Controversies in venous thromboembolism: the unique case of isolated distal deep vein thrombosis

A risk prediction model for evaluating thrombosis extension of muscle calf venous thrombosis after craniotomy

Objective

To explore the risk factors of muscle calf venous thrombosis (MCVT) after craniotomy and construct a risk prediction model, so as to provide tool for evaluating the prognosis of MCVT after craniotomy.

Methods

Retrospective analysis was performed on the data of patients undergoing craniotomy complicated with MCVT from January 1, 2018 to December 31, 2020. A prediction model was established by Logistic regression, and the predictive efficacy of the model was tested by ROC curve. The accuracy of the risk model was evaluated by Hosmer-Lemeshow (H-L) test, and the model was verified internally by cross validation.

Results

Among the 446 patients who underwent craniotomy complicated with MCVT, 112 cases (25.11%) had thrombosis extension. D-dimer, Capirini scores, length of hospital stay, malignant tumor, fracture, use of dehydrating agents and hemostatic agents were independently related to thrombosis extension after craniotomy. The area under ROC curve (AUROC) of the prediction model was 0.918 (0.888, 0.942), and the sensitivity and specificity of the maximum Youden index were 85.3% and 78.2%, respectively. H-L test showed that the prediction model was accurate (χ² = 12.426, P = 0.133). The internal verification results of the prediction model showed that the AUROC value of the prediction model is 0.892.

Conclusion

The prediction model has a good prediction efficacy on the prognosis of post-craniotomy patients complicated with MCVT, and can be used as a tool to evaluate the risk of thrombosis extension.

Clinical Presentation and Short- and Long-term Outcomes in Patients With Isolated Distal Deep Vein Thrombosis vs Proximal Deep Vein Thrombosis in the RIETE Registry

Importance

Insufficient data exist about the clinical presentation, short-term, and long-term outcomes of patients with isolated distal deep vein thrombosis (IDDVT), that is, thrombosis in infrapopliteal veins without proximal extension or pulmonary embolism (PE).

Objective

To determine the clinical characteristics, short-term, and 1-year outcomes in patients with IDDVT and to compare the outcomes in unadjusted and multivariable adjusted analyses with patients who had proximal DVT.

Design, Setting, and Participants

This was a multicenter, international cohort study in participating sites of the Registro Informatizado Enfermedad Tromboembólica (RIETE) registry conducted from March 1, 2001, through February 28, 2021. Patients included in this study had IDDVT. Patients with proximal DVT were identified for comparison. Patients were excluded if they had a history of asymptomatic DVT, upper-extremity DVT, coexisting PE, or COVID-19 infection.

Main Outcomes and Measures

Primary outcomes were 90-day and 1-year mortality, 1-year major bleeding, and 1-year venous thromboembolism (VTE) deterioration, which was defined as subsequent development of proximal DVT or PE.

Results

A total of 33 897 patients were identified with isolated DVT (without concomitant PE); 5938 (17.5%) had IDDVT (mean [SD] age, 61 [17] years; 2975 male patients [50.1%]), and 27 959 (82.5%) had proximal DVT (mean [SD] age, 65 [18] years; 14 315 male patients [51.2%]). Compared with individuals with proximal DVT, those with IDDVT had a lower comorbidity burden but were more likely to have had recent surgery or to have received hormonal therapy. Patients with IDDVT had lower risk of 90-day mortality compared with those with proximal DVT (odds ratio [OR], 0.47; 95% CI, 0.40-0.55). Findings were similar in 1-year unadjusted analyses (hazard ratio [HR], 0.52; 95% CI, 0.46-0.59) and adjusted analyses (HR, 0.72; 95% CI, 0.64-0.82). Patients with IDDVT had a lower 1-year hazard of VTE deterioration (HR, 0.83; 95% CI, 0.69-0.99). In 1-year adjusted analyses of patients without an adverse event within the first 3 months, IDDVT was associated with lower risk of VTE deterioration (adjusted HR, 0.48; 95% CI, 0.24-0.97). By 1-year follow-up, symptoms or signs of postthrombotic syndrome were less common in patients with IDDVT (47.6% vs 60.5%).

Conclusions and Relevance

Results of this cohort study suggest that patients with IDDVT had a less ominous prognosis compared with patients with proximal DVT. Such differences were likely multifactorial, including the differences in demographics, risk factors, comorbidities, particularly for all-cause mortality, and a potential association of thrombus location with VTE deterioration and postthrombotic syndrome. Randomized clinical trials are needed to assess the optimal long-term management of IDDVT.

Outcomes of isolated distal thrombosis managed with serial compression ultrasonography

BACKGROUND

Isolated distal deep vein thrombosis (IDDVT) is a common subtype of deep vein thrombosis (DVT). Consensus guidelines provide conflicting recommendations for IDDVT management; some recommend anticoagulant treatment, while others suggest serial compression ultrasonography (CUS) monitoring for patients not at "high risk" of proximal extension. The purpose of this study was to describe outcomes of serial CUS-monitored IDDVT and identify risk factors for proximal thrombus extension or anticoagulant treatment initiation.

METHODS

A retrospective descriptive study was conducted using electronic data from University of Utah Health. Adult subjects with objectively confirmed, serial CUS-monitored IDDVT were included. Subjects were followed for 30 days for occurrence of a composite outcome of proximal thrombus extension or anticoagulant treatment initiation. Descriptive statistics were used to summarize characteristics of the study population. Characteristics were compared across outcome groups using inferential statistics.

RESULTS

A total of 182 subjects were included, with 53 subjects (29.1%) experiencing the composite outcome. Of these, 12 (22.6%) experienced proximal thrombus extension and 41 (77.4%) initiated anticoagulant treatment. A prior history of venous thromboembolism (VTE) was significantly higher in those who experienced the composite outcome than in those who did not.

CONCLUSIONS

Our results suggest that 70% of patients with serial CUS-monitored IDDVT did not experience thrombus extension or require anticoagulant treatment within 30 days of diagnosis, regardless of risk factors for proximal extension. Serial CUS monitoring may be a useful management strategy for IDDVT. A history of VTE may identify patients more likely to experience proximal thrombus extension or require anticoagulation.

Risk Factors and Anticoagulation Therapy in Patients With Isolated Distal Deep Vein Thrombosis in the Early Post-operative Period After Thoracic Surgery

Background: Isolated distal deep vein thrombosis (IDDVT) accounts for ~50% of all patients diagnosed with deep venous thrombosis (DVT), but the diagnosis and optimal management of IDDVT remains unclear and controversial. The aim of this study was to explore potential risk factors and predictors of IDDVT, and to evaluate different strategies of anticoagulation therapy.

Methods: A total of 310 consecutive patients after thoracic surgery, who underwent whole-leg ultrasonography as well as routine measurements of D-dimer levels before and after surgery were evaluated. The general clinical data, anticoagulant therapy, pre- and postoperative D-dimer levels were collected. Differences between IDDVT, DVT and non-DVT groups were calculated. Logistic regression analysis was used to analyze risk factors of postoperative IDDVT.

Results: Age and postoperative D-dimer levels were significantly higher in IDDVT group than in non DVT group (p = 0.0053 and p < 0.001, respectively). Logistic regression analysis showed that postoperative D-dimer level was a significant independent predictor of IDDVT even when adjusted for age and operation method (p = 0.0003). There were no significant side effects associated with both full-dose and half-dose anticoagulation regimens. Half-dose therapy was associated with a significant decrease in the requirement for anticoagulation medications after discharge (p = 0.0002).

Conclusion: Age and D-dimer levels after surgery are strong predictors of IDDVT following thoracic surgery. Half-dose therapeutic anticoagulation has the same efficiency in preventing IDDVT progression, is not associated with any additional risks of adverse effects compared to a full-dose regimen, and may be adopted for treating IDDVT patients after thoracic surgery.

Direct-access to sonographic diagnosis of deep vein thrombosis in general practice: a descriptive cohort study

Background

Suspicion of deep vein thrombosis (DVT) is common and requires urgent and efficient investigation due to hazardous prognosis. The traditional diagnostic pathway can be complex and time-consuming, and innovative solutions may provide easy access to diagnostics and better use of healthcare resources. We aimed to describe use, clinical outcomes and time used when providing general practitioners (GPs) with a direct-access pathway to hospital-based, single whole-leg compression ultrasound (CUS) for patients with suspected DVT. Furthermore we aimed to describe the resources used in the new direct-access pathway and compare it with the previous pathway.

Methods

We conducted a 2-year descriptive cohort study (2016–2017) including 449 consecutively referred patients for diagnosis of DVT in a Danish regional hospital. The previous pathway included pre-test at the medical department, a proximal leg CUS if required based on the pre-test and a re-scan if the first CUS was negative. The new pathway included two strategies: 1) a ‘yes-no strategy’, where GPs referred patients directly to whole-leg CUS and if positive, treated at the medical department and if negative, discharged to the GP, 2) a ‘follow-up strategy’ where GPs could require that patients were seen at the medical department, irrespective of the CUS result. Data included extractions from the Radiology Information and Patient Administrative Systems, and mean salaries of healthcare professionals at Silkeborg Regional Hospital, Denmark. Descriptive statistics were used to describe prevalence, timelines and costs.

Results

GPs referred 318 (71%) patients through the yes-no strategy and 131 (29%) via the follow-up strategy with DVT diagnosed in 48 (15%) and 51 (39%) patients, respectively (p < 0.001). For the 263 patients completed after CUS in the yes-no strategy, median pathway time was 24 min (IQI: 16–36), and for those with DVT (including both strategies) 202 min (IQI: 158–273). Direct-access pathway costs were €49.7 less per patient than the previous pathway.

Conclusion

Direct-access to CUS for suspected DVT was achievable, had short time intervals and required fewer resources. The difference in DVT prevalence indicates that GPs distinguish between patients with low and high risk of DVT.

Differences in Clinical Presentation, Rate of Pulmonary Embolism, and Risk Factors Among Patients With Deep Vein Thrombosis in Unusual Sites

Unusual site deep vein thrombosis (USDVT) is an uncommon form of venous thromboembolism with heterogeneous signs and symptoms, unknown rate of pulmonary embolism (PE), and poorly defined risk factors. We conducted a retrospective analysis of 107 consecutive cases of USDVTs, discharged from our University Hospital over a period of 2 years. Patients were classified based on the site of thrombosis and distinguished between patients with cerebral vein thrombosis, jugular vein thrombosis, thrombosis of the deep veins of the upper extremities, and abdominal vein thrombosis. We found statistically significant differences between groups in terms of age (P < .0001) and gender distribution (P < .05). We also found that the rate of symptomatic patients was significantly different between groups (P < .0001). Another interesting finding was the significant difference between groups in terms of rate of PE (P < .01). Finally, we found statistically significant differences between groups in terms of risk factors for thrombosis, in particular cancer (P < .01). Unprovoked cases were differently distributed among groups (P < .0001). This study highlights differences between patients with USDVT, which depend on the site of thrombosis, and provides data which might be useful in clinical practice.

Proximal and isolated distal deep vein thrombosis and Wells score accuracy in hospitalized patients

Deep vein thrombosis (DVT) is an important cause of morbidity and mortality in hospitalized patients. The Wells score for DVT pretest probability (PTP) was validated in outpatients, but its utility for inpatients is unclear. The aim of this study was to establish the prevalence of inpatient proximal and distal DVT and the Wells score performance in inpatients. A single-center cross-sectional study was conducted in a university hospital. During 183 days, all inpatients with suspected lower-extremity DVT were evaluated with the Wells score and whole-leg ultrasound. Among 634 inpatients (age 77.5 ± 13.8 years, males 39.3%), 507 (80.0%) were from medical wards and 127 (20.0%) from surgical wards. During the study period, there were 11,662 hospital admissions in the surgical/medical services. Whole-leg ultrasound detected 128 DVTs (20.2%); 51 (39.8%) were proximal and 77 (60.1%) were isolated distal DVTs. Estimated DVT prevalence in hospital setting was 1.09% (95% CI 0.93-1.31), and isolated distal DVT prevalence was 0.66% (95% CI 0.53-0.82). DVT frequency in low-, moderate-, and high-PTP groups was 9.8%, 24.3%, and 41.5%, respectively (p = 0.001). The area under the receiver operating characteristic curve for the Wells score was 0.67 ± 0.03 for all DVTs and 0.75 ± 0.04 for only proximal DVTs. A high PTP had a sensitivity of 24% (95% CI 14-37%) and a specificity of 93% (95% CI 91-95%) for proximal DVT diagnosis. In hospitalized patients, isolated distal DVT has a higher incidence than expected, and the Wells score accuracy for proximal DVT is similar to that found in outpatients.

Landmark trials in thrombotic vascular disease: a critical appraisal of potential practice-changing trials in 2016-2017

Recent years have witnessed an onslaught of large, multicenter, randomized controlled trials evaluating the prevention and management of thrombotic vascular diseases. While these trials have applied rigorous methodology to pragmatic and clinically relevant questions, several important gaps in knowledge remain. In this review, we critically appraise landmark studies in thrombosis published between 2016 and 2017 that address several ongoing areas of clinical uncertainty. Specifically, we review the role of endovascular therapy in the prevention of post-thrombotic syndrome following acute lower limb deep vein thrombosis (DVT) (ATTRACT trial), the efficacy of edoxaban as the first direct oral anticoagulant used for the treatment of cancer-associated thrombosis (HOKUSAI VTE-Cancer study), whether aspirin can be considered for thromboprophylaxis post-major orthopedic surgery (EPCAT-2 trial), and the need for anticoagulant therapy for treatment of isolated distal DVT (CACTUS trial). Using illustrative cases, we highlight the applicability of these trials to current practice and emphasize the unanswered questions that remain.

Anticoagulation in patients with isolated distal deep vein thrombosis: a meta-analysis

Essentials The optimal management of isolated distal deep vein thrombosis (IDDVT) is undefined. This meta-analysis aimed to assess the clinical benefit of anticoagulation for IDDVT. Anticoagulation reduced the rate of pulmonary embolism without increasing major bleeding risk. Recurrent thromboembolism was less common with more than 6 weeks vs. 6 weeks of anticoagulation.

SUMMARY

Background The optimal management of patients with isolated distal deep vein thrombosis (IDDVT), concerning both the need for anticoagulation and its duration, is undefined. Objectives We performed a meta-analysis of randomized and cohort studies in patients with IDDVT to assess the clinical benefit of: (i) anticoagulation versus no anticoagulation; and (ii) anticoagulant treatment for 6 weeks versus for > 6 weeks. Methods The primary outcome of this analysis was recurrent venous thromboembolism (proximal propagation, recurrence of deep vein thrombosis, and pulmonary embolism). Data were pooled and compared by the use of odds ratio (OR) and 95% confidence interval (CI). Results A reduction in the rate of recurrent venous thromboembolism was observed in patients who received anticoagulation relative to those who did not receive anticoagulation (either therapeutic or prophylactic) (20 studies, 2936 patients; OR 0.50, 95% CI 0.31-0.79), without an increase in the risk of major bleeding (OR 0.64, 95% CI 0.15-2.73). The rate of pulmonary embolism was lower in anticoagulant-treated patients than in controls (15 studies, 1997 patients; OR 0.48, 95% CI 0.25-0.91). A lower rate of recurrent venous thromboembolism was observed in patients who received > 6 weeks of anticoagulant therapy than in those who received 6 weeks of anticoagulant therapy (four studies, 1136 patients; OR 0.39, 95% CI 0.17-0.90). Conclusions In patients with IDDVT, anticoagulation (both therapeutic and prophylactic) reduces the rate of recurrent venous thromboembolism and the incidence of pulmonary embolism as compared with no anticoagulation, without an increased risk of major bleeding. Anticoagulation for > 6 weeks should be preferred over shorter durations.

Incidence of Deep Vein Thrombosis and Venous Thromboembolism following TKA in Rheumatoid Arthritis versus Osteoarthritis: A Meta-Analysis

This meta-analysis was designed to compare the incidence of deep vein thrombosis (DVT) and venous thromboembolism (VTE) following total knee arthroplasty (TKA) in patients with rheumatoid arthritis (RA) and osteoarthritis (OA). All studies directly comparing the post-TKA incidence of DVT and/or VTE in patients with RA and OA were included. For all comparisons, odds ratios and 95% confidence intervals (CI) were calculated for binary outcomes. Six studies were included in the meta-analysis. The pooled data showed that the combined rates of asymptomatic and symptomatic DVT did not differ significantly in the RA and OA groups (1065/222,714 [0.5%] vs. 35,983/6,959,157 [0.5%]; OR 0.77, 95% CI: 0.57 to 1.02; P = 0.07). The combined rates of asymptomatic and symptomatic DVT and pulmonary embolism (PE) after TKA were significantly lower in the RA than in the OA group (1831/225,406 [0.8%] vs. 63,953/7,018,721 [0.9%]; OR 0.76, 95% CI: 0.62 to 0.93; P = 0.008). Conclusiviely, the DVT rates after primary TKA were similar in RA and OA patients. In contrast, the incidence of VTE (DVT plus PE) after primary TKA was lower in RA than in OA patients, despite patients with RA being at theoretically higher risk of thrombi due to chronic inflammation.