Heart Research Follow-Up Program, University of Rochester Medical Center, Rochester, NY, USA.
Ann Noninvasive Electrocardiol. 2020 Jul;25(4):e12744. doi: 10.1111/anec.12744. Epub 2020 Jan 29.
Implantation of the subcutaneous implantable cardioverter-defibrillator (S-ICD) is spreading and has been shown to be safe and effective; however, it does not provide brady-pacing. Currently, data on the need for brady-pacing and cardiac resynchronization therapy (CRT) implantation in patients with ICD indication are limited.
The Multicenter Automatic Defibrillator Implantation Trial (MADIT)-II enrolled post-MI patients with reduced ejection fraction (EF ≤ 35%), randomized to either an implantable cardioverter-defibrillator (ICD) or conventional medical therapy. Kaplan-Meier analyses and multivariate Cox models were performed to assess the incidence and predictors of pacemaker (PM), or CRT implantation in the conventional arm of MADIT-II, after excluding 32 patients (6.5%) with a previously implanted PM.
During the median follow-up of 20 months, 24 of 458 patients (5.2%) were implanted with a PM or a CRT (19 PM, 5 CRT). Symptomatic sinus bradycardia was the primary indication for PM implantation (n = 9, 37%), followed by AV block (n = 5, 21%), tachy-brady syndrome (n = 4, 17%), and carotid sinus hypersensitivity (n = 1, 4%). Baseline PR interval >200 ms (HR = 3.07, 95% CI: 1.24-7.57, p = .02), and CABG before enrollment (HR = 6.88, 95% CI: 1.58-29.84, p = .01) predicted subsequent PM/CRT implantation. Patients with PM/CRT implantation had a significantly higher risk for heart failure (HR = 2.67, 95% CI = 1.38-5.14, p = .003), but no increased mortality risk (HR = 1.06, 95% CI = 0.46-2.46, p = .89).
The short-term need for ventricular pacing or CRT implantation in patients with MADIT-II ICD indication was low, especially in those with a normal baseline PR interval, and such patients are appropriate candidates for the subcutaneous ICD.
皮下植入式心律转复除颤器（S-ICD）的植入正在普及，且已被证实安全有效；然而，它不能提供心脏起搏器起搏。目前，关于 ICD 适应证患者对心脏起搏器起搏和心脏再同步治疗（CRT）植入的需求的数据有限。
多中心自动除颤器植入试验（MADIT）-II 纳入了心梗后射血分数（EF≤35%）降低的患者，随机分为植入式心律转复除颤器（ICD）或常规药物治疗组。采用 Kaplan-Meier 分析和多变量 Cox 模型评估 MADIT-II 常规治疗组中排除 32 例（6.5%）先前植入心脏起搏器的患者后，发生心脏起搏器（PM）或 CRT 植入的发生率和预测因素。
在中位随访 20 个月期间，458 例患者中有 24 例（5.2%）植入了 PM 或 CRT（19 例 PM，5 例 CRT）。症状性窦性心动过缓是植入 PM 的主要指征（n=9，37%），其次是房室传导阻滞（n=5，21%）、心动过速-心动过缓综合征（n=4，17%）和颈动脉窦过敏（n=1，4%）。基线 PR 间期>200ms（HR=3.07，95%CI：1.24-7.57，p=0.02）和纳入前 CABG（HR=6.88，95%CI：1.58-29.84，p=0.01）预测了随后的 PM/CRT 植入。植入 PM/CRT 的患者心力衰竭风险显著增加（HR=2.67，95%CI=1.38-5.14，p=0.003），但死亡率无增加风险（HR=1.06，95%CI=0.46-2.46，p=0.89）。
MADIT-II ICD 适应证患者短期对心室起搏或 CRT 植入的需求较低，尤其是那些基线 PR 间期正常的患者，这些患者是皮下 ICD 的合适人选。
