Department of Internal Medicine, Division of Cardiology, Section of Cardiac Electrophysiology and Pacing, Emory University School of Medicine, Atlanta, Georgia, USA.
Medtronic PLC, Mounds View, Minnesota, USA.
JACC Clin Electrophysiol. 2021 Apr;7(4):502-512. doi: 10.1016/j.jacep.2020.09.010. Epub 2020 Dec 24.
This study sought to formulate a predictive model for describing the long-term electrical performance of Micra (Medtronic, Mounds View, Minnesota).
The Micra leadless pacemaker is an alternative ventricular pacing option that avoids the pitfalls of transvenous leads. However, well-defined metrics to predict the long-term electrical performance of the device are lacking.
We identified all patients who underwent successful Micra implantation enrolled in the investigational device exemption study, continued access study, or post-approval registry with complete 1-year post-implantation data or system revision due to elevated thresholds (N = 1,843). The analysis endpoint was an elevated pacing capture threshold (PCT) at ≥12 months post-implantation, defined as ≥2.0 V at 0.24 ms or an increase of ≥1.5 V from implantation or need for system revision due to elevated thresholds at ≤12 months post-implantation. We evaluated for univariate and multivariate associations between patient and device characteristics at implantation and for elevated thresholds at 12 months.
Among the total cohort, 75 patients (4.1%) had elevated thresholds at 12 months; of these, 13 required system revisions. Predictors associated with elevated thresholds in univariate analysis included the total number of deployments (excluded from the multivariable model), impedance and PCT at implantation, male sex, history of diabetes, and ischemic cardiomyopathy. Multivariable regression modeling found that male sex, history of diabetes, implantation PCT of ≥2 V, and impedance of <800 Ω were independent predictors of elevated PCT at 12 months (all p < 0.05).
A history of diabetes, male sex, elevated PCT, and low impedance at implantation were independent predictors of elevated thresholds at 12 months. These metrics represent the foundation of a simple tool to aid in procedural decision making.
本研究旨在构建一个预测模型，用于描述 Micra（美敦力，明尼苏达州芒茨维尤）的长期电性能。
Micra 无导线起搏器是一种替代心室起搏的选择，可以避免经静脉导线的缺陷。然而，目前缺乏明确的指标来预测该设备的长期电性能。
我们确定了所有在研究性器械豁免研究、持续接入研究或批准后注册中成功植入 Micra 的患者，这些患者具有完整的 1 年植入后数据，或因阈值升高（N=1843）而进行系统修订。分析终点为植入后≥12 个月时出现的起搏捕获阈值（PCT）升高，定义为 0.24ms 时≥2.0V 或与植入时相比增加≥1.5V，或植入后≤12 个月时因阈值升高而需要系统修订。我们评估了植入时患者和设备特征与 12 个月时阈值升高之间的单变量和多变量关联。
在总队列中，有 75 名患者（4.1%）在 12 个月时出现阈值升高，其中 13 名患者需要进行系统修订。单变量分析中与阈值升高相关的预测因素包括总部署次数（排除在多变量模型之外）、植入时的阻抗和 PCT、男性、糖尿病史和缺血性心肌病。多变量回归模型发现，男性、糖尿病史、植入时的 PCT≥2V 和阻抗<800Ω是 12 个月时 PCT 升高的独立预测因素（均 p<0.05）。
糖尿病史、男性、植入时的 PCT 升高和阻抗降低是 12 个月时阈值升高的独立预测因素。这些指标构成了一种简单工具的基础，有助于决策。
