Association Between Bicuspid Aortic Valve Raphe Morphology and Aortopathy Phenotype.
Maude Pagé, Maxime Laflamme, Omar Nawaytou, Laurent de Kerchove, Gébrine EL-Khoury, Jean-Louis Vanoverschelde
Hôpital Sacré-Coeur de Montréal, Montreal, Canada, Cliniques Saint-Luc, Brussels, Belgium and Institut Universitaire de Cardiologie et Pneumologie de Québe, Quebec, Canada
Background: Heterogeneity of bicuspid aortic valve (BAV) disease is increasingly recognized and pathophysiology of aortopathy remains debated. Recent data suggest that valve-related hemodynamics mediate BAV aortopathy via increased shear stress and altered aortic wall matrix architecture. On the other hand, BAV classifications are currently reconsidered to account for the wide spectrum of phenotypes and to tailor surgical approaches. How these newly described phenotypes relate to BAV aortopathy is poorly documented.
Objectives: To assess whether BAV phenotype, according to a new classification based on raphe presence and morphology, was associated with specific dilatation patterns.
Methods: 86 consecutive BAV patients undergoing valve-sparing surgery for aortic regurgitation and/or aneurysm at our institution were included (76 males; mean age 43 ± 12 years). BAV were classified according to the absence (type 0) or presence of a complete (type 1A) or incomplete/restrictive (type 1B) raphe on pre-operative transoesophageal echocardiography.
Results: Eleven patients had a type 0 BAV; 7 had antero-posterior orientation of the free edges and 4 had a right-left orientation. A complete raphe (type 1A) was identified in 57 patients; an incomplete, restrictive raphe (1B) was identified in 18. The indexed diameters of the ventriculo-aortic junction (VAJ), sinuses of Valsalva (SOV) and sino-tubular junction (STJ) were significantly larger among type 0 compared to types 1A and 1B (VAJ 16.1±1.5 vs. 14.4±1.9mm/m2, p=0.009; SOV 22.3±2.4 vs. 19.3±2.3mm/m2, p<0.001; STJ 19.4±4.3 vs. 16.9±2.8mm/m2 ,p=0.013; proximal ascending aorta 19.3±4.3 vs. 18.8±3.7mm/m2, p=0.72). Aortic phenotypes were divided into three clusters: A: Diameter of the ascending aorta (DASC)>DSOV>DSTJ; B: DSOV³DASC and DSOV>DSTJ; C: DSOV£DSTJ. Distribution of the aortic patterns is shown in Figure (p<0.001 for comparison across groups).
Conclusions: When classified according to raphe presence and morphology, BAV phenotypes seem to be associated with distinct aortic dilatation patterns. Type 0 are more frequently associated with large VAJ and SOV. Investigation into dynamic flow patterns according to this repair-oriented BAV classification would allow further understanding of BAV aortopathy and perhaps better risk-stratification to guide aortic intervention.