Background
Despite studies demonstrating an increase in myocardial steatotic burden in adults with HIV on antiretroviral therapy (ART), no studies have evaluated this phenomenon in youth with perinatally-acquired HIV (YPHIV).
Methods
The Cape Town Adolescent Antiretroviral Cohort (CTAAC)-Heart study enrolled youth to assess myocardial fibrosis and inflammation using cardiovascular magnetic resonance (CMR). A magnetic resonance proton spectroscopy (1H-MRS) sub-study was conducted among YPHIV to assess myocardial triglyceride (mTG) content. 1H-MRS was acquired by means of an ECG-triggered, respiratory-gated sequence using a 6x16x18mm voxel placed within the intra-ventricular septum. Fibrosis was assessed using pre-and post-contrast T1 mapping with Siemens MyoMapsTM modified Look-Locker inversion recovery sequence and post-contrast T1-weighted phase sensitive inversion recovery sequences with mean extracellular volume fraction (ECV%) calculated. T2 mapping was performed using a T2-prepared fast low angle shot sequence to assess for inflammation. Pathologically elevated mTG content was defined as >0.5%. Logistic regression models were fit to assess the association of sex with mTG content >0.5% adjusting for confounders.
Results
Overall, 72 YPHIV [median age (interquartile range (IQR)) 18 years (17-19), 44% females] were included. Females had a higher BMI [24 vs. 20kg/m2, p=0.002] and waist to height ratio [0.48 vs. 0.43, p<0.001] compared to males. There were no differences in serum lipid levels, viral load (VL), CD4 count or current integrase inhibitor (INSTI) use; 28% of participants were on INSTI-based ART and 63% had CD4 counts >500 cells/mm3 with a median VL of 3.91 log10 copies/ml (IQR 3.66-6.02). In addition to higher mean ECV% and native T1, females were noted to have higher mTG content [0.34 vs. 0.13%, p=0.003]. (Table 1) A higher proportion of females had mTG content >0.5% (42 vs. 17%). This relationship persisted even after adjusting for age, BMI, VL, and INSTI-based ART use [unadjusted odds ratio (OR)=3.67, 95% confidence interval (CI): 1.14-11.84, p=0.03; adjusted OR=3.78, 95%CI: 0.98-14.63, p=0.05].
Conclusions
In the first study of 1H-MRS among YPHIV on ART, we report elevated mTG in YPHIV, with females found to have increased myocardial steatosis and fibrosis compared to males. Based on these findings, we propose there is a role for early screening, prevention, and possible intervention in YPHIV, particularly females.