Deep venous thrombosis or pulmonary embolism and factor V Leiden: enigma or paradox

Do antiangiogenics promote clot instability? Data from the TESEO prospective registry and Caravaggio clinical trial

Background  Venous thromboembolism (VTE) is a common complication in cancer patients. Much of its morbidity stems from the development of fatal pulmonary embolisms (PE). Little is known about the factors involved in clot stability, with angiogenesis possibly being implicated.

Methods  The database is from the TESEO prospective registry that recruits cancer patients with VTE from 41 Spanish hospitals. Independent validation was conducted in a cohort from the Caravaggio trial. The objective is to evaluate the association between exposure to antiangiogenic therapies and the PE/VTE proportion in oncological patients.

Results  In total, 1,536 subjects were evaluated; 58.4% ( n  = 894) had a PE and 7% ( n  = 108) received antiangiogenic therapy (bevacizumab in 75%). The PE/VTE proportion among antiangiogenic-treated individuals was 77/108 (71.3%) versus 817/1,428 (57.2%) among those receiving other alternative therapies ( p  = 0.004). The effect of the antiangiogenics on the PE/VTE proportion held up across all subgroups except for active smokers or those with chronic obstructive pulmonary disease. Exposure to antiangiogenics was associated with increased PEs, odds ratio (OR) 2.27 (95% CI, 1.42–3.63). In the Caravaggio trial, PE was present in 67% of the individuals treated with antiangiogenics, 50% of those who received chemotherapy without antiangiogenic treatment, and 60% without active therapy ( p  = 0.0016).

Conclusion  Antiangiogenics are associated with increased proportion of PE in oncological patients with VTE. If an effect on clot stability is confirmed, the concept of thrombotic risk in cancer patients should be reconsidered in qualitative terms.

Thrombophilia testing in the real-world clinical setting of thrombosis centres taking part in the Italian Start 2-Register

BACKGROUND

Even though it rarely influences venous thromboembolism (VTE) treatment and the fact that it is generally discouraged, thrombophilia testing is still largely prescribed. We assessed: 1) whether/how frequently Italian thrombosis centres requested thrombophilia testing; 2) what results were obtained; and 3) if the results affected treatment and clinical results.

MATERIALS AND METHODS

We examined data from 4,826 VTE patients enrolled by 19 clinical centres participating in the START 2-Register.

RESULTS

57.2% of patients were tested. Numbers varied widely among centres (2.9-99.7%). Thrombophilic alterations were recorded in 18.2% of patients and the percentage of positive results was inversely correlated with that of patients tested. Significantly less patients with deep vein thrombosis (DVT) were tested, whereas more were tested when the event was idiopathic, presenting as isolated pulmonary embolism (PE), or in unusual sites. Patients with thrombophilic alterations were younger, more frequently treated with direct oral anticoagulants (DOACs), with lower mortality and less frequently discontinued anticoagulation. DOACs were more frequently prescribed in patients with heterozygous Factor V (FV) Leiden or prothrombin mutations, whereas vitamin K antagonists were preferred in patients with inhibitor deficiencies, combined alterations or antiphospholipid syndrome (APLS). There was no difference in duration of treatment among those with or without alterations, though more APLS patients received an extended treatment course. Bleeding and thrombotic complications occurred with a similar and fairly low incidence in patients with or without thrombophilic alterations.

DISCUSSION

Although general testing for thrombophilia in VTE patients is currently discouraged, more than half of the VTE patients included in the START2-Register were tested. However, there were marked differences in practice between Italian thrombosis centres. About 60% of all patients with alterations were treated with DOACs, confirming that DOACs can be a useful option for treatment of thrombophilic VTE patients, with the exclusion of those with APLS.

Factor V Leiden paradox in a middle-aged Swedish population: A prospective study

Few prospective studies have examined the factor V paradox: factor V Leiden (FVL) is a stronger risk factor for deep venous thrombosis (DVT) than for pulmonary embolism (PE). The present study, to the best of our knowledge, is the first population-based study aimed to examine the relationship between FVL and incidence of venous thromboembolism (VTE), DVT and PE in a prospective cohort study of middle-aged Swedish individuals. FVL was determined in 4890 subjects (aged 46–68 years, 57% women) from the general population without previous VTE or cancer, who participated in the Malmö Diet and Cancer study between 1991 and 1994. Incident cases of VTE were identified from the Swedish patient register during a mean follow-up of 15.6 years. Of 4890 subjects with determination of FVL (10.2% carriers), 220 had VTE during follow-up (113 DVT, 78 PE, 29 both). Incidence of VTE was significantly higher in subjects with heterozygous and homozygous FVL: adjusted hazard ratios (HR) were 1.8 (95% CI 1.3–2.6, p=0.001) and 6.5 (2.1–21, p=0.001), respectively. The population attributable fraction was 8.7% for FVL. Adjusted HRs for DVT were 2.2 (1.4–3.3, p<0.001) for heterozygotes and 3.3 (0.5–24, p=0.233) for homozygotes. Adjusted HRs for PE were 1.2 (0.65–2.2, p=0.582) for heterozygotes and 8.7 (2.1–36, p=0.003) for homozygotes. The FVL paradox was confirmed for heterozygotes for FVL. However, homozygotes for FVL had a high risk for PE, suggesting that the FVL paradox is related to the carriership of one wild type and one mutated factor V allele.

A case of pulmonary thromboembolism due to coagulation factor V Leiden in Japan ~ usefulness of next generation sequencing~

Background

Because the venous thromboembolisms (VTEs) due to the coagulation factor V R506Q (FV Leiden) mutation is often seen in Caucasians, the VTE onset in Japan has not been reported.

Case presentation

A 34-year-old man from north Africa experiencing sudden dyspnea went to a hospital for advice.

The patient had pain in his right leg and a high plasma D-dimer level. A contrast-enhanced computed tomography scan revealed a contrast deficit in the bilateral pulmonary artery and in the right lower extremity. The patient was diagnosed with VTE, and anticoagulation therapy was initiated. Our targeted gene panel sequencing revealed that the occurrence of VTE was attributed to a presence of the FV Leiden mutation.

Conclusions

This is the first report demonstrating VTE caused by the FV Leiden mutation in Japan.

Risk of venous thrombosis in persons with increased body mass index and interactions with other genetic and acquired risk factors

Essentials Obesity, factor V Leiden (FVL) and blood group non-O are common. We studied the combined effect of these factors on the risk of venous thrombosis (VT). The combination of obesity, non-O blood group and FVL increased VT risk up to ten-fold. Identifying high VT may be beneficial in thrombosis prevention.

SUMMARY

Background Overweight/obesity has a substantial effect on the occurrence of venous thrombosis (VT). Blood group non-O has a high prevalence in Western populations, and the factor V Leiden mutation could be present in 5% of Caucasians. These frequent prothrombotic risk factors will have a considerable impact on the incidence of VT, especially when combined. Objectives We investigated whether FV Leiden with blood group non-O modifies VT risk in individuals with different body mass index (BMI) strata in a case-control study (n = 11253). Results We observed a progressively increasing risk of VT with higher BMI, with an odds ratio of 1.9 (95% confidence interval [CI] 1.6-2.3) for those in the upper BMI tertile (BMI > 26.7 kg m(-2) ), as compared with the first BMI tertile (BMI < 23.5 kg m(-2) , blood group O, and no FV Leiden) (reference group). The addition of FV Leiden and blood group non-O to the model increased the risk in all BMI tertiles; the odds ratios were 3.8 (95% CI 3.2-4.6) in the third BMI tertile of individuals with blood group non-O, and 5.4 (95% CI 3.5-8.5) in the third BMI tertile of individuals with FV Leiden. When both FV Leiden and blood group non-O were present, the odds ratios were 9.1 (95% CI 5.9-14.0) in the first BMI tertile, 9.4 (95% CI 6.6-13.5) in the second BMI tertile, and 12.5 (95% CI 8.9-17.6) in the third BMI tertile. Conclusion Individuals with a high BMI, blood group non-O and/or FV Leiden have a high VT risk. The high VT risks in some subgroups may justify targeted screening and thromboprophylaxis decisions in these patients.

Joint effects of cancer and variants in the factor 5 gene on the risk of venous thromboembolism

Venous thromboembolism occurs frequently in cancer patients. Two variants in the factor 5 gene (F5), rs6025 encoding for the factor V Leiden mutation R506Q, and rs4524 encoding K858R, have been found to be associated with venous thromboembolism. We assessed the joint effect of active cancer and these two F5 variants on venous thromboembolism risk in a case-cohort study. Cases with a first venous thromboembolism (n=609) and a randomly selected age-weighted cohort (n=1,691) were sampled from the general population in Tromsø, Norway. Venous thromboembolism was classified as cancer-related if it occurred in the period 6 months before to 2 years after a diagnosis of cancer. Active cancer was associated with an 8.9-fold higher risk of venous thromboembolism (95% CI 7.2-10.9). The risk of cancer-related venous thromboembolism was 16.7-fold (95% CI 9.9-28.0) higher in subjects heterozygous for rs6025 compared with non-carriers of this variant without active cancer. In subjects with active cancer the risk of venous thromboembolism was 15.9-fold higher (95% CI 9.1-27.9) in those with one risk allele at rs4524, and 21.1-fold (95% CI 12.4-35.8) higher in those with two risk alleles compared with non-carriers without active cancer. A synergistic interaction was observed between active cancer and factor V Leiden (relative excess risk due to interaction 7.0; 95% CI 0.5-14.4) and rs4524 (relative excess risk due to interaction 15.0; 95% CI 7.5-29.2). The incidence of venous thromboembolism during the initial 6 months following a diagnosis of cancer was particularly high in subjects with risk alleles at these loci. This implies that the combination of cancer and F5 variants synergistically increases venous thromboembolism risk.

To determine the frequency of Factor V Leiden in cases of Deep Vein Thrombosis and Healthy controls

Objective:

To determine the frequency of Factor V Leiden in cases of Deep Vein Thrombosis and Healthy controls.

Methods:

This case control study was performed in Armed Forces Institute of Pathology Rawalpindi, From 21^st March to 25^th September 2013. One hundred patients with diagnostic evidence of Deep vein thrombosis on Doppler ultrasound/Magnetic resonance imaging (MRI) scan were included in the study through non probability convenient sampling and compared with 100 matched healthy controls. DNA was extracted from the blood sample by kit method. In order to identify Factor V Leiden mutation, the polymerase chain reaction (PCR) method was utilized combined with the Amplification refractory mutation system. Data was analyzed using statistical package for social sciences (SPSS) version 17.

Results:

In 100 patients of Deep Vein Thrombosis (DVT), frequency of Factor V Leiden (FVL) was 13% and it is was 2% in healthy control group. A significant association was found between FVL and DVT with odds ratio of 7.32 and with P value (P = 0.003).

Conclusion:

FVL was found to be highly prevalent among patients of DVT, Signifying strong association between the two.

Association between inherited thrombophilia and impaired right ventricular function in deep vein thrombosis without symptomatic pulmonary embolism

The aim was to evaluate the right ventricular function in patients with inherited thrombophilia and deep vein thrombosis (DVT) without pulmonary embolism. A total of 38 patients with DVT without symptomatic pulmonary embolism and 30 patients with varicose veins were enrolled. Clinical data, echocardiography, and 2 thrombophilic mutations were analyzed. Factor V Leiden (FVL) polymorphism was significantly frequent in the study group (P = .007). The difference in prothrombin G20210A polymorphism between the study and control groups was at a near-significant level (P = .058). There was statistically significant decrease in tricuspid annular plane systolic excursion values in patients with FVL and prothrombin G20210A polymorphism. Combined FVL and prothrombin G20210A polymorphisms were more closely related to the decrease in this value (P = .006). Deep vein thrombosis had no additional adverse effects on right ventricle. Impaired right ventricular systolic function occurs in FVL and prothrombin G20210A polymorphisms.

The relationship between body mass index, activated protein C resistance and risk of venous thrombosis

BACKGROUND

High body mass index (BMI) is associated with an increased risk of venous thrombosis (VT). Clotting factor VIII levels are increased in obese subjects, possibly because of a chronic inflammatory state, which increases activated protein C (APC) resistance. The APC resistance in FV Leiden carriers could be aggravated and further worsened by high FVIII levels in blood group non-O carriers. We hypothesized that an association exists between BMI and APC resistance, and that this is amplified by the presence of FV Leiden and/or blood group non-O.

METHODS

We used the Leiden Thrombophilia Study (LETS) to determine whether an association exists between BMI and APC resistance, and whether the combination of high BMI and APC resistance increases the risk of VT. In a pooled analysis of LETS and a Norwegian case-cohort study (TROL), we verified whether FV Leiden modified the risk of the occurrence of VT with increasing BMI, and whether this risk was further increased by blood group non-O.

RESULTS

APC resistance increased linearly with increasing BMI, partly because of a concurrent rise in FVIII. A BMI in the median or upper tertile was associated with a 1.9-fold (95% confidence interval [CI] 1.0-2.5) and 2.2-fold (95% CI 1.4-3.4) increased risk as compared with the lowest tertile. Both relative risks decreased slightly after FVIII and APC resistance adjustments. The effect of BMI on VT risk was enhanced two-fold to 10-fold in FV Leiden or blood group non-O carriers.

CONCLUSIONS

The increased risk of VT in individuals with high BMI is partly mediated by FVIII-related APC resistance. This risk is more pronounced when other causes of increased APC resistance are also present.

Pulmonary embolism and deep vein thrombosis

Pulmonary embolism is the third most common cause of death from cardiovascular disease after heart attack and stroke. Sequelae occurring after venous thromboembolism include chronic thromboembolic pulmonary hypertension and post-thrombotic syndrome. Venous thromboembolism and atherothrombosis share common risk factors and the common pathophysiological characteristics of inflammation, hypercoagulability, and endothelial injury. Clinical probability assessment helps to identify patients with low clinical probability for whom the diagnosis of venous thromboembolism can be excluded solely with a negative result from a plasma D-dimer test. The diagnosis is usually confirmed with compression ultrasound showing deep vein thrombosis or with chest CT showing pulmonary embolism. Most patients with venous thromboembolism will respond to anticoagulation, which is the foundation of treatment. Patients with pulmonary embolism should undergo risk stratification to establish whether they will benefit from the addition of advanced treatment, such as thrombolysis or embolectomy. Several novel oral anticoagulant drugs are in development. These drugs, which could replace vitamin K antagonists and heparins in many patients, are prescribed in fixed doses and do not need any coagulation monitoring in the laboratory. Although rigorous clinical trials have reported the effectiveness and safety of pharmacological prevention with low, fixed doses of anticoagulant drugs, prophylaxis remains underused in patients admitted to hospital at moderate risk and high risk for venous thromboembolism. In this Seminar, we discuss pulmonary embolism and deep vein thrombosis of the legs.

[Pulmonary circulation: what has 2010 brought?]

In both thromboembolic disease and pulmonary hypertension, 2010 has been a prodigious year for interesting publications. Some data have helped to elucidate the factors associated with a greater risk of thromboembolic disease, such as long journeys and certain polymorphisms. New recommendations on diagnosis have been made, giving a greater role to computed tomography angiography. Magnetic resonance imaging is also gaining ground. More accurate risk evaluation is one of the objectives of the new guidelines of the European Society of Cardiology, which substitute some terms such as massive or submassive for high- and low-risk. Maintaining anticoagulation indefinitely in idiopathic pulmonary thromboembolism is recommended. Evidence on the efficacy of new drugs such as rivaroxaban, dabigatran and indraparinux is beginning to appear. In pulmonary hypertension, smoking seems to play a role as a risk factor. Some registries indicate that new treatments have not improved survival. Greater knowledge has been gained of the role of inflammation in the pathogenesis of the disease and a Spanish study supports the role of the 6-minute walk test in patient evaluation. Some drugs are highlighted in the literature. Imatinib is promising but probably only in some patients. Riociguat provides good results and inhaled treprostinil has emerged as a new option.