COVID-19-associated venous thromboembolism: risk of recurrence and major bleeding.

Background: Complications under anticoagulant treatment in patients with COVID-19-associated venous thromboembolism (VTE) have not been consistently reported. Objectives: This study aimed to compare the 90-day rates of VTE recurrences and major bleeding in patients with COVID-19-associated VTE versus those with VTE without COVID-19. Methods: We used the RIETE registry to compare the 3-month outcomes in patients with COVID-19-associated VTE versus those with VTE without COVID-19. Results: The study included 1,747 patients with COVID-19-associated VTE and 8,711 with VTE without COVID-19. Patients with COVID-19-associated VTE were more likely to be hospitalized at baseline and to present with pulmonary embolism. During the first 90 days, 123 patients (1.17%) developed VTE recurrences, and 266 (2.54%) experienced major bleeding. Patients with COVID-19-associated VTE had a similar rate of VTE recurrences (0.9% vs 1.2%) but a higher rate of major bleeding (4.6% vs 2.1%; P < .001) than those without COVID-19. Multivariable analysis adjusted for competing risks showed that patients with COVID-19-associated VTE had an increased risk of major bleeding (subhazard ratio, 1.395; 95% confidence interval, 1.037-1.877). The 30-day mortality after major bleeding was 26.3% in patients with COVID-19-associated VTE and 17.7% in those without COVID-19. Conclusion: Patients with COVID-19-associated VTE had a 5-fold higher rate of major bleeding than VTE recurrences during the first 90 days of anticoagulation. In VTE patients without COVID-19, both rates were similar. These findings highlight the importance of carefully monitoring and optimizing anticoagulation in these patients.

Refinement of a modified simplified Pulmonary Embolism Severity Index for elderly patients with acute pulmonary embolism.

OBJECTIVE: To evaluate the utility of a modified (i.e., without the variable "Age >80 years") simplified Pulmonary Embolism Severity Index (sPESI) in elderly patients with acute symptomatic pulmonary embolism (PE), and to derive and validate a refined version of the sPESI for identification of elderly patients at low risk of adverse events. METHODS: The study included normotensive patients aged >80 years with acute PE enrolled in the RIETE registry. We used multivariable logistic regression analysis to create a new risk score to predict 30-day all-cause mortality. We externally validated the new risk score in elderly patients from the COMMAND VTE registry. RESULTS: Multivariable logistic regression identified four predictors for mortality: high-risk sPESI, immobilization, coexisting deep vein thrombosis (DVT), and plasma creatinine >2 mg/dL. In the RIETE derivation cohort, the new model classified fewer patients as low risk (4.0% [401/10,106]) compared to the modified sPESI (35% [3522/10,106]). Low-risk patients based on the new model had a lower 30-day mortality than those based on the modified sPESI (1.2% [95% CI, 0.4-2.9%] versus 4.7% [95% CI, 4.0-5.4%]). In the COMMAND VTE validation cohort, 1.5% (3/206) of patients were classified as having low risk of death according to the new model, and the overall 30-day mortality of this group was 0% (95% CI, 0-71%), compared to 5.9% (95% CI, 3.1-10.1%) in the high-risk group. CONCLUSIONS: For predicting short-term mortality among elderly patients with acute PE, this study suggests that the new model has a substantially higher sensitivity than the modified sPESI. A minority of these patients might benefit from safe outpatient therapy of their disease.

Comparison of seven prognostic tools to identify low-risk pulmonary embolism in patients aged <50 years.

In young patients with acute pulmonary embolism (PE), the predictive value of currently available prognostic tools has not been evaluated. Our objective was to compare prognostic value of 7 available tools (GPS, PESI, sPESI, Prognostic Algorithm, PREP, shock index and RIETE) in patients aged <50 years. We used the RIETE database, including PE patients from 2001 to 2017. The major outcome was 30-day all-cause mortality. Of 34,651 patients with acute PE, 5,822 (17%) were aged <50 years. Of these, 83 (1.4%) died during the first 30 days. Number of patients deemed low risk with tools was: PREP (95.9%), GPS (89.6%), PESI (87.2%), Shock index (70.9%), sPESI (59.4%), Prognostic algorithm (58%) and RIETE score (48.6%). The tools with a highest sensitivity were: Prognostic Algorithm (91.6%; 95% CI: 85.6-97.5), RIETE score (90.4%; 95%CI: 84.0-96.7) and sPESI (88%; 95% CI: 81-95). The RIETE, Prognostic Algorithm and sPESI scores obtained the highest overall sensitivity estimates for also predicting 7- and 90-day all-cause mortality, 30-day PE-related mortality, 30-day major bleeding and 30-day VTE recurrences. The proportion of low-risk patients who died within the first 30 days was lowest using the Prognostic Algorithm (0.2%), RIETE (0.3%) or sPESI (0.3%) scores. In PE patients less 50 years, 30-day mortality was low. Although sPESI, RIETE and Prognostic Algorithm scores were the most sensitive tools to identify patients at low risk to die, other tools should be evaluated in this population to obtain more efficient results.

Epidemiology, patterns of care and mortality for patients with hemodynamically unstable acute symptomatic pulmonary embolism.

BACKGROUND: Limited information exists about the epidemiology, management and outcomes of hemodynamically unstable patients with acute pulmonary embolism (PE). We aimed to evaluate the prevalence and outcomes of unstable PE, and to assess the acute management in routine clinical practice. METHODS: This study included 34,380 patients from the RIETE registry with PE between 2001 and 2016. Primary outcomes included all-cause and PE-specific 30-day mortality. We used multivariable adjustments to calculate hazard ratios among unstable patients who did and did not receive reperfusion. RESULTS: Overall, 1207 patients (3.5%) presented with hemodynamic instability. All-cause 30-day mortality was 14% and 5.4% in those with versus those without hemodynamic instability (P < 0.001). Two hundred and thirty eight (20%) unstable patients received reperfusion therapy. After multivariable adjustment, reperfusion therapy was associated with non-significantly reduced 30-day all-cause mortality (hazard ratio [HR] 0.71; 95% CI, 0.45 to 1.10; P = 0.12), and significantly reduced 30-day PE-related mortality (HR 0.56; 95% CI, 0.31 to 0.99; P = 0.04). When limiting the adjusted analyses to unstable patients with right ventricular dysfunction, the difference was significant for both all-cause (HR 0.65; 95% CI, 0.42 to 1.00; P = 0.05) and PE-related mortality (HR 0.52; 95% CI, 0.30 to 0.92; P = 0.02). CONCLUSIONS: In a multinational registry of patients with PE, prevalence of hemodynamic instability was 3.5%, with high associated 30-day mortality rates. Although use of reperfusion was associated with lower mortality rates, particularly in patients with right ventricular dysfunction, it was used in only a fifth of patients.

Dynamics of case-fatalilty rates of recurrent thromboembolism and major bleeding in patients treated for venous thromboembolism.

In patients with venous thromboembolism (VTE), assessment of the risk of fatal recurrent VTE and fatal bleeding during anticoagulation may help to guide intensity and duration of therapy. We aimed to provide estimates of the case-fatality rate (CFR) of recurrent VTE and major bleeding during anticoagulation in a 'real life' population, and to assess these outcomes according to the initial presentation of VTE and its etiology. The study included 41,826 patients with confirmed VTE from the RIETE registry who received different durations of anticoagulation (mean 7.8 ± 0.6 months). During 27,110 patient-years, the CFR was 12.1% (95% CI, 10.2-14.2) for recurrent VTE, and 19.7% (95% CI, 17.4-22.1) for major bleeding. During the first three months of anticoagulant therapy, the CFR of recurrent VTE was 16.1% (95% CI, 13.6-18.9), compared to 2.0% (95% CI, 0-4.2) beyond this period. The CFR of bleeding was 20.2% (95% CI, 17.5-23.1) during the first three months, compared to 18.2% (95% CI, 14.0-23.2) beyond this period. The CFR of recurrent VTE was higher in patients initially presenting with PE (18.5%; 95% CI, 15.3-22.1) than in those with DVT (6.3%; 95% CI, 4.5-8.6), and in patients with provoked VTE (16.3%; 95% CI, 13.6-19.4) than in those with unprovoked VTE (5.5%; 95% CI, 3.5-8.0). In conclusion, the CFR of recurrent VTE decreased over time during anticoagulation, while the CFR of major bleeding remained stable. The CFR of recurrent VTE was higher in patients initially presenting with PE and in those with provoked VTE.

Effects of low concentrations of the phenylurea herbicide diuron on biofilm algae and bacteria.

A system of recirculating channels was used in this study to examine the long-term effects (29d) of environmentally realistic concentrations of the herbicide diuron (from 0.07 to 7 microg L(-1)) on biofilm communities. The autotrophic activity of biofilms was affected by this herbicide, as reflected by a marked decrease in the photosynthetic efficiency. Diuron exposure also increased chlorophyll-a content and reduced the biovolume of diatom taxa at low concentrations. The effects on bacteria were also remarkable. Bacterial abundance was reduced after a week of exposure to the herbicide at a range of concentrations. Effects were on the number of live bacteria and on the increase in the leucine-aminopeptidase activity. It is suggested that inputs of herbicides to the river ecosystem at low concentrations may cause a chain of effects in the biofilm, which include inhibitory effects on algae but also indirect effects on the relationships between biofilm components.

Monitoring the effect of chemicals on biological communities. The biofilm as an interface.

Biofilms can be regarded as early warning systems for detection of the effects of toxicants on aquatic systems, because they have been successfully used for detection of other environmental stressors (e.g. pH, salinity, organic pollution). A variety of methods is used for detection of the effects of toxicants by use of biofilms. The methods range from structurally-based to functionally-based, and from in vitro-based to systemic approaches. Physiological approaches may be appropriate for detection of acute effects. Among these methods, photosynthesis is more related to the effect of toxicants affecting algal communities, directly or indirectly, and extracellular enzyme activity is less specific. Selecting one or the other may depend on the suspected direct effect of the toxicant. Integrated studies have revealed the relevance of toxicants to top-down or bottom-up regulation of the biofilm community. Persistent or chronic effects should affect other biofilm indicators, for example growth or biomass-related factors (e.g. chlorophyll), or community composition. Among these, community composition might better reflect the effects of the toxicant(s), because this may cause a shift from a sensitive to a progressively tolerant community. Community composition-based approaches do not usually adequately reflect cause-effect relationships and require complementary analysis of properties affected in the short-term, for example physiological properties. The current array of methods available must be wisely combined to disentangle the effects of chemicals on biofilms, and whether these effects are transient or persistent, to successfully translate the chemical action of toxicants into the effect they might have on the river ecosystem.