Cancer-associated thrombosis in Asia

The impact of KRAS mutations on risk of venous thromboembolism recurrence in patients with metastatic colorectal cancer

BACKGROUND

The relationship between KRAS mutations and the risk of venous thromboembolism (VTE) recurrence in metastatic colorectal cancer (mCRC) patients with established cancer-associated thrombosis (CAT) remains uncertain. This study aims to (1) evaluate the predictive value of seven KRAS mutation subtypes for VTE recurrence and (2) assess the impact of incorporating these mutations into two existing VTE risk scores: the Khorana score and the Ottawa score.

METHODS

Between 2019 and 2023, we identified patients with histologically confirmed mCRC who had symptomatic or incidental index VTE and received anticoagulation therapy. Regression analyses were conducted to calculate hazard ratios (HRs) for recurrent VTE associated with the seven KRAS mutation subtypes. We used receiver operating characteristic (ROC) curves to assess the performance of both the original scores and the modified scores that included KRAS mutations. To quantify the improvements of the modified scores, we calculated the net reclassification improvement (NRI).

RESULTS

A total of 2,195 patients were enrolled. KRAS G12C, KRAS G12A, and KRAS G13D mutations were significantly associated with a higher risk of recurrent VTE compared to other subtypes, with HRs of 1.84 (95% CI: 1.09-2.97), 2.02 (95% CI: 1.07-3.79), and 1.55 (95% CI: 1.02-2.27), respectively. The original Khorana and Ottawa scores demonstrated moderate predictive ability for VTE recurrence, each with an area under the ROC curve (ROC-AUC) of 0.56 (95% CI: 0.52-0.60). Incorporating the KRAS G12C, KRAS G12A, and KRAS G13D mutations improved the AUCs to 0.70 (95% CI: 0.67-0.74) for the modified Khorana score and 0.71 (95% CI: 0.67-0.74) for the modified Ottawa score. After dichotomizing risk using thresholds from ROC analysis, the NRI values were 0.54 (95% CI: 0.43-0.65) for the modified Khorana score and 0.48 (95% CI: 0.37-0.60) for the modified Ottawa score.

CONCLUSIONS

The KRAS G12C, KRAS G12A, and KRAS G13D mutations are significantly associated with an increased risk of recurrent VTE. Incorporating these specific KRAS mutations into existing risk scores may enhance their predictive accuracy for recurrent VTE in patients with mCRC.

The efficacy of atorvastatin on inflammation and coagulation markers in high-risk thrombotic cancer patients undergoing chemotherapy: a randomized controlled trial

BACKGROUND

Deep vein thrombosis (DVT) is a prevalent complication associated with malignancy. Clinical use of thromboprophylaxis is recommended, however its usage is limited due to bleeding complications, more cost associated, and reluctance to receive anticoagulant injections. Rivaroxaban a relatively easy to administer anticoagulant but it has a risk of bleeding and is expensive. Inflammation is the important factor in pathogenesis of cancer-associated thrombosis. Statins have the anti-inflammatory property that could decrease proinflammatory cytokines. Consequently, statins may be used as thromboprophylaxis for cancer patients receiving chemotherapy.

OBJECTIVE

To provide comparison between atorvastatin and rivaroxaban on affecting inflammatory biomarkers (interleukin 6 [IL-6], C reactive protein [CRP]) and coagulation activation biomarkers (Tissue Factor [TF], prothrombin fragment 1 + 2 [F1 + 2], D-Dimer) in cancer patients at high risk of thrombosis receiving chemotherapy.

METHODS

A randomized controlled study that was double-blinded and involved high-risk cancer patients undergoing chemotherapy. For up to ninety days, participants were randomized to receiver either atorvastatin 20 mg or rivaroxaban 10 mg daily. The level of plasma of IL-6, CRP, TF, F1 + 2, and D-dimer were assessed 24 h before chemotherapy, 30, 60, and 90 day after chemotherapy. The latest observation carried forward (LOCF) approach was used to examine the data. The laboratory results were evaluated using an independent T test or Mann-Whitney U test prior to and after chemotherapy.

RESULTS

Eighty-six randomized patients were enrolled, although both groups showed a decreasing trend in plasma level of IL-6, CRP, TF, F1 + 2, and D-dimer, there were no significant differences between the two groups (p > 0.05). In the atorvastatin group, there was a significant correlation between delta level of IL-6 and F1 + 2 (r = 0.313, p = 0.043) and delta level of CRP and F1 + 2 (r = 0.398, p = 0.009), whereas in the rivaroxaban group there was a significant correlation between delta CRP and D-dimer level (r = 0.387, p = 0.009).

CONCLUSION

Atorvastatin decreases IL-6 and CRP level, which also decreases F1 + 2 level. Atorvastatin did not substantially differ from rivaroxaban in decreasing plasma levels of inflammatory biomarkers IL-6, CRP, and coagulation activation biomarkers TF, F1 + 2, D-dimer in high-risk cancer patients undergoing chemotherapy.

TRIAL REGISTRATION

ISRCTN71891829, Registration Date: 17/12/2020.

Trends in Anticoagulant Utilization and Clinical Outcomes for Cancer-Associated Thrombosis: A Multicenter Cohort Study in Thailand's Upper-Middle-Income Country Setting

PURPOSE

To evaluate anticoagulant trends and clinical outcomes in the management of cancer-associated thrombosis (CAT) within Thailand, an upper-middle-income country (UMIC).

METHODS

This multicenter retrospective cohort study included adult patients with cancer diagnosed with venous thromboembolism (VTE) hospitalized in Thailand from 2017 to 2021. Anticoagulants were classified as low-molecular-weight heparin (LMWH), direct oral anticoagulants (DOACs), and warfarin. Prescription trends were assessed, and patients were followed for 1 year, or until 2022 to evaluate outcomes. The primary effectiveness outcome was recurrent VTE, whereas the primary safety outcome was major bleeding. Secondary outcomes included net clinical benefit and all-cause mortality. Treatment effects were examined using inverse probability of treatment weighting (IPTW) Cox proportional hazards models.

RESULTS

Among 1,611 patients (61.3% female; mean age, 58.8 years; standard deviation, 13.1 years), 86% received LMWH, 10% warfarin, and 4% DOACs. In the study cohort, LMWH prescriptions remained consistent, warfarin use declined, and DOAC prescriptions notably increased. In IPTW analysis, DOACs showed comparable rates of VTE recurrence (weighted hazard ratio [HR], 0.77 [95% CI, 0.22 to 2.70]; P = .679) and major bleeding (weighted HR, 0.62 [95% CI, 0.15 to 2.55]; P = .506) with LMWH. Warfarin had a higher risk of major bleeding (weighted HR, 2.74 [95% CI, 1.12 to 6.72]; P = .028) but a similar rate of VTE recurrence (weighted HR, 1.46 [95% CI, 0.75 to 2.84]; P = .271) compared with LMWH. Secondary outcomes were consistent across groups.

CONCLUSION

LMWH remains the primary treatment for CAT, in line with current guidelines. The study highlights the challenges faced in these settings with the continuous use of warfarin. The comparable efficacy and safety of DOACs with LMWH suggest a potential shift in CAT management within UMICs.

Stratifying the risks of venous thromboembolism in the lateral skull base surgery using Caprini risk assessment model

PURPOSE

To analyze and stratify the possible risk factors of venous thromboembolism (VTE) in lateral skull base surgery (LSBS) using the Caprini risk assessment model.

METHODS

In a single center, a retrospective study was conducted with patients who underwent LSBS from June 2016 to August 2021. The clinical characteristics and blood chemistry tests were collected. The incidence of VTE within 30 days of surgery was recorded. The Caprini risk score was calculated to assess the postoperative VTE risk.

RESULTS

Among the 123 patients in this study, the VTE incidence within 30 postoperative days was 8.9%. The total Caprini risk score in VTE patients (5.6 ± 1.9 points) was significantly higher than that of non-VTE patients (4.6 ± 1.4 points; p = 0.028). The binary logistic regression showed the total Caprini score as the only independent indicator of postoperative VTE. The receiver operating characteristic curve analysis showed that the Caprini score at 6.5 points had low sensitivity (36.4%) but high specificity (91.1%), with the largest area under the curve being 0.659. The VTE rate was significantly higher in patients with a total Caprini score ≥ 7 points (28.6%) compared to those with a total Caprini score ≤ 6 points (7.3%; p = 0.022).

CONCLUSION

LSBS patients have a high risk of developing postoperative VTE. Patients with a Caprini score ≥ 7 points had a significantly higher risk of developing VTE after LSBS. The Caprini risk system was useful in assessing the VTE risk in LSBS. However, more data, calibration, and validation are necessary to establish an exclusive Caprini risk system for LSBS.

The effectiveness of atorvastatin for the prevention of deep vein thrombosis in cancer patients undergoing chemotherapy : A randomised controlled trial: open label

BACKGROUND

Deep vein thrombosis (DVT) is a common complication in cancer. Although thromboprophylaxis in cancer patients is recommended by the guidelines, clinicians' use of thromboprophylaxis remains limited due to cost, bleeding complications, and reluctance to give injectable anticoagulants. Inflammation plays essential roles in the pathogenesis of cancer-associated thrombosis. Owing to its ability to decrease proinflammatory cytokines, statins have anti-inflammatory properties. Thus, statins can be possibly utilized as thromboprophylaxis therapy in cancer patients undergoing chemotherapy.

OBJECTIVE

To compare the effectiveness of atorvastatin and rivaroxaban for DVT prevention in high-risk thrombosis patients with cancer undergoing chemotherapy.

METHODS

Double-blind, randomized controlled trial involving cancer patients with high-risk of thrombosis undergoing chemotherapy. We randomly assigned patients without deep-vein thrombosis at screening to receive atorvastatin 20 mg or rivaroxaban 10 mg daily for up to 90 days. Doppler ultrasonography was performed 90 days following chemotherapy to diagnose DVT. Average cost-effectiveness analysis was performed to analyze the cost of atorvastatin compared to rivaroxaban.

RESULTS

Of the eighty six patients who underwent randomization, primary efficacy end point was observed in 1 of 42 patients (2.3%) in the atorvastatin group and in 1 of 44 (2.2%) in the rivaroxaban group (Odds Ratio [OR], 0.953; 95% confidence interval [CI], 0.240 to 3.971; p = 1.000). There was a significant difference in the incidence of major bleeding, 2 of 42 patients (4.8%) in the atorvastatin group and 12 of 44 (27.3%) in the rivaroxaban group (OR, 0.257; 95% CI, 0.07 to 0.94; p = 0.007). The average cost-effectiveness ratio of using atorvastatin was lower than that of rivaroxaban.

CONCLUSION

Atorvastatin did not differ significantly from rivaroxaban in reducing the incidence of DVT, lower bleeding risk, and cost-effectiveness for thromboprophylaxis in high-risk thrombosis patients with cancer undergoing chemotherapy. The presence of limited statistical power and wide confidence intervals in this study needs further study to strengthen the efficacy of atorvastatin as DVT prophylaxis in cancer patients.

TRIAL REGISTRATION

ISRCTN71891829, Registration Date: 17/12/2020.

Impact of antiphospholipid antibodies on thrombotic events in ambulatory cancer patients

BACKGROUND

Despite the conflicting data, the positivity of antiphospholipid antibodies (aPL) in cancer patients may be associated with an increased risk of thrombosis.

OBJECTIVE

To identify the prevalence and impact of aPL on venous thromboembolic events (VTE) and arterial thrombosis (ATE) in ambulatory cancer patients.

METHODS

In this single-center, prospective cohort study, we enrolled newly diagnosed ambulatory cancer patients receiving chemotherapy. Non-cancer controls were age- and sex-matched. Participants were evaluated for aPL. Primary outcomes were the composite outcome of VTE or ATE and the prevalence of aPL positivity in cancer patients. Secondary outcomes included the risk of VTE and ATE in cancer patients and all-cause mortality at six-month follow-up duration.

RESULTS

There were 137 cases and 137 controls with mean age of 56.0±12.3 and 55.5±12.1 years, respectively. Cancer patients were more likely to have positive aPL compared to controls, with the risk difference of 9.4% (95%CI 1.5 to 17.5). Composite of ATE or VTE occurred in 9 (6.6%) in cancer patients and 2 (1.5%) in controls. Cancer patients with aPL positivity were associated with higher risk of ATE or VTE (risk ratio [RR] 3.6, 95% CI 1.04-12.4). Positive LA in cancer patients were associated with higher risk of composites of ATE or VTE (RR 5.3 95%CI 1.3-21.0), whereas the anti-β2-GPI positivity were associated with increased risk of VTE (RR 4.7, 95%CI 1.1-19.2).

CONCLUSION

aPL was more prevalent in active cancer patients and positive aPL in cancer patients was associated with arterial or venous thrombosis.

Safe and effective treatment of venous Thromboembolism associated with Cancer: focus on direct Oral Anticoagulants in Asian patients

Cancer-associated thrombosis (CAT) poses a significant disease burden and the incidence in Asian populations is increasing. Anticoagulation is the cornerstone of treatment, but can be challenging due to the high bleeding risk in some cancers and the high risk of recurrent venous thromboembolism (VTE) in patients with malignancies. Direct oral anticoagulants (DOACs) are well established as first-choice treatments for VTE in non-cancer patients, offering a more convenient and less invasive treatment option than low-molecular-weight heparin (LMWH). Asian patients have exhibited comparable efficacy and safety outcomes with other races in trials of DOACs for VTE in the general population. Although no specific data are available in Asian patients with CAT, results from randomized controlled trials of apixaban, edoxaban, or rivaroxaban versus the LMWH, dalteparin, indicate that DOACs are a reasonable alternative to LMWH for anticoagulation in Asian patients with CAT. This is further supported by analyses of real-world data in Asian populations demonstrating the efficacy and safety of DOACs in Asian patients with CAT. Apixaban, edoxaban, or rivaroxaban are recommended in the most recently updated international guidelines as first-line therapy for CAT in patients without gastrointestinal or genitourinary cancers and at low risk of bleeding. An increased risk of major gastrointestinal bleeding was evident with edoxaban or rivaroxaban, but not apixaban, versus dalteparin in the clinical trials, suggesting that apixaban could be a safe alternative to LMWH in patients with gastrointestinal malignancies. Determining the optimal anticoagulant therapy for patients with CAT requires careful consideration of bleeding risk, tumor type, renal function, drug-drug interactions, financial costs, and patients' needs and preferences.

Incidence and risk factors for venous thromboembolism, bleeding, and death in colorectal cancer (Cancer-VTE Registry)

The impact of venous thromboembolism in Japanese colorectal cancer patients has not been elucidated. This prespecified subanalysis of the Cancer‐VTE Registry aimed to report venous thromboembolism and event data after 1 year of follow‐up in 2477 patients with colorectal cancer and investigate risk factors of venous thromboembolism. Of 2477 patients, 158 (6.4%) had venous thromboembolism in venous thromboembolism screening at enrollment. Asymptomatic distal deep‐vein thrombosis accounted for 123/158 (77.8%) of venous thromboembolism cases. During the follow‐up period, symptomatic, incidental events requiring treatment and composite venous thromboembolism incidences were 0.3%, 0.8%, and 1.0%, respectively. The incidence of bleeding events, cerebral infarction/transient ischemic attack/systemic embolic event, and all‐cause death were 1.0%, 0.3%, and 4.8%, respectively. These results were consistent with the main study results. In multivariable analysis, venous thromboembolism at baseline was a risk factor of composite venous thromboembolism during the follow‐up period. Japanese patients with colorectal cancer and advancing cancer stage before treatment had more frequent venous thromboembolism complications at baseline, higher incidence of venous thromboembolism events during cancer treatment, and higher mortality.

Venous thromboembolism in Asia and worldwide: Emerging insights from GARFIELD-VTE

BACKGROUND

Although epidemiological studies report a lower risk of venous thromboembolism (VTE) than in the Western world, VTE rates in Asia may be underestimated. Furthermore, it is uncertain whether VTE outcomes differ in Asia and the rest of the world (ROW).

METHODS

GARFIELD-VTE is a global, prospective, non-interventional study of real-world treatment practices. In this study, we compared baseline characteristics, treatment patterns, and 12-month outcomes in Asia and ROW.

RESULTS

Of the 10,684 enrolled patients, 1822 (17.1%) were Asian (China n = 420, Hong Kong n = 98, Japan n = 148, Malaysia n = 244, South Korea n = 343, Taiwan n = 232, Thailand n = 337). Compared with ROW patients, those from Asia were more often female (57.4% vs. 48.0%), non-smokers (74.0% vs. 58.9%) and had a lower BMI (24.8 kg/m² vs. 29.1 kg/m²). Asian patients were more likely to be managed in the hospital (86.9% vs. 70.4%) and to have active cancer (19.8% vs. 8.1%) or a history of cancer (19.1% vs. 12.0%). Asian patients received no anticoagulation more frequently than ROW patients (6.5% vs. 2.1%). Over 12-months follow-up, the rate of all-cause mortality (per 100 person-years [95% confidence interval]) was higher in Asians (15.2 [13.4-17.3] vs. 5.9 [5.4-6.5]). Adjusted hazard ratios indicated a higher risk of all-cause mortality in Asian patients than the ROW (1.32 [1.08-1.62]). The frequencies of major bleeding and recurrent VTE were similar.

CONCLUSION

Asian patients have different risk profiles, treatment patterns and a higher risk of mortality compared with the ROW.

Ethnoracial variations in venous thrombosis: Implications for management, and a call to action

Despite decades of improvement in its diagnosis and management, venous thromboembolism (VTE) remains a significant cause of cardiovascular morbidity and mortality. Clinically relevant differences exist in the risk of symptomatic VTE among ethnoracial groups. Underlying these differences in rates of VTE are patterns of known genetic thrombophilias, which may also influence the risks of major bleeding related to vitamin K antagonists or direct oral anticoagulants. In addition, social factors, differential access to care, and disease awareness differ between ethnoracial groups, which contributes to disparities in VTE outcomes that include higher fatal events. The vast majority of participants included in clinical trials for the prevention and treatment of VTE have been White Caucasian, which limits our understanding of the differential impact of these agents in non-White ethnoracial groups. Increasing the participation in clinical trials of diverse ethnoracial groups should be a priority, especially those groups who are disproportionately affected by the burden of VTE, or possible bleeding complications when exposed to anticoagulants. Advocacy by patients, researchers, and regulatory bodies is crucial to ensure adequate enrolment of diverse ethnoracial groups in order to best inform clinical decisions to optimize VTE prevention and treatment for non-White populations.

The Impact of MTHFR 1298 A > C and 677 C > T Gene Polymorphisms as Susceptibility Risk Factors in Cervical Intraepithelial Neoplasia Related to HPV and Sexually Transmitted Infections

BACKGROUND

HPV genotypes are the most common etiological factor for genital neoplasia. It would appear that sexually transmitted infections accompanied with HPV genotypes might have synergistic interactions in cancer progression. The genetic polymorphisms are involved in metabolizing carcinogens which may contribute to the susceptibility of developing genital cancers by less efficient or overly down metabolic pathways and cell signaling. MTHFR polymorphisms are related to several metabolic disorders and human cancers. We investigated the contribution of MTHFR 1298 and MTHFR 677 polymorphisms as potential risk factors for outcomes with HPV genotypes and STIs in Iranian population.

MATERIALS AND METHODS

As a case-control study, MTHFR A1298C and C677T were assessed for SNPs analysis using a PCR-RFLP assay in 50 cervical intraepithelial neoplasia (CIN) cases, 98 HPV-positive subjects and 47 non-cancerous/non-HPV patients as healthy controls.

RESULTS

Finding suggested a significant association between the MTHFR 1298 CC polymorphisms (OR = 3.5, 95% CI = 1.13-10.82, P ≤ 0.05) in women with CIN as compared to non-cancerous/non-HPV subjects. There was not a significant difference of MTHFR 677 between outcomes.

DISCUSSION

It would seem MTHFR 1298 CC is more likely to be a potential risk factor for HPV-cervical cancer progression. Consequences support further attempts to understand the clinical manifestations of neoplasia related to genital infections and gene mutations.

Effectiveness of Platelet Function Analyzer-100 for Laboratory Detection of Anti-Platelet Drug-Induced Platelet Dysfunction

BACKGROUND

High on-treatment platelet reactivity (HTPR) is the phenomenon wherein patients exhibit normal platelet activity in laboratory testing despite adequate adherence to anti-platelet treatment. We investigated the detection rates of Platelet Function Analyzer (PFA)-100 (Dade Behring AG, Düdingen, Switzerland) for drug-induced platelet dysfunction and analyzed potential contributors to HTPR with practical PFA-100 data over six years.

METHODS

We used data from 6,957 patients who underwent PFA-100 testing after receiving aspirin, clopidogrel, or non-steroidal anti-inflammatory drugs (NSAIDs). Of these, 6,163 patients were tested with only the collagen/epinephrine cartridge (Col/EPI) of PFA-100; 794 were tested with both Col/EPI and the collagen/ADP cartridge (Col/ADP). We calculated PFA-100 closure time (CT) for each drug and compared the clinical and laboratory characteristics of the patients with prolonged CTs and normal CTs (i.e., HTPR).

RESULTS

In Col/EPI, 73.2% (365/499), 72.6% (390/537), and 55.3% (3,442/6,228) patients showed prolonged CTs for aspirin, clopidogrel, and NSAIDs, respectively. In Col/ADP, prolonged CTs were observed in 37.4% (34/91), 43.2% (35/81), and 29.6% (200/676) of patients receiving aspirin, clopidogrel, and NSAIDs, respectively. Of the patients tested with both cartridges, 88.9% (48/54), 95.3% (41/43), and 89.0% (577/648) of the patients receiving aspirin, clopidogrel, and NSAIDs had prolonged CTs, and 10.0% (79/794) showed normal CTs regardless of drugs. For clopidogrel users (both cartridges), there were more patients with malignancies in the normal CT than prolonged CT group.

CONCLUSIONS

PFA-100 is not sufficiently effective for laboratory screening of drug-induced platelet dysfunction. Malignancy may contribute to clopidogrel-related HTPR in PFA-100.

Effect of dexmedetomidine on blood coagulation in patients undergoing radical gastrectomy under general anesthesia: A prospective, randomized controlled clinical trial

BACKGROUND

Dexmedetomidine can inhibit the perioperative stress response, which plays an important role in postoperative hypercoagulability. This study aimed to investigate whether dexmedetomidine could attenuate the activation of postoperative coagulation.

METHODS

Patients undergoing open radical gastrectomy under total intravenous anesthesia were randomly allocated to the control group (group Con) and the dexmedetomidine group (group Dex). Dexmedetomidine was intravenously infused at 0.5 μg/kg over 10 minutes before anesthesia induction and then infused at a rate of 0.5 μg/kg/h until peritoneal closure in group Dex, whereas saline was administered in group Con. Blood samples were collected for thrombelastograph (TEG) analysis [reaction time (R time), clot formation time (K time), and clot formation rate (α angle)] and laboratory coagulation testing before dexmedetomidine administration and at the end of surgery.

RESULTS

Coagulation was activated after radical gastrectomy, as indicated by TEG analysis and the increased concentrations of plasma fibrin (fibrinogen) degradation product (FDP) and thrombin-antithrombin complex (TAT). The R and K times were significantly prolonged and α angle was significantly decreased in group Dex compared with that in group Con at the end of surgery (P < .05). The concentrations of plasma TAT and FDP in group Dex were significantly lower than those in group Con at the end of surgery (P < .05 or .01).

CONCLUSION

Adjunctive dexmedetomidine with general anesthesia attenuates the activation of coagulation following radical gastrectomy.

Monitoring of anticoagulant therapy in cancer patients with thrombosis and the usefulness of blood activation markers

Thrombotic diseases caused by cancer progression have been reported as one of the major causes of cancer associated morbidity and mortality along with cancer invasiveness and infectious complications. Moreover, anticoagulant therapy with heparin and heparin-like drugs, or vitamin K antagonists, or the Direct Oral Anticoagulants, is seeing an extended application in cancer patients and offers prolonged life expectancy to oncology patients for whom blood activation and thrombotic events have a variable incidence, depending on cancer type. Laboratory tools are highly useful for identifying patients at thrombotic risk through the measurement of blood activation markers and selecting those appropriate for anticoagulant therapy. Among the pathological markers, DDimer or Extracellular Vesicles have the highest diagnostic value in these pathological conditions. Global assays are useful for dosage adjustment, such as assessing either an induced anticoagulant effect or the measurement of drug activity. Various assays are also developed such as platelet aggregometry techniques for evaluating drug induced- aggregates or methods allowing measurement of the drug activity to its targeted coagulation factors such as: heparin to thrombin or Factor Xa; DOACs to Thrombin or Factor Xa (Dabigatran to thrombin and DiXaIs, Rivaroxaban, Apixaban, and Edoxaban, to Factor Xa). Such explorative techniques help to find the right dosage adjustment to protect patients from developing thrombosis without exposing them bleeding. It also permits exploration of unexpected drug behavior in treated patients, to check the right adherence to therapy in long-term anticoagulant protocols, and prevention of bleeding in patients with impaired renal or hepatic function. Complementary use of blood activation markers brings additional information on the curative effects of the anticoagulant therapy, and allows identification of pro-thrombotic activity in the clinically silent state. These issues are concisely addressed below.