Heart and Vascular Institute, University of Pittsburgh, Pittsburgh, PA 15213-2582, USA.
Circ Heart Fail. 2013 Jul;6(4):685-93. doi: 10.1161/CIRCHEARTFAILURE.112.000112. Epub 2013 Jun 3.
Mechanisms of mitral regurgitation (MR) reduction with cardiac resynchronization therapy (CRT) are complex, and their association with long-term outcome is unclear. We sought to elucidate mechanistic features of reduction in MR with CRT, which impact long-term patient survival.
A prospective longitudinal study of 277 patients with heart failure with QRS width ≥ 120 ms and ejection fraction ≤ 35% for CRT was performed. Quantitative echocardiography, including dyssynchrony analysis, was performed at baseline. MR was quantified by color Doppler before and 6 months after CRT. Predefined end points of death, transplant, or left ventricular assist device were tracked during 4 years. There were 114 (48%) patients with CRT with significant MR (≥ moderate) at baseline; of whom 48 (42%) patients had MR improvement, and 24 (19%) patients had MR worsening after CRT. The 66 events (47 deaths, 10 transplantations, and 9 left ventricular assist devices) were strongly associated with significant MR after CRT (hazard ratio, 3.58; 95% confidence interval, 2.18-5.87; P<0.0001). Three echocardiographic features were independently associated with amelioration of significant MR after CRT by multivariable analysis: anteroseptal to posterior wall radial strain dyssynchrony >200 ms, lack of severe left ventricular dilatation (end-systolic dimension index <29 mm/m(2)), and lack of echocardiographic scar at papillary muscle insertion sites (all P<0.05) and, when combined, were additively associated with long-term survival (P=0.0001).
Significant MR after CRT was strongly associated with less favorable long-term survival. Echocardiographic mechanistic features were identified that were associated with improvement in MR after CRT and favorable long-term survival.
心脏再同步治疗（CRT）减少二尖瓣反流（MR）的机制很复杂，其与长期预后的关系尚不清楚。我们旨在阐明 CRT 减少 MR 的机制特征，这些特征会影响患者的长期生存。
对 277 例 QRS 宽度≥120ms 且射血分数≤35%的心力衰竭患者进行了前瞻性纵向研究，这些患者适合 CRT。在基线时进行了定量超声心动图检查，包括对不同步性进行分析。在 CRT 前和 CRT 后 6 个月使用彩色多普勒评估 MR。在 4 年内跟踪死亡、移植或左心室辅助装置的预定终点。基线时有 114 例（48%）患者的 CRT 伴中重度以上的 MR；其中 48 例（42%）患者的 MR 改善，24 例（19%）患者的 MR 恶化。66 例事件（47 例死亡、10 例移植、9 例左心室辅助装置）与 CRT 后严重 MR 密切相关（危险比，3.58；95%置信区间，2.18-5.87；P<0.0001）。多变量分析显示，3 种超声心动图特征与 CRT 后 MR 改善独立相关：前间隔至后间隔径向应变不同步性>200ms、无严重左心室扩张（收缩末期内径指数<29mm/m2）和心肌乳头肌插入部位无超声心动图瘢痕（均 P<0.05），当这些因素结合时，与长期生存呈累加相关（P=0.0001）。
CRT 后严重的 MR 与预后较差的长期生存密切相关。确定了与 CRT 后 MR 改善和良好的长期生存相关的超声心动图机制特征。
