ABC | Volume 113, Nº4, October 2019

Original Article Rodrigues et al. Myocardial strain measured by speckle tracking Arq Bras Cardiol. 2019; 113(4):737-745 Table 3 – Behavior of global longitudinal strain according to the group Variable NT (n = 11) PI (n = 24) NNRTI (n = 33) Control (n = 30) Kruskal-Wallis test (p) Global longitudinal strain M ± SD -18.11 ± 1.28 -17.96 ± 4.89 -18.15 ± 3.07 -20.66 ± 0.79 0.001 Md ± IQR -17.70 ± 2.07 -18.27 ± 6.14 -18.47 ± 4.27 -20.77 ± 1.00 M: mean; SD: standard deviation; Md: median; IQR: interquartile range. Speckle tracking is an advanced echocardiographic technique that has much greater sensitivity than transthoracic echocardiography to detect functional abnormalities, mainly cardiac strain variables that assess left ventricular mechanical efficiency, identifying abnormalities earlier than other imaging techniques. Sims et al., 15 using transthoracic echocardiography, evaluated 28 HIV-infected young adults (aged seven to twenty-nine), compared to 28 controls, and no abnormalities of systolic and diastolic parameters were found. However, on the study of cardiac strain, a decrease in the percentage of longitudinal strain was observed in the patients in comparison with the control group. HIV-infected patients, regardless of ART, had a lower longitudinal strain rate than the control group. Multiple studies have found high triglyceride levels in HIV‑infected patients using protease inhibitors, 16-18 as these drugs stimulate the synthesis of hepatic triglycerides. 19 In our study, the group of patients using protease inhibitors presented the highest serum triglyceride levels. Studies in the literature show the importance of monitoring the lipid profile of HIV-infected patients using ART, especially when using protease inhibitors. 20 In this study, it was observed that groups of HIV-infected patients, regardless of the type of ART, presented lower global longitudinal strain percentage than healthy controls. Barbaro et al. 3 evidenced in their study the need to monitor this group of patients, seeking to identify individuals with higher cardiovascular risk. Previous studies evaluated left ventricular systolic and diastolic function in the population of HIV-infected individuals using one-dimensional and two-dimensional echocardiography and spectral Doppler. Hsue et al. 21 and Reinsch et al. 22 studied left ventricular diastolic and systolic functions using tissue Doppler, which uses filters for high velocities (blood) obtaining systolic and diastolic myocardial velocities in the septal and lateral mitral annulus. Lang et al. 12 focused their research on the complete study of LV diastolic function, following a scaled evaluation flowchart according to the guidelines of the American Society of Echocardiography. 12 Others identified anatomical and functional abnormalities in infected patients on ART. 23-28 The most recent studies use myocardial strain and myocardial strain rate percentage using speckle tracking to detect subclinical ventricular dysfunction in HIV-infected patients on ART. 12,29,30 We know that the longitudinal cardiac fiber strain can be used to study the behavior of myocardial fibers arranged in the subendocardial area, as we know that 77% of these fibers are disposed longitudinally, and this makes speckle tracking play an important role in the study of ischemic disease, since ischemia begins in the subendocardial region. This study revealed lower longitudinal strain percentages in HIV-infected individuals compared tohealthy controls. Therewere no differences between the percentages of longitudinal strain in groups of HIV-infected patients using or not using ART. Accurate and reproducible estimate of myocardial damage in patients with HIV infection and using ART has been considered to be increasingly important. The CHAART-2 study, which identified the long-term cardiovascular effects in HIV-infected children on ART, showed that cardiac structure and function were superior in HIV-infected children exposed to ART in the perinatal period compared with children in the pre-ART 31 era, which demonstrates the importance of early treatment in preventing cardiac damage. Besides, it reinforces the need for monitoring cardiac function in HIV-infected patients using ART to identify early myocardial injury, thereby decreasing long-term cardiovascular complications. Several published papers have demonstrated the relationship between AIDS and cardiovascular diseases, with pericardial effusion and pericarditis being the best known. 32–39 Okoshi andMontenegro 40 studied the incidence and etiology of heart lesions in patients with AIDS through a retrospective study of 72 necropsies. In none of the patients, death was considered a consequence of cardiac lesion, but macro and microscopic abnormalities were found in 90% of the cases. Several studies report that the prevalence of cardiac abnormalities may be underestimated. Interstitial lymphocytic myocarditis 41,42 is found in 50 to 70% of asymptomatic infected individuals. Myocardial abnormalities appear to be associated with more severe cases of immunosuppression and low TCD4 counts. 43 Limitations The limitations of the study are the limited sample size and the relatively broad age range of HIV-infected participants. Neither the effect of disease duration nor ART duration were analyzed. The absence of coronary artery disease documentation on computed tomography angiography did not allow to evaluate the influence of ART on the development of CAD. Currently, there are few patients not on antiretroviral therapy, therefore the group of HIV-infected patients not on ART was smaller than the other groups. We know that speckle tracking is a technique that depends on image quality and on the observer’s experience in evaluating the main curves of myocardial strain. We have observed a large number of studies using speckle tracking in an attempt to identify patients with subclinical left ventricular dysfunction, but we should increasingly stimulate further research with a greater number of investigated patients to better understand the significance of the findings in the prognosis of patients. 742