Aortopathy in Bicuspid vs. Tricuspid Aortic Valve Stenosis

Study Questions:

Are there differences in aortopathy in patients undergoing aortic valve replacement with bicuspid versus tricuspid aortic valves?

Methods:

This study examined 190 consecutive patients <70 years of age with aortic stenosis undergoing elective aortic valve replacement; patients with more than mild aortic regurgitation were excluded. Aortic valve morphology, aortic size, histology at the site of the stenotic jet, and functional aortic root parameters were compared.

Results:

Cohorts were similar in regard to age, gender, and body surface area. Bicuspid and tricuspid aortic valves were observed in 137 and 53 patients, respectively. Of bicuspid valve patients, 99 had left/right cusp fusion, while 38 had right/noncoronary cusp fusion; there were no patients with left/noncoronary cusp fusion or patients with a true bicuspid valve. Patients with a bicuspid valve had larger diameters for the annulus, sinus, sinotubular junction, and mid ascending aorta (p < 0.05 for each). A phenotype of mid-ascending aorta dilatation was more common in the bicuspid valve cohort (45% vs. 21%, p = 0.03). There were no significant differences in between groups in the histologic scores at sites where the jet hit the aorta or at control sites. On multivariable analysis, the left ventricle/aorta angle (p = 0.02) and jet/aorta angle (p = 0.01) were each independently associated with increased aorta diameter, while a bicuspid versus tricuspid morphology was not (p = 0.7).

Conclusions:

Younger patients with bicuspid aortic valves undergoing valve replacement for aortic stenosis have increased rates of ascending aorta dilatation, which appears related to functional aortic root parameters rather than the presence of a bicuspid aortic valve.

Perspective:

These results suggest that the ascending aorta dilatation commonly seen in patients with bicuspid aortic valve stenosis may be due to the left ventricle/aorta and jet/aorta angles rather than the number of functional cusps. These data are interesting, and are supported by the lack of histologic differences between cohorts at the site of the aorta hit by the stenotic jet. This study finds that aortic dilatation may be predominantly related to the altered hemodynamics associated with bicuspid aortic valves. However, the sample size was small, which limits our ability to draw strong conclusions. Further, the study did not find any patients with a true bicuspid valve, so it is unclear whether these findings would apply to this population.

Clinical Topics: Cardiac Surgery, Congenital Heart Disease and Pediatric Cardiology, Invasive Cardiovascular Angiography and Intervention, Valvular Heart Disease, Aortic Surgery, Cardiac Surgery and CHD & Pediatrics, Cardiac Surgery and VHD, Congenital Heart Disease, CHD & Pediatrics and Interventions, Interventions and Structural Heart Disease

Keywords: Aorta, Aortic Valve Insufficiency, Aortic Valve Stenosis, Bicuspid, Body Surface Area, Cardiac Surgical Procedures, Constriction, Pathologic, Dilatation, Heart Defects, Congenital, Heart Valve Diseases, Mitral Valve, Phenotype, Transcatheter Aortic Valve Replacement, Tricuspid Valve


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