Department of Radiology University of Michigan Ann Arbor MI.
Department of Cardiac Surgery University of Michigan Ann Arbor MI.
J Am Heart Assoc. 2024 Oct 15;13(20):e036896. doi: 10.1161/JAHA.124.036896. Epub 2024 Oct 11.
Patients with ascending thoracic aortic aneurysm are recommended to undergo routine imaging surveillance. Although maximal diameter is the primary metric of disease severity, recent American College of Cardiology/American Heart Association guidelines emphasize the importance of aortic growth in determining surgical candidacy and risk. As diameter increases, it is assumed that aortic growth rate accelerates because of increased wall tension; however, this relationship is poorly studied. We aim to investigate the relationship between ascending thoracic aortic aneurysm diameter and growth rate using vascular deformation mapping, a validated technique for 3-dimensional growth mapping with submillimeter accuracy.
We retrospectively identified adult patients with ascending aortic dilation (≥4.0 cm) and serial gated computed tomography angiograms separated by ≥2 years, excluding confirmed heritable thoracic aortic disease. Ascending growth rate was defined as 90th percentile radial wall deformation by vascular deformation mapping. Maximal diameter measurements were derived from the baseline computed tomography angiogram, and aortic length and body size-adjusted indexes were calculated. Among 258 included patients (63.2% men; age of 63 years [interquartile range, 55-69 years]), mean±SD baseline diameter was 46.3±3.6 mm and median growth rate was 0.21 mm/year (interquartile range, 0.13-0.38 mm/year). No correlation was noted between growth rate and baseline diameter (=0.02, =0.74) or other aortic size metrics. On multivariate analysis, age was independently predictive of growth rate (β=-0.007, =0.021), alongside weight (β=0.003, =0.016) and the presence of moderate or severe aortic valve insufficiency (β=0.146, =0.049).
Maximal aortic diameter is not predictive of aortic growth rate, in this contemporary cohort of patients with sizes under current surgical thresholds (<55 mm).
升主动脉瘤患者建议进行常规影像学监测。尽管最大直径是疾病严重程度的主要指标，但最近的美国心脏病学会/美国心脏协会指南强调了主动脉生长在确定手术适应证和风险方面的重要性。随着直径的增加，由于壁张力的增加，假设主动脉生长速度会加快；然而，这种关系研究甚少。我们旨在使用血管变形映射来研究升主动脉瘤直径与生长率之间的关系，血管变形映射是一种具有亚毫米精度的三维生长映射的验证技术。
我们回顾性地确定了升主动脉扩张（≥4.0cm）的成年患者，并进行了≥2 年的系列门控 CT 血管造影检查，排除了确诊的遗传性胸主动脉疾病。升主动脉生长率定义为血管变形映射的 90 百分位径向壁变形。最大直径测量值来自基线 CT 血管造影，计算了主动脉长度和身体大小调整指数。在 258 例纳入患者（63.2%为男性；年龄 63 岁[四分位间距，55-69 岁]）中，平均±SD 基线直径为 46.3±3.6mm，中位数生长率为 0.21mm/年（四分位间距，0.13-0.38mm/年）。生长率与基线直径之间无相关性（r=0.02，P=0.74）或其他主动脉大小指标。多元分析显示，年龄（β=-0.007，P=0.021）、体重（β=0.003，P=0.016）和中度或重度主动脉瓣关闭不全的存在（β=0.146，P=0.049）是生长率的独立预测因素。
在当前手术阈值（<55mm）以下的当代患者队列中，最大主动脉直径不能预测主动脉生长率。
