Factors influencing cardiomegaly and cardiac size changes after endovascular treatment in peripheral arteriovenous malformations

Background: Although prior studies on peripheral arteriovenous malformations (AVMs) have addressed diagnosis and treatment, the prevalence and risk factors for cardiomegaly remain underexplored. Purpose: To assess the prevalence of cardiomegaly in peripheral AVMs, identify associated factors, and evaluate changes in cardiac size and function following endovascular treatment. Material and Methods: A retrospective review was conducted on 437 patients treated for peripheral AVMs between 2000 and 2022 at a single vascular anomalies center. AVM types were classified according to the Cho-Do angiographic classification. Cardiomegaly was defined as a cardiothoracic ratio (CTR) >0.5 on chest radiographs. Factors associated with cardiomegaly and post-treatment changes in CTR and cardiac function were analyzed. Results: Cardiomegaly was observed in 108/437 (24.7%) patients. Multivariate analysis identified type I/II (vs. III) (P = 0.002), lesion diameter >10 cm (P = 0.013), and bone involvement (P = 0.021) as significant risk factors. Abdominopelvic (P <0.001) and thoracic-neck AVMs (P = 0.018) had higher cardiomegaly prevalence than extremity AVMs. Among the 108 patients with cardiomegaly, 84 underwent follow-up chest radiographs. The median CTR reduction rate was 8.9% (interquartile range [IQR] 4.1–15.8), with a significant decrease (P <0.001). Higher angiographic devascularization was associated with greater CTR reductions (P = 0.013). Echocardiography was selectively performed in patients with suspected cardiac involvement. Among 27 patients with both pre- and post-treatment echocardiography, 44% showed functional improvement. Conclusion: AVM type, extent, location, and bone involvement were significant factors influencing cardiomegaly risk. Endovascular treatment was effective in reducing cardiac enlargement and functional improvement was observed in a subset of patients.