Rationale and design of GISSI OUTLIERS VAR Study in bicuspid aortic valve patients: Prospective longitudinal, multicenter study to investigate correlation between surgical, echo distinctive features, histologic and genetic findings in phenotypically homogeneous outlier cases

Background/objectives Bicuspid aortic valve (BAV) is the most common congenital heart disorder, affecting up to 2% of the population. Involvement of aortic root and ascending aorta (aneurysm or, eventually, dissection) is frequent in patients with pathologic or normal functioning BAV. Unfortunately, there are no well-known correlations between valvular and vascular diseases. In VAR protocol, with a new strategy of research, we analysemultiple aspects of BAV disease through correlation between surgical, echo, histologic and genetic findings in phenotypically homogeneous outlier cases. Methods VAR protocol is a prospective, longitudinal, multicenter study. It observes 4 homogeneous small groups of BAV surgical patients (15 patients each): isolated aortic regurgitation, isolated ascending aortic aneurysm, aortic regurgitation associated with aortic aneurysm, isolated aortic stenosis in older patients (> 60 years). Echo analysis is extended to first-degree relatives and, in case of BAV, genetic test is performed. Patients and relatives are enrolled in 10 cardiac surgery/cardiologic centers throughout Italy. Conclusions The aim of the study is to identify predictors of favorable or unfavorable evolution of BAV in terms of valvular dysfunction and/or aortic aneurysm. Correlations between different features could help in identification of various BAV risk groups, rationalizing follow-up and treatment.