Assessment of Temporary Warfarin Reversal in Patients With Left Ventricular Assist Devices: the KVAD Study.

BACKGROUND: Patients with left ventricular assist devices (LVADs) require interruption of warfarin for invasive procedures, but parenteral bridging is associated with many complications. Four-factor prothrombin complex concentrate (4F-PCC) can temporarily restore hemostasis in patients undergoing anticoagulation with warfarin. OBJECTIVES: This pilot study evaluated the strategy of using variable-dose 4F-PCC to immediately and temporarily reverse warfarin before invasive procedures without holding warfarin in patients with LVADs. The duration of effect of 4F-PCC on factor levels and time to reestablish therapeutic anticoagulation post procedure were assessed. METHODS: Adult patients with LVADs and planned invasive procedures were enrolled from a single center. Warfarin was continued uninterrupted. The 4F-PCC dose administered immediately pre-procedure was based on study protocol. International normalized ratio (INR)- and vitamin K-dependent factor levels were collected before and during the 48 hours after 4F-PCC administration. The use of parenteral bridging, International Society for Thrombosis and Haemostasis major and clinically relevant nonmajor bleeding (CRNMB) and thromboembolic events at 7 and 30 days were collected. RESULTS: In 21 episodes of 4F-PCC reversal, median baseline INR was 2.7 (IQR 2.2-3.2). The median dosage of 4F-PCC administered was 1794 units (IQR 1536-2130). At 24 and 48 hours post 4F-PCC administration, median INRs were 1.8 (IQR 1.7-2.0) and 2.0 (IQR 1.9-2.4). Two patients required postoperative bridging. One patient experienced major bleeding within 72 hours, and 2 experienced CRNMB within 30 days. There were no thromboembolic events. Baseline and post 4F-PCC vitamin K-dependent factor levels corresponded with changes in INR values. The median time to achieve therapeutic INR post-procedure was 2.5 days (IQR, 1-4). CONCLUSION: Administration of 4F-PCC for temporary reversal of warfarin for invasive procedures in patients with LVADs allowed for continued warfarin dosing with minimal use of post-intervention bridging, limited bleeding and no thromboembolic events.

One-year retrospective analysis of anti-FXa apixaban and rivaroxaban levels demonstrates utility for management decisions in various urgent and nonurgent clinical situations.

OBJECTIVES: Quantification of direct oral anticoagulant (DOAC) plasma levels can guide clinical management, but insight into clinical scenarios surrounding DOAC-calibrated anti-FXa assays is limited. METHODS: Apixaban- and rivaroxaban-calibrated chromogenic anti-Xa assays performed over a 1-year period were retrospectively analyzed. Patient demographics, DOAC history, concomitant medications, and renal/liver comorbidities were obtained. Indications for testing and associated clinical actions were reviewed. Machine learning (ML) models predicting clinical actions were evaluated. RESULTS: In total, 371 anti-FXa apixaban and 89 anti-FXa rivaroxaban tests were performed for 259 and 67 patients in recurring urgent (acute bleeding, unplanned procedures) and nonurgent situations, including several scenarios not captured by existing testing recommendations (eg, drug monitoring, recurrent thromboembolic events, bleeding tendency). In urgent settings, andexanet reversal was guided by radiologic and clinical findings over DOAC levels in 14 of 32 instances, while 51% of apixaban patients qualified for nonreversal strategies through the availability of levels. Levels also informed procedure/intervention timing and supported management decisions when DOAC clearance or DOAC target levels were in question. The importance of clinical context was emphasized by exploratory ML models predicting particular clinical actions. CONCLUSIONS: Although clinical situations are complex, DOAC testing facilitates clinical decision-making, including reversal, justifying more widespread implementation of these assays.

Thrombosis-Related Loss of Arterial Lines in the First Wave of COVID-19 and Non-COVID-19 Intensive Care Unit Patients.

BACKGROUND: Patients with coronavirus disease 2019 (COVID-19) can present with severe respiratory distress requiring intensive care unit (ICU)-level care. Such care often requires placement of an arterial line for monitoring of pulmonary disease progression, hemodynamics, and laboratory tests. During the first wave of the COVID-19 pandemic in March 2020, experienced physicians anecdotally reported multiple attempts, decreased insertion durations, and greater need for replacement of arterial lines in patients with COVID-19 due to persistent thrombosis. Because invasive procedures in patients with COVID-19 may increase the risk for caregiver infection, better defining difficulties in maintaining arterial lines in COVID-19 patients is important. We sought to explore the association between COVID-19 infection and arterial line thrombosis in critically ill patients. METHODS: In this primary exploratory analysis, a multivariable Fine-Gray subdistribution hazard model was used to retrospectively estimate the association between critically ill COVID-19 (versus sepsis/acute respiratory distress syndrome [ARDS]) patients and the risk of arterial line removal for thrombosis (with arterial line removal for any other reason treated as a competing risk). As a sensitivity analysis, we compared the number of arterial line clots per 1000 arterial line days between critically ill COVID-19 and sepsis/ARDS patients using multivariable negative binomial regression. RESULTS: We retrospectively identified 119 patients and 200 arterial line insertions in patients with COVID-19 and 54 patients and 68 arterial line insertions with non-COVID ARDS. Using a Fine-Gray subdistribution hazard model, we found the adjusted subdistribution hazard ratio (95% confidence interval [CI]) for arterial line clot to be 2.18 (1.06-4.46) for arterial lines placed in COVID-19 patients versus non-COVID-19 sepsis/ARDS patients ( P = .034). Patients with COVID-19 had 36.3 arterial line clots per 1000 arterial line days compared to 19.1 arterial line clots per 1000 arterial line days in patients without COVID-19 (adjusted incidence rate ratio [IRR] [95% CI], 1.78 [0.94-3.39]; P = .078). CONCLUSIONS: Our study suggests that arterial line complications due to thrombosis are more likely in COVID-19 patients and supports the need for further research on the association between COVID-19 and arterial line dysfunction requiring replacement.

Evaluation of the use of direct oral anticoagulants for the management of heparin-induced thrombocytopenia.

Historically, treatment of heparin-induced thrombocytopenia (HIT) includes a non-heparin parenteral anticoagulant with bridging to warfarin once platelets recover. Data supporting the use of direct oral anticoagulants (DOACs) for HIT treatment are limited. Given the paucity of evidence for the use of DOACs in HIT, the aim of this study is to describe the prescribing patterns of DOACs for HIT at our institution. This is a single center, retrospective chart evaluation of patients admitted from January 2017 to October 2020 with a confirmed diagnosis of HIT. Twenty-six patients were identified; 21 patients (81%) received initial parenteral treatment and 5 patients (19.2%) with initial DOAC treatment. The most frequently used DOAC was apixaban at the VTE treatment dose [15 (57.7%)] followed by the reduced dose of apixaban [5 (19.2%)]. Of the patients initially treated with a parenteral agent, 11 (42.3%) were transitioned to a DOAC after platelet recovery, 7 (26.9%) transitioned as platelets were steadily increasing, and 3 (11.5%) transitioned at the time of discharge (prior to platelet recovery). Platelet recovery was achieved in 23 patients (88.5%) at a median of 5 days (IQR 2.8-8.3) after HIT diagnosis. No new thrombotic or bleeding events occurred within 30 days of HIT diagnosis. In our patients treated with a DOAC for HIT, no progression of HIT was observed. Apixaban was the most frequently utilized DOAC. Most patients received a parenteral anticoagulant prior to DOAC initiation. All patients managed with a DOAC as initial treatment achieved platelet recovery within 30 days of HIT diagnosis.