Nicoletta Riva

Efficacy and Safety of the Novel Oral Anticoagulants in Atrial Fibrillation A Systematic Review and Meta-Analysis of the Literature

Background— Novel oral anticoagulants (NOACs) have been proposed as alternatives to vitamin K antagonists for the prevention of stroke and systemic embolism in patients with atrial fibrillation. Individually, NOACs were at least noninferior to vitamin K antagonists, but a clear superiority in overall and vascular mortality was not consistently proven. Methods and Results— We performed a meta-analysis of phase II and phase III randomized, controlled trials comparing NOACs with vitamin K antagonists in patients with atrial fibrillation. The MEDLINE and EMBASE databases, supplemented with conference abstract books and www.clinicaltrials.gov, were searched up to the first week of July 2012 with no language restriction. Two reviewers performed independent article review and study quality assessment. Data on overall and cardiovascular mortality, stroke or systemic embolism, ischemic stroke, major and intracranial bleeding, and myocardial infarction were collected. NOACs were pooled to perform a comparison with vitamin K antagonists, calculating pooled relative risks (RRs) and associated 95% confidence intervals (CIs). We retrieved 12 studies (3 administering dabigatran, 4 administering rivaroxaban, 2 administering apixaban, and 3 administering edoxaban) enrolling a total of 54 875 patients. NOACs significantly reduced total mortality (5.61% versus 6.02%; RR, 0.89; 95% CI, 0.83–0.96), cardiovascular mortality (3.45% versus 3.65%; RR, 0.89; 95% CI, 0.82–0.98), and stroke/systemic embolism (2.40% versus 3.13%; RR, 0.77; 95% CI, 0.70–0.86). There was a trend toward reduced major bleeding (RR, 0.86; 95% CI, 0.72–1.02) with a significant reduction of intracranial hemorrhage (RR, 0.46; 95% CI, 0.39–0.56). No difference in myocardial infarction was observed. Conclusions— NOACs are associated with an overall clinical benefit compared with vitamin K antagonists. Additional research is required to confirm these findings outside the context of randomized trials.Background— Novel oral anticoagulants (NOACs) have been proposed as alternatives to vitamin K antagonists for the prevention of stroke and systemic embolism in patients with atrial fibrillation. Individually, NOACs were at least noninferior to vitamin K antagonists, but a clear superiority in overall and vascular mortality was not consistently proven. Methods and Results— We performed a meta-analysis of phase II and phase III randomized, controlled trials comparing NOACs with vitamin K antagonists in patients with atrial fibrillation. The MEDLINE and EMBASE databases, supplemented with conference abstract books and [www.clinicaltrials.gov][1], were searched up to the first week of July 2012 with no language restriction. Two reviewers performed independent article review and study quality assessment. Data on overall and cardiovascular mortality, stroke or systemic embolism, ischemic stroke, major and intracranial bleeding, and myocardial infarction were collected. NOACs were pooled to perform a comparison with vitamin K antagonists, calculating pooled relative risks (RRs) and associated 95% confidence intervals (CIs). We retrieved 12 studies (3 administering dabigatran, 4 administering rivaroxaban, 2 administering apixaban, and 3 administering edoxaban) enrolling a total of 54 875 patients. NOACs significantly reduced total mortality (5.61% versus 6.02%; RR, 0.89; 95% CI, 0.83–0.96), cardiovascular mortality (3.45% versus 3.65%; RR, 0.89; 95% CI, 0.82–0.98), and stroke/systemic embolism (2.40% versus 3.13%; RR, 0.77; 95% CI, 0.70–0.86). There was a trend toward reduced major bleeding (RR, 0.86; 95% CI, 0.72–1.02) with a significant reduction of intracranial hemorrhage (RR, 0.46; 95% CI, 0.39–0.56). No difference in myocardial infarction was observed. Conclusions— NOACs are associated with an overall clinical benefit compared with vitamin K antagonists. Additional research is required to confirm these findings outside the context of randomized trials. # Clinical Perspective {#article-title-45} [1]: http://www.clinicaltrials.gov

Prevalence and Clinical History of Incidental, Asymptomatic Pulmonary Embolism: A Meta-Analysis

CONTEXT Recently, there has been an increasing number of reports of incidental pulmonary embolism (PE) in patients undergoing chest computer tomography (CT) for reasons other than the research of suspected PE. Natural history of incidental PE remains unclear. OBJECTIVES To estimate the prevalence of incidental PE, to assess potential factors associated with incidental PE, and to evaluated its clinical history. DATA SOURCES MEDLINE, EMBASE databases (up to January 2009). STUDY SELECTION Studies were included if the prevalence of incidental PE was assessed using CT scanning. DATA EXTRACTION The prevalence of incidental PE in these patients was documented. Separate data for inpatients and outpatients and according to the reason for CT scanning were collected. Weighted mean proportion of the prevalence of incidental PE was calculated. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to test the association with potential predictors of incidental PE. RESULTS Twelve studies for a total of more than 10 thousand patients were included. The weighted mean prevalence of incidental PE was 2.6% (95% CI 1.9, 3.4). Hospitalization at the time of CT scanning and the presence of cancer were associated with a significantly increased risk of incidental PE (OR 4.27 and OR 1.80 respectively). CONCLUSIONS The prevalence of incidental PE is clinically relevant. Future studies are necessary to properly evaluate the clinical history of these patients.

Long-term Clinical Outcomes of Splanchnic Vein Thrombosis: Results of an International Registry

IMPORTANCE Little information is available on the long-term clinical outcome of patients with splanchnic vein thrombosis (SVT). OBJECTIVE To assess the incidence rates of bleeding, thrombotic events, and mortality in a large international cohort of patients with SVT. DESIGN, SETTING, AND PARTICIPANTS A prospective cohort study was conducted beginning May 2, 2008, and completed January 30, 2014, at hospital-based centers specialized in the management of thromboembolic disorders; a 2-year follow-up period was completed January 30, 2014, and data analysis was conducted from July 1, 2014, to February 28, 2015. Participants included 604 consecutive patients with objectively diagnosed SVT; there were no exclusion critieria. Information was gathered on baseline characteristics, risk factors, and antithrombotic treatment. Clinical outcomes during the follow-up period were documented and reviewed by a central adjudication committee. MAIN OUTCOMES AND MEASURES Major bleeding, defined according to the International Society on Thrombosis and Hemostasis; bleeding requiring hospitalization; thrombotic events, including venous and arterial thrombosis; and all-cause mortality. RESULTS Of the 604 patients (median age, 54 years; 62.6% males), 21 (3.5%) did not complete follow-up. The most common risk factors for SVT were liver cirrhosis (167 of 600 patients [27.8%]) and solid cancer (136 of 600 [22.7%]); the most common sites of thrombosis were the portal vein (465 of 604 [77.0%]) and the mesenteric veins (266 of 604 [44.0%]). Anticoagulation was administered to 465 patients in the entire cohort (77.0%) with a mean duration of 13.9 months; 175 of the anticoagulant group (37.6%) received parenteral treatment only, and 290 patients (62.4%) were receiving vitamin K antagonists. The incidence rates (reported with 95% CIs) were 3.8 per 100 patient-years (2.7-5.2) for major bleeding, 7.3 per 100 patient-years (5.8-9.3) for thrombotic events, and 10.3 per 100 patient-years (8.5-12.5) for all-cause mortality. During anticoagulant treatment, these rates were 3.9 per 100 patient-years (2.6-6.0) for major bleeding and 5.6 per 100 patient-years (3.9-8.0) for thrombotic events. After treatment discontinuation, rates were 1.0 per 100 patient-years (0.3-4.2) and 10.5 per 100 patient-years (6.8-16.3), respectively. The highest rates of major bleeding and thrombotic events during the whole study period were observed in patients with cirrhosis (10.0 per 100 patient-years [6.6-15.1] and 11.3 per 100 patient-years [7.7-16.8], respectively); the lowest rates were in patients with SVT secondary to transient risk factors (0.5 per 100 patient-years [0.1-3.7] and 3.2 per 100 patient-years [1.4-7.0], respectively). CONCLUSIONS AND RELEVANCE Most patients with SVT have a substantial long-term risk of thrombotic events. In patients with cirrhosis, this risk must be balanced against a similarly high risk of major bleeding. Anticoagulant treatment appears to be safe and effective in most patients with SVT.

Clinical approach to splanchnic vein thrombosis: risk factors and treatment.

Splanchnic vein thrombosis (SVT) is an unusual manifestation of venous thromboembolism which involves one or more abdominal veins (portal, splenic, mesenteric and supra-hepatic veins). SVT may be associated with different underlying disorders, either local (abdominal cancer, liver cirrhosis, intra-abdominal inflammation or surgery) or systemic (hormonal treatment, thrombophilic conditions). In the last decades, myeloproliferative neoplasm (MPN) emerged as the leading systemic cause of SVT. JAK2 mutation, even in the absence of known MPN, showed a strong association with the development of SVT, and SVT was suggested to be the first clinical manifestation of MPN. Recently, an association between SVT, in particular supra-hepatic vein thrombosis, and paroxysmal nocturnal hemoglobinuria has also been reported. SVT occurs with heterogeneous clinical presentations, ranging from incidentally detected events to extensive thrombosis associated with overt gastrointestinal bleeding, thus representing a clinical challenge for treatment decisions. In the absence of major contraindications, anticoagulant therapy is generally recommended for all patients presenting with acute symptomatic SVT, but there is no consensus about the use of anticoagulant drugs in chronic or incidentally detected SVT. High quality evidence on the acute and long-term management is substantially lacking and the risk to benefit-ratio of anticoagulant therapy in SVT still needs to be better assessed.

Epidemiology and pathophysiology of venous thromboembolism: similarities with atherothrombosis and the role of inflammation

Venous thromboembolism (VTE) is a multifactorial disease. Major provoking factors (e. g. surgery, cancer, major trauma, and immobilisation) are identified in 50-60 % of patients, while the remaining cases are classified as unprovoked. However, minor predisposing conditions may be detectable in these patients, possibly concurring to the pathophysiology of the disease, especially when co-existing. In recent years, the role of chronic inflammatory disorders, infectious diseases and traditional cardiovascular risk factors has been extensively investigated. Inflammation, with its underlying prothrombotic state, could be the potential link between these risk factors, as well as the explanation for the reported association between arterial and venous thromboembolic events.

Poor predictive value of contemporary bleeding risk scores during long-term treatment of venous thromboembolism. A multicentre retrospective cohort study.

Bleeding is a common and feared complication of oral anticoagulant therapy. Several prediction models have been recently developed, but there is a lack of evidence in patients with venous thromboembolism (VTE). The aim of this study was to validate currently available bleeding risk scores during long-term oral anticoagulation for VTE. We retrospectively included adult patients on vitamin K antagonists for VTE secondary prevention, followed by five Italian Anticoagulation Clinics (Cuneo, Livorno, Mantova, Napoli, Varese), between January 2010 and August 2012. All bleeding events were classified as major bleeding (MB) or clinically-relevant-non-major-bleeding (CRNMB). A total of 681 patients were included (median age 63 years; 52.0% female). During a mean follow-up of 8.82 (± 3.59) months, 50 bleeding events occurred (13 MB and 37 CRNMB), for an overall bleeding incidence of 9.99/100 patient-years. The rate of bleeding was higher in the first three months of treatment (15.86/100 patient-years) than afterwards (7.13/100 patient-years). The HAS-BLED showed the best predictive value for bleeding complications during the first three months of treatment (area under the curve [AUC] 0.68, 95% confidence interval [CI] 0.59-0.78), while only the ACCP score showed a modest predictive value after the initial three months (AUC 0.61, 95%CI 0.51-0.72). These two scores had also the highest sensitivity and the highest negative predictive value. None of the scores predicted MB better than chance. Currently available bleeding risk scores had only a modest predictive value for patients with VTE. Future studies should aim at the creation of a new prediction rule, in order to better define the risk of bleeding of VTE patients.

Antithrombotic treatment of splanchnic vein thrombosis: results of an international registry.

Treatment of splanchnic vein thrombosis (SVT) is a clinical challenge due to heterogeneity of clinical presentations, increased bleeding risk, and lack of evidences from clinical trials. We performed an international registry to describe current treatment strategies and factors associated with therapeutic decisions in a large prospective cohort of unselected SVT patients. A total of 613 patients were enrolled (mean age 53.1 years, standard deviation ± 14.8); 62.6% males; the majority (468 patients) had portal vein thrombosis. Most common risk factors included cirrhosis (27.8%), solid cancer (22.3%), and intra-abdominal inflammation/infection (11.7%); in 27.4% of patients, SVT was idiopathic. During the acute phase, 470 (76.7%) patients received anticoagulant drugs, 136 patients (22.2%) remained untreated. Incidental diagnosis, single vein thrombosis, gastrointestinal bleeding, thrombocytopenia, cancer, and cirrhosis were significantly associated with no anticoagulant treatment. Decision to start patients on vitamin K antagonists after an initial course of parenteral anticoagulation was significantly associated with younger age, symptomatic onset, multiple veins involvement, and unprovoked thrombosis. Although a nonnegligible proportion of SVT patients did not receive anticoagulant treatment, the majority received the same therapies recommended for patients with usual sites thrombosis, with some differences driven by the site of thrombosis and the pathogenesis of the disease.

Incidence of thromboembolic complications in patients with mechanical heart valves with a subtherapeutic international normalized ratio

OBJECTIVE Subtherapeutic international normalized ratios are frequently encountered in clinical practice, and patients with mechanical heart valves with inadequate anticoagulation may be exposed to an increased risk of thromboembolic events. There are no data on thromboembolic event risk for these patients. METHODS We assessed the current practice patterns in the management of patients with mechanical heart valves with subtherapeutic international normalized ratios and assessed the risk of thromboembolic complications in this setting. The charts of patients with mechanical heart valves followed up in two anticoagulation clinics were reviewed. Patients with a history of stable, therapeutic anticoagulation but with a subtherapeutic international normalized ratio were included. Patients who underwent invasive procedures requiring temporary suspension of antithrombotic therapy were excluded. Data on use and dose of low-molecular weight heparin bridging therapy were collected. RESULTS The incidence of objectively confirmed thromboembolic events within 90 days after obtaining the index international normalized ratio was assessed. Two hundred ninety-four patients with mechanical heart valves were included (mean age 63.3 years, 47.3% male). Low-molecular weight heparin was prescribed in 14 cases (4.8%). At 90 days, 1 patient had a thromboembolic complication (0.3%, 95% confidence interval 0%-1.9%). CONCLUSION Patients with previously stable, therapeutic anticoagulation with a subtherapeutic international normalized ratio have a low risk of thromboembolic events. Withholding low-molecular weight heparin bridging therapy is a reasonable therapeutic option in these cases.

Safety and efficacy of low‐dose fondaparinux (1.5 mg) for the prevention of venous thromboembolism in acutely ill medical patients with renal impairment: the FONDAIR study

Summary.  Background:  Renal impairment is common, affecting around 40% of acutely ill medical patients, and is associated with an increased risk of both venous thromboembolism (VTE) and bleeding. The clinical benefit of effective thromboprophylactic strategies may be outweighed in these patients by an excessive rate of hemorrhage.

Analysis of an algorithm incorporating limited and whole-leg assessment of the deep venous system in symptomatic outpatients with suspected deep-vein thrombosis (PALLADIO): A prospective, multicentre, cohort study

BACKGROUND Compression ultrasonography is the mainstay of diagnosis of deep-vein thrombosis (DVT) of the legs. Compression ultrasonography can be extended to the entire deep venous system (whole-leg) or restricted to the proximal veins only (limited), and the two approaches are clinically equivalent. We aimed to assess the diagnostic value of an algorithm combining whole-leg and limited compression ultrasonography. METHODS We did a prospective, multicentre, cohort study at eight centres in five countries. Consecutive outpatients aged 18 years or older with suspected DVT underwent D-dimer measurement and pretest clinical probability assessment. DVT was ruled out without further testing if pretest probability was unlikely and D-dimer was negative (group 1). Patients in whom either pretest probability was likely or who were positive for D-dimer underwent limited compression ultrasonography only (group 2). Finally, patients in whom pretest probability was likely and who had a positive measurement for D-dimer underwent extended whole-leg compression ultrasonography (group 3). All patients in whom DVT was ruled out were followed up for 3 months. The primary outcome was the incidence of objectively recorded venous thromboembolism. The primary analysis included all patients managed according to the study protocol. This study is registered with ClinicalTrials.gov, number NCT01412242. The final results are reported here. FINDINGS Between March 1, 2011, and July 31, 2014, 1348 consecutive outpatients were referred for this study, of whom 1162 were eligible to participate. After pretest probability assessment and D-dimer testing, 351 were in group 1, 401 in group 2, and 410 in group 3. Limited compression ultrasonography was positive in 12 (3%) patients in group 2 and extended whole-leg compression ultrasonography was positive in 200 (49%) patients in group 3. 82 (39%) of all DVT diagnosed at baseline were isolated distal thromboses. 26 protocol violations were reported. Thus, 351 patients from group 1, 371 patients in group 2, and 202 patients in group 3 who had been excluded for DVT by the algorithm were included in the primary analysis at 3 months. One, four, and three DVTs were reported, respectively. Thus, the 3-month incidence of venous thromboembolism in untreated patients after a negative diagnostic strategy was 0·87% (95% CI 0·44-1·70). INTERPRETATION An algorithm combining limited and whole-leg compression ultrasonography could be a reliable, safe, and convenient method for diagnostic management of outpatients with clinically suspected DVT. FUNDING None.