HIV-infected Children in Malawi Have Decreased Performance on the 6-minute Walk Test With Preserved Cardiac Mechanics Regardless of Antiretroviral Treatment Status
The aims of this study were to 1) determine if cardiac disease can be detected in HIV-infected children by strain imaging and 2) to evaluate differences in exercise performance between HIV-infected children on antiretroviral therapy (ART) and HIV-infected children not yet on ART and in HIV-uninfected children by 6-minute walk tests (6MWTs).Methods:
This cross-sectional study evaluated cardiac function by echocardiogram and exercise performance by 6MWT in HIV-infected and HIV-uninfected children 4–18 years of age in Lilongwe, Malawi. Analyses compared HIV uninfected, HIV infected not yet on ART, and HIV infected on ART. Comparisons used χ2 test, t test, analysis of variance and multiple linear regression.Results:
No differences were found in ejection fraction, shortening fraction or strain in 73 children not yet on ART, 149 on ART and 77 HIV-uninfected controls. As viral load increased, children had worse circumferential strain. In addition, children receiving ART had better circumferential strain than those not yet on ART. Increased CD4 percentage was associated with better longitudinal strain and farther 6MWT distance. As longitudinal strain worsened, the 6MWT distance decreased. HIV-infected children not yet on ART walked a mean of 25.8 m less than HIV-uninfected children, and HIV-infected children on ART walked 25.9 m less (P = 0.015 comparing 3 groups).Conclusions:
HIV-uninfected children performed better on the 6MWT than HIV-infected children. Lower viral load, being on ART, and higher CD4 percentage were associated with better strain measures. Better longitudinal strain was associated with a farther 6MWT distance. Overall, ejection fraction, shortening fraction and strain measures between groups were similar, so cardiac strain did not detect cardiac dysfunction in this young population.