Cardioprotective effects of antiretroviral treatment in adolescents with perinatal HIV infection are heterogeneous depending on age at treatment initiation.

The cardioprotective effects of antiretroviral treatment (ART) in adolescents with perinatal HIV infection (APHIV) may depend on age at ART initiation. We used cardiovascular magnetic resonance (CMR) to characterize and compare residual cardiac changes in apparently healthy APHIV with early and delayed ART initiation compared to sex- and age-similar HIV uninfected peers. We defined early and delayed ART as, respectively, treatment initiated at <5 years and ≥5 years of age. Cardiac function, mechanical deformation, geometry and tissue composition were assessed. APHIV had distinct albeit subclinical cardiac phenotypes depending on timing of ART initiation. For example, changes in early ART suggested comparatively worse diastology with preserved systolic function while delayed ART was associated with comparatively increased diffuse fibrosis and LV dilatation with reduced systolic function. The long-term clinical significance of these changes remains to be determined.

Simulating Subject-Specific Aortic Hemodynamic Effects of Valvular Lesions in Rheumatic Heart Disease.

Rheumatic heart disease (RHD) is a neglected tropical disease despite the substantial global health burden. In this study, we aimed to develop a lower cost method of modeling aortic blood flow using subject-specific velocity profiles, aiding our understanding of RHD's consequences on the structure and function of the ascending aorta. Echocardiography and cardiovascular magnetic resonance (CMR) are often used for diagnosis, including valve dysfunction assessments. However, there is a need to further characterize aortic valve lesions to improve treatment options and timing for patients, while using accessible and affordable imaging strategies. Here, we simulated effects of RHD aortic valve lesions on the aorta using computational fluid dynamics (CFD). We hypothesized that inlet velocity distribution and wall shear stress (WSS) will differ between RHD and non-RHD individuals, as well as between subject-specific and standard Womersley velocity profiles. Phase-contrast CMR data from South Africa of six RHD subjects with aortic stenosis and/or regurgitation and six matched controls were used to estimate subject-specific velocity inlet profiles and the mean velocity for Womersley profiles. Our findings were twofold. First, we found WSS in subject-specific RHD was significantly higher (p < 0.05) than control subject simulations, while Womersley simulation groups did not differ. Second, evaluating spatial velocity differences (ΔSV) between simulation types revealed that simulations of RHD had significantly higher ΔSV than non-RHD (p < 0.05), these results highlight the need for implementing subject-specific input into RHD CFD, which we demonstrate how to accomplish through accessible methods.

Left ventricular remodeling and its correlates among adolescents with perinatally acquired HIV in South Africa.

BACKGROUND: Left ventricular (LV) remodeling and its transitions from compensatory adaptations to LV dysfunction have not been examined in adolescents with perinatally acquired HIV infection (PHIV). We used cardiovascular magnetic resonance (CMR) in a cross-sectional study to characterize PHIV-related progressive LV remodeling in adolescents in South Africa. METHODS: Adolescents with PHIV on antiretroviral treatment and their HIV uninfected peers completed 3 T CMR examination. We defined LV remodeling by LV mass/volume (M/V) ratio, modelling progressive LV remodeling as increasing M/V ratio. Linear regression models were applied to estimate the correlates of progressive LV remodeling. RESULTS: Overall, 71 adolescents with PHIV [mean age: 15.2 years; 54% male] and 36 HIV uninfected [15.1 years; 42% male] peers were enrolled. Adolescents with PHIV had lower mean LV M/V ratio (0.68 vs. 0.75 g/mL; p = 0.004) than HIV uninfected peers, without LV hypertrophy in either group. Among adolescents with PHIV, increasing M/V ratio was accompanied by increasing interstitial volume [adjusted mean change (AMC) per 0.1 g/mL M/V ratio: 1.75 mL, p < 0.001] with no change in global circumferential strain (GCS) [AMC per 0.1 g/mL M/V ratio: -0.21%, p = 0.48]. However, in HIV uninfected individuals, increasing M/V ratio was accompanied by increasing peak GCS [AMC per 0.1 g/mL M/V ratio: -1.25%, p = 0.039] with no change in interstitial volume (AMC per 0.1 g/mL M/V ratio: 1.16 mL, p = 0.32]. CONCLUSIONS: Successfully treated PHIV is associated with less severe LV remodeling in adolescence when compared to HIV uninfected controls. LV remodeling in PHIV is associated with disproportionate expansion of the non-contractile interstitium not accompanied by improved GCS.

Cardiovascular imaging modalities in the diagnosis and management of rheumatic heart disease.

Rheumatic heart disease (RHD) is prevalent in sub-Saharan Africa, where the capacity for diagnosis and evaluation of disease severity and complications is not always optimal. While the medical history and physical examination are important in the assessment of patients suspected to have RHD, cardiovascular imaging techniques are useful for confirmation of the diagnosis. Echocardiography is the workhorse modality for initial evaluation and diagnosis of RHD. Cardiovascular magnetic resonance is complementary and may provide additive information, including tissue characteristics, where echocardiography is inadequate or non-diagnostic. There is emerging evidence on the role of computed tomography, particularly following valve replacement surgery, in the monitoring and management of RHD. This article summarises the techniques used in imaging RHD patients, considers the evidence base for their utility, discusses their limitations and recognises the clinical contexts in which indications and imaging with various modalities are expanding.

Review of cardiovascular magnetic resonance in human immunodeficiency virus-associated cardiovascular disease.

Despite ongoing advances in the treatment of patients with human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS), they remain a major global public health concern conferring an increased risk of morbidity and mortality in affected individuals. This is, in part, because of the widespread dysfunction imposed by HIV and its treatment on the cardiovascular system, including the myocardium, valvular apparatus, pericardium and coronary, pulmonary and peripheral vasculature. In recent times, cardiovascular magnetic resonance (CMR) imaging has emerged as the gold standard tool for assessment of a variety of indications, allowing comprehensive characterisation of functional, morphological, metabolic and haemodynamic sequelae of several cardiovascular pathologies. Furthermore, continued advancement in imaging techniques has yielded novel insights into the underlying pathophysiology and guides future therapeutic strategies. In this article, we review the various clinical phenotypes of HIV-associated cardiovascular disease and highlight the utility of CMR in their assessment.

Diagnosing cardiac disease during pregnancy: imaging modalities.

Pregnant women with known or suspected cardiovascular disease (CVD) often require cardiovascular imaging during pregnancy. The accepted maximum limit of ionising radiation exposure to the foetus during pregnancy is a cumulative dose of 5 rad. Concerns related to imaging modalities that involve ionising radiation include teratogenesis, mutagenesis and childhood malignancy. Importantly, no single imaging study approaches this cautionary dose of 5 rad (50 mSv or 50 mGy). Diagnostic imaging procedures that may be used in pregnancy include chest radiography, fluoroscopy, echocardiography, invasive angiography, cardiovascular computed tomography, computed tomographic pulmonary angiography, cardiovascular magnetic resonance (CMR) and nuclear techniques. Echocardiography and CMR appear to be completely safe in pregnancy and are not associated with any adverse foetal effects, provided there are no general contra-indications to MR imaging. Concerns related to safety of imaging tests must be balanced against the importance of accurate diagnosis and thorough assessment of the pathological condition. Decisions about imaging in pregnancy are premised on understanding the physiology of pregnancy, understanding basic concepts of ionising radiation, the clinical manifestations of existent CVD in pregnancy and features of new CVD. The cardiologist/physician must understand the indications for and limitations of, and the potential harmful effects of each test during pregnancy. Current evidence suggests that a single cardiovascular radiological study during pregnancy is safe and should be undertaken at all times when clinically justified. In this article, the different imaging modalities are reviewed in terms of how they work, how safe they are and what their clinical utility in pregnancy is. Furthermore, the safety of contrast agents in pregnancy is also reviewed.