Instituto do Coração do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP - Brasil.
Universidade São Francisco, Bragança Paulista, SP - Brasil.
Arq Bras Cardiol. 2023 Sep 4;120(8):e20220833. doi: 10.36660/abc.20220833. eCollection 2023.
Sudden cardiac death (SCD) resulting from ventricular arrhythmia is the main complication of hypertrophic cardiomyopathy (HCM). Microvolt T-wave alternans (MTWA) is associated with the occurrence of ventricular arrhythmias in several heart diseases, but its role in HCM remains uncertain.
To evaluate the association of MTWA with the occurrence of SCD or potentially fatal ventricular arrhythmias in HCM patients in a long-term follow-up.
Patients diagnosed with HCM and NYHA functional class I-II were consecutively selected. At the beginning of the follow-up, the participants performed the MTWA evaluation using the modified moving average during the stress test. The results were classified as altered or normal. The composite endpoint of SCD, ventricular fibrillation, sustained ventricular tachycardia (SVT) or appropriate implantable cardiac defibrillation (ICD) therapy was assessed. The level of significance was set at 5%.
A total of 132 patients (mean age of 39.5 ± 12.6 years) were recruited and followed for a mean of 9.5 years. The MTWA test was altered in 74 (56%) participants and normal in 58 (44%). Nine events (6.8%) occurred during the follow-up, with a prevalence of 1.0%/year - six SCDs, two appropriate ICD shocks and one episode of (SVT). Altered MTWA was associated with non-sustained ventricular tachycardia on Holter (p = 0.016), septal thickness ≥30 mm (p < 0.001) and inadequate blood pressure response to effort (p = 0.046). Five patients with altered MTWA (7%) and four patients with normal MTWA (7%) had the primary outcome [OR = 0.85 (95% CI: 0.21 - 3.35, p=0.83)]. Kaplan-Meir event curves showed no differences between normal and altered MTWA.
Altered MTWA was not associated with the occurrence of SCD or potentially fatal ventricular arrhythmias in HCM patients, and the low rate of these events during long-term follow-up suggests the good prognosis of this heart disease.
由室性心律失常引起的心脏性猝死（SCD）是肥厚型心肌病（HCM）的主要并发症。微伏级 T 波交替（MTWA）与几种心脏病发生室性心律失常有关，但在 HCM 中的作用仍不确定。
在长期随访中评估 MTWA 与 HCM 患者 SCD 或潜在致命性室性心律失常发生的相关性。
连续选择诊断为 HCM 和 NYHA 心功能 I-II 级的患者。在随访开始时，参与者使用应激试验中的改良移动平均值进行 MTWA 评估。结果分为改变或正常。评估 SCD、心室颤动、持续性室性心动过速（SVT）或适当的植入式心脏除颤器（ICD）治疗的复合终点。显著性水平设定为 5%。
共纳入 132 例患者（平均年龄 39.5 ± 12.6 岁），平均随访 9.5 年。74 例（56%）参与者的 MTWA 试验异常，58 例（44%）正常。随访期间发生 9 起事件（6.8%），发生率为 1.0%/年-6 例 SCD、2 例适当的 ICD 电击和 1 例（SVT）。MTWA 改变与 Holter 检查中非持续性室性心动过速（p=0.016）、室间隔厚度≥30mm（p＜0.001）和运动时血压反应不足（p=0.046）相关。5 例 MTWA 改变的患者（7%）和 4 例 MTWA 正常的患者（7%）出现主要结局[OR=0.85（95%CI：0.21-3.35，p=0.83）]。Kaplan-Meier 事件曲线显示正常和改变的 MTWA 之间没有差异。
在 HCM 患者中，MTWA 改变与 SCD 或潜在致命性室性心律失常的发生无关，长期随访中这些事件的发生率较低表明这种心脏病的预后良好。
