The burden and natural history of cardiac pathology at TB diagnosis in a high-HIV prevalence district in Zambia: protocol for the TB-Heart study.

BACKGROUND: Tuberculosis (TB) continues to be a major cause of death across sub-Saharan Africa (SSA). In parallel, non-communicable disease and especially cardiovascular disease (CVD) burden has increased substantially in the region. Cardiac manifestations of TB are well-recognised but the extent to which they co-exist with pulmonary TB (PTB) has not been systematically evaluated. The aim of this study is to improve understanding of the burden of cardiac pathology in PTB in those living with and without HIV in a high-burden setting. METHODS: This is a cross-sectional and natural history study to evaluate the burden and natural history of cardiac pathology in participants with PTB in Lusaka, Zambia, a high burden setting for TB and HIV. Participants with PTB, with and without HIV will be consecutively recruited alongside age- and sex-matched TB-uninfected comparators on a 2:1 basis. Participants will undergo baseline assessments to collect clinical, socio-demographic, functional, laboratory and TB disease impact data followed by point-of-care and standard echocardiography. Participants with PTB will undergo further repeat clinical and functional examination at two- and six months follow-up. Those with cardiac pathology at baseline will undergo repeat echocardiography at six months. DISCUSSION: The outcomes of the study are to a) determine the burden of cardiac pathology at TB diagnosis, b) describe its association with patient-defining risk factors and biochemical markers of cardiac injury and stretch and c) describe the natural history of cardiac pathology during the course of TB treatment.

Barriers and facilitators for the provision of radiology services in Zimbabwe: A qualitative study based on staff experiences and observations.

Despite its fundamental role in diagnostic and curative care, radiology has been described as a neglected essential service in many low and middle-income countries (LMICs). Previous studies have demonstrated basic equipment and infrastructure shortages in LMIC settings, but no studies to date have gone further in understanding the perceptions and experiences of staff delivering radiology services, as a way of identifying their perspectives on barriers and facilitators for delivering services, and the potential for where improvements can be made. Our qualitative study aimed to: (a) identify barriers for delivering radiology services, and (b) suggest potential facilitators for improvement of radiology service delivery in the Zimbabwean context; from the perspective of radiology staff. We conducted semi-structured interviews (n = 13) and three focus groups (n = 24 radiographers), followed by four half- to full- days of field observations to validate insights from the interviews and focus groups in all three public hospitals and one private hospital in the Harare metropolitan area. Our study identified four main barriers for delivering radiology services: (i) poor basic infrastructure, equipment, and consumables; (ii) suboptimal equipment maintenance; (iii) shortage of radiology staff and skills development; and (iv) lack of wider integration and support for radiology services. We also identified a strong sense of motivation among staff to keep radiology services, pointing to what may be an enabler and facilitator for improving radiology services. These findings point to potential risks to patient safety and quality of delivering radiology services. More importantly, we found a strong sense of personal motivation displayed by the staff, suggesting there is the potential to maintain and improve existing practices, but this would require investments to train and remunerate more radiology staff, as well as investing in continuing professional development.

Association of HIV Infection With Cardiovascular Pathology Based on Advanced Cardiovascular Imaging: A Systematic Review.

Importance: HIV-associated cardiovascular disease is increasing in prevalence, but its mechanisms remain poorly understood. Objective: To systematically review data from advanced cardiovascular imaging studies evaluating computed tomographic coronary angiography, positron emission tomography (PET), and cardiac magnetic resonance (MR), in people living with HIV compared with uninfected individuals. Data Sources: Three databases and Google Scholar were searched for studies assessing cardiovascular pathology using computed tomographic coronary angiography, cardiac MR, PET, and HIV from inception to February 11, 2022. Study Selection: Two reviewers selected original studies without any restrictions on design, date, or language, investigating HIV and cardiovascular pathology. Data Extraction and Synthesis: One investigator extracted data checked by a second investigator. Prevalence ratios (PRs) and differences in inflammation among people living with HIV and uninfected individuals were qualitatively synthesized in terms of cardiovascular pathology. Study quality was assessed using the National Heart, Lung, and Blood Institute quality assessment tool for observational studies. Main Outcomes and Measures: Primary outcomes were computed tomographic coronary angiography-defined moderate to severe (≥50%) coronary stenosis, cardiac MR-defined myocardial fibrosis identified by late gadolinium enhancement, and PET-defined vascular and myocardial target to background ratio. Prevalence of moderate to severe coronary disease, as well as myocardial fibrosis, and PRs compared with uninfected individuals were reported alongside difference in vascular target to background ratio. Results: Forty-five studies including 5218 people living with HIV (mean age, 48.5 years) and 2414 uninfected individuals (mean age, 49.1 years) were identified. Sixteen studies (n = 5107 participants) evaluated computed tomographic coronary angiography; 16 (n = 1698), cardiac MRs; 10 (n = 681), vascular PET scans; and 3 (n = 146), both computed tomographic coronary angiography and vascular PET scans. No studies originated from low-income countries. Regarding risk of bias, 22% were classified as low; 47% moderate; and 31% high. Prevalence of moderate to severe coronary disease among those with vs without HIV ranged from 0% to 52% and 0% to 27%, respectively, with PRs ranging from 0.33 (95% CI, 0.01-15.90) to 5.19 (95% CI, 1.26-21.42). Prevalence of myocardial fibrosis among those with vs without HIV ranged from 5% to 84% and 0% to 68%, respectively, with PRs ranging from 1.01 (95% CI, 0.85-1.21) to 17.35 (95% CI, 1.10-274.28). Differences in vascular target to background ratio among those with vs without HIV ranged from 0.06 (95% CI, 0.01-0.11) to 0.37 (95% CI, 0.02-0.72). Conclusions and Relevance: In this systematic review of studies of advanced cardiovascular imaging, the estimates of the associations between HIV and cardiovascular pathologies demonstrated large amounts of heterogeneity. The findings provide a summary of the available data but may not be representative of all individuals living with HIV, including those from low-income countries with higher HIV endemicity.

Proinflammatory and cardiovascular biomarkers are associated with echocardiographic abnormalities in children with HIV taking antiretroviral therapy.

OBJECTIVES: Children with perinatally acquired HIV (PHIV) and taking antiretroviral therapy (ART) have a high prevalence of subclinical cardiac disease. We hypothesized that cardiac disease may be a consequence of dysregulated systemic immune activation driven by HIV infection. We examined cardiovascular and proinflammatory biomarkers and their association with echocardiographic abnormalities in children with PHIV. DESIGN: Cross-sectional analysis of soluble biomarkers from a prospective cohort of children aged 6-16 years with PHIV and age-matched HIV-uninfected comparison group. METHODS: Cryopreserved plasma samples were used to measure seven soluble biomarkers using multiplex bead assay (Luminex). Multivariable logistic regression assessed how biomarker levels related to cardiac abnormalities. RESULTS: A total of 406 children participated in this study (195 PHIV and 211 HIV-uninfected). Mean [standard deviation (SD)] ages of PHIV and HIV-uninfected participants were 10.7 (2.6) and 10.8 (2.8) years, respectively. Plasma levels of CRP, TNF-α, ST2, VCAM-1 and GDF-15 were significantly higher in the PHIV group compared with uninfected control ( P  < 0.001). Among children with PHIV, with one-unit representing one SD in biomarker level, a one-unit increase in CRP and GDF-15, was associated with increased odds of having left ventricular (LV) diastolic dysfunction [adjusted odds ratio (aOR), 1.49 (1.02-2.18; P  < 0.040)] and [aOR 1.71 (1.18-2.53; P  = 0.006)], respectively. Each one unit increase in GDF-15 was associated with increased odds of LV hypertrophy [aOR 1.84 (95% CI 1.10-3.10; P  < 0.021)]. CONCLUSION: Children with PHIV had higher levels of proinflammatory and cardiovascular biomarkers compared with HIV-uninfected children. Increased CRP and GDF-15 were associated with cardiac abnormalities in children with PHIV.

The effect of perinatal HIV and antiretroviral therapy on vascular structure and function in young people: A systematic review and meta-analysis.

BACKGROUND AND AIMS: Perinatal HIV infection (PHIV) and prolonged use of antiretroviral therapy (ART) may increase the likelihood of developing subclinical vascular dysfunction at an early age. We conducted a systematic review to assess the effect of PHIV and ART on intima-media thickness (IMT), arterial stiffness and endothelial function in individuals aged 6-25 years. METHODS: Medline, Embase and Web of Science were searched, and studies screened by two independent reviewers. We performed a meta-analysis on selected studies reporting on IMT. RESULTS: A total of 680 studies were retrieved from the databases, with 21 studies deemed eligible for qualitative analysis. There were few studies assessing IMT, arterial stiffness and endothelial function. More than half of the studies found either increased IMT, stiffer arteries or impaired endothelial function in PHIV compared to uninfected controls. A minority of the studies reported that the two groups had similar vascular parameters, a conflicting finding. There was a lack of standardisation for IMT assessment and reporting in numerous studies. In a meta-analysis of seven studies with matching methodologies, IMT was higher in PHIV compared to uninfected controls, (mean difference, 0.05 (0.01-0.09; p = 0.01) but heterogeneity between the studies was substantial (I2, 96.7%; p < 0.001). CONCLUSIONS: PHIV may affect vascular structure and function. Existing studies are generally small, often contradictory, and predominantly cross-sectional in design. Further studies are required to understand vascular health in PHIV to identify cardiovascular disease risk and improve interventional strategies aimed at prevention and treatment of early vascular changes in this population.

The effect of azithromycin for management of HIV-associated chronic lung disease on right heart function: Results from the BREATHE trial.

BACKGROUND: Right heart abnormalities and pulmonary hypertension (PH) may be secondary to chronic lung disease. Chronic lung disease is common in children with HIV. In the BREATHE trial ( Trial registration: NCT02426112), azithromycin (AZM) reduced the risk of acute respiratory exacerbations in children aged 6-19 years with HIV-associated chronic lung disease (HCLD) taking antiretroviral therapy. We assessed the possible effect of AZM on right heart dysfunction and/or PH in the trial. METHODS: A standardised transthoracic echocardiogram using M-mode, two-dimensional and Doppler was performed, at baseline and at completion of weight-based AZM given weekly for 48 weeks. Linear regression was used to compare trial arms. RESULTS: A total of 169 participants (82 AZM arm; 87 placebo arm) were included. Participants in the placebo arm were older, median age 16.2 (13.0-18.2) vs 15.3 (12.9-17.4) years, p = 0.184 in the AZM arm. At baseline, right heart abnormalities (right ventricular systolic dysfunction (RVSD), dilatation, or PH) were observed in 7(4%). Following treatment, there was no difference in prevalence of RVSD between arms (p = 0.761). There was one incident case of suspected PH, and overall, no difference in pulmonary pressures. CONCLUSION: In children with HCLD, there was evidence of secondary cardiac effects, but AZM had no effect on right heart function. Long-term follow-up in children with HIV should be part of future research to understand the clinical implications of right heart abnormalities.

Effect of Once-Weekly Azithromycin vs Placebo in Children With HIV-Associated Chronic Lung Disease: The BREATHE Randomized Clinical Trial.

Importance: HIV-associated chronic lung disease (HCLD) in children is associated with small airways disease, is common despite antiretroviral therapy (ART), and is associated with substantial morbidity. Azithromycin has antibiotic and immunomodulatory activity and may be effective in treating HCLD through reducing respiratory tract infections and inflammation. Objective: To determine whether prophylactic azithromycin is effective in preventing worsening of lung function and in reducing acute respiratory exacerbations (AREs) in children with HCLD taking ART. Design, Setting, and Participants: This double-blind, placebo-controlled, randomized clinical trial (BREATHE) was conducted between 2016 and 2019, including 12 months of follow-up, at outpatient HIV clinics in 2 public sector hospitals in Malawi and Zimbabwe. Participants were randomized 1:1 to intervention or placebo, and participants and study personnel were blinded to treatment allocation. Participants included children aged 6 to 19 years with perinatally acquired HIV and HCLD (defined as forced expiratory volume in 1 second [FEV1] z score < -1) who were taking ART for 6 months or longer. Data analysis was performed from September 2019 to April 2020. Intervention: Once-weekly oral azithromycin with weight-based dosing, for 48 weeks. Main Outcomes and Measures: All outcomes were prespecified. The primary outcome was the mean difference in FEV1 z score using intention-to-treat analysis for participants seen at end line. Secondary outcomes included AREs, all-cause hospitalizations, mortality, and weight-for-age z score. Results: A total of 347 individuals (median [interquartile range] age, 15.3 [12.7-17.7] years; 177 boys [51.0%]) were randomized, 174 to the azithromycin group and 173 to the placebo group; 162 participants in the azithromycin group and 146 placebo group participants had a primary outcome available and were analyzed. The mean difference in FEV1 z score was 0.06 (95% CI, -0.10 to 0.21; P = .48) higher in the azithromycin group than in the placebo group, a nonsignificant difference. The rate of AREs was 12.1 events per 100 person-years in the azithromycin group and 24.7 events per 100 person-years in the placebo groups (hazard ratio, 0.50; 95% CI, 0.27 to 0.93; P = .03). The hospitalization rate was 1.3 events per 100 person-years in the azithromycin group and 7.1 events per 100 person-years in the placebo groups, but the difference was not significant (hazard ratio, 0.24; 95% CI, 0.06 to 1.07; P = .06). Three deaths occurred, all in the placebo group. The mean weight-for-age z score was 0.03 (95% CI, -0.08 to 0.14; P = .56) higher in the azithromycin group than in the placebo group, although the difference was not significant. There were no drug-related severe adverse events. Conclusions and Relevance: In this randomized clinical trial specifically addressing childhood HCLD, once-weekly azithromycin did not improve lung function or growth but was associated with reduced AREs; the number of hospitalizations was also lower in the azithromycin group but the difference was not significant. Future research should identify patient groups who would benefit most from this intervention and optimum treatment length, to maximize benefits while reducing the risk of antimicrobial resistance. Trial Registration: ClinicalTrials.gov Identifier: NCT02426112.

Distinct lung microbiota associate with HIV-associated chronic lung disease in children.

Chronic lung disease (CLD) is a common co-morbidity for HIV-positive children and adolescents on antiretroviral therapy (ART) in sub-Saharan Africa. In this population, distinct airway microbiota may differentially confer risk of CLD. In a cross-sectional study of 202 HIV-infected children aged 6-16 years in Harare, Zimbabwe, we determined the association of sputum microbiota composition (using 16S ribosomal RNA V4 gene region sequencing) with CLD defined using clinical, spirometric, or radiographic criteria. Forty-two percent of children were determined to have CLD according to our definition. Dirichlet multinomial mixtures identified four compositionally distinct sputum microbiota structures. Patients whose sputum microbiota was dominated by Haemophilus, Moraxella or Neisseria (HMN) were at 1.5 times higher risk of CLD than those with Streptococcus or Prevotella (SP)-dominated microbiota (RR = 1.48, p = 0.035). Cell-free products of HMN sputum microbiota induced features of epithelial disruption and inflammatory gene expression in vitro, indicating enhanced pathogenic potential of these CLD-associated microbiota. Thus, HIV-positive children harbor distinct sputum microbiota, with those dominated by Haemophilus, Moraxella or Neisseria associated with enhanced pathogenesis in vitro and clinical CLD.

Chronic comorbidities in children and adolescents with perinatally acquired HIV infection in sub-Saharan Africa in the era of antiretroviral therapy.

Globally, 1·7 million children are living with HIV, of which 90% are in sub-Saharan Africa. The remarkable scale-up of combination antiretroviral therapy has resulted in increasing numbers of children with HIV surviving to adolescence. Unfortunately, in sub-Saharan Africa, HIV diagnosis is often delayed with children starting antiretroviral therapy late in childhood. There have been increasing reports from low-income settings of children with HIV who have multisystem chronic comorbidities despite antiretroviral therapy. Many of these chronic conditions show clinical phenotypes distinct from those in adults with HIV, and result in disability and reduced quality of life. In this Review, we discuss the spectrum and pathogenesis of comorbidities in children with HIV in sub-Saharan Africa. Prompt diagnosis and treatment of perinatally acquired HIV infection is a priority. Additionally, there is a need for increased awareness of the burden of chronic comorbidities. Diagnostic and therapeutic strategies need to be collectively developed if children with HIV are to achieve their full potential.

Carotid intima media thickness in older children and adolescents with HIV taking antiretroviral therapy.

Increased carotid intima-media thickness (cIMT) is reported in both adults and children with human immunodeficiency virus (HIV) in high income settings and is associated with an increased risk of cardiovascular disease, but data from sub-Saharan Africa is lacking.We assessed cIMT using ultrasound in perinatally HIV-infected children aged 6 to 16 years taking antiretroviral therapy (ART) for ≥6 months compared with HIV-uninfected controls in Harare, Zimbabwe. Groups were compared using unpaired t test and potential predictors of cIMT were assessed using multiple linear regression.A total of 117 participants with HIV, of whom 55 (45%) were female and 75 healthy uninfected controls were included. Participants with HIV were younger than uninfected controls, 10.7 (2.4) years versus 11.9 (2.6) years (P = .001). Mean cIMT was 0.40 (0.05) mm in those with HIV versus 0.40 (0.04) mm in healthy controls (P = .377). There was no association between cluster of differentiation 4 count, HIV viral load, and duration on ART and cIMT.Children with HIV taking ART have similar cIMT to uninfected children. Increasing numbers of children with HIV are reaching adulthood and longitudinal studies to assess the effect of long-term HIV and ART on vascular changes are required.

Incidence and Progression of Echocardiographic Abnormalities in Older Children with Human Immunodeficiency Virus and Adolescents Taking Antiretroviral Therapy: A Prospective Cohort Study.

BACKGROUND: A high prevalence of cardiac abnormalities has been reported in children with human immunodeficiency virus (HIV) taking antiretroviral therapy (ART) in sub-Saharan Africa. We investigated the incidence and progression of cardiac abnormalities among children taking ART in Zimbabwe. METHODS: A prospective cohort study was conducted at a pediatric HIV clinic from 2014 to 2017. Children with HIV aged between 6 and 16 years and taking ART ≥6 months were enrolled. Transthoracic echocardiography was performed at baseline and after 18 months. RESULTS: Of 197 participants recruited at baseline, 175 (89%; 48% female; median age 12 years, interquartile range 10-14 years) were followed up. The incidences of left and right heart abnormalities were 3.52 and 5.64 per 100 person-years, respectively. Stunting was associated with the development of any cardiac abnormality (adjusted odds ratio 2.59, 95% confidence interval 1.03-6.49; P = .043). Right ventricular (RV) dilatation persisted at follow-up in 92% of participants and left ventricular (LV) diastolic dysfunction in 88%. Cardiac abnormalities present at baseline reverted to normal over the follow-up period in 11 (6%). There was an overall increase in mean z scores for LV, left atrium (LA), RV, interventricular septum, and LV posterior wall diameters at 18 months (P < .001). CONCLUSIONS: Despite ART, children with HIV have a high incidence of cardiac abnormalities, with only a minority being transient. Mean z scores for LV, LA, RV, interventricular septum, and LV posterior wall diameters increased over a relatively short follow-up period, suggesting the potential for progression of cardiac abnormalities. Longer follow-up is required to understand the clinical implications of these abnormalities.

History of tuberculosis is associated with lower exhaled nitric oxide levels in HIV-infected children.

OBJECTIVE: HIV disrupts host defense mechanisms and maintains chronic inflammation in the lung. Nitric oxide is a marker of lung inflammation and can be measured in the exhaled air. We investigated the relationship between exhaled nitric oxide (eNO), HIV status and airway abnormalities in perinatally HIV-infected children aged 6-19 years. DESIGN: A cross-sectional study. METHODS: HIV-infected individuals on antiretroviral therapy and HIV-uninfected children with no active tuberculosis (TB) or acute respiratory tract infection were recruited from a public hospital in Harare, Zimbabwe. Clinical history was collected and eNO testing and spirometry was performed. The association between eNO and explanatory variables (HIV, FEV1 z-score, CD4 cell count, viral load, history of TB) was investigated using linear regression analysis adjusted for age, sex and time of eNO testing. RESULTS: In total, 222 HIV-infected and 97 HIV-uninfected participants were included. Among HIV-infected participants, 57 (25.7%) had a history of past TB; 56 (25.2%) had airway obstruction, but no prior TB. HIV status was associated with lower eNO level [mean ratio 0.79 (95% confidence interval, 95% CI 0.65-0.97), P = 0.03]. Within the HIV-infected group, history of past TB was associated with lower eNO levels after controlling for age, sex and time of eNO testing [0.79 (95% CI 0.67-0.94), P = 0.007]. CONCLUSION: HIV infection and history of TB were associated with lower eNO levels. eNO levels may be a marker of HIV and TB-induced alteration in pulmonary physiology; further studies focused on potential causes for lower eNO levels in HIV and TB are warranted.

Unexpectedly High Prevalence of Cytomegalovirus DNAemia in Older Children and Adolescents With Perinatally Acquired Human Immunodeficiency Virus Infection.

BACKGROUND: Older children and adolescents with perinatally acquired human immunodeficiency virus (PHIV) infection in Africa experience multiple comorbidities that are not typical of HIV-associated opportunistic infections, including growth impairment and chronic lung disease. We examined associations between plasma cytomegalovirus (CMV) DNA and lung function and growth. METHODS: Plasma CMV DNA loads were measured children aged 6-16 years with PHIV (n = 402) and HIV-uninfected controls (n = 224). The HIV-infected children were either newly diagnosed or known HIV infected and stable on antiretroviral therapy (ART) for >6 months. CMV DNA loads were measured using quantitative polymerase chain reaction. CMV DNAemia was modeled as a time-varying outcome using longitudinal mixed-effects logistic regression. RESULTS: At enrollment, CMV DNAemia ≥1000 copies/mL (defined as "clinically significant") was detected in 5.8% of uninfected children, 14.7% of HIV-infected participants stable on ART, and 22.6% of HIV-infected ART-naive children (χ2 = 23.8, P < .001). The prevalence of CMV DNAemia ≥1000 copies/mL was associated with CD4 counts <350 cells/µL. Among HIV-infected ART-naive children, the presence of CMV DNAemia of ≥1000 copies/mL was independently associated with reduced lung function (adjusted odds ratio [aOR] = 3.23; 95% confidence interval [CI], 1.23-8.46; P = .017). Among ART-treated children, stunting was associated with CMV DNAemia of ≥1000 copies/mL (aOR = 2.79; 95% CI, 0.97-8.02; P = .057). CONCLUSIONS: Clinically significant levels of CMV DNAemia were common in older children with PHIV, even those on ART, suggesting a role for inadequately controlled CMV infection in the pathogenesis of PHIV comorbidities in Africa.

High prevalence of echocardiographic abnormalities in older HIV-infected children taking antiretroviral therapy.

BACKGROUND: Antiretroviral therapy (ART) has decreased mortality so that increasing numbers of children with HIV are reaching adolescence. However, longstanding HIV infection and/or its treatment in children is associated with noninfectious complications including cardiac disease. We investigated the prevalence, spectrum and risk factors for echocardiographic abnormalities among children established on ART. METHODS: HIV-infected children aged 6-16 years, on ART at least 6 months were enrolled into a cross-sectional study from a public-sector paediatric HIV clinic in Harare, Zimbabwe. A standardized examination including transthoracic echocardiography was performed. Local echocardiographic reference ranges were used to define cardiac abnormalities. Logistic regression was used to examine the association between cardiac abnormalities and risk factors. RESULTS: Of the 201participants recruited, 92 (46%) were girls and median age was 11 (IQR 9-12) years; CD4+ cell count was 727 cells/µl (IQR 473-935) and 154 (78%) had viral load less than 400 copies/ml. Echocardiographic abnormalities were found in 83 (42%); left ventricular (LV) diastolic dysfunction was the most common abnormality 45 (23%) and LV hypertrophy in 22 (11%). LV and left atrial dilatation were found in 9 (5%) and 16 (8%), respectively. Right ventricular dilatation and systolic dysfunction were found in 13 (7%) and 4 (2%), respectively, of whom 60% had concurrent left heart abnormalities. Current use of nevirapine was associated with LVH [aOR 3.14 (1.13-8.72; P = 0.03)] and hypertension was associated with LV diastolic dysfunction [aOR 3.12 (1.48-6.57; P < 0.01)]. CONCLUSION: HIV-infected children established on ART have a high burden of echocardiographic abnormalities. Right heart disease was predominantly associated with left heart abnormalities and may be part of a global cardiomyopathic process. Further studies are needed to investigate the natural history, aetiology, and pathogenesis of these abnormalities, so that appropriate monitoring and treatment strategies can be developed.

Racial Variation in Echocardiographic Reference Ranges for Left Chamber Dimensions in Children and Adolescents: A Systematic Review.

Echocardiography plays a critical role in the assessment of cardiac disease. Important differences in echocardiographically derived cardiac chamber dimensions have been previously highlighted in different population groups in adult studies, but this has not been systematically studied in children, whose body size changes throughout childhood. The aim of this study was to review the distribution of available reference ranges for the left cardiac chamber dimensions in older children and adolescents. The following electronic data bases were searched: Medline, Embase and Web of Science were searched to identify studies which have established echocardiographic reference ranges of left heart parameters in children and adolescents from 1975 to December 2017. There was no geographical limitation. All results were imported into Endnote. Retrieved articles were screened and data extracted by two independent reviewers. A total of 4398 studies were retrieved, with 36 studies finally included in this review. 29 (81%) references were from North America and European (Caucasians) populations, with only one study each from Africa and South America. Two-dimensional and M-mode techniques were the most commonly used echocardiography techniques. There were methodological variations in techniques and normalisation of references. Comparison of selected cardiac measures showed significant differences for interventricular septal thickness among Black African, Indian, German and US American children. Available echocardiographic references cannot be generalised to all settings and therefore, there is need for locally relevant reference ranges. Africa and South America are particularly under-represented. Future studies should focus on developing comprehensive echocardiographic reference ranges for children from different racial backgrounds and should use standardised techniques.

Echocardiographic reference ranges in older children and adolescents in sub-Saharan Africa.

BACKGROUND: Echocardiographic reference ranges are important to identify abnormalities of cardiac dimensions. Reference ranges for children in sub-Saharan Africa have not been established. The aim of this study was to establish echocardiographic z-score references for Black children in sub-Saharan Africa. METHODS: 282 healthy subjects aged 6-16years (143 [51%] males) with no known history of cardiac disease were enrolled in the study in Harare, Zimbabwe between 2014 and 2016. Standard M-mode echocardiography was performed and nine cardiac chamber dimensions were obtained. Two non-linear statistical models (gamma weighted model and cubic polynomial model) were tested on the data and the best fitting model was used to calculate z-scores of these cardiac chamber measures. The reference ranges are presented on scatter plots against BSA. RESULTS: Normative data for the following cardiac measures were obtained and z-scores calculated: right ventricular diameter at end diastole (RVEDD); left ventricular diameter at end diastole (LVEDD) and systole (LVESD); interventricular septal wall thickness at end diastole (IVSd) and systole (IVSs); left ventricular posterior wall thickness at end diastole (LVPWd) and systole (LVPWs); left atrium diameter at end systole (LA) and tricuspid annular plane systolic excursion (TAPSE). Girls had higher values for BMI and heart rate than boys (p=0.048 and p=0.001, respectively). Mean interventricular septal and left ventricular posterior walls thickness was higher than published normal values in predominantly Caucasian populations. CONCLUSION: These are the first echocardiographic reference ranges for children from sub Saharan Africa and will allow accurate assessment of cardiac dimensions in clinical practice.