The Use of Two-Dimensional Strain Measured by Speckle Tracking in the Identification of Incipient Ventricular Dysfunction in HIV-Infected Patients on Antiretroviral Therapy, Untreated HIV Patients and Healthy Controls

Abstract Background: Most cardiovascular abnormalities in patients infected with the human immunodeficiency virus (HIV) have been associated with myocardial damage directly caused by the virus. Some cases, however, may be associated with adverse effects from antiretroviral therapy (ART). New ventricular function assessment techniques are capable of detecting early changes in the cardiac function of HIV-infected patients using or not using ART. The usefulness of these techniques has been little employed in these patients. Objectives: To investigate the potential influence of antiretroviral therapy (ART) on the occurrence of subclinical left ventricular systolic dysfunction evaluated by myocardial strain rate analysis using two-dimensional speckle tracking echocardiography (2-D Echo) in treated HIV patients compared to untreated patients and healthy individuals. Methods: Sixty-eight HIV-infected patients with no cardiovascular symptoms, normal left ventricular (LV) ejection fraction (> 0.55 on 2-D Echo) were divided into three groups: 11 patients not using antiretroviral therapy (NT), 24 using protease inhibitor (PI) and 33 using non-nucleoside reverse transcriptase inhibitor (NNRTI). We also studied 30 normal non-HIV infected individuals (Ctrl). Demographic, clinical, biochemical and anthropometric data were collected. Preliminary transthoracic echocardiography included study of myocardial strain using two-dimensional speckle tracking. We studied strain and strain rate in the seventeen left ventricular (LV) myocardial segments in the longitudinal, circumferential and radial axes. Statistical analysis of the data was done with IBM SPSS - version 20 for Windows. Upon analysis of the data, namely the normality of independent variables in the different groups and the homogeneity of the variances between the groups, Kruskal-Wallis’ non-parametric test was done, followed by Dunn’s multiple comparison tests to test the significance of the differences between the values measured in the study groups. A significance level of 5% was adopted for decision-making on statistical tests. Results: The mean age of HIV patients was 40 ± 8.65 years and the mean age of controls was 50 ± 11.6 years (p < 0.001). Median LV global longitudinal strain (GLS) of NT patients (-17.70%), PI patients (-18.27%) and NNRTIs (-18.47%) were significantly lower than that of the Ctrl group (-20.77%; p = 0.001). There was no significant difference in mean SLG between treated patients (PI, NNRTI) and untreated (NT) patients. No significant differences were observed in mean circumferential and radial strain, nor on circumferential and radial strain rates between the NT, PI, NNRTI and Ctrl groups. Conclusion: The data suggest that HIV patients present, on myocardial strain measured by speckle tracking, signs of early LV systolic dysfunction that seem to be unrelated to the presence of ART. The prognostic significance of this condition in these patients deserves further studies.

**背景**：人类免疫缺陷病毒（HIV）感染者的多数心血管异常既往认为与病毒直接介导的心肌损伤相关。但部分病例的心血管异常可能与抗逆转录病毒治疗（ART）的不良反应有关。目前已有新型心室功能评估技术，可在接受或未接受ART的HIV感染者中检测心功能的早期变化，但此类技术在该类患者中的应用价值尚未得到充分挖掘。

**研究目的**：本研究旨在对比接受ART的HIV感染者、未接受ART的HIV感染者与健康个体，通过二维斑点追踪超声心动图（2-D Echo）行心肌应变率分析，探讨ART对亚临床左心室收缩功能障碍发生的潜在影响。

**研究方法**：本研究纳入68例无心血管症状、二维斑点追踪超声心动图提示左心室射血分数（LV）>0.55的HIV感染者，将其分为3组：未接受ART者（NT组，11例）、接受蛋白酶抑制剂（PI）治疗者（24例）、接受非核苷类逆转录酶抑制剂（NNRTI）治疗者（33例）；另纳入30例HIV阴性健康个体作为对照组（Ctrl组）。收集所有受试者的人口学、临床、生化及人体测量学数据。初步经胸超声心动图检查包含二维斑点追踪心肌应变分析，我们对左心室17个心肌节段的纵向、圆周及径向应变与应变率进行检测。数据分析采用IBM SPSS 20.0 for Windows软件完成：首先对各组自变量的正态性及组间方差齐性进行检验，随后采用克鲁斯卡尔-沃利斯非参数检验，再通过邓恩多重比较检验分析各组测量指标间的差异显著性，统计学检验的显著性水平设定为5%。

**研究结果**：HIV感染者的平均年龄为40±8.65岁，对照组健康个体的平均年龄为50±11.6岁（p<0.001）。NT组、PI组及NNRTI组患者的左心室整体纵向应变（GLS）中位数分别为-17.70%、-18.27%及-18.47%，均显著低于对照组的-20.77%（p=0.001）；接受ART治疗的患者（PI组、NNRTI组）与未接受ART的NT组患者之间，整体纵向应变均值无显著差异。NT组、PI组、NNRTI组与对照组之间，圆周应变、径向应变及其应变率的均值均无显著差异。

**研究结论**：本研究数据显示，通过斑点追踪检测的心肌应变结果提示，HIV感染者存在早期左心室收缩功能障碍的相关征象，且该征象似乎与ART治疗无关。此类征象在该类患者中的预后价值尚需进一步研究阐明。