Major Bleeding in Adults Undergoing Peripheral Extracorporeal Membrane Oxygenation (ECMO): Prognosis and Predictors

Background. Major bleeding has been a common and serious complication with poor outcomes in ECMO patients. With a novel, less-invasive cannulation approach and closer coagulation monitoring regime, the incidence of major bleeding is currently not determined yet. Our study aims to examine the incidence of major bleeding, its determinants, and association with mortality in peripheral-ECMO patients. Method. We conducted a single-center retrospective study on adult patients undergoing peripheral-ECMO between January 2019 and January 2020 at a tertiary referral hospital. Determinants of major bleeding were defined by logistic regression analysis. Risk factors of in-hospital mortality were determined by Cox proportional hazard regression analysis. Results. Major bleeding was reported in 33/105 patients (31.4%) and was associated with higher in-hospital mortality [adjusted hazard ratio (aHR) 3.56, 95% confidence interval (CI) 1.63–7.80, p < 0.001 ). There were no significant difference in age, sex, ECMO indications, ECMO modality, pre-ECMO APACHE-II and SOFA scores between two groups with and without major bleeding. Only APTT >72 seconds [adjusted odds ratio (aOR) 7.10, 95% CI 2.60–19.50, p < 0.001 ], fibrinogen <2 g/L [aOR = 7.10, 95% CI 2.60–19.50, p < 0.001 ], and ACT >220 seconds [aOR = 3.9, 95% CI 1.20–11.80, p = 0.017 ] on days with major bleeding were independent predictors. Conclusions. In summary, major bleeding still had a fairly high incidence and poor outcome in peripheral-ECMO patients. APTT > 72 seconds, fibrinogen < 2 g/L were the strongest predicting factors for major bleeding events.

Pharmacokinetic Parameter Driven Outcomes Model Predicts a Reduction in Bleeding Events Associated with BAY 81-8973 Versus Antihemophilic Factor (Recombinant) Plasma/Albumin- Free Method in a Chinese Healthcare Setting

Background: Long-term prophylactic therapy is considered the standard of care for hemophilia A patients. This study models the long-term clinical and cost outcomes of two factor VIII (FVIII) products using a pharmacokinetic (PK) simulation model in a Chinese population. Methods: Head-to-head PK profile data of BAY 81-8973 (KOVALTRY®) and antihemophilic factor (recombinant) plasma/albumin-free method (rAHF-PFM, ADVATE®) were applied to a two-state (alive and dead) Markov model to simulate blood FVIII concentrations at a steady state in prophylactically-treated patients with hemophilia A. Worsening of the Pettersson score was simulated and decline was associated with the probability of having orthopaedic surgery. The only difference between the compounds was FVIII concentration at a given time; each subject was treated with 25 IU/kg every 3 days. The model used a lifetime horizon, with cycle lengths of 1 year. Results: Cumulative bleeding events, joint bleeding events, and major bleeding events were reduced by 19.3%, 9.3% and 19.3%, respectively for BAY 81-8973 compared to rAHF-PFM. Hospitalizations and hospitalization days were also reduced by 19.3% for BAY 81-8973 compared to rAHF-PFM. BAY 81-8973 resulted in both cost savings and a gain in quality adjusted life years (QALYs) compared to rAHF-PFM. Conclusion: Based on modeled head-to-head comparisons, differences in PK-properties between BAY 81-8973 and rAHF-PFM result in a reduced number of bleeding events, leading to reduced costs and increased quality of life for BAY 81-8973. These results should be used to inform clinical practice in China when caring for patients with severe hemophilia A.

Evaluation of the Clinical Impact of Thromboprophylaxis in Patients With COVID-19 Following Hospital Discharge

Background: Data are limited regarding the incidence of thromboembolism post-hospital discharge among COVID-19 patients. Guidelines addressing the role of extended thromboprophylaxis for COVID-19 patients are limited and conflicting. Objective: The purpose of this study was to evaluate the incidence of post-discharge thromboembolic and bleeding events and the role of thromboprophylaxis among COVID-19 patients. Methods: A retrospective analysis was conducted of hospitalized patients with symptomatic COVID-19 infection who were discharged from a University of Colorado Health (UCHealth) hospital between March 1, 2020, and October 31, 2020. The primary outcome was objectively confirmed thromboembolism within 35 days post-discharge. The main secondary outcome was the incidence of bleeding events within 35 days post-discharge. Outcomes were compared between those who received extended prophylaxis and those who did not. Results: A total of 1171 patients met the study criteria. A total of 13 (1.1%) of patients had a documented thromboembolic event and 10 (0.9%) patients had a documented bleeding event within 35 days post-discharge. None of the 132 patients who received extended prophylaxis had a thromboembolic event compared to 13 of 1039 who did not receive extended prophylaxis (0 and 1.3%, respectively; P = .383). The incidence of bleeding was higher among patients who received extended prophylaxis compared to those who did not (3.0% vs 0.6%, P = .019). Conclusions and Relevance: These results suggest that post-discharge extended prophylaxis may be beneficial for select COVID-19 patients, while carefully weighing the risk of bleeding. Application of our findings may assist institutions in development of thromboprophylaxis protocols for discharged COVID-19 patients.

Thrombotic vs. Bleeding Events of Interruption of Dual Antiplatelet Therapy within 12 Months among Patients with Stent-Driven High Ischemic Risk Definition following PCI

Background. There is a paucity of real-world data regarding the clinical impact of dual antiplatelet therapy (DAPT) interruption (temporary or permanent) among patients at high ischemic risk. The aim of this study was to assess the risk of cardiovascular events after interruption of DAPT in high-risk PCI population. Methods. This study used data from the Fuwai PCI registry, a large, prospective cohort of consecutive patients who underwent PCI. We assessed 3,931 patients with at least 1 high ischemic risk criteria of stent-related recurrent ischemic events proposed in the 2017 ESC guidelines for focused update on DAPT who were free of major cardiac events in the first 12 months. The primary ischemic endpoint was 30-month major adverse cardiac and cerebrovascular events, and the key safety endpoints were BARC class 2, 3, or 5 bleeding and net adverse clinical events. Results. DAPT interruption within 12 months occurred in 1,122 patients (28.5%), most of which were due to bleeding events or patients’ noncompliance to treatment. A multivariate Cox regression model, propensity score (PS) matching, and inverse probability of treatment weighting (IPTW) based on the propensity score demonstrated that DAPT interruption significantly increased the risk of primary ischemic endpoint compared with prolonged DAPT (3.9% vs. 2.2%; Cox-adjusted hazard ratio (HR): 1.840; 95% confidence interval (CI): 1.247 to 2.716; PS matching-HR: 2.049 [1.236–3.399]; IPTW-adjusted HR: 1.843 [1.250–2.717]). This difference was driven mainly by all-cause death (1.8% vs. 0.7%) and MI (1.3% vs. 0.5%). Furthermore, the rate of net adverse clinical events (4.9% vs. 3.2%; Cox-adjusted HR: 1.581 [1.128–2.216]; PS matching-HR: 1.639 [1.075–2.499]; IPTW-adjusted HR: 1.554 [1.110–2.177]) was also higher in patients with DAPT interruption (≤12 months), whereas no significant differences between groups were observed in terms of BARC 2, 3, or 5 bleeding. These findings were consistent across various stent-driven high-ischemic risk subsets with respect to the primary ischemic endpoints, with a greater magnitude of harm among patients with diffuse multivessel diabetic coronary artery disease. Conclusions. In patients undergoing high-risk PCI, interruption of DAPT in the first 12 months occurred infrequently and was associated with a significantly higher adjusted risk of major adverse cardiovascular events and net adverse clinical events. 2017 ESC stent-driven high ischemic risk criteria may help clinicians to discriminate patient selection in the use of long-term DAPT when the ischemic risk certainly overcomes the bleeding one.

Discovery of Novel Reductive Elimination Pathway for 10-Hydroxywarfarin

Coumadin (R/S-warfarin) anticoagulant therapy is highly efficacious in preventing the formation of blood clots; however, significant inter-individual variations in response risks over or under dosing resulting in adverse bleeding events or ineffective therapy, respectively. Levels of pharmacologically active forms of the drug and metabolites depend on a diversity of metabolic pathways. Cytochromes P450 play a major role in oxidizing R- and S-warfarin to 6-, 7-, 8-, 10-, and 4′-hydroxywarfarin, and warfarin alcohols form through a minor metabolic pathway involving reduction at the C11 position. We hypothesized that due to structural similarities with warfarin, hydroxywarfarins undergo reduction, possibly impacting their pharmacological activity and elimination. We modeled reduction reactions and carried out experimental steady-state reactions with human liver cytosol for conversion of rac-6-, 7-, 8-, 4′-hydroxywarfarin and 10-hydroxywarfarin isomers to the corresponding alcohols. The modeling correctly predicted the more efficient reduction of 10-hydroxywarfarin over warfarin but not the order of the remaining hydroxywarfarins. Experimental studies did not indicate any clear trends in the reduction for rac-hydroxywarfarins or 10-hydroxywarfarin into alcohol 1 and 2. The collective findings indicated the location of the hydroxyl group significantly impacted reduction selectivity among the hydroxywarfarins, as well as the specificity for the resulting metabolites. Based on studies with R- and S-7-hydroxywarfarin, we predicted that all hydroxywarfarin reductions are enantioselective toward R substrates and enantiospecific for S alcohol metabolites. CBR1 and to a lesser extent AKR1C3 reductases are responsible for those reactions. Due to the inefficiency of reactions, only reduction of 10-hydroxywarfarin is likely to be important in clearance of the metabolite. This pathway for 10-hydroxywarfarin may have clinical relevance as well given its anticoagulant activity and capacity to inhibit S-warfarin metabolism.

Risk Factors Associated With Bleeding in Children With Cardiac Disease Receiving Extracorporeal Membrane Oxygenation: A Multi-Center Data Linkage Analysis

Background: Bleeding is a common complication of extracorporeal membrane oxygenation (ECMO) for pediatric cardiac patients. We aimed to identify anticoagulation practices, cardiac diagnoses, and surgical variables associated with bleeding during pediatric cardiac ECMO by combining two established databases, the Collaborative Pediatric Critical Care Research Network (CPCCRN) Bleeding and Thrombosis in ECMO (BATE) and the Extracorporeal Life Support Organization (ELSO) Registry.Methods: All children (&lt;19 years) with a primary cardiac diagnosis managed on ECMO included in BATE from six centers were analyzed. ELSO Registry criteria for bleeding events included pulmonary or intracranial bleeding, or red blood cell transfusion &gt;80 ml/kg on any ECMO day. Bleeding odds were assessed on ECMO Day 1 and from ECMO Day 2 onwards with multivariable logistic regression.Results: There were 187 children with 114 (61%) bleeding events in the study cohort. Biventricular congenital heart disease (94/187, 50%) and cardiac medical diagnoses (75/187, 40%) were most common, and 48 (26%) patients were cannulated directly from cardiopulmonary bypass (CPB). Bleeding events were not associated with achieving pre-specified therapeutic ranges of activated clotting time (ACT) or platelet levels. In multivariable analysis, elevated INR and fibrinogen were associated with bleeding events (OR 1.1, CI 1.0–1.3, p = 0.02; OR 0.77, CI 0.6–0.9, p = 0.004). Bleeding events were also associated with clinical site (OR 4.8, CI 2.0–11.1, p &lt; 0.001) and central cannulation (OR 1.75, CI 1.0–3.1, p = 0.05) but not with cardiac diagnosis, surgical complexity, or cannulation from CPB. Bleeding odds on ECMO day 1 were increased in patients with central cannulation (OR 2.82, 95% CI 1.15–7.08, p = 0.023) and those cannulated directly from CPB (OR 3.32, 95% CI 1.02–11.61, p = 0.047).Conclusions: Bleeding events in children with cardiac diagnoses supported on ECMO were associated with central cannulation strategy and coagulopathy, but were not modulated by achieving pre-specified therapeutic ranges of monitoring assays.

Comparison of Anti-factor Xa Levels in Female and Male Patients with Obesity After Enoxaparin Application for Thromboprophylaxis

Purpose Venous thromboembolic events (VTEs) are common complications after bariatric surgery, and enoxaparin is commonly used to prevent VTEs. The risk for VTEs is sex-specific. Whether enoxaparin application results in similar anti-factor Xa activities (aFXa) in males and females with obesity remains to be determined. We investigated whether our dosage regimen of enoxaparin resulted in similar serum aFXa levels in female and male patients undergoing bariatric surgery. Materials and Methods We administered enoxaparin twice daily in patients undergoing bariatric surgery. Patients with a body mass index (BMI) > 60 kg/m2 (n = 11) received 60 mg enoxaparin (group 2), and patients with lower BMI (n = 86) received 40 mg per dose (group 1). Peak aFXa levels were measured 3 days after surgery. The primary outcome was the aFXa level. As a secondary outcome, we detected VTEs and major bleeding events and explored the possible influencing factors of aFXa. Results Women had higher aFXa than men, but after matching for anthropometric values, the two groups were similar (females: 0.17 ± 0.08 U/ml; males: 0.18 ± 0.08 U/ml). Linear regression revealed a moderate relationship between weight and aFXa levels. The 3-month follow-up was attended by 94.9%, at which one patient had pulmonary embolism. Conclusion Individual enoxaparin dosage regimens for men and women do not seem to be required. Weight-based dosing regimen seems to be a more reasonable choice. Graphical abstract

Genotype-Guided Antiplatelet Therapy Versus Standard Therapy for Patients with Coronary Artery Disease: An Updated Systematic Review and Meta-Analysis

Objective: Previous studies on the efficacy and safety of genotype-guided antiplatelet therapy in patients with coronary artery disease (CAD) or undergoing percutaneous coronary intervention (PCI) have been inconclusive. Aim: We conducted a meta-analysis to evaluate if the genotype-guided antiplatelet strategy is superior to the standard therapy in patients with CAD or undergoing PCI. Method: PubMed, Web of Science, Embase, and Cochrane Central Register of Controlled Trials databases were searched up to October 1st, 2021. Studies reporting efficacy and safety outcomes in the genotype-guided treatment and standard treatment groups were included. The two groups were statistically compared. Result: Eleven randomized controlled trials (RCTs) involving 11740 patients were included in this meta-analysis. Compared with the standard treatment group, the genotype-guided group had significant lower risks of all efficacy outcomes, including major adverse cardiovascular events (MACEs) (RR 0.60, 95%, CI 0.44-0.82, P=0.001), all-cause death (RR 0.70, 95% CI 0.51-0.95, P=0.02), cardiovascular death (RR 0.71, 95% CI 0.53-0.95, P=0.02), myocardial infarction (RR 0.53, 95% CI 0.42-0.67, P<0.0001), stroke (RR 0.64, 95% CI 0.41-0.98, P=0.04), stent thrombosis (RR 0.63, 95% CI 0.43-0.91, P=0.01) and targeted vessel revascularization (RR 0.79, 95% CI 0.67-0.92, P=0.003). There was no significant difference in any bleeding events between the two groups. As a result of the subgroup analyses, the genotype-guided treatment was more likely to reduce the incidence of MACEs in the subgroup where the proportion of patients with ACS was ≥ 90%, and subgroup of the Chinese population. Conclusion: Genotype-guided antiplatelet treatment could reduce the risk of MACEs without increasing the risk of bleeding events as compared with the standard treatment in patients with CAD or those undergoing PCI. In addition, Genotype-guided antiplatelet treatment might benefit Chinese population or patients with ACS.

Associations of Atrial Fibrillation Patterns With Mortality and Cardiovascular Events: Implications of the MISOAC-AF Trial

Aim: This retrospective cohort study aimed to evaluate the prognostic implications of the distinct atrial fibrillation (AF) temporal patterns: first diagnosed, paroxysmal, and persistent or permanent AF. Methods: In this post hoc analysis of the MISOAC-AF trial (NCT02941978), a total of 1052 patients with AF (median age 76 years), discharged from the cardiology ward between 2015 and 2018, were analyzed. Kaplan-Meier and Cox-regression analyses were performed to compare the primary outcome of all-cause mortality, the secondary outcomes of stroke, major bleeding and the composite outcome of cardiovascular (CV) mortality or hospitalization among AF patterns. Results: Of patients, 121 (11.2%) had first diagnosed, 356 (33%) paroxysmal, and 575 (53.2%) persistent or permanent AF. During a median follow-up of 31 months (interquartile range 10 to 52 months), 37.3% of patients died. Compared with paroxysmal AF, patients with persistent or permanent AF had higher mortality rates (adjusted hazard ratio (aHR), 1.37; 95% confidence interval [CI], 1.08-1.74, P = .009), but similar CV mortality or hospitalization rates (aHR, 1.09; 95% CI, 0.91-1.31, P = .35). Compared with first diagnosed AF, patients with persistent or permanent AF had similar mortality (aHR, 1.26; 95% CI, 0.87-1.82, P = .24), but higher CV mortality or hospitalization rates (aHR, 1.35; 95% CI, 1.01-1.8, P = .04). Stroke and major bleeding events did not differ across AF patterns (all P > .05). Conclusions: In conclusion, in recently hospitalized patients with comorbid AF, the presence of persistent or permanent AF was associated with a higher incidence of mortality and morbidity compared with paroxysmal and first diagnosed AF.