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Abstract Background Warfarin monitoring may be done at the point-of-care (POC) at home, in a clinic environment, or be performed using plasma specimens in a central laboratory. With a goal of standardizing International Normalization Ratio (INR) measurements and improving data integrity by enabling electronic transmission of results from any location, we evaluated two POC INR devices against an internal plasma INR reference method. Methods We conducted a multicenter study to test the accuracy of two commercially available point of care devices: Coag-Sense PT2 Meter (Coagusense, Inc., Fremont, CA) and CoaguChek XS Pro or XS Plus (Roche Diagnostics, Indianapolis, IN) compared with plasma INR values among warfarin treated patients. Bias and linear regression analysis were assessed for device-plasma INR comparisons. Warfarin dosing decisions were assessed for each device compared to an internal plasma INR reference method (Instrumentation Laboratories ACLTOP 500, 550, 750 analyzers (Werfen Diagnostics, Bedford MA) in one of three CLIA-certified laboratories. The thromboplastin used at our institution for INR measures is HemosIL RecombiPlasTin 2G (R2G) reagent (Werfen Diagnostics, Bedford MA) which has an International Sensitivity Index (ISI) of 1.0. Results Two hundred ninety-nine warfarin patients treated across three Mayo Clinic sites agreed to participate in the study. Common anticoagulant indications were atrial fibrillation (63.9%), venous thromboembolism (21.7%) and heart valve prosthesis (15.4%) with a 2.0–3.0 INR target range for 93.6% of patients. For the CoaguChek devices, 81.3% of values fell within 0.2 INR units of plasma INR referent and 95.3% within 0.4 units. The correlation between CoaguChek whole blood and plasma INR was excellent (R2 = 0.93). For the Coag-Sense device, 34.1% of values fell within 0.2 INR units and 60.2% within 0.4 INR units of plasma INR values, with a slightly weaker correlation between Coag-Sense whole blood and plasma INR (R2 = 0.83; P < 0.0001). Mean (± standard deviation) deviation from plasma INR was 0.04 ± 0.2 for CoaguChek compared to 0.4 ± 0.3 for Coag-Sense (P < 0.0001). The difference between POC devices was largely attributed to systematic negative bias between Coag-Sense and ACL TOP plasma INR values. Using the plasma INR as the reference method for dosing decision making, appropriate dosing recommendations would have occurred for 97.7% of CoaguChek and 81.6% of Coag-Sense results. Conclusion Compared to our institution's plasma reference method, INR values obtained from the CoaguChek devices (XS Pro and XS Plus) exhibited less systematic bias compared to the Coag-Sense values. This translates to greater percentage of concordant management decisions between POC and laboratory plasma INR methods when the CoaguChek device is used.

ImportancePatterns of clinical utilization and comparative effectiveness of anticoagulants for cancer-associated thrombosis (CAT) remain largely unexplored.ObjectivesTo assess patterns of and factors associated with anticoagulant use and to evaluate the comparative effectiveness of contemporary anticoagulants in patients with active cancer in a clinical setting.Design, Setting, and ParticipantsThis retrospective cohort study obtained deidentified OptumLabs electronic health record claims data from January 1, 2012, to September 30, 2019. Adult patients (≥18 years of age) with a primary cancer diagnosis (except skin cancer) during at least 1 inpatient or 2 outpatient visits within 6 months before the venous thromboembolism (VTE) date were included. Data were analyzed from April 2020 to September 2021.ExposuresThe patients were grouped according to the anticoagulant prescribed: (1) direct oral anticoagulants (DOACs), (2) low-molecular-weight heparin (LMWH), and (3) warfarin.Main Outcomes and MeasuresOdds ratios (ORs) were used to present the association between factors of interest and utilization of anticoagulants. Main efficacy outcomes included risk of VTE recurrence and all-cause mortality. Main safety outcomes included the risk of hospitalization due to major bleeding. Relative treatment effect estimates were expressed as hazard ratios (HRs) with 95% CIs.ResultsThis study included 5100 patients (mean [SD] age, 66.3 [12.3] years; 2670 [52.4%] women; 799 [15.7%] Black, 389 [7.6%] Hispanic, and 3559 [69.8%] White individuals). Overall, 2512 (49.3%), 1488 (29.2%), and 1460 (28.6%) filled prescriptions for DOACs, LMWH, and warfarin, respectively. The median (IQR) treatment duration was 3.2 (1.0-6.5) months for DOACs, 3.1 (1.0-6.8) months for warfarin, and 1.8 (0.9-3.8) months for LWMH. Patients with lung (OR, 2.07; 95% CI, 1.12-3.65), urological (OR, 1.94; 95% CI,1.08-3.49), gynecological (OR, 4.25; 95% CI, 2.31-7.82), and colorectal (OR, 2.26; 95% CI, 1.20-4.32) cancer were associated with increased prescriptions for LMWH compared with DOACs. LMWH (HR, 1.47; 95% CI, 1.14-1.90) and warfarin (HR, 1.46; 95% CI, 1.13-1.87) were associated with an increased risk of VTE recurrences compared with DOACs. LMWH was associated with an increased risk of major bleeding (HR, 2.27; 95% CI, 1.62-3.20) and higher all-cause mortality (HR, 1.61; 95% CI, 1.15-2.25) compared with DOACs.Conclusions and RelevanceIn this comparative effectiveness study of claims-based data, patients with CAT received anticoagulation for a remarkably short duration in clinical settings. DOACs was associated with a lower risk of VTE recurrence, major bleeding, and mortality. Warfarin may still be considered for patients with contraindications to DOACs and those with poor persistence on LMWH.

Introduction: In seniors, the prevalence of abdominal aortic aneurysms (AAA) is high (9-10%). We aim to characterize AAA growth rates (slow vs. rapid) to help inform management strategies, including individualized imaging surveillance frequency. Hypothesis: Modeling thrombosis may improve the characterization of AAAs' growth status. Methods: 3D geometrical AAA models with and without thrombosis (vessel lumen only) were generated for 70 human subjects using available contrast-enhanced CTA data. AAA growth rates were categorized as slow (< 5 mm/year) or rapid (≥ 5 mm/year) based on serial imaging. Python scripts were used to calculate geometrical parameters (83) with and without thrombosis. Patient-specific relevant health information was retrieved through a review of medical records. Support vector machine (SVM), a well-established machine learning method, was run with 10-fold cross-validation (100 iterations) to assess the predictive accuracy. Results: Among 70 AAAs studied, the ratio between rapidly-growing and slowly-growing was nearly 1:2. The combination of antihypertensive medication, coronary artery disease, juxta-aneurysm aortic size, and five geometrical parameters quantifying the extent of thrombosis provided the best accuracy for AAA's growth status. The area under receiving operating curve (AUROC) was 0.85, and total accuracy was 0.81, with 57% and 93% of rapidly- and slowly-growing AAAs correctly identified, respectively. Excluding patients with aneurysm thrombus, the AUROC and accuracy in predicting rapidly-growing AAAs decreased to 0.82 and 48%, respectively. Conclusions: machine-learning-based predictive modeling appears feasible for characterizing AAA's growth rate status. Manual aortic image segmentation, required for data analytics, is labor-intensive (on average, 1 hour). Leveraging artificial intelligence-based segmentation methodology may provide an automated solution to improve workflow and feasibility.

Introduction: The Safety and efficacy of DOACs is unknown in patients with left ventricular thrombus as these patients were excluded from DOAC trials. Hypothesis: The safety and efficacy of DOACs is comparable to vitamin K antagonists Methods: Databases including Medline, Scopus and Cochrane Central Registration of Controlled Trials were queried from inception to March 30 th 2022. Studies reporting efficacy and safety outcomes were selected for the analysis. Results: We included 11 studies comprising 1920 patients with left ventricular thrombus. The mean age in the DOAC group was 57.5 years (SD 12.8) and 58.6 years (SD 13.0) in the VKA group; 26.8% were females. Pooled results showed no difference in mortality (RR, 0.64 [95% CI, 0.16-2.52]) embolic events (RR, 0.94 [95% CI, 0.59-1.50]) or major bleeding (RR, 0.95[95% CI, 0.66-1.36]) in the DOACs compared to VKA groups. Event rate for DOAC group compared to VKA group was 12.7 vs 17.5 per 100 patient-years (mean follow up of 4.0 months) for mortality, 19.5 vs 26.5 per 100 patient-years (mean follow up of 8.9 months) for embolic events and 8.0 vs 10.0 per 100 patient-years (mean follow up of 9.5 months) for major bleeding. Conclusions: These data, from observational and randomized studies, demonstrate promising safety and efficacy of DOACs for treatment of left ventricular thrombus. Elevated embolic and mortality rates regardless of anticoagulant choice emphasize the need for further research to improve outcomes for patients with this complication.

Abstract While being a relatively prevalent condition particularly among aging patients, peripheral arterial disease (PAD) of lower extremities commonly goes undetected or misdiagnosed due to its symptoms being nonspecific. Additionally, progression of PAD in the absence of timely intervention can lead to dire consequences. Therefore, development of non-invasive and affordable diagnostic approaches can be highly beneficial in detection and treatment planning for PAD patients. In this study, we present a contrast-free ultrasound-based quantitative blood flow imaging technique for PAD diagnosis. The method involves monitoring the variations of blood flow in the calf muscle in response to thigh-pressure-cuff-induced occlusion. Four quantitative metrics are introduced for analysis of these variations. We examine the feasibility of this method through an in vivo study consisting of 14 PAD patients with abnormal ankle-brachial index (ABI) and 8 healthy volunteers. Ultrasound data acquired from 13 legs in the patient group and 13 legs in the healthy group are analyzed. Out of the four utilized metrics, three exhibited significantly different distributions between the two groups (p-value < 0.05). The results of this feasibility study indicate the diagnostic potential of the proposed method for the detection of PAD.

AbstractPatients with thrombophilia remain concerned about venous thromboembolism (VTE) risk with COVID‐19 vaccinations. The aim of this study was to examine VTE outcomes in patients with inherited or acquired thrombophilia who were vaccinated for COVID‐19. Vaccinated patients ≥18 years between November 1, 2020 and November 1, 2021 were analyzed using electronic medical records across the Mayo Clinic enterprise. The primary outcome was imaging confirmed acute VTE occurring 90 days before and after the date of the first vaccine dose. Thrombophilia patients were identified through laboratory testing results and ICD‐10 codes. A total of 792 010 patients with at least one COVID‐19 vaccination were identified. Six thousand sixty‐seven of these patients were found to have a thrombophilia, among whom there was a total of 39 VTE events after compared to 51 VTE events before vaccination (0.64% vs. 0.84%, p = .20). In patients with Factor V Leiden or prothrombin gene mutation, VTE occurred in 27 patients before and in 29 patients after vaccination (0.61 vs. 0.65%, p = .79). In patients with antiphospholipid syndrome, VTE occurred in six patients before and four patients after vaccination (0.59% vs. 0.39%, p = .40). No difference was observed in the overall VTE rate when comparing the postvaccination 90 days to the prevaccination 90 days, adjusted hazard ratio 0.81 (95% confidence interval: 0.53–1.23). In this subgroup of COVID‐19 vaccinated patients with thrombophilia, there was no increased risk for acute VTE postvaccination compared to the prevaccination timeframe. These results are consistent with prior studies and should offer additional reassurance to patients with inherited or acquired thrombophilia.

Background Study aims were to analyze prospectively collected data from patients with cancer-associated venous thromboembolism (VTE) to determine the impact of VTE recurrence and anticoagulant-related bleeding on all-cause mortality. Patients/Methods Consecutive cancer patients with acute VTE treated with anticoagulants (March 1, 2013–November 30, 2021) were included in this analysis. Anticoagulant therapy-associated VTE recurrences, major bleeding, and clinically relevant nonmajor bleeding (CRNMB) were assessed for their impact on all-cause mortality outcomes. Results This study included 1,812 cancer patients with VTE. Of these, there were 97 (5.4%) with recurrent VTE, 98 (5.4%) with major, and 104 (5.7%) with CRNMB while receiving anticoagulants. Recurrent VTE (hazard ratio [HR]: 1.52; 95% confidence interval [CI]: 1.16–2.00; p = 0.0028), major bleeding (HR: 1.82; 95% CI: 1.41–2.31; p = 0.006), and CRNMB (HR; 1.38; 95% CI: 1.05–1.81; p = 0.018) each adversely influenced mortality outcomes. Deep vein thrombosis as the incident thrombotic event type was associated with VTE recurrence (HR: 1.78; 95% CI: 1.08–2.89; p = 0.02). Neither cancer type nor stage, chemotherapy, or Ottawa risk category influenced VTE recurrence. Higher body weights (HR: 1.01; 95% CI: 1.00–1.01; p = 0.005) were associated with increased major bleeding, while high Ottawa scores (HR: 0.66; 95% CI: 0.46–0.96; p = 0.03) and apixaban treatment (HR: 0.62; 95% CI: 0.45–0.84; p = 0.002) were associated with fewer major bleeding outcomes. Conclusion Among cancer patients receiving anticoagulant therapy for VTE, adverse outcomes such as VTE recurrence, major bleeding, or CRNMB increase mortality risk by 40 to 80%. Identifying variables predicting these outcomes may help risk-stratify patients with poor prognosis.

AbstractBackgroundNecrobiosis lipoidica (NL) is complicated by ulceration in up to 35% of cases.MethodsRetrospective study of patients with NL seen at our institution between January 1, 1992, and May 25, 2021, was conducted. Ulcerated NL (UNL, n = 83) and non‐ulcerated NL (NUNL, n = 233) groups were compared.ResultsTwenty‐six percent (83/316) of patients with NL experienced ulceration. UNL was significantly more likely to be painful (52% vs. 36%, P = 0.01), was more likely to have a lesion‐associated cutaneous malignancy (7% vs. 0%, P < 0.001), and had a larger median size (7 vs. 5 cm, P = 0.004) compared to NUNL. Vascular studies were performed on a subset of patients and revealed transcutaneous oxygen pressure (TcPO2) < 40 mm Hg in 53% and venous insufficiency in 62% with no significant differences between UNL and NUNL groups. In patients with unilateral ulceration, mean TcPO2 values (39.7 vs. 46.6 mm Hg), regional perfusion index <0.6 (29% vs. 14%), and TcPO2 < 40 mm Hg (43% vs. 14%) were worse in the ulcerated leg compared to the non‐ulcerated leg, but these differences were not statistically significant.ConclusionsUNL was more likely to be painful, develop lesion‐associated malignancy, and be larger in size compared to NUNL. There were no statistically significant differences in venous insufficiency, arterial Doppler/ankle brachial index, or TcPO2 values between UNL and NUNL patients, however, a significant portion of the cohort demonstrated abnormal vascular studies, particularly on TcPO2 and venous insufficiency testing.