Department of Cardiovascular Sciences, University of Leicester, Leicester, UK.
NIHR Leicester Biomedical Research Centre, Glenfield Hospital, Leicester, UK.
Pacing Clin Electrophysiol. 2021 Feb;44(2):284-292. doi: 10.1111/pace.14143. Epub 2021 Jan 4.
Sudden cardiac death (SCD) risk assessment is limited, particularly in patients with nonischemic cardiomyopathies. This is the first application, in patients with cardiomyopathies, of two novel risk markers, regional restitution instability index (R2I2) and peak electrocardiogram restitution slope (PERS), which have been shown to be predictive of ventricular arrhythmias (VA) or death in ischemic heart disease patients.
Blinded retrospective study of 50 patients: 33 dilated cardiomyopathy and 17 other; undergoing electrophysiological study (EPS) for SCD risk stratification, and 29 controls with structurally normal hearts undergoing EPS. R2I2 was calculated from an EPS using electrocardiogram surrogates for action potential duration and diastolic interval. Cut-offs for high and low R2I2/PERS were predefined.
R2I2 was significantly higher in study than control patients (0.99 ± 0.05 vs. 0.63 ± 0.04, p < .001). PERS showed a trend to higher values in the study group (1.18[0.63] vs. 1.09[0.54], p = .07). During median follow up of 5.6 years [interquartile range 1.9 years], nine study patients reached the endpoint of VA/death. Patients who experienced VA/death showed trends to higher mean R2I2 (1.14 ± 0.07 vs.0.95 ± 0.05, p = .12) and PERS (1.46[0.49] vs. 1.13[0.62], p = .22). A Cox proportional hazards model using grouped markers: R2I2 < 1.03 + PERS < 1.21/either R2I2 ≥ 1.03 or PERS ≥ 1.21/R2I2 ≥ 1.03 + PERS ≥ 1.21; significantly predicted VA/death (p = .02) with a hazard ratio per positive component of 3.2 (95% confidence interval 1.2-8.8).
R2I2≥ 1.03 + PERS ≥ 1.21 may predict VA/death in patients with cardiomyopathies. R2I2 ≥ 1.03 + PERS ≥ 1.21 have the potential to play an important role in SCD risk stratification in cardiomyopathies but their validity should be confirmed in a larger study.
心脏性猝死 (SCD) 风险评估存在局限性，尤其是在非缺血性心肌病患者中。这是首次在心肌病患者中应用两个新的风险标志物，即局部复极不稳定指数 (R2I2) 和心电图复极斜率峰值 (PERS)，这两个标志物已被证明可预测缺血性心脏病患者的室性心律失常 (VA) 或死亡。
对 50 例接受电生理研究 (EPS) 以进行 SCD 风险分层的患者（33 例扩张型心肌病和 17 例其他类型心肌病）和 29 例结构正常心脏接受 EPS 的对照患者进行了盲法回顾性研究。从 EPS 中使用动作电位持续时间和舒张间隔的心电图替代物计算 R2I2。高和低 R2I2/PERS 的截断值预先设定。
研究组的 R2I2 明显高于对照组（0.99 ± 0.05 vs. 0.63 ± 0.04，p <.001）。研究组的 PERS 显示出更高值的趋势（1.18[0.63] vs. 1.09[0.54]，p =.07）。在中位数为 5.6 年（四分位距为 1.9 年）的随访期间，9 例研究患者达到了 VA/死亡终点。经历 VA/死亡的患者 R2I2 均值呈升高趋势（1.14 ± 0.07 vs.0.95 ± 0.05，p =.12），PERS 呈升高趋势（1.46[0.49] vs. 1.13[0.62]，p =.22）。使用分组标志物的 Cox 比例风险模型：R2I2 < 1.03 + PERS < 1.21/任何 R2I2 ≥ 1.03 或 PERS ≥ 1.21/R2I2 ≥ 1.03 + PERS ≥ 1.21；显著预测 VA/死亡（p =.02），每个阳性成分的风险比为 3.2（95%置信区间为 1.2-8.8）。
R2I2≥ 1.03 + PERS≥ 1.21 可能预测心肌病患者的 VA/死亡。R2I2≥ 1.03 + PERS≥ 1.21 有可能在心肌病的 SCD 风险分层中发挥重要作用，但需要在更大的研究中证实其有效性。
