Role of Atrial Pacing Support in Cardiac Resynchronization Therapy: A Noninferiority Randomized Trial.

Methods

We conducted a randomized, parallel-group, noninferiority trial to evaluate whether a 2-lead CRT-D capable of atrial sensing (but no pacing) by a floating dipole on the right ventricular lead (CRT-DX) is not inferior to a 3-lead CRT-D with a conventional atrial lead.

我们进行了一项随机、平行组、非劣效试验，以评估一种具备心房感知功能（但无起搏功能）的2导联CRT-D（通过右心室电极上的浮动偶极实现）（CRT-DX）是否不劣于具有传统心房电极的3导联CRT-D。

Between October 17, 2018, and March 5, 2024, a total of 636 patients (68±10 years old, 28.6% women) with standard CRT-D indication, optimized medical therapy, and resting sinus rate ≥45 beats/min were randomized 1:1 to CRT-DX (atrial tracking without atrial pacing mode 35 beats/min) or CRT-D (atrial tracking with atrial pacing mode 50 beats/min) at 23 Italian sites.

在2018年10月17日至2024年3月5日期间，共有636名患者（平均年龄68±10岁，女性占28.6%），这些患者符合标准的CRT-D指征，接受了优化的药物治疗，并且静息时窦性心率≥45次/分钟，被随机分为1:1的两组，一组接受CRT-DX治疗（房室追踪模式，无房室起搏，追踪频率为35次/分钟），另一组接受CRT-D治疗（房室追踪模式，房室起搏频率为50次/分钟），研究在意大利的23个地点进行。

A centralized block-randomization procedure stratified by site was used, with patients and primary outcome assessors blinded to treatment assignment.

使用了按地点分层的集中化分块随机化程序，患者和主要结果评估者对治疗分配情况保持盲态。

The primary end point was a 1-year composite of all-cause mortality, cardiovascular hospitalization, and lead-related complications (loss of functionality not correctable by device reprogramming).

主要终点是一年内所有原因的死亡率、心血管住院和与导线相关的并发症（无法通过设备重新编程纠正的功能丧失）的综合评估。

Secondary end points included each individual component of the primary end point separately, echocardiographic reverse remodeling, and 6-minute walk test distance at 12 months.

次要终点包括单独评估主要终点的每个组成部分、12个月时的超声心动图逆向重塑以及6分钟步行测试距离。

Results

The primary end point occurred in 41 (13.1%) patients in the CRT-DX group and 47 (15.6%) patients in the CRT-D group, corresponding to a hazard ratioof 0.82 (95% CI, 0.54-1.25).

主要终点事件在CRT-DX组的41名（13.1%）患者和CRT-D组的47名（15.6%）患者中发生，相应的风险比为0.82（95% 置信区间，0.54-1.25）。

This confirmed noninferiority (prespecified relative margin of 1.20) in both the per-protocol (P=0.039) and intention-to-treat(P=0.044) analyses.

这在按方案（P=0.039）和意向治疗（P=0.044）分析中确认了非劣效性（预设相对边界为1.20）。

Individual components showed no significant differences, except for lead complications related to right atrial functionality (4 [1.3%] patients in the CRT-DX group versus 13 [4.2%] patients in the CRT-D group; P=0.040).

除了与右心房功能相关的导线并发症外，个体组成部分没有显著差异（CRT-DX组有4名[1.3%]患者，CRT-D组有13名[4.2%]患者；P=0.040）。

Reverse remodeling responders were 203 (77.5% of 262) patients receiving CRT-DX and 190 (76.3% of 249) patients receiving CRT-D (P=0.83).

逆重构反应者为接受CRT-DX治疗的262名患者中的203名（77.5%），以及接受CRT-D治疗的249名患者中的190名（76.3%）（P=0.83）。

Walking distance did not differ between 2 study arms (404 versus 398 m; P=0.62).

两研究组之间的步行距离没有差异（404米对比398米；P=0.62）。

After a median follow-up of 2.4 years, only 1 patient receiving CRT-DX required implantation of a standard atrial lead.

中位随访2.4年后，仅1名接受CRT-DX治疗的患者需要植入标准房性起搏电极。

Conclusions

The 2-lead CRT-DX system without atrial pacing is noninferior to conventional 3-lead CRT-D, with fewer atrial lead-related complications.

两导联无房室起搏功能的CRT-DX系统与传统三导联CRT-D相比，非劣效性显著，且房室起搏导线相关并发症较少。

registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03587064.

网址：https://www.clinicaltrials.gov；唯一标识符：NCT03587064。