, clinical SVT characteristics, and co-morbidities including (history of any) cardiovascular disease, diabetes, autoimmune disease, malignancy, thrombophilia, pregnancy or puerperium and presence of varicose veins. The prediction models will be developed using multivariable logistic regression analysis techniques for models i and ii, and for model iii, a Cox proportional hazards model will be used. They will be validated by internal-external cross-validation as well as external validation.

DISCUSSION

There are currently no prediction models available for predicting the risk of serious complications for SVT patients presenting in primary care settings. We aim to develop and validate new prediction models that should help identify patients at highest risk for complications and to support clinical decision making for this understudied thrombo-embolic disorder. Challenges that we anticipate to encounter are mostly related to performing research in large, routine healthcare databases, such as patient selection, endpoint classification, data harmonisation, missing data and avoiding (predictor) measurement heterogeneity.

Prognostic Significance of Concomitant Superficial Vein Thrombosis in Patients with Deep Vein Thrombosis of the Lower Limbs

BACKGROUND

 The prognostic significance of concomitant superficial vein thrombosis (SVT) in patients with lower-limb deep vein thrombosis (DVT) has not been consistently evaluated.

METHODS

 We used the RIETE (Registro Informatizado de Enfermedad TromboEmbólica) registry to compare the rates of subsequent pulmonary embolism (PE), recurrent DVT, major bleeding or death in patients with lower-limb DVT, according to the presence or absence of concomitant SVT.

RESULTS

 From March 2015 to May 2020, there were 8,743 patients with lower-limb DVT. Of these, 745 (8.5%) had concomitant SVT. Most patients (97.4% in both subgroups) received anticoagulant therapy (median duration: 138 vs. 147 days). During follow-up (median: 193 vs. 210 days), 156 (1.8%) patients developed subsequent PE, 336 (3.8%) had recurrent DVT, 201 (2.3%) had major bleeding and 844 (9.7%) died. Patients with concomitant SVT had a higher rate of subsequent PE (rate ratio [RR]: 2.11; 95% confidence interval [95%CI]: 1.33-3.24) than those with isolated DVT, with no significant differences in the rates of recurrent DVT (RR: 0.80; 95%CI: 0.50-1.21), major bleeding (RR: 0.77; 95%CI: 0.41-1.33) or death (RR: 0.81; 95%CI: 0.61-1.06). On multivariable analysis, patients with DVT and SVT concomitantly were at increased risk of subsequent PE during anticoagulation (adjusted hazard ratio [HR]: 2.23; 95%CI: 1.22-4.05) and also during the entire follow-up period (adjusted HR: 2.33; 95%CI: 1.49-3.66).

CONCLUSION

 Patients with lower-limb DVT and SVT concomitantly are at increased risk of developing PE. Further studies are needed to externally validate our findings and to determine if these patients could benefit from a different management strategy.