British Heart Foundation Cardiovascular Research Centre, University of Glasgow, 126 University Place, Glasgow, UK.
Eur J Heart Fail. 2012 Apr;14(4):377-86. doi: 10.1093/eurjhf/hfs010. Epub 2012 Feb 14.
Observational studies in selected populations have suggested that microvolt T-wave alternans (MTWA) testing may identify patients with heart failure (HF) at risk of sudden cardiac death. The aims of this study were to investigate the utility of MTWA testing in an unselected population of patients with HF and to evaluate the clinical characteristics associated with the MTWA results.
A total of 1003 patients hospitalized with decompensated HF were enrolled. MTWA testing was planned 1 month post-discharge; 648 patients returned for MTWA testing. Mean age was 70.8 ± 10.6 years and 58% were male. Of these patients who returned, 318 (49%) were ineligible for MTWA testing due to atrial fibrillation (AF), pacemaker dependency, or physical inability to undertake the test. Of the MTWA tests, 100 (30%) were positive, 78 (24%) were negative, and 152 (46%) were indeterminate; 112/152 indeterminate tests (74%) occurred because of failure to achieve target heart rate (HR) due to chronotropic incompetence or physical limitations. There were differences in patient characteristics according to MTWA result. Independent predictors of a negative result included younger age and higher left ventricular ejection fraction (LVEF). Independent predictors of a positive result included higher HR during MTWA testing and lower LVEF. Independent predictors of an indeterminate result included older age and history of previous/paroxysmal AF.
Only half of patients with HF are eligible for MTWA testing and the most common result is an indeterminate test. Patients with positive and indeterminate tests have different clinical characteristics. MTWA treadmill testing is not widely applicable in typical HF patients and is unlikely to refine risk stratification for sudden death on a population level.
一些观察性研究表明，微伏级 T 波电交替（MTWA）检测可能可以识别心力衰竭（HF）患者中发生心源性猝死的高危人群。本研究旨在探讨 MTWA 检测在 HF 未选择人群中的应用，并评估与 MTWA 结果相关的临床特征。
共纳入 1003 例因失代偿性 HF 住院的患者。计划在出院后 1 个月进行 MTWA 检测；其中 648 例患者返回进行 MTWA 检测。平均年龄为 70.8±10.6 岁，58%为男性。这些返回的患者中，由于房颤（AF）、起搏器依赖或身体无法进行测试，有 318 例（49%）不适合进行 MTWA 检测。在进行的 MTWA 检测中，100 例（30%）阳性，78 例（24%）阴性，152 例（46%）不确定；152 例不确定的检测中（74%），由于心动过缓或身体限制而无法达到目标心率（HR）而导致检测失败。MTWA 结果的患者特征存在差异。阴性结果的独立预测因素包括年龄较小和左心室射血分数（LVEF）较高。阳性结果的独立预测因素包括 MTWA 检测时 HR 较高和 LVEF 较低。不确定结果的独立预测因素包括年龄较大和既往/阵发性 AF 病史。
只有一半的 HF 患者适合进行 MTWA 检测，最常见的结果是不确定的检测。阳性和不确定检测的患者具有不同的临床特征。MTWA 踏车检测在典型 HF 患者中并不广泛适用，不太可能在人群水平上细化猝死风险分层。
