Intrathoracic Impedance Monitoring, Audible Patient Alerts, and Outcome in Patients With Heart Failure
Intrathoracic Impedance Monitoring, Audible Patient Alerts, and Outcome in Patients With Heart Failure
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DOI：
10.1161/circulationaha.111.043042
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发表时间：
2011-10-18
期刊：
影响因子：
37.8
通讯作者：
Borggrefe, Martin
中科院分区：
文献类型：
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作者：
van Veldhuisen, Dirk J.;Braunschweig, Frieder;Borggrefe, Martin
背景-心力衰竭与频繁的住院有关，通常是由于容量超负荷造成的。用植入的装置测量胸腔内阻抗，并发出患者警报，可以早期发现肺液滞留的增加。我们假设早期干预可以防止住院和影响结果。方法和结果-我们研究了335名慢性心力衰竭患者，他们接受了单独植入植入性心律转复除颤器(18%)或接受心脏再同步治疗(82%)。所有设备都有一个监测工具来跟踪胸腔内阻抗(OptiVol)和其他诊断参数的变化。患者被随机分为医生和患者可获得的信息，以在预设阈值跨越(进入组)或未设置阈值(控制组)的情况下发出声音警报。主要终点是所有原因死亡率和心力衰竭住院人数的组合。在14.9+/-5.4月期间，进入组48名患者(29%)和对照组33名患者(20%)发生这种情况(P=0.063；危险比1.52；95%可信区间0.97-2.37)。这主要是由于更多的心力衰竭住院(风险比为1.79；95%可信区间为1.08-2.95；P=0.022)，而死亡人数相似(19对15；P=0.54)。进入组的门诊就诊次数较高(250例对84例；P<；0.0001)，而对照组患者在门诊就诊期间出现心力衰竭的迹象相对较多。尽管试验因登记缓慢而终止，但一项特殊的无效性分析表明，阳性结果不太可能。结论-使用植入式诊断工具测量胸腔内阻抗并发出患者警报并不能改善结果，并增加心力衰竭患者的住院和门诊就诊次数。
Background-Heart failure is associated with frequent hospitalizations, often resulting from volume overload. Measurement of intrathoracic impedance with an implanted device with an audible patient alert may detect increases in pulmonary fluid retention early. We hypothesized that early intervention could prevent hospitalizations and affect outcome.Methods and Results-We studied 335 patients with chronic heart failure who had undergone implantation of an implantable cardioverter-defibrillator alone (18%) or with cardiac resynchronization therapy (82%). All devices featured a monitoring tool to track changes in intrathoracic impedance (OptiVol) and other diagnostic parameters. Patients were randomized to have information available to physicians and patients as an audible alert in case of preset threshold crossings (access arm) or not (control arm). The primary end point was a composite of all-cause mortality and heart failure hospitalizations. During 14.9 +/- 5.4 months, this occurred in 48 patients (29%) in the access arm and in 33 patients (20%) in the control arm (P = 0.063; hazard ratio, 1.52; 95% confidence interval, 0.97-2.37). This was due mainly to more heart failure hospitalizations (hazard ratio, 1.79; 95% confidence interval, 1.08-2.95; P = 0.022), whereas the number of deaths was comparable (19 versus 15; P = 0.54). The number of outpatient visits was higher in the access arm (250 versus 84; P < 0.0001), with relatively more signs of heart failure among control patients during outpatient visits. Although the trial was terminated as a result of slow enrollment, a post hoc futility analysis indicated that a positive result would have been unlikely.Conclusion-Use of an implantable diagnostic tool to measure intrathoracic impedance with an audible patient alert did not improve outcome and increased heart failure hospitalizations and outpatient visits in heart failure patients.