Leow Ryan, Li Tony Yi-Wei, Chan Meei-Wah, Kong William Kf, Poh Kian-Keong, Kuntjoro Ivandito, Sia Ching-Hui, Yeo Tiong-Cheng
Department of Cardiology, National University Heart Centre Singapore, Singapore.
Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
Int J Cardiol Cardiovasc Risk Prev. 2025 Jan 7;24:200366. doi: 10.1016/j.ijcrp.2025.200366. eCollection 2025 Mar.
The severity of mitral stenosis (MS) is commonly assessed using mitral valve area (MVA) measured with transthoracic echocardiography (TTE). The dimensionless index (DI) of mitral valve (MV) was recently studied in degenerative MS. We evaluated DI MV in rheumatic MS and studied its relationship with clinical outcomes.
We studied 406 cases of rheumatic MS in a retrospective single centre cohort study, with 174 in a derivation cohort, 121 in a TTE validation cohort, and 111 in a transoesophageal echocardiography (TEE) validation cohort. DI MV was calculated by dividing the left ventricular outflow tract pulsed-wave Doppler time-velocity integral (TVI) by the MV continuous-wave Doppler TVI. DI MV was compared against MV area using the two-dimensional planimetry, pressure half-time and continuity equation methods, or, in the TEE validation cohort, TEE-derived three-dimensional planimetry. Severe MS was defined as an MV area ≤1.5 cm. Outcomes pertaining to all-cause death and mitral valve intervention were studied in the former two cohorts.
All-in-all, 231 patients (56.9 %) across the three cohorts had severe MS. In the derivation cohort, ROC analysis showed that DI MV could accurately classify MS severity (AUC = 0.838, 95 % CI, 0.780-0.897, < 0.001). DI MV ≤ 0.25 and DI MV ≥ 0.40 had high specificity for identifying severe (93.7 %) and non-severe MS (93.7 %) respectively. In the validation cohorts, these respectively showed similar specificity for identifying severe (93.8 %) and non-severe MS (91.4 %). In the derivation and TTE validation cohorts, the median follow up duration was 6.32 years (interquartile range, 4.22-10.3 years) with 90 deaths (30.5 %) and 50 patients (17.0 %) undergoing MV intervention. DI MV was univariately significant (HR = 0.075, 95 % CI 0.0215-0.378, = 0.002) in Cox regression for a composite outcome of death and MV intervention. DI MV remained independently associated with the composite outcome in multivariate analysis.
DI MV can help rule-in or rule-out severe MS with high specificity, and is independently associated with composite outcomes of death and MV intervention.
二尖瓣狭窄（MS）的严重程度通常采用经胸超声心动图（TTE）测量二尖瓣瓣口面积（MVA）来评估。二尖瓣（MV）的无量纲指数（DI）最近在退行性MS中得到研究。我们评估了风湿性MS中的DI MV，并研究了其与临床结局的关系。
我们在一项回顾性单中心队列研究中纳入了406例风湿性MS患者，其中174例在推导队列，121例在TTE验证队列，111例在经食管超声心动图（TEE）验证队列。DI MV通过左心室流出道脉冲波多普勒时间速度积分（TVI）除以MV连续波多普勒TVI来计算。DI MV与使用二维平面测量法、压力减半时间法和连续方程法测得的MV面积进行比较，或者在TEE验证队列中与TEE衍生的三维平面测量法测得的MV面积进行比较。重度MS定义为MV面积≤1.5 cm²。在前两个队列中研究了全因死亡和二尖瓣干预相关的结局。
总体而言，三个队列中的231例患者（56.9%）患有重度MS。在推导队列中，ROC分析显示DI MV能够准确分类MS严重程度（AUC = 0.838，95% CI，0.780 - 0.897，P < 0.001）。DI MV≤0.25和DI MV≥0.40分别对识别重度（93.7%）和非重度MS（93.7%）具有高特异性。在验证队列中，这些分别对识别重度（93.8%）和非重度MS（91.4%）显示出相似的特异性。在推导队列和TTE验证队列中，中位随访时间为6.32年（四分位间距，4.22 - 10.3年），有90例死亡（30.5%）和50例患者（17.0%）接受了MV干预。在Cox回归分析中，对于死亡和MV干预的复合结局，DI MV具有单变量显著性（HR = 0.075，95% CI 0.0215 - 0.378，P = 0.002）。在多变量分析中，DI MV仍然与复合结局独立相关。
DI MV能够以高特异性帮助确诊或排除重度MS，并且与死亡和MV干预的复合结局独立相关。
