Natural History of Scimitar Syndrome Patients

Study Questions:

What is the natural history of the scimitar syndrome (SS), and the efficacy of surgical treatment in terms of survival and clinical status?


The investigators collected data on 485 SS patients from 51 institutions; 279 (57%) patients were treated surgically (STPs) and 206 (43%) were clinically monitored (CMPs). Survival curves were calculated with the Kaplan-Meier method, and difference in survival probability by the log-rank test.


Median age at last follow-up was 11.6 years (interquartile range, 4-22 years). Overall survival probability at 30 years of age was 88% (85-92% confidence intervals [CIs]), and was lower in patients with associated congenital heart disease (CHD) (p < 0.001) and pulmonary hypertension (p < 0.001). Most patients were asymptomatic at last follow-up (279/451, 62%); STPs were more frequently asymptomatic than CMPs (73% vs. 47%, p < 0.001), with fewer cardiac (odds ratio [OR], 0.42; 95% CI, 0.22-0.82) and respiratory symptoms (OR, 0.08; 95% CI, 0.02-0.28). Many STPs (63/254, 25%) had stenosis/occlusion of the scimitar drainage, and this was associated with a younger age at surgery (OR, 0.4; 95% CI, 0.21-0.78).


The authors concluded that patients with SS have a high overall survival, but survival probability was lower in patients with associated CHDs and in patients with pulmonary hypertension.


This cohort study reports that while the overall survival rate of patients with SS is high, survival probability is lower in patients with associated CHDs and in patients with pulmonary hypertension. Surgical repair is indicated in symptomatic patients and in those with significantly increased pulmonary blood flow. Asymptomatic patients should have comprehensive hemodynamic evaluation, and surgical redirection should be considered only when the scimitar drainage causes considerable pulmonary overload (Qp:Qs > 1.5:1). Continuous clinical and noninvasive monitoring (with magnetic resonance imaging) is indicated to identify clinical or physiological changes in order to administer timely treatment and to check postoperative outcomes.

Clinical Topics: Cardiac Surgery, Congenital Heart Disease and Pediatric Cardiology, Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Pulmonary Hypertension and Venous Thromboembolism, Vascular Medicine, Cardiac Surgery and CHD and Pediatrics, Cardiac Surgery and Heart Failure, Congenital Heart Disease, CHD and Pediatrics and Imaging, CHD and Pediatrics and Interventions, Pulmonary Hypertension, Interventions and Imaging, Interventions and Structural Heart Disease, Interventions and Vascular Medicine, Magnetic Resonance Imaging

Keywords: Cardiac Surgical Procedures, Constriction, Pathologic, Coronary Stenosis, Heart Defects, Congenital, Hemodynamics, Hypertension, Pulmonary, Magnetic Resonance Imaging, Scimitar Syndrome, Survival Rate

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