D-dimer and risk of venous thromboembolism recurrence: Comparison of two studies with similar designs but different laboratory and clinical results.

BACKGROUND: D-dimer testing may help deciding the duration of anticoagulation in subjects at high risk of venous thromboembolism (VTE) recurrence. Two management studies on this issue have been published (DULCIS in 2014 and APIDULCIS in 2022). They had similar designs but had important different results. Aim of this article is to compare their results. METHODS: Both studies were finalized to extend anticoagulation [with vitamin K anticoagulants (VKAs) in DULCIS or apixaban 2.5 mg BID (kindly provided by BMS-Pfizer Collaboration) in APIDULCIS] only in patients with positive D-dimer results. RESULTS: More D-dimer assays resulted positive in APIDULCIS than in DULCIS (61.1 % vs 47.7 %, respectively; p < 0.0001). While only 4 (0.5 %) refused low dose apixaban in APIDULCIS, the 22.6 % of patients with positive D-dimer refused to resume VKAs in DULCIS; their rates of recurrence were 187 and 8.8 per 100 person-years, respectively (incidence rate ratio [IRR]: 21.2). The incidence of bleeding was low in those receiving apixaban vs those who resumed VKAs (0.4 vs 2.3 per 100 person-years, respectively; IRR 0.17;). While the recurrence rate was low and similar in the studies in subjects who resumed anticoagulation, it was significantly higher in APIDULCIS than in DULCIS in those who stopped anticoagulation for negative D-dimer (5.6 vs 3.0 per 100 person-years, respectively; IRR 1.9). CONCLUSION: The low dose Apixaban for extended VTE treatment is effective and safe, and well accepted by patients. Why subjects who stopped anticoagulation for negative D-dimer had a higher recurrence rate in APIDULCIS than in DULCIS remains to be explained.

Long-Term Outcomes in Two-Year Follow-Up after Primary Treatment in Patients with a Prior Venous Thromboembolic Event: A Prospective, Observational, Real-Life Study.

BACKGROUND: Patients with acute venous thromboembolism (VTE) need anticoagulation (AC) therapy for at least 3/6 months (primary treatment); after that period, they should receive a decision on the duration of therapy. METHODS: This study examined the complications occurring during two years of follow-up (FU) in patients with a first VTE who were recruited in 20 clinical centers and had discontinued or prolonged AC. They were included in the START2-POST-VTE prospective observational study. RESULTS: A total of 720 patients (53.5% males) who, after the completion of primary treatment, had received the decision to continue (n = 281, 39%; 76.1% with a DOAC) or discontinue (n = 439, 61%) AC were followed up for 2 years (total FU = 1318 years). The decision to prolong or suspend AC was made in similar proportions in patients with unprovoked or provoked index events. Courses of sulodexide treatment or Aspirin (100 mg daily) were prescribed to 20.3% and 4.5%, respectively, of the patients who discontinued AC. The bleeding rate was significantly higher in patients who extended AC (1.6% pt/y) than in those who stopped AC (0.1% pt/y; p = 0.001) and was higher in patients using standard-dose DOACs (3.1% pt/y) than in those using reduced-dose DOACs (0.4% pt/y). The recurrent VTE rates were similar between the two groups (2.2% pt/y during AC vs. 3% pt/y off AC). CONCLUSION: Physicians' decisions about AC duration were independent of the unprovoked/provoked nature of the index event. The bleeding rate was higher in patients who continued AC using standard-dose DOACs. Surprisingly, the rate of thrombotic recurrence was not different between those who continued or discontinued AC. Randomized studies comparing different procedures to decide on the duration of AC after a first VTE are needed.

Patients with antiphospholipid syndrome and a first venous or arterial thrombotic event: clinical characteristics, antibody profiles and estimate of the risk of recurrence.

OBJECTIVES: Thrombosis in antiphospholipid syndrome (APS) involves in most cases the venous circulation. Why in some patients thrombotic APS affects the arterial circulation and in particular cerebral circulation is unknown. In previous studies, both patient characteristics and antiphospholipid antibody types and titers have been associated with arterial thrombosis. Aim of this study was to compare the clinical characteristics and laboratory findings of venous and arterial thrombotic APS from a large series of patients. METHODS: Data were retrieved from the Start 2 antiphospholipid, a multicenter prospective register of long-term collected data from Thrombosis Centers in Italy. RESULTS: Of 167 patients with thrombotic APS, 114 (68 %) had a venous and 53 (32 %) had an arterial event as first clinical manifestation. Several clinical characteristics and risk factors were different among groups in univariate analysis. Using logistic regression analysis, reduced creatinine clearance and hyperlipidemia were independent variable for the occurrence of arterial APS. Notably, no difference in antiphospholipid antibody profiles and aß2-Glycoprotein I levels were found between groups. A higher adjusted global antiphospholipid syndrome score (aGAPSS) was found in arterial group indicating a possible high recurrence rate in arterial APS. CONCLUSIONS: These data have pathophysiological and clinical implication since associated conditions might predispose patients to arterial rather than venous events and call to a close monitoring and treatment of arterial APS due to their increased tendency to recurrence.

Machine learning approach for prediction of outcomes in anticoagulated patients with atrial fibrillation.

BACKGROUND: The accuracy of available prediction tools for clinical outcomes in patients with atrial fibrillation (AF) remains modest. Machine Learning (ML) has been used to predict outcomes in the AF population, but not in a population entirely on anticoagulant therapy. METHODS AND AIMS: Different supervised ML models were applied to predict all-cause death, cardiovascular (CV) death, major bleeding and stroke in anticoagulated patients with AF, processing data from the multicenter START-2 Register. RESULTS: 11078 AF patients (male n = 6029, 54.3%) were enrolled with a median follow-up period of 1.5 years [IQR 1.0-2.6]. Patients on Vitamin K Antagonists (VKA) were 5135 (46.4%) and 5943 (53.6%) were on Direct Oral Anticoagulants (DOAC). Using Multi-Gate Mixture of Experts, a cross-validated AUC of 0.779 ± 0.016 and 0.745 ± 0.022 were obtained, respectively, for the prediction of all-cause death and CV-death in the overall population. The best ML model outperformed CHA2DSVA2SC and HAS-BLED for all-cause death prediction (p < 0.001 for both). When compared to HAS-BLED, Gradient Boosting improved major bleeding prediction in DOACs patients (0.711 vs. 0.586, p < 0.001). A very low number of events during follow-up (52) resulted in a suboptimal ischemic stroke prediction (best AUC of 0.606 ± 0.117 in overall population). Body mass index, age, renal function, platelet count and hemoglobin levels resulted the most important variables for ML prediction. CONCLUSIONS: In AF patients, ML models showed good discriminative ability to predict all-cause death, regardless of the type of anticoagulation strategy, and major bleeding on DOAC therapy, outperforming CHA2DS2VASC and the HAS-BLED scores for risk prediction in these populations.

Inappropriate Underdosing of Direct Oral Anticoagulants in Atrial Fibrillation Patients: Results from the START2-AF Registry.

Background: Direct oral anticoagulants (DOACs) are recommended for stroke prevention in non-valvular atrial fibrillation (NVAF) patients. We aimed to describe the prevalence of inappropriate DOACs dose prescription in the START2-AF Registry, the outcomes according to the appropriateness of the dosage, and the factors associated with inappropriate dose prescription. Methods: Patients' demographics and clinical data were prospectively collected as electronic files in an anonymous form on the website of the START2-Registry; DOACs dosage was determined to be appropriate when prescribed according to the European Heart Rhythm Association Guidelines. Results: We included 5943 NVAF patients on DOACs; 2572 (46.3%) were female patients. The standard dose (SD) was prescribed to 56.9% of patients and the low dose (LD) was prescribed to 43.1% of patients; 38.9% of all NVAF patients received an inappropriate LD DOAC and 0.3% received inappropriate SD. Patients treated with LD DOAC had a significantly higher rate of all bleedings (RR 1.5; 95% CI 1.2-2.0), major bleedings (RR 1.8; 95% CI 1.3-1.7), and mortality (RR 2.8; 95% CI 1.9-4.1) with respect to patients treated with SD DOAC. No difference was found among patients treated with appropriate and inappropriate LD regarding bleeding, thrombotic, and mortality rates. Age, body weight <60 kg, and renal failure were significantly associated with inappropriate LD DOAC prescription. Conclusions: Inappropriate LD DOACs in NVAF patients is not associated with a reduction in bleeding risk, nor with an increased thrombotic risk. Instead, it is associated with higher mortality rate, suggesting that, in clinical practice, underdosing is preferred for patients at particularly high risk for adverse events.

Sex Differences in Clinical Presentation of Lower Extremity Deep Vein Thrombosis.

Background: Differences between men and women in the clinical features and extent of lower limb deep vein thrombosis (DVT) may influence DVT diagnostic algorithms involving pretest clinical probability (PTP) assessment, D-dimer, and compression ultrasonography (CUS). Aims: To assess differences in DVT clinical presentation between men and women and their effect on PTP and D-dimer. Methods: We conducted a retrospective study in outpatients referred for suspected DVT of the lower limbs to our vascular emergency department from January 2005 to December 2019. Patients underwent PTP assessment with the Wells score, D-dimer testing, and CUS. Results: More women were referred for suspected DVT than men (M/F: 1,785/2,821; F: 61.4%; p < 0.0001). Women were older than men (median age: 71 vs. 67 years; p = 0.0001), DVT was diagnosed in 436 patients (9.4%) but in more men than women (M: 210 [11.8%] vs. F: 226 [8%]; p = 0.0002), with more proximal DVT in men than women (M: 131 7.3% vs. F: 124 [4.4%]; p = 0.00021). PTP was more likely in men (355 [19.9%]) than women (455 [16.2%]) (p = 0.0011); more men had swelling in the entire limb, increased calf circumference by >3 cm compared with the contralateral limb, and pitting edema, than women. D-dimer levels (available in 65% of patients) were more frequently positive in women with DVT than in men (94.6% vs. 85.7%; p = 0.016). However, a positive D-dimer and/or likely PTP was similarly frequent in men (92%) and women (96%) with DVT. Conclusions: More women than men are referred for suspected DVT, and men have a higher prevalence of proximal DVT. However, current algorithms for DVT diagnosis perform similarly in men and in women.

Thrombotic events associated with low baseline direct oral anticoagulant levels in atrial fibrillation: the MAS study.

ABSTRACT: Although effective and safe, treatment with direct oral anticoagulants (DOAC) in atrial fibrillation (AF) is still associated with thrombotic complications. Whether the measurement of DOAC levels may improve treatment efficacy is an open issue. We carried out the observational, prospective, multicenter Measure and See (MAS) study. Blood was collected 15 to 30 days after starting DOAC treatment in patients with AF who were followed-up for 1 year. Plasma samples were centralized for DOAC level measurement. Patients' DOAC levels were converted into drug/dosage standardized values to allow a pooled analysis in a time-dependent, competitive-risk model. The measured values were transformed into standardized values (representing the distance of each value from the overall mean) by subtracting the DOAC-specific mean value from the original values and dividing by the standard deviation. Trough and peak DOAC levels were assessed in 1657 and 1303 patients, respectively. In total, 21 thrombotic complications were recorded during 1606 years of follow-up (incidence of 1.31% of patients per year). Of 21 thrombotic events, 17 occurred in patients whose standardized activity levels were below the mean of each DOAC (0); the incidence was the highest (4.82% of patients per year) in patients whose standardized values were in the lowest class (-1.00 or less). Early measurement of DOAC levels in patients with AF allowed us to identify most of the patients who, having low baseline DOAC levels, subsequently developed thrombotic complications. Further studies are warranted to assess whether thrombotic complications may be reduced by measuring baseline DOAC levels and modifying treatment when indicated. This trial was registered at www.ClinicalTrials.gov as #NCT03803579.

Renin-angiotensin-aldosterone system inhibitors and mortality risk in elderly patients with atrial fibrillation. Insights from the nationwide START registry.

BACKGROUND: Arterial hypertension is the most common cardiovascular comorbidity in atrial fibrillation (AF). Few studies investigated management strategies of hypertension in AF. MATERIALS AND METHODS: We included 5769 AF patients on oral anticoagulants from the nationwide ongoing Italian START registry. We investigated the prescription of antihypertensive drugs and mortality risk. Subgroup analyses according to sex and major cardiovascular comorbidities were performed. RESULTS: Mean age was 80.8 years, 46.1% were women; 80.3% of patients were hypertensive. Furosemide (30.1%) was the most frequent diuretic followed by hydrochlorothiazide (15.4%) and potassium canrenoate (7.9%). 61.1% received ß-blockers: 34.2% bisoprolol, 6.2% atenolol. Additionally, 36.9% were on angiotensin converting enzyme inhibitors (ACE-I): ramipril (20.9%), enalapril (5.3%) and perindopril (2.8%); 31.7% were on angiotensin receptors blockers (ARBs): valsartan (7.6%) and irbesartan (6.4%). Amlodipine and lercanidipine were prescribed in 14.0% and 2.3%, respectively. ACE-I (p < 0.001), α-blockers (p = 0.020) and Dihydropyridines calcium channel blockers (p = 0.004) were more common in men, while ARBs (p = 0.008), thiazide diuretics (p < 0.001) and ß-blockers (p < 0.001) in women. During 22.61 ± 17.1 months, 512 patients died. Multivariable Cox regression analysis showed that ACE-I (Hazard ratio [HR] 0.758, 95% Confidence Interval [95%CI] 0.612-0.940, p = 0.012) and ARBs (HR 0.623, 95%CI 0.487-0.796, p < 0.001) inversely associated with mortality. ACE-I/ARBs inversely associated with mortality in both sexes and in patients with diabetes. This associastion was evident for ACE-I in patients with previous cardiovascular disease, and for ARBs in HF. CONCLUSION: A lower mortality risk was found in AF patients on ACE-I/ARBs. Different prescription patterns of antihypertensive drugs between men and women do exist.

D-Dimers in diagnosis and prevention of venous thrombosis: recent advances and their practical implications.

D­Dimers derive from degradation of cross­linked fibrin by plasmin, and thus their level is a marker of coagulation and fibrinolytic system activation. Guidelines recommend that D­dimers are determined if the pretest probability (PTP) is low or intermediate, to exclude venous thromboembolism (VTE), either deep vein thrombosis or pulmonary embolism, and to avoid imaging tests. If the PTP is high or D­dimer level is above the suggested thresholds, imaging is recommended. D­Dimer assays offer high sensitivity and low specificity, as D­dimer levels can be above the threshold in several other conditions than thrombosis, and they increase with age. As a result, there have been several proposals to improve the diagnostic accuracy of D­dimer levels by adjusting the cutoffs according to patient characteristics, such as age, PTP, pregnancy, renal function, or cancer. D­Dimer levels can also predict clinical severity of COVID­19, and escalated anticoagulation based on D­dimer levels can be associated with a lower risk of mortality in patients with severe COVID­19. Finally, D­dimer levels have been incorporated in prediction models for recurrent VTE to help identify patients who may benefit from prolonged anticoagulation.

Management and 1-Year Outcome in Elderly Patients with Hip Fracture Surgery Receiving Anticoagulation (Warfarin or DOAc) or P2Y12 Antiplatelet Agents.

(1) Background: Little prospective data exist regarding the perioperative management and long-term prognosis of elderly patients receiving treatment with antithrombotic drugs and undergoing urgent surgery for a hip fracture. (2) Methods: The study included patients who required hip surgery and were receiving warfarin, DOAc or P2Y12 antiplatelet agents at the moment of trauma. Ongoing antithrombotic treatment was managed according to existing recommendations. The endpoints of the study were the time to surgery, perioperative bleeding, the need for transfusion and, finally, mortality, major cardiovascular events and re-hospitalization at 6 and 12 months. (3) Results: The study included a total of 138 patients. The mean age was 86 years; 75.4% were female. Eighty-two received DOAc, thirty-six received warfarin and twenty received P2Y12 inhibitors. The controls were 283 age- and sex-matched patients who did not receive antithrombotic treatment. A total of 38% of patients receiving warfarin underwent surgery <48 h, 52% receiving DOAc, 55% receiving P2Y12 inhibitors and, finally, 82% in the control group. Perioperative bleeding and the need for transfusion were not different between the four groups. Mortality at 6 months was higher in patients receiving warfarin and P2Y12 inhibitors (30% and 25%) in comparison to DOAc and the control group (11.6% and 10% p < 0.0001). Similarly, the other endpoints were more frequent in patients receiving warfarin and P2Y12 inhibitors. The trend was maintained for 12 months. No significant differences in mortality were found between early (<48 h) and late (>48 h) surgery independent of the type of treatment. (4) Conclusions: Our study confirmed that anticoagulants delay surgery in patients with hip fractures; however, intervention > 48 h is not associated with a poorer prognosis. This finding is relevant as it underlines that, in patients at high risk of postoperative cardiovascular complications, the careful management of anticoagulation before surgery may compensate for the delay of surgery with a very low in-hospital mortality rate (<1%). One-year survival was significantly lower in patients receiving warfarin, probably related to their worse risk profile at the moment of trauma survival.

Incidence and clinical outcomes of heparin-induced thrombocytopenia: 11 year experience in a tertiary care university hospital.

Heparin-induced thrombocytopenia (HIT) is a rare immuno-mediated adverse reaction with high thrombotic and mortality risk. To evaluate incidence and outcomes of HIT cases diagnosed at a tertiary care hospital from 2007 to 2018. A retrospective study was conducted. Patients with suspected HIT underwent 4Ts score assessment and anti-heparin PF4 IgG antibodies ELISA screening test. If the latter was positive, platelet aggregation test (PAT) was performed. If the latter was positive, any form of heparin was stopped, alternative anticoagulants were started and then overlapped with warfarin. HIT incidence was calculated by dividing HIT cases by the mean yearly number of admitted patients over 11 years. Follow-up was 90 days. Among 2125 screening tests, 96 (4.5%) were positive with confirmatory PAT in 82/90 (3.8% for missing data in 6). Median age was 75; 39 patients were surgical and 51 medical. The median 4Ts score was 5. Unfractionated heparin was employed in 34 (37%). HIT incidence was 0.16/1000/patient/years (95% CI: 0.12-0.23) in surgical and 0.15/1000/patient/years (95%: 0.12-0.20) in medical patients. HIT with thrombosis (HIT-T) was observed in 31 patients (0.05/1000/patient/years 95% CI: 0.04-0.1), with venous thromboses in 25 (80%). HIT without thrombosis was observed in 59 patients (0.1/1000 patient/years; 95% CI: 0.08-0.13, twofold vs HIT-T). All cause mortality was 25.5% (95% CI: 17.6-35.4), major bleeding 7.7% (95% CI:3.2-15.3), and thromboembolic complications 3.3% (95% CI:1.1-9.3). HIT is a rare event with high mortality, despite the use of non heparin anticoagulants.

Statins under-treatment and mortality in patients with atrial fibrillation. Insights from the nationwide START registry.

BACKGROUND AND AIMS: Statins are mainstream drugs for cardiovascular (CV) prevention, but under-prescription is an important clinical challenge. Data on the use of single statins and on the rate of under-prescription in atrial fibrillation (AF) are lacking. We evaluated the association of statin underuse with mortality risk in a large AF cohort. METHODS AND RESULTS: As many as 5477 patients from the Italian nationwide START registry were included. The prevalence of different statins was reported and the association of under prescription with all-cause and CV mortality investigated. Mean age was 80.2 years, and 46.4% were women. Among 2899 patients with a clinical indication to statin, only 1578 (54.4%) were on treatment. In a mean follow-up of 22.5 ± 17.1 months, 491 (4.7%/year) deaths occurred (106 CV deaths, 1.0%/year). Atorvastatin and Simvastatin were inversely associated with all-cause (HR 0.692, 95% CI 0.519-0.923, p = 0.012 and HR 0.598, 95% CI 0.428-0.836, p = 0.003, respectively) and CV death (HR 0.372, 95% CI 0.178-0.776, p = 0.008 and HR 0.306, 95% CI 0.123-0.758, p = 0.010, respectively). The 1321 untreated patients were older, more frequently women and with a higher prevalence of diabetes, previous cerebrovascular disease, peripheral artery disease compared to those on treatment. Statin undertreatment was associated with higher risk of all-cause (HR 1.400, 95% CI 1.078-1.819, p = 0.012) and CV death (HR 2.057, 95% CI 1.188-3.561, p = 0.010). CONCLUSIONS: AF patients with an indication to statins but left untreated show a high risk of all-cause and CV mortality. Implementation of statin prescription in the AF population can help reducing the residual mortality risk.

DOACs use in extreme body-weighted patients: results from the prospective START-register.

BACKGROUND: Direct oral anticoagulants (DOACs) are widely used for the treatment of venous thromboembolism (VTE) and for stroke prevention in atrial fibrillation (AF). However, evidence in obese and underweight patients is limited. We assessed the safety and effectiveness of DOACs and vitamin K antagonists (VKAs) in patients ≥ 120 kg or ≤ 50 kg enrolled in an observational prospective cohort study, the START-Register. METHODS: Adult patients started on anticoagulant therapy were followed up for a median of 1.5 years (IQR 0.6-2.8). Primary efficacy outcome was the occurrence of VTE recurrence, stroke and systemic embolism. Primary safety outcome was major bleeding (MB). RESULTS: 10,080 AF and VTE patients were enrolled between March 2011 and June 2021, 295 patients weighted ≤ 50 kg and 82 patients ≥ 120 kg. Obese patients were significantly younger than underweight patients. Rates of thrombotic events were low and similar between DOACs and VKAs in underweight patients (1 event on DOACs therapy [0.9% 95% CI 0.11-5.39] and 2 on VKAs [1.1% 95% CI 0.01-47.68]) and in overweight patients (0 events on DOACs, 1 on VKAs [1.6%, 95% CI 0.11-5.79]. Two MB events occurred on DOACs (1.9%, 95% CI 0.38-6.00) and 3 on VKAs (1.6%, 95% CI 0.04-22.06) in the underweight group; 1 MB on DOACs (5.3% 95% CI 0.33-16.68) and 2 on VKAs (3.3%, 95% CI 0.02-130.77) in the overweight group. CONCLUSIONS: DOACs seem to be effective and safe also for the treatment of patients with extreme body weights, both underweight and overweight. Further prospective studies are needed to support these findings.

Venous Thromboembolism in Women of Childbearing Age: Insights from the START Registry.

BACKGROUND: Women of childbearing age are exposed to venous thromboembolic risk mainly for pregnancy and use of oral contraceptives. The impact of risk factors (RF) on venous thromboembolism (VTE) in these circumstances is still unclear. AIM: In the context of START registry, we aimed to investigate the weight of a series of RF on the occurrence of pregnancy- or combined oral contraceptive (COC)-associated VTE. MATERIALS AND METHODS: We selected all women included in the START for VTE occurred between 18-42 years and compared those with a first or recurrent pregnancy/postpartum- (group A) or COC-VTE (group B) with those who had VTE outside these circumstances (group C). Final analysis included a cohort of 532 women. Follow-up data showed that there were no significant differences between the groups in terms of thrombotic and haemorrhagic complications. As for pregnancy-associated VTE, the overall outcome was good in terms of both maternal and fetal prognosis. RESULTS: In a binary model of logistic regression, correcting for potential confounders, VTE family history conferred a significant and independent higher risk of COC-VTE compared with group C. Similarly, comparison between group A and C documented that family history significantly affected the risk of pregnancy-associated VTE. VTE in the group C was significantly associated with older age. Lastly, smoke was a significant risk factor for pregnancy/postpartum VTE when group A and group B were compared. CONCLUSION: Present data suggest that in the setting of fertile women, family history of VTE has a greater role in predicting COC- and pregnancy/postpartum- VTE than outside these circumstances.

Venous thromboembolism secondary to hospitalization for COVID-19: patient management and long-term outcomes.

Background: Venous thromboembolism (VTE) is a complication of COVID-19 in hospitalized patients. Little information is available on long-term outcomes of VTE in this population. Objectives: We aimed to compare the characteristics, management strategies, and long-term clinical outcomes between patients with COVID-19-associated VTE and patients with VTE provoked by hospitalization for other acute medical illnesses. Methods: This is an observational cohort study, with a prospective cohort of 278 patients with COVID-19-associated VTE enrolled between 2020 and 2021 and a comparison cohort of 300 patients without COVID-19 enrolled in the ongoing START2-Register between 2018 and 2020. Exclusion criteria included age <18 years, other indications to anticoagulant treatment, active cancer, recent (<3 months) major surgery, trauma, pregnancy, and participation in interventional studies. All patients were followed up for a minimum of 12 months after treatment discontinuation. Primary end point was the occurrence of venous and arterial thrombotic events. Results: Patients with VTE secondary to COVID-19 had more frequent pulmonary embolism without deep vein thrombosis than controls (83.1% vs 46.2%, P <.001), lower prevalence of chronic inflammatory disease (1.4% and 16.3%, P <.001), and history of VTE (5.0% and 19.0%, P <.001). The median duration of anticoagulant treatment (194 and 225 days, P = 0.9) and the proportion of patients who discontinued anticoagulation (78.0% and 75.0%, P = 0.4) were similar between the 2 groups. Thrombotic event rates after discontinuation were 1.5 and 2.6 per 100 patient-years, respectively (P = 0.4). Conclusion: The risk of recurrent thrombotic events in patients with COVID-19-associated VTE is low and similar to the risk observed in patients with VTE secondary to hospitalization for other medical diseases.

Recurrences and bleeding during extended treatment of patients with venous thromboembolism: results of the international, prospective, observational WHITE study.

BACKGROUND: Little data are available on real-life long-term treatments after a venous thromboembolism (VTE), and on recurrent VTE or bleeds events during treatments. METHODS: We investigated the complications occurring during follow-up (FU) in VTE patients who had received the treatment decisions given by the clinical centers, active in 7 countries (China, Czechia, Poland, Portugal, Russia, Slovakia, Tunisia), which participated in the international, prospective, observational WHITE study. RESULTS: FU information was collected in 1004 patients, recruited by 62 clinical centers (17 centers did not participate in FU collection). Extended treatments were proposed to 811 patients: direct oral anticoagulants (DOACs) (475), sulodexide (202), antiplatelet agents (73), vitamin K antagonists (VKAs) (45), low molecular weight heparin (LMWH) (16). All specific treatments were stopped in the remaining 193 patients. Patients who during FU used treatments different than those prescribed by the local investigators (263) or for other causes (26) were excluded from analysis. 50 primary events occurred throughout 1044 years FU in 715 patients, 4.8 incidence (×100 patient-years) [3.8 for recurrences, and 0.96 for bleeding (major or clinically relevant)]. Primary event incidence differed according to treatments (LMWH=33.3, antiplatelets =7.6, VKAs = 6.1, DOACs = 4.7, sulodexide = 4.2, all treatment stopped = 2.5), and differed across the involved countries. CONCLUSIONS: DOACs were the most used drugs for extended treatments. Overall, the rate of primary events during FU was low. The investigators identified patients at low risk of recurrence and high bleeding risk. Sulodexide use for secondary prevention deserves further studies.

Management and outcomes of calf deep vein thrombosis in patients with contraindication to full anticoagulation due to bleeding.

BACKGROUND: This prospective observational study was aimed at assessing early outcomes of inpatients with isolated distal deep vein thrombosis (IDDVT) and coexisting bleeding. METHODS: Patients received enoxaparin 4000 units daily or intermediate doses, and ultrasound surveillance (US). Primary outcomes were extension to the popliteal vein (PDVT) or symptomatic pulmonary embolism (PE), bleeding complications during the treatment and the composite of PDVT and bleeding complications. Secondary outcomes were recurrent IDDVTs and death. RESULTS: 90/95 patients completed the study period (30 days). PDVT occurred in 2/41 (4.9%) and in 3/45 (6.7%) subjects receiving enoxaparin 4000 units and intermediate doses respectively (OR 1.39; 95% CI: 0.22-11; P=0.72). PE occurred in only one of the 4 untreated subjects (25% vs. 0 patients taking enoxaparin 4000 units or intermediate doses; P=1.0). Recurrent IDDVTs occurred in 29 subjects (32.2%), more frequently during enoxaparin 4000 (19/29, 65.5%). Four patients died (4.4%). Bleeding complications occurred in 8 subjects (8.9%), all treated with intermediate doses (0 vs. 17.8%; P=1.0). Enoxaparin 4000 units significantly reduced the risk of the composite outcome compared with higher doses (4.9% vs. 24.4%; OR 6.31; 95% CI: 1.56-42.65; P=0.02). Major trauma significantly increased the risk of PDVT (OR 20.92; 95% CI: 2.82-427.51, P=0.01; logistic regression P=0.01). Patients with major trauma are also at increased bleeding risk (OR 5; 95% CI: 1.06-23.76, P=0.04; logistic regression P=0.03). CONCLUSIONS: Enoxaparin 4000 units daily, supported by US, may be an option for selected patients.

Prevalence of pulmonary embolism among patients with recent onset of dyspnea on exertion. A cross-sectional study.

BACKGROUND: Exertional dyspnea is a frequently encountered complaint in clinical practice. However, the prevalence of pulmonary embolism (PE) among patients with dyspnea on exertion has not been reported. OBJECTIVE: The objective of this study was to assess the prevalence of objectively confirmed PE among consecutive patients visiting an emergency department because of recent onset of exertional dyspnea. METHODS: Patients aged ≤75 years with recent (<1 month) marked exertional dyspnea had a systematic workup for PE, irrespective of concomitant signs or symptoms of venous thromboembolism and alternative explanations for dyspnea. PE was excluded on the basis of a low pretest clinical probability and normal age-adjusted D-dimer. All other patients had computed tomography pulmonary angiography. An interim analysis after inclusion of 400 patients would stop recruitment if the 95% confidence interval (CI) of the PE prevalence had a lower limit exceeding 20%. RESULTS: The study was prematurely terminated after the inclusion of 417 patients. In 134 patients (32.1%), PE was excluded based on low clinical probability and normal D-dimer. PE was found in 134 (47.3%) of the remaining 283 patients, for an overall prevalence of 32.1% (95% CI, 27.8-36.8). PE was present in 40 of 204 (19.6%) patients without other findings suspicious for PE and in 94 of 213 patients (44.1%) with such findings. PE involved a main pulmonary artery in 37% and multiple lobes in 87% of the patients. CONCLUSION: The angiographic demonstration of PE is common in patients presenting with recent onset of marked exertional dyspnea, including 20% without other findings suggesting pulmonary embolism.

Rivaroxaban treatment for six weeks versus three months in patients with symptomatic isolated distal deep vein thrombosis: randomised controlled trial.

OBJECTIVE: To compare two different treatment durations of rivaroxaban in patients with symptomatic isolated distal deep vein thrombosis (DVT). DESIGN: Randomised, double blind, placebo controlled clinical trial. SETTING: 28 outpatient clinics specialising in venous thromboembolism. PARTICIPANTS: 402 adults (≥18 years) with symptomatic isolated distal DVT. INTERVENTIONS: After receiving standard dose rivaroxaban for six weeks, participants were randomly assigned to receive rivaroxaban 20 mg or placebo once daily for an additional six weeks. Follow-up was for 24 months from study inclusion. MAIN OUTCOMES MEASURES: The primary efficacy outcome was recurrent venous thromboembolism during follow-up after randomisation, defined as the composite of progression of isolated distal DVT, recurrent isolated distal DVT, proximal DVT, symptomatic pulmonary embolism, or fatal pulmonary embolism. The primary safety outcome was major bleeding after randomisation until two days from the last dose of rivaroxaban or placebo. An independent committee adjudicated the outcomes. RESULTS: 200 adults were randomised to receive additional rivaroxaban treatment and 202 to receive placebo. Isolated distal DVT was unprovoked in 81 (40%) and 86 (43%) patients, respectively. The primary efficacy outcome occurred in 23 (11%) patients in the rivaroxaban arm and 39 (19%) in the placebo arm (relative risk 0.59, 95% confidence interval 0.36 to 0.95; P=0.03, number needed to treat 13, 95% confidence interval 7 to 126). Recurrent isolated distal DVT occurred in 16 (8%) patients in the rivaroxaban arm and 31 (15%) in the placebo arm (P=0.02). Proximal DVT or pulmonary embolism occurred in seven (3%) patients in the rivaroxaban arm and eight (4%) in the placebo arm (P=0.80). No major bleeding events occurred. CONCLUSIONS: Rivaroxaban administered for six additional weeks in patients with isolated distal DVT who had an uneventful six week treatment course reduces the risk of recurrent venous thromboembolism, mainly recurrent isolated distal DVT, over a two year follow-up without increasing the risk of haemorrhage. TRIAL REGISTRATION: EudraCT 2016-000958-36; ClinicalTrials.gov NCT02722447.