Corrected QT interval on the electrocardiogram after liver transplantation: Surrogate marker of poor clinical outcomes?

BackgroundProlongation of corrected QT interval (QTc) on the electrocardiogram is associated with cardiac arrhythmia and sudden death. Changes in the QTc (corrected QT) interval before and after liver transplantation (LT) for the treatment of liver cirrhosis (LC) and its association with clinical outcomes have not been fully evaluated.MethodsFrom January 2011 to May 2016, consecutive 516 consecutive recipients were enrolled into LT registry and the median follow-up was 31 months (IQR 12–52). Patients with an available electrocardiogram before LT and 1 month after from LT were analyzed. Patients were divided into 2 groups according to prolonged QTc interval. The patient groups were analyzed separately according whether the electrocardiogram was preoperative or postoperative. The primary outcome was all-cause death during the follow-up period.ResultsA total of 283 patients were enrolled in the study. In the preoperative QTc prolongation group, there was not a significant rate difference in all-cause mortality in multivariate analysis (hazard ratio [HR], 0.94; 95% confidence interval [CI], 0.53–1.66; P = 0.26). However, in the postoperative QTc prolongation group, mortality was significantly increased (HR, 1.78; 95%CI, 1.05–3.03; P = 0.03) in patients who underwent LT.ConclusionIn patients who underwent LT for LC, postoperative QTc prolongation on ECG, rather than preoperative, is associated with mortality. Larger clinical trials are needed to support this finding.【背景】心电图（electrocardiogram, ECG）上校正QT间期（corrected QT interval, QTc）延长与心律失常及心源性猝死密切相关。针对采用肝移植（liver transplantation, LT）治疗肝硬化（liver cirrhosis, LC）的患者，其术前与术后QTc间期的变化情况，以及该变化与临床结局的关联，目前尚未得到充分评估。【方法】本研究纳入2011年1月至2016年5月期间纳入肝移植登记系统的516例连续入组肝移植受者，中位随访时间为31个月（四分位间距interquartile range, IQR：12~52）。最终纳入分析的为术前及肝移植术后1个月均获取有效心电图资料的患者。根据QTc间期是否延长将患者分为两组，并分别按心电图检测时点（术前或术后）开展亚组分析。本研究的主要结局为随访期间的全因死亡。【结果】本研究最终共纳入283例患者。多因素分析显示，术前QTc间期延长组患者的全因死亡率无显著统计学差异（风险比hazard ratio, HR=0.94；95%置信区间confidence interval, CI：0.53~1.66；P=0.26）。然而，术后QTc间期延长组的肝移植受者全因死亡率显著升高（HR=1.78；95%CI：1.05~3.03；P=0.03）。【结论】针对因肝硬化接受肝移植的患者，心电图提示术后QTc间期延长（而非术前QTc延长）与全因死亡率显著相关。未来需开展更大样本量的临床试验以验证该研究结果。