Cardiovascular Department, Azienda Sanitaria Universitaria Giuliano Isontina and University of Trieste, Trieste, Italy.
Biostatistics Unit, Department of Medical Sciences, University of Trieste, Trieste, Italy.
J Am Soc Echocardiogr. 2022 Aug;35(8):801-809.e3. doi: 10.1016/j.echo.2022.03.019. Epub 2022 Mar 31.
Practice guidelines suggest the use of implantable cardioverter-defibrillators in patients with left ventricular ejection fractions (LVEF) ≤ 35% despite 3 to 6 months of guideline-directed medical therapy (GDMT). It remains unclear whether this strategy is appropriate for patients with dilated cardiomyopathy (DCM), who can experience reverse ventricular remodeling for up to 24 months after the initiation of GDMT. The aim of this study was to assess the longitudinal dynamic relationship between LVEF ≤ 35% and arrhythmic risk in patients with recent-onset nonischemic DCM on GDMT.
A retrospective analysis was conducted among patients with recent-onset DCM (≤6 months) and recent initiation of GDMT (≤3 months) consecutively enrolled in a longitudinal registry. Risk for major ventricular arrhythmic events or sudden cardiac death was assessed in relationship to LVEF ≤ 35% at enrollment and 6 and 24 months after initiation of GDMT.
Five hundred forty-four patients met the inclusion criteria. LVEF ≤ 35% identified patients with increased risk for major ventricular arrhythmic events or sudden cardiac death starting from 24 months after initiation of GDMT (hazard ratio, 2.126; 95% CI, 1.065-4.245; P = .03). However, LVEF ≤ 35% at presentation or 6 months after enrollment did not have prognostic significance. Sixty-seven percent of 131 patients with LVEF ≤ 35% at 6 months after initiation of GDMT had improved LVEFs (to >35%) by 24 months. This late LVEF improvement correlated with lower arrhythmic risk (P = .012) and was preceded by a reduction of LV dimensions in the first 6 months of GDMT.
In patients with DCM, the present findings suggest that risk stratification for major ventricular arrhythmic events or sudden cardiac death on the basis of LVEF ≤ 35% is effective after 2 years of GDMT, but not after 6 months. In selected patients with DCM, it would be appropriate to wait 24 months before primary prevention ICD implantation.
尽管有 3 至 6 个月的指南导向的药物治疗（GDMT），但实践指南建议将植入式心脏复律除颤器用于左心室射血分数（LVEF）≤35%的患者。目前尚不清楚这种策略是否适用于扩张型心肌病（DCM）患者，这些患者在 GDMT 开始后长达 24 个月内可经历心室重构的逆转。本研究旨在评估 GDMT 治疗的新发非缺血性 DCM 患者中 LVEF≤35%与心律失常风险之间的纵向动态关系。
对连续入组的纵向登记研究中近期发病（≤6 个月）和近期开始 GDMT（≤3 个月）的新发 DCM 患者进行回顾性分析。在 GDMT 开始后 6 和 24 个月时，评估 LVEF≤35%与主要室性心律失常事件或心源性猝死风险之间的关系。
符合纳入标准的患者共 544 例。GDMT 开始后 24 个月时，LVEF≤35%可识别出具有更高发生主要室性心律失常事件或心源性猝死风险的患者（危险比，2.126；95%置信区间，1.065-4.245；P=0.03）。然而，GDMT 开始时或入组后 6 个月的 LVEF≤35%并无预后意义。GDMT 开始后 6 个月时 131 例 LVEF≤35%的患者中，67%的患者 LVEF 改善（>35%）至 24 个月时。这种晚期 LVEF 改善与较低的心律失常风险相关（P=0.012），并在 GDMT 的前 6 个月 LV 尺寸减小之前发生。
在 DCM 患者中，本研究结果表明，基于 LVEF≤35%的风险分层对 GDMT 2 年后的主要室性心律失常事件或心源性猝死具有预测作用，但在 6 个月后无预测作用。对于某些 DCM 患者，在进行原发性预防 ICD 植入前等待 24 个月可能是合适的。
