Institute of Medical Epidemiology, Biostatistics and Informatics, Martin-Luther-University Halle-Wittenberg, Halle/Saale, Germany
Institute of Medical Epidemiology, Biostatistics and Informatics, Martin-Luther-University Halle-Wittenberg, Halle/Saale, Germany.
Eur J Prev Cardiol. 2016 Mar;23(4):428-36. doi: 10.1177/2047487315587271. Epub 2015 May 21.
There is convincing evidence of an association between the QT interval on electrocardiograms and general mortality. However, results are inconclusive regarding the extent to which this association depends on ventricular mass and size.
Data were obtained from the prospective, population-based CARLA study, with a mean follow-up of 8.8 years, after exclusion of subjects with atrial fibrillation (919 men, 797 women aged 45-83 years remained eligible). Echocardiographic parameters were left ventricular mass index, left ventricular diastolic dimension index, diastolic interventricular septum thickness, diastolic left ventricular posterior wall and the relative left ventricular wall thickness. Heart rate-corrected QT interval (QTc) was measured with standard 12-lead electrocardiograms using the MEANS algorithm. The association between QTc and survival was modelled using Cox-regression models (crude- and covariate-adjusted). Values were standardized by dividing the QTc by the standard deviation. The association between QTc and survival was assessed in terms of tertiles of echocardiographic parameters.
In covariate-adjusted models, QTc was associated with general mortality (hazard ratio (HR): 1.19; 95% confidence interval (CI): 1.03, 1.38). Compared with higher tertiles, subjects in the lowest tertile of left ventricular mass index (HR=1.73, 95% CI: 1.26, 2.36) showed the strongest association with general mortality, which was also true for the lowest tertile of diastolic left ventricular posterior wall thickness (HR=1.49, 95% CI: 1.10, 2.02).
In the general population, the association between QTc and general mortality is strongest in subjects with low left ventricular mass index and diastolic thickness of the left ventricular posterior wall, thus the prognostic value of QTc needs to be interpreted with regard to these echocardiographic parameters.
心电图 QT 间期与全因死亡率之间存在明确关联。然而，关于这种关联在多大程度上取决于心室质量和大小，目前结果尚无定论。
数据来自前瞻性、基于人群的 CARLA 研究，平均随访 8.8 年，排除心房颤动患者（919 名男性，797 名年龄 45-83 岁的女性符合条件）。超声心动图参数包括左心室质量指数、左心室舒张末期内径指数、舒张期室间隔厚度、舒张期左心室后壁和相对左心室壁厚度。采用 MEANS 算法对标准 12 导联心电图进行心率校正 QT 间期（QTc）测量。使用 Cox 回归模型（未校正和校正协变量）对 QTc 与生存之间的关系进行建模。将 QTc 值除以标准差进行标准化。根据超声心动图参数的三分位值评估 QTc 与生存的关系。
在调整协变量的模型中，QTc 与全因死亡率相关（危险比（HR）：1.19；95%置信区间（CI）：1.03，1.38）。与较高三分位组相比，左心室质量指数最低三分位组（HR=1.73，95%CI：1.26，2.36）与全因死亡率的相关性最强，最低三分位组的舒张期左心室后壁厚度（HR=1.49，95%CI：1.10，2.02）也是如此。
在一般人群中，QTc 与全因死亡率之间的关联在左心室质量指数和舒张期左心室后壁厚度较低的患者中最强，因此需要结合这些超声心动图参数来解释 QTc 的预后价值。
