Dataset Information

Aortic valve adaptation to aortic root dilatation: insights into the mechanism of functional aortic regurgitation from 3-dimensional cardiac computed tomography.

ABSTRACT: BACKGROUND:The 3-dimensional relationship between aortic root and cusp is essential to understand the mechanism of aortic regurgitation (AR) because of aortic root dilatation (ARD). We sought to test the hypothesis that the stretched cusps in ARD enlarge to compensate for ARD. METHODS AND RESULTS:Computed tomography imaged 92 patients (57 with ARD, 29 with moderate to severe AR, 28 without significant AR) and 35 normal controls. Specialized 3-dimensional software measured individual cusp surface areas relative to maximal mid-sinus cross-sectional area and minimal 3-dimensional annular area, coaptation area fraction, and asymmetry of sinus volumes and intercommissural distances. Total open cusp surface area increased (P<0.001) from 7.6±1.4 cm(2)/m(2) in normals to 12.9±2.2 cm(2)/m(2) in AR-negative and 15.2±3.3 cm(2)/m(2) in AR-positive patients. However, the ratio of closed cusp surface area to maximal mid-sinus area, reflecting cusp adaptation, decreased from normals to AR-negative to AR-positive patients (1.38±0.20, 1.15±0.15, 0.88±0.15; P<0.001), creating the lowest coaptation area fraction. Cusp distensibility (closed diastolic versus open area) decreased from 20% in controls and AR-negative patients to 5% in AR-positive patients (P<0.001). Multivariate determinants of AR and coaptation area fraction reflected both sinus size and cusp-to-annular adaptation. ARD was also progressively asymmetrical with root size, and individual cusp surface areas failed to match this asymmetry. CONCLUSIONS:Aortic cusp enlargement occurs in ARD, but cusp adaptation and distensibility become limited in prominent, asymmetrical ARD, leading to AR. Optimal AR repair tailored to individual patient anatomy can benefit from appreciating valve adaptation and 3-dimensional relationships; understanding cusp adaptation mechanisms may ultimately provide therapeutic opportunities to improve such compensation.

SUBMITTER: Kim DH

PROVIDER: S-EPMC4373603 | biostudies-literature | 2014 Sep

REPOSITORIES: biostudies-literature

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Aortic valve adaptation to aortic root dilatation: insights into the mechanism of functional aortic regurgitation from 3-dimensional cardiac computed tomography.

Kim Dae-Hee DH Handschumacher Mark D MD Levine Robert A RA Sun Byung Joo BJ Jang Jeong Yoon JY Yang Dong Hyun DH Kang Joon-Won JW Song Jong-Min JM Kang Duk-Hyun DH Lim Tae-Hwan TH Song Jae-Kwan JK

Circulation. Cardiovascular imaging 20140722 5

<h4>Background</h4>The 3-dimensional relationship between aortic root and cusp is essential to understand the mechanism of aortic regurgitation (AR) because of aortic root dilatation (ARD). We sought to test the hypothesis that the stretched cusps in ARD enlarge to compensate for ARD.<h4>Methods and results</h4>Computed tomography imaged 92 patients (57 with ARD, 29 with moderate to severe AR, 28 without significant AR) and 35 normal controls. Specialized 3-dimensional software measured individu ...[more]

PMID: 25051951

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Project description:BackgroundCardiac computed tomography angiography was used to identify anatomical characteristics of the aortic root in patients with severe aortic regurgitation (AR) as compared to those with aortic stenosis (AS) to judge feasibility of transcatheter aortic valve replacement (TAVR) with the JenaValve Trilogy system.MethodsCardiac computed tomography angiography was performed prior to planned TAVR for 107 patients with severe AR and 92 patients with severe AS. Measurements related to aortic root and coronary artery anatomy were obtained and compared between groups. Perimeter >90 mm and aortic annulus angle >70 degrees were defined as the theoretical exclusion criteria for TAVR. A combination of sinus of Valsalva diameter <30 mm and coronary height <12 mm was defined as high risk for coronary occlusion.ResultsThe mean age of patients in the AR group was 74.9 ± 11.2 years, 46% were women, and the mean Society of Thoracic Surgeons risk score for mortality was 3.6 ± 2.1. Comparatively, the mean age of patients in the AS group was 82.3 ± 5.53 years, 65% were women, and the mean Society of Thoracic Surgeonsrisk score was 5.5 ± 3.3. Annulus area, perimeter, diameter, and angle were larger in patients with severe AR. Sinus of Valsalva diameters and heights were larger in patients with severe AR. More AR patients were excluded based on perimeter (14 vs. 2%) and annulus angle (6 vs. 1%). More AS patients exhibited high-risk anatomy for left main coronary occlusion (21 vs. 7%) and right coronary occlusion (14 vs. 3%). The maximum dimension of the ascending aorta was larger in patients with severe AR (39 vs. 35 mm). The percentage of referred AR patients with significant aortopathy requiring surgical intervention was very low (only 1 AR patient with ascending aorta diameter >5.5 cm).ConclusionsA significantly larger proportion of patients with severe AR are excluded from TAVR as compared to AS due to large aortic annulus size and steep annulus angulation. By far the most prevalent excluding factor is aortic annulus size, with fewer patients excluded due to angulation. AR patients have lower-risk anatomy for coronary occlusion. Larger transcatheter valve sizes and further delivery system modifications are required to treat a larger proportion of AR patients.

Dataset Information

Aortic valve adaptation to aortic root dilatation: insights into the mechanism of functional aortic regurgitation from 3-dimensional cardiac computed tomography.

Publications

Aortic valve adaptation to aortic root dilatation: insights into the mechanism of functional aortic regurgitation from 3-dimensional cardiac computed tomography.

Similar Datasets

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