Long-term cardiovascular outcome of Williams syndrome

Objective Cardiovascular lesions are the leading cause of morbidity and mortality in patients with Williams syndrome. Recent studies have rebutted conventional reports about the natural course of cardiovascular anomalies in Williams syndrome. Design Retrospective study. Setting Single tertiary center. Patients Eighty patients with Williams syndrome followed up for more than 5 years. Interventions Not applicable. Outcome Measures Long-term outcome of cardiovascular lesions, peak velocity change in obstructive cardiovascular lesions over time, post-interventional courses of disease-specific intervention, and intervention-free survival of obstructive cardiovascular lesions. Results The median follow-up duration was 11.0 (5.1-28.3) years. Among 80 patients, supravalvular aortic stenosis (87.5%) was the most common cardiovascular lesion, followed by branch pulmonary stenosis (53.8%), mitral valve prolapse (22.5%), and aortic arch hypoplasia/coarctation (5.0%). During the follow-up period, the peak flow velocity of supravalvular aortic stenosis did not change on peak Doppler echocardiography. Initially, severe supravalvular aortic stenosis was aggravated (P < .027). Conversely, the peak velocity of branch pulmonary stenosis decreased (from 3.08 to 1.65 m/s; P < .001) within age 3.2 (0.4-6.9) years. Even the group with severe branch PS improved over time. Twenty-two patients (27.5%) with Williams syndrome underwent disease-specific interventions without mortality, mostly for supravalvular aortic stenosis or mitral valve prolapse. No patient in the late-onset and initially mild supravalvular aortic stenosis group needed intervention and 37.5%, 48.4%, and 65.1% in initially moderate and severe supravalvular aortic stenosis groups needed intervention at age 5, 10, and 20 years, respectively. Unlike the conventional therapeutic concept, the intervention for branch pulmonary stenosis was almost unnecessary. Conclusions In Williams syndrome, initially severe supravalvular aortic stenosis worsened over time and most branch pulmonary stenoses, including those in the severe group, improved spontaneously. Most patients with branch pulmonary stenosis did not require disease-specific intervention. Surgical repairs for cardiovascular abnormalities in Williams syndrome showed favorable results.