OC 67.4 - Intracardiac Thrombosis in Pediatrics: Anticoagulation Approach and Treatment Outcomes

Background: Intracardiac thrombi (ICT) are associated with significant morbidity and mortality. Anticoagulation is the first line of treatment and may be complemented by thrombectomy or thrombolysis, when clinically indicated. However, length of anticoagulation remains not well defined. Additionally, there is paucity of data regarding high-risk features of ICT that warrant prolonged anticoagulation therapy.

Aims: 1. Determine optimal duration of anticoagulation for ICT 2. Identify potential risk factors for lack of resolution with anticoagulation 3. Describe thromboembolic and bleeding complications.

Methods: Single institution retrospective chart review study. Patients were identified by the presence of ICT on echocardiogram between January 2014 to January 2022. Descriptive and logistic regression analyses were used as indicated.

Results: Sixty-one patients with ICT were identified. Median age at diagnosis was 8.5 years (range 0.02-22.38). Most common underlying diagnoses were congenital heart disease (44%), infection (25%), and malignancy (21%). Majority of the ICT were in the right atrium (n=34), 82% of which were associated with a central venous catheter. Median longest dimension was 1.3 cm (range 0.4 - 4.0).

Most (93%) of the patients received anticoagulation as first line therapy, while remainder four patients underwent thrombectomy. Median duration of anticoagulation was 138 days (range 0-2895). The majority of ICT (70%) had some resolution after 12 months of anticoagulation (Figure 1). Decreased left ventricle ejection fraction (LVEF) defined as LVEF less than 50%, was associated with lower odds of ICT resolution (Table 1). Thromboembolic events included stroke (n=5) and pulmonary embolism (n=1). Major and clinically relevant non-major bleeding rate with anticoagulation was 7%.

Conclusion(s): Our study demonstrates the wide variability in the duration of anticoagulation for children with ICT. Decreased LVEF was associated with lower odds of ICT resolution. Further studies are recommended to identify high-risk subgroups that may benefit from longer duration of anticoagulation for optimal response.