Risk Factors for Left Ventricular Dysfunction Following Surgical Management of Cardiac Fibroma

Background: Surgical resection of cardiac fibromas in children reduces hemodynamic and arrhythmia burden; however, little is known about postoperative left ventricular (LV) function. We aimed to evaluate factors associated with postoperative LV dysfunction. Methods: In this retrospective observational cohort study, imaging data were reviewed from 41 patients who had undergone surgical resection of a cardiac fibroma. Tumor volume was indexed to body surface area (tumor volume index). Right ventricular tumors were excluded from analysis of postoperative ventricular function. Postoperative regional wall motion abnormality score was defined as number of wall segments with regional wall motion abnormality, and LV dysfunction was defined as LV ejection fraction <50%. Cardiovascular magnetic resonance-derived strain was low if <5%ile by previously published normative data. Results: Of 41 patients who underwent resection at a median age of 2.1 years (range, 0.5–19), 37 fibromas were in the LV, (29 free wall and 8 septal), and 4 in the right ventricle. Preoperative median tumor volume index was 66 mL/m 2 (range, 11–376). Of 37 patients with LV tumors, younger patients had larger tumor volume index and higher grades of preoperative mitral regurgitation ( P <0.001). Larger tumor volume index correlated with higher postoperative regional wall motion abnormality score ( P <0.001). By paired pre- and post-operative cardiovascular magnetic resonance (n=14), LV end-diastolic volume increased (mean 76 versus 101 mL/m 2 , P =0.011), with decreased LV ejection fraction (mean 60% versus 55%, P =0.014), a higher prevalence of low global circumferential strain (36% versus 64%, P =0.045), and decreased cardiac index (mean 4.8 versus 3.9 L/min·m 2 , P =0.039). More than mild preoperative mitral regurgitation was the only independent predictor of predischarge LV dysfunction (odds ratio, 22 95% CI, 2.8–179, P =0.008). Conclusions: Surgical resection of LV fibroma is associated with regional wall motion abnormality, increased LV volume, and reduced systolic function. Children with significant preoperative mitral regurgitation are at highest risk for LV dysfunction and warrant ongoing close surveillance.