目的:目前对二尖瓣环分离(MAD)作为一种可能与室性心律失常相关的解剖学异常的认识引发了关于其患病率和临床意义的争议。本研究旨在使用增强心脏CT来调查无明显结构异常的个体中MAD的患病率和程度。在探索潜在因素的同时,比如年龄,这可能与MAD有关。
方法:回顾性纳入742名受试者的心脏CT收缩数据集。通过围绕二尖瓣环的中心轴旋转正交多平面重建图像来确定MAD。最大分离距离(DMAD)和所涉及的段(SI,对左心室壁的0至5个基底段)进行定量以评估分离程度。
结果:总计,449(60.5%)患有MAD。MAD患者年龄明显较大(51.3±19.9岁与29.6±20.3年,P<0.001)。年龄是MAD的独立相关因素(OR=1.059;95CI:1.033,1.085;P<0.001)。然后将MAD受试者分为4个亚组(G1:≤20岁,G2:21-40年,G3:41-60岁,G4:≥61岁)。每个年龄亚组的DMAD和SI为1.9±0.2mm,2.0±1.2(G1,n=36),2.7±0.8mm,2.9±1.3(G2,n=51),3.0±0.8mm,3.0±1.3(G3,n=183),和3.0±1.0毫米,3.7±1.1(G4,n=179)。年龄是DMAD的独立相关因素(R2=0.132;β=0.014;95CI:0.004,0.024;P=0.007)和SI(OR=1.030;95CI:1.005,1.055;P=0.016)。
结论:MAD是心脏CT的常见发现。其患病率和程度随年龄增长而增加。
OBJECTIVE: The current recognition of mitral annular disjunction (MAD) as an anatomical abnormality potentially associated with ventricular arrhythmias has sparked controversy regarding its prevalence and clinical implications. This study aimed to investigate the prevalence and extent of MAD in individuals with no significant structural abnormalities involving the left heart using enhanced cardiac CT, while also exploring potential factors, such as age, that may be associated with MAD.
METHODS: Systolic datasets of cardiac CT from 742 subjects were retrospectively included. MAD was determined by rotating orthogonal multiplanar reconstruction images around the central axis of the mitral annulus. The maximal distance of disjunction (DMAD) and segments involved (SI, 0 to 5 basal segments at left ventricular wall) was quantified to evaluate the extent of separation.
RESULTS: In total, 449 (60.5%) had MAD. Subjects with MAD were significantly older (51.3 ± 19.9 years vs. 29.6 ± 20.3 years, P < 0.001). Age was found to be an independent relevant factor for MAD (OR = 1.059; 95%CI: 1.033, 1.085; P < 0.001). Subjects with MAD were then divided into 4 subgroups (G1: ≤20 years, G2: 21-40 years, G3: 41-60 years, G4: ≥61 years). DMAD and SI of each age subgroup were 1.9 ± 0.2 mm, 2.0 ± 1.2 (G1, n = 36), 2.7 ± 0.8 mm, 2.9 ± 1.3 (G2, n = 51), 3.0 ± 0.8 mm, 3.0 ± 1.3 (G3, n = 183), and 3.0 ± 1.0 mm, 3.7 ± 1.1 (G4, n = 179). Age was an independent relevant factor associated with DMAD (R2 = 0.132; β = 0.014; 95%CI: 0.004, 0.024; P = 0.007) and SI (OR = 1.030; 95%CI: 1.005, 1.055; P = 0.016).
CONCLUSIONS: MAD is a common finding on cardiac CT. Its prevalence and extent increase with age.