Goldberg Adam S, Alraies M Chadi, Cerqueira Manuel D, Jaber Wael A, Aljaroudi Wael A
Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH, USA.
J Nucl Cardiol. 2014 Feb;21(1):57-66. doi: 10.1007/s12350-013-9787-y. Epub 2013 Oct 4.
Left ventricular mechanical dyssynchrony (LVMD) by phase analysis of gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) is a useful tool for predicting response to cardiac resynchronization therapy and has prognostic value. While most of the studies were done on patients with ischemic cardiomyopathy or those with LV ejection fraction (EF) < 35%, there are little data on the prognostic value of LVMD in patients with non-ischemic cardiomyopathy (NICM), particularly those with mildly decreased systolic function and narrow or intermediate QRS duration.
From the stress SPECT-MPI database at Cleveland Clinic, we identified 324 consecutive patients (mean age 62 ± 13 years, 62% male, 36% diabetics) with NICM, LVEF 35-50% (median [Q1,Q3] 45 [41,49]), and QRS < 150 ms (13% with QRS 120-149 ms). LVMD was determined from gated stress images and expressed as phase standard deviation (SD) and histogram BW (% R-R cycle). For easier graphical illustration, patients were divided into tertiles of LVMD. All-cause death was the primary endpoint and determined using the Social Security Death Index. Cox proportional hazard model was performed to determine the independent predictive value of LVMD, and next Cox models for incremental value. After a mean follow-up time of 1,689 days, 86 (26.5%) of patients died. These patients were older, had more diabetes, more use of diuretics, with wider QRS duration, and with a trend for higher phase SD and BW. After adjusting for age, hypertension, diabetes, aspirin, beta-blockers, diuretics, QRS, and EF, phase SD was an independent predictor of all-cause mortality with hazard ratio [95% CI] 1.97 [1.06,3.66] for the highest tertile, and added incremental prognostic value (P = .025). Similar findings were obtained using histogram BW.
In patients with NICM, EF 35-50%, and QRS < 150 ms, increased LVMD on peak stress SPECT was an independent predictor of all-cause mortality. The utility and applicability of such findings in clinical practice need further evaluation in larger and prospective studies.
通过门控单光子发射计算机断层扫描（SPECT）心肌灌注成像（MPI）的相位分析得出的左心室机械性不同步（LVMD）是预测心脏再同步治疗反应的有用工具，且具有预后价值。虽然大多数研究是在缺血性心肌病患者或左心室射血分数（EF）<35%的患者中进行的，但关于LVMD在非缺血性心肌病（NICM）患者中的预后价值的数据很少，特别是那些收缩功能轻度下降且QRS时限窄或中等的患者。
从克利夫兰诊所的负荷SPECT-MPI数据库中，我们确定了324例连续的NICM患者（平均年龄62±13岁，62%为男性，36%为糖尿病患者），左心室射血分数为35%-50%（中位数[四分位间距1，四分位间距3]为45[41，49]），且QRS<150毫秒（13%的患者QRS为120-149毫秒）。LVMD由门控负荷图像确定，并表示为相位标准差（SD）和直方图带宽（%R-R周期）。为了更便于图形展示，将患者分为LVMD三分位数组。全因死亡是主要终点，并通过社会保障死亡指数确定。采用Cox比例风险模型确定LVMD的独立预测价值，然后采用Cox模型评估其增量价值。平均随访1689天后，86例（26.5%）患者死亡。这些患者年龄更大，糖尿病更多，利尿剂使用更多，QRS时限更宽，且相位SD和带宽有升高趋势。在调整年龄、高血压、糖尿病、阿司匹林、β受体阻滞剂、利尿剂、QRS和EF后，相位SD是全因死亡率的独立预测因素，最高三分位数组的风险比[95%置信区间]为1.97[1.06，3.66]，并具有增量预后价值（P = 0.025）。使用直方图带宽也得到了类似的结果。
在NICM、EF为35%-50%且QRS<150毫秒的患者中，负荷峰值SPECT上LVMD增加是全因死亡率的独立预测因素。这些发现在临床实践中的实用性和适用性需要在更大规模的前瞻性研究中进一步评估。
