TpTe and TpTe/QT: novel markers to predict sudden cardiac death in ESRD?

ABSTRACT Introduction: Reliable markers to predict sudden cardiac death (SCD) in patients with end stage renal disease (ESRD) remain elusive, but echocardiogram (ECG) parameters may help stratify patients. Given their roles as markers for myocardial dispersion especially in high risk populations such as those with Brugada syndrome, we hypothesized that the Tpeak to Tend (TpTe) interval and TpTe/QT are independent risk factors for SCD in ESRD. Methods: Retrospective chart review was conducted on a cohort of patients with ESRD starting hemodialysis. Patients were US veterans who utilized the Veterans Affairs medical centers for health care. Average age of all participants was 66 years and the majority were males, consistent with a US veteran population. ECGs that were performed within 18 months of dialysis initiation were manually evaluated for TpTe and TpTe/QT. The primary outcomes were SCD and all-cause mortality, and these were assessed up to 5 years following dialysis initiation. Results: After exclusion criteria, 205 patients were identified, of whom 94 had a prolonged TpTe, and 61 had a prolonged TpTe/QT interval (not mutually exclusive). Overall mortality was 70.2% at 5 years and SCD was 15.2%. No significant difference was observed in the primary outcomes when examining TpTe (SCD: prolonged 16.0% vs. normal 14.4%, p=0.73; all-cause mortality: prolonged 55.3% vs. normal 47.7%, p=0.43). Likewise, no significant difference was found for TpTe/QT (SCD: prolonged 15.4% vs. normal 15.0%, p=0.51; all-cause mortality: prolonged 80.7% vs. normal 66.7%, p=0.39). Conclusions: In ESRD patients on hemodialysis, prolonged TpTe or TpTe/QT was not associated with a significant increase in SCD or all-cause mortality.

摘要
引言：目前仍缺乏可用于预测终末期肾病（end stage renal disease, ESRD）患者心搏骤停（sudden cardiac death, SCD）的可靠标志物，但心电图（electrocardiogram, ECG）参数或可用于患者风险分层。鉴于其作为心肌复极离散度标志物的作用，尤其在布鲁加达综合征（Brugada syndrome）等高风险人群中，我们假设T波顶峰至T波终末（Tpeak to Tend, TpTe）间期以及TpTe/QT比值可作为终末期肾病患者发生心搏骤停的独立危险因素。
方法：本研究对启动血液透析的终末期肾病患者队列开展回顾性病历审查。研究对象为利用退伍军人事务部医疗中心提供医疗服务的美国退伍军人。所有受试者的平均年龄为66岁，且绝大多数为男性，这与美国退伍军人人群的特征相符。对透析启动前18个月内采集的心电图进行人工评估，以测算TpTe间期及TpTe/QT比值。本研究的主要结局指标为心搏骤停及全因死亡率，随访时长至透析启动后5年。
结果：经排除标准筛选后，共纳入205例患者，其中94例存在TpTe间期延长，61例存在TpTe/QT比值延长（二者并非互斥）。5年随访期间，总体死亡率为70.2%，心搏骤停发生率为15.2%。针对TpTe间期的亚组分析显示，主要结局未出现显著差异：心搏骤停发生率分别为延长组16.0%、正常组14.4%（p=0.73）；全因死亡率分别为延长组55.3%、正常组47.7%（p=0.43）。同样，针对TpTe/QT比值的分析亦未发现显著差异：心搏骤停发生率分别为延长组15.4%、正常组15.0%（p=0.51）；全因死亡率分别为延长组80.7%、正常组66.7%（p=0.39）。
结论：在接受血液透析的终末期肾病患者中，TpTe间期延长或TpTe/QT比值升高与心搏骤停及全因死亡率的显著升高并无关联。