Anti-Factor Xa-Based Monitoring of Unfractionated Heparin: Clinical Outcomes in a Pediatric Cohort.

OBJECTIVES: To assess clinical outcomes in children treated with unfractionated heparin and monitored using an anti-factor Xa (Anti-FXa)-based nomogram. We also sought to assess the correlation between activated partial thromboplastin time (APTT) and Anti-FXa. STUDY DESIGN: This was a single-center, observational cohort study conducted over a 20-month period that included all pediatric patients (<21 years) who received therapeutic unfractionated heparin and were monitored using an anti-FXa-based nomogram. RESULTS: In total, 95 patients met prespecified inclusion criteria, and 1098 pairs of APTT and Anti-FXa measurements were performed. The median unfractionated heparin dose required to reach therapeutic Anti-FXa goal was significantly greater in infants compared with older children (P <.0001). The median time to achieve therapeutic Anti-FXa was 10 hours (range 2-96 hours) and was significantly shorter in patients who received a bolus compared with those who did not (P = .03). Five (5.3%) major bleeding events were noted. Age, peak Anti-FXa, peak APTT, lowest platelet count, and fibrinogen were not predictive of major and clinically relevant nonmajor bleeds. Moderate correlation between the APTT and Anti-FXa (r = 0.75; 95% CI 0.72-0.77) assays was appreciated. CONCLUSIONS: Using an anti-FXa-based nomogram to monitor unfractionated heparin in children is feasible. Although moderate correlation was observed between the APTT and Anti-FXa assays, the APTT frequently overestimated heparin activity. Safety and efficacy of an Anti-FXa nomogram needs further validation.

Treatment-Related Outcomes in Paget-Schroetter Syndrome-A Cross-Sectional Investigation.

OBJECTIVE: To investigate treatment-related outcomes, namely radiological clot resolution, post-thrombotic syndrome (PTS), and health related quality-of-life (HRQoL) scores, in children with Paget-Schroetter syndrome (PSS) undergoing multidisciplinary management, including anticoagulation and decompressive rib-resection surgery, with or without thrombolytic therapy. STUDY DESIGN: We identified all patients treated for PSS at our institution between the years 2010 and 2017. Baseline clinical and radiologic data were abstracted from medical records. Two validated survey instruments to quantify PTS and HRQoL were mailed to eligible patients. Standard statistical methods were used to summarize these measures. RESULTS: In total, 22 eligible patients were identified; 10 were treated with thrombolysis followed by anticoagulation and rib resection, and 12 were treated with anticoagulation and rib resection alone. Nineteen patients responded to the survey instruments. Median age at deep vein thrombosis diagnosis and survey completion were 16.3 and 20.4 years, respectively. Nineteen of 22 patients had thrombus resolution on radiologic follow-up. Fourteen of 19 survey respondents reported signs/symptoms of PTS of which the majority (12/14) reported mild PTS. Aggregate total, physical, and psychosocial HRQoL scores reported were 90.6, 96.7, and 93.3, respectively. Thrombolytic therapy was not associated with a significant improvement in radiologic, clinical or HRQoL outcomes. CONCLUSIONS: Most patients with PSS had complete thrombus resolution on imaging. Only 11% of survey respondents reported moderate PTS. The entire cohort reported excellent HRQoL scores. The role for thrombolytic therapy in the management of childhood PSS remains incompletely elucidated.