Cardiovascular Division, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA.
Eur Heart J. 2011 Jul;32(14):1720-9. doi: 10.1093/eurheartj/ehr185. Epub 2011 May 24.
To assess long-term effects of cardiac resynchronization therapy (CRT) on left ventricular (LV) dyssynchrony and contractile function, by two-dimensional speckle-tracking echocardiography, compared with implantable cardioverter defibrillator (ICD) only in MADIT-CRT.
We studied 761 patients in New York Heart Association I/II, ejection fraction ≤30%, and QRS ≥130 ms [n = 434, CRT-defibrillator (CRT-D), n = 327, ICD] with echocardiographic studies available at baseline and 12 months. Dyssynchrony was determined as the standard deviation of time to peak transverse strain between 12 segments of apical four- and two-chamber views, and contractile function as global longitudinal strain (GLS) by averaging longitudinal strain over these 12 segments. We compared changes in LV dyssynchrony and contractile function between treatment groups and assessed relationships between these changes over the first year and subsequent outcomes (median post 1-year follow-up = 14.9 months). Mean changes in LV dyssynchrony and contractile function measured by GLS in the overall population were, respectively, -29 ± 83 ms and -1 ± 2.9%. However, both LV dyssynchrony (CRT-D: -47 ± 83 ms vs. ICD: -6 ± 76 ms, P < 0.001) and contractile function (CRT-D: -1.4 ± 3.1% vs. ICD: -0.4 ± 2.5%, P < 0.001) improved to a greater extent in the CRT-D group compared with the ICD-only group. A greater improvement in dyssynchrony and contractile function at 1 year was associated with lower rates of the subsequent primary outcome of death or heart failure, adjusting for baseline dyssynchrony and contractile function, treatment arm, ischaemic status, and change in LV end-systolic volume. Each 20 ms decrease in LV dyssynchrony was associated with a 7% reduction in the primary outcome (P = 0.047); each 1% improvement in GLS over the 12-month period was associated with a 24% reduction in the primary outcome (P < 0.001).
Cardiac resynchronization therapy resulted in a significant improvement in both LV dyssynchrony and contractile function measured by GLS compared with ICD only and these improvements were associated with better subsequent outcomes.
通过二维斑点追踪超声心动图评估心脏再同步治疗（CRT）对左心室（LV）不同步和收缩功能的长期影响，并与植入式心脏复律除颤器（ICD）进行比较，该研究来自 MADIT-CRT 试验。
我们研究了 761 名纽约心脏协会 I/II 级、射血分数≤30%和 QRS 波≥130 ms 的患者[n = 434，CRT-除颤器（CRT-D），n = 327，ICD]，这些患者在基线和 12 个月时均有超声心动图研究资料。通过心尖四腔和两腔视图的 12 个节段的横向应变达峰时间的标准差来确定不同步，通过对这 12 个节段的纵向应变进行平均来确定收缩功能（GLS）。我们比较了两组间 LV 不同步和收缩功能的变化，并评估了第一年的这些变化与随后的结局（中位随访时间为 1 年后 14.9 个月）之间的关系。整个研究人群中，GLS 测量的 LV 不同步和收缩功能的平均变化分别为-29 ± 83 ms 和-1 ± 2.9%。然而，与 ICD 相比，CRT-D 组的 LV 不同步（CRT-D：-47 ± 83 ms 与 ICD：-6 ± 76 ms，P < 0.001）和收缩功能（CRT-D：-1.4 ± 3.1% 与 ICD：-0.4 ± 2.5%，P < 0.001）改善更为明显。与 CRT-D 组相比，1 年内不同步和收缩功能改善更大与随后主要结局（死亡或心力衰竭）的发生率较低相关，该结局与基线不同步和收缩功能、治疗组、缺血状态和 LV 收缩末期容积变化相关。LV 不同步减少 20 ms 与主要结局降低 7%相关（P = 0.047）；12 个月期间 GLS 每增加 1%与主要结局降低 24%相关（P < 0.001）。
与单纯 ICD 相比，心脏再同步治疗可显著改善 LV 不同步和 GLS 测量的收缩功能，这些改善与随后更好的结局相关。
