Division of Cardiology, Pulmunology and Vascular Medicine, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany.
Philips Healthcare, Hamburg, Germany.
Int J Cardiol. 2018 Sep 1;266:262-268. doi: 10.1016/j.ijcard.2018.02.029.
Patients with severe aortic stenosis (AS) are subjected to left ventricular hypertrophy (LVH) with increasing morbidity and mortality. Transcatheter aortic valve replacement (TAVR) induces reverse left ventricular remodeling which can be monitored by cardiovascular magnetic resonance (CMR). CMR is able to analyze myocardial tissue properties by magnetic relaxation times (parametric CMR). The objective of this study was to study myocardial T2 relaxation in reverse ventricular remodeling after TAVR.
Forty-three patients with severe AS (19 males, 81.9 ± 4.9 years) underwent CMR with T2 mapping before and 6 months after TAVR. A cohort of age- and gender-matched volunteers served as controls. Analyzed parameters included left ventricular ejection fraction (LV-EF), mass indexed to body surface area (LVMi), interventricular septum thickness (IVS), end-diastolic volume (LVEDV), global longitudinal strain (GLS), peak diastolic strain rate (SRe) and myocardial T2 values.
CMR characteristics for patients with AS displayed LVH concomitant to elevated myocardial T2 values, reduced GLS and SRe. Patients with T2 values above 70.2 ms at baseline were characterized by eccentric hypertrophy with reduced LV-EF. T2 values decreased after TAVR (67.4 ± 3.4 to 63.3 ± 4.2 ms, p < 0.01) during left ventricular remodeling. Patients with T2 values above 70.2 ms at baseline exhibited pronounced reverse remodeling which proved to be a significant predictor of LV-EF improvement and LVEDV reduction in uni- and multivariate analyses.
Multiparametric CMR can be used to characterize myocardial hypertrophy due to severe AS and to monitor myocardial adaptations after TAVR. It may provide additional information in the prediction of left ventricular remodeling after TAVR.
严重主动脉瓣狭窄（AS）患者会出现左心室肥厚（LVH），导致发病率和死亡率增加。经导管主动脉瓣置换术（TAVR）可诱导逆向左心室重构，这可以通过心血管磁共振（CMR）进行监测。CMR 能够通过磁共振弛豫时间（参数 CMR）分析心肌组织特性。本研究的目的是研究 TAVR 后逆向心室重构时心肌 T2 弛豫。
43 例严重 AS 患者（男 19 例，年龄 81.9±4.9 岁）在 TAVR 前后 6 个月进行 CMR 检查和 T2 映射。年龄和性别匹配的志愿者队列作为对照组。分析参数包括左心室射血分数（LV-EF）、体表面积校正的左心室质量指数（LVMi）、室间隔厚度（IVS）、舒张末期容积（LVEDV）、整体纵向应变（GLS）、舒张末期峰值应变率（SRe）和心肌 T2 值。
AS 患者的 CMR 特征表现为 LVH 伴心肌 T2 值升高、GLS 和 SRe 降低。基线 T2 值高于 70.2ms 的患者表现为偏心性肥厚，LV-EF 降低。TAVR 后 T2 值降低（67.4±3.4 至 63.3±4.2ms，p<0.01），左心室重构期间。基线 T2 值高于 70.2ms 的患者表现出明显的逆向重构，这在单变量和多变量分析中均被证明是 LV-EF 改善和 LVEDV 减少的显著预测因素。
多参数 CMR 可用于描述严重 AS 导致的心肌肥厚，并监测 TAVR 后的心肌适应。它可能为 TAVR 后左心室重构的预测提供额外信息。
