Heart and Vascular Institute, University of Pittsburgh, 200 Lothrop Str. PUH B535 Pittsburgh, PA, USA.
Europace. 2017 Oct 1;19(10):1689-1694. doi: 10.1093/europace/euw323.
Patients with non-ischaemic cardiomyopathy (NICM) and left bundle-branch block (LBBB) often benefit markedly from cardiac resynchronization therapy (CRT). Cardiac resynchronization therapy responders have a lower risk of appropriate device shocks from CRT-defibrillators (CRT-D) than do non-responders. Larger baseline left ventricular (LV) dimensions may be associated with less CRT response and thus greater risk of appropriate shocks.
We analysed all (n = 249; 55% female) primary prevention CRT-D recipients at our institution with LBBB, NICM, and measured LV dimensions prior to device implant for the outcomes of (i) appropriate shocks, (ii) any appropriate tachyarrhythmia therapies, and (iii) risk of death, transplant, or left ventricular assist device (LVAD). During 59 months (interquartile range 21.5-91.5) follow-up, 19 (8%) patients received ≥1 appropriate shock, and 67 (27%) patients died, received a transplant, or required LVAD. Receiver-operating characteristic analysis of LV end-diastolic diameter (LVEDD) per meter height vs. appropriate shock(s) revealed an area under the curve of 0.75 (95% CI 0.65-0.85; P < 0.001). No patient with indexed LVEDD <3.36 cm/m (n = 76) received a shock. There was no statistically significant difference in risk of death, transplant, or LVAD (corrected HR 1.67, 95% CI 0.90-3.03; P = 0.103) in patients with indexed LVEDD above this cut-off compared to those with smaller dimension. Among 102 patients with paired quantitative echocardiograms, there was no difference in LVEF change between patients with indexed LVEDD <3.36 cm/m (n = 27; median 11%) and larger (n = 75; median 14%).
Patients with LVEDD <3.36 cm/m height prior to CRT-D implant in the setting of NICM and LBBB have minimal risk of appropriate shocks but similar risk of death, transplant- and LVAD and similar extent of LV functional improvement as patients with larger LVEDD. CRT-pacemakers may be appropriate in such patients.
患有非缺血性心肌病（NICM）和左束支传导阻滞（LBBB）的患者通常从心脏再同步治疗（CRT）中显著获益。与非应答者相比，心脏再同步治疗除颤器（CRT-D）的 CRT 应答者发生适当设备电击的风险较低。较大的基线左心室（LV）尺寸可能与 CRT 反应较差相关，因此发生适当电击的风险更高。
我们分析了我们机构中所有（n=249；55%为女性）患有 LBBB、NICM 的原发性预防 CRT-D 接受者，在植入设备之前测量 LV 尺寸，以评估以下结局：（i）适当电击；（ii）任何适当的心动过速治疗；（iii）死亡、移植或左心室辅助装置（LVAD）的风险。在 59 个月（四分位距 21.5-91.5）的随访期间，19 名（8%）患者接受了≥1 次适当电击，67 名（27%）患者死亡、接受了移植或需要 LVAD。LV 舒张末期直径（LVEDD）与身高的受试者工作特征分析与适当电击（s）的结果显示，曲线下面积为 0.75（95%CI 0.65-0.85；P<0.001）。在 LVEDD<3.36cm/m（n=76）的患者中，没有患者接受电击。在 LVEDD 高于该截点的患者与较小尺寸的患者相比，死亡、移植或 LVAD 的风险无统计学差异（校正 HR 1.67，95%CI 0.90-3.03；P=0.103）。在 102 名具有配对定量超声心动图的患者中，LVEDD<3.36cm/m（n=27；中位数 11%）和较大（n=75；中位数 14%）患者的 LVEF 变化无差异。
在 NICM 和 LBBB 的背景下，植入 CRT-D 前 LVEDD<3.36cm/m 的患者发生适当电击的风险极小，但死亡、移植和 LVAD 的风险以及 LV 功能改善的程度与 LVEDD 较大的患者相似。在这种情况下，CRT 起搏器可能是合适的。
