Predictive impact of the decreasing rate of intrathoracic impedance in worsening chronic heart failure
Predictive impact of the decreasing rate of intrathoracic impedance in worsening chronic heart failure
复制标题
胸内阻抗下降率对慢性心力衰竭恶化的预测影响
DOI：
10.1007/s10840-014-9881-3
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发表时间：
2014
影响因子：
1.8
通讯作者：
Takeishi Y
中科院分区：
文献类型：
--
作者：
Yamada S;Suzuki H;Kamiyama Y;Saitoh S;Takeishi Y
目的胸内阻抗监测对于心脏再同步治疗 (CRT) 患者的心力衰竭 (HF) 管理很有用。然而，临床环境中需要更准确地识别恶化的慢性心力衰竭 (CHF)。我们通过估计阻抗变化来研究这个问题。方法我们使用能够进行阻抗监测的 CRT 除颤器对 38 名 CHF 患者（29 名男性，平均年龄 67 岁）进行了研究。在随访期间（20.7±7.8个月），受试者总共经历了129次体液指数阈值（60欧姆·天）跨越事件。这些事件分为两组：心力衰竭事件 (n= 70) 和无心力衰竭事件 (n= 59)。根据流体指数增加开始时 (S) 和 60 欧姆·天交叉点 (E) 时的阻抗，估计阻抗变化率 (S−E/S)。另外，评价了从StoE(T)起的经过时间。然后，计算各组每天的阻抗变化率（S−E/S×T）。结果发生HF事件的每天阻抗变化率显着高于无HF事件的情况（0.86 ± 0.48 vs. 0.37 ± 0.22%/天，P< 0.01）。通过识别 HF 事件的受试者工作特征曲线，阻抗变化率的最佳截止值为 0.48%/天（敏感性 80%，特异性 81%，曲线下面积 0.85）。结论这些结果表明，胸内阻抗更快下降反映了使用 CRT 除颤器的患者 CHF 恶化。因此，基于阻抗变化率的胸内阻抗监测可以更准确地识别恶化的CHF。
PurposeIntrathoracic impedance monitoring is useful for heart failure (HF) management in patients with cardiac resynchronization therapy (CRT). However, more accurate identification of worsening chronic HF (CHF) is required in the clinical setting. We investigated this issue by estimating changes in impedance.MethodsWe studied 38 CHF patients (29 males, mean age 67 years) with CRT-defibrillator capable of impedance monitoring. During the follow-up period (20.7 ± 7.8 months), the subjects experienced a total of 129 fluid index threshold (60 ohm·days) crossing events. These events were divided into two groups: HF events (n= 70) and no HF events (n= 59). Based on the impedance at the beginning of increasing fluid index (S) and at the crossing of 60 ohm·days (E), the rate of impedance change (S−E/S) was estimated. In addition, the elapsed time fromStoE(T) was evaluated. Then, we calculated the rate of impedance change per day (S−E/S×T) in each group.ResultsThe rate of impedance change per day was significantly higher in HF events than in no HF events (0.86 ± 0.48 vs. 0.37 ± 0.22 %/day,P< 0.01). By receiver operating characteristic curve for identification of HF events, the best cutoff value of the rate of impedance change was 0.48 %/day (sensitivity 80 %, specificity 81 %, and area under the curve 0.85).ConclusionsThese results suggest that a faster drop in intrathoracic impedance reflected worsening CHF in patients with CRT-defibrillator. Thus, intrathoracic impedance monitoring based on the rate of impedance change may provide a more accurate identification of worsening CHF.