title: Shone Complex: An Under-recognized Congenital Heart Disease With Substantial Morbidity in Adulthood.
abstract: Shone complex consists of a constellation of left-sided, usually obstructive, cardiac lesions, including supravalvar mitral ring, parachute mitral valve, subaortic stenosis, and aortic coarctation. Incomplete Shone complex consists of a mitral valve anomaly associated with lesions involving the subaortic region, aortic valve, or thoracic aorta. There is a paucity of data regarding long-term outcomes in adults with Shone complex.
  
  
  
  We reviewed records of adults with complete or incomplete Shone complex followed at the Montreal Heart Institute between 1982 and 2014.
  
  
  
  Among 4189 adults with congenital heart disease, 28 (0.67%) patients (mean age, 35 ± 11 years; 50% women) had complete or incomplete Shone complex and were followed for a median of 8 years. Only 39% were previously diagnosed as having Shone complex. The most common defects were congenital mitral stenosis (93%), aortic coarctation (75%), and bicuspid aortic valve (71%). Heart transplantation was required in 2 patients (7.1%) at age 22 and 28 years, respectively. Overall, 48% had cardiovascular hospitalizations during adulthood, predominantly for arrhythmias or heart failure. Freedom from cardiovascular intervention was 55%, 18%, and 8% at 10, 20, and 30 years of age, respectively. Although aortic coarctation was the most common indication for initial intervention (61%), adult interventions occurred predominantly for aortic valve/left ventricular outflow tract (60%) and mitral valve (33%) lesions.
  
  
  
  Shone complex is an under-recognized entity associated with relatively low mortality in adulthood but substantial morbidity related to arrhythmias, heart failure, and interventions. Increased awareness of this condition and associated complications may allow for more tailored follow-up.
authors.affiliation: Adult Congenital Heart Center, Montreal Heart Institute, Université de Montréal, Montréal, Québec, Canada; Manchester Royal Infirmary, Manchester, United Kingdom.
authors.forename: Sajid
authors.initials: S
authors.lastname: Aslam
authors.affiliation: Adult Congenital Heart Center, Montreal Heart Institute, Université de Montréal, Montréal, Québec, Canada.
authors.forename: Paul
authors.initials: P
authors.lastname: Khairy
authors.affiliation: Biostatistics Department, Montreal Health Innovation Coordinating Center, Montréal, Québec, Canada.
authors.forename: Azadeh
authors.initials: A
authors.lastname: Shohoudi
authors.affiliation: Adult Congenital Heart Center, Montreal Heart Institute, Université de Montréal, Montréal, Québec, Canada.
authors.forename: Lise-Andrée
authors.initials: LA
authors.lastname: Mercier
authors.affiliation: Adult Congenital Heart Center, Montreal Heart Institute, Université de Montréal, Montréal, Québec, Canada.
authors.forename: Annie
authors.initials: A
authors.lastname: Dore
authors.affiliation: Adult Congenital Heart Center, Montreal Heart Institute, Université de Montréal, Montréal, Québec, Canada.
authors.forename: François
authors.initials: F
authors.lastname: Marcotte
authors.affiliation: Adult Congenital Heart Center, Montreal Heart Institute, Université de Montréal, Montréal, Québec, Canada.
authors.forename: Joaquim
authors.initials: J
authors.lastname: Miró
authors.affiliation: Adult Congenital Heart Center, Montreal Heart Institute, Université de Montréal, Montréal, Québec, Canada; Department of Cardiology, Instituto de Investigación Sanitaria, Hospital Gregorio Marañón, Universidad Complutense, Madrid, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Avila-Alonso
authors.affiliation: Adult Congenital Heart Center, Montreal Heart Institute, Université de Montréal, Montréal, Québec, Canada.
authors.forename: Réda
authors.initials: R
authors.lastname: Ibrahim
authors.affiliation: Adult Congenital Heart Center, Montreal Heart Institute, Université de Montréal, Montréal, Québec, Canada.
authors.forename: Anita
authors.initials: A
authors.lastname: Asgar
authors.affiliation: Adult Congenital Heart Center, Montreal Heart Institute, Université de Montréal, Montréal, Québec, Canada.
authors.forename: Nancy
authors.initials: N
authors.lastname: Poirier
authors.affiliation: Adult Congenital Heart Center, Montreal Heart Institute, Université de Montréal, Montréal, Québec, Canada. Electronic address: francois.pierre.mongeon@umontreal.ca.
authors.forename: François-Pierre
authors.initials: FP
authors.lastname: Mongeon
mesh_terms: D000015:Abnormalities, Multiple; D000328:Adult; D001017:Aortic Coarctation / Q000175:diagnosis* / Q000453:epidemiology; D001021:Aortic Valve / Q000002:abnormalities*; D001024:Aortic Valve Stenosis / Q000151:congenital / Q000175:diagnosis* / Q000453:epidemiology; D000082882:Bicuspid Aortic Valve Disease; D003951:Diagnostic Errors / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D006330:Heart Defects, Congenital / Q000175:diagnosis* / Q000453:epidemiology; D006349:Heart Valve Diseases / Q000151:congenital / Q000175:diagnosis* / Q000453:epidemiology; D006801:Humans; D008297:Male; D008946:Mitral Valve Stenosis / Q000151:congenital / Q000175:diagnosis* / Q000453:epidemiology; D009017:Morbidity / Q000639:trends; D011792:Quebec / Q000453:epidemiology; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends; D013997:Time Factors