Preintervention Wait Time and Survival in People With Rheumatic Heart Disease in Uganda.

BACKGROUND: There is an unmet surgical burden among people living with rheumatic heart disease (RHD) in Uganda. Nevertheless, risk factors associated with time to first intervention and preoperative mortality are poorly understood. METHODS: Individuals with RHD who met indications for valve surgery were identified using the Uganda National RHD Registry (January 2010-August 2022). Kaplan-Meier estimates and multivariable Cox proportional hazard models were used. RESULTS: Of the cohort with clinical RHD, 64% (1452 of 2269) met criteria for an index operation. Of those, 13.5% obtained a surgical intervention, whereas 30.6% died before the operation. The estimated likelihood of first operation was 50% at 9.3 years of follow-up (95% CI, 8.1-upper limit not reached). Intervention was more likely in men vs women (hazard ratio [HR], 1.78; 95% CI, 1.21-2.64), those with postsecondary education vs primary school or less (HR, 3.60; 95% CI, 1.88-6.89), and those with a history of atrial fibrillation (HR, 2.78; 95% CI, 1.63-4.76). Surgical intervention was less likely for adults vs those aged <18 years (HR, 0.49; 95% CI, 0.32-0.77) and those with New York Heart Association Functional Class III/IV vs I/II (HR, 0.51; 95% CI, 0.32-0.83). The median preoperative survival time among those awaiting first operation was 4.6 years (95% CI, 3.9-5.7 years). History of infective endocarditis, right ventricular dysfunction, pericardial effusion, atrial fibrillation, and having surgical indications for multiple valves were associated with increased probability of death. CONCLUSIONS: Our analysis revealed a prolonged time to first surgical intervention and high preintervention death for RHD in Uganda, with factors such as age, sex, and education level remaining barriers to obtaining surgery.

Quality of Life in Ugandan Children and Young Adults After Surgery for Congenital Heart Disease: Mixed Methods Approach.

Background: Health-related quality of life (HRQOL) is a critical issue for patients undergoing surgery for congenital heart disease (CHD) but has never been assessed in a low-income country. We conducted a cross-sectional mixed methods study with age-matched healthy siblings serving as controls at the Uganda Heart Institute. Methods: One-hundred fifteen CHD pediatric and young adult patients and sibling control participants were recruited. Health-related quality of life was assessed using the Pediatric Quality of Life Inventory Version 4.0 in participants ages 5-17 and 36-Item Short Form Survey for young adults aged 18-25. A subset of 27 participants completed face-to-face interviews to supplement quantitative findings. Results: Eighty-six pediatric (age 5-17) sibling and parent pairs completed Peds QOL surveys, and 29 young adult (age 18-25) sibling pairs completed SF-36 surveys. One third of patients had surgery in Uganda. Ventricular septal defects and tetralogy of Fallot were the most common diagnoses. Health-related quality of life scores in patients were lower across all domains compared to control participants in children. Reductions in physical and emotional domains of HRQOL were also statistically significant for young adults. Variables associated with lower HRQOL score on multivariate analysis in pediatric patients were younger age in the physical and emotional domains, greater number of surgeries in the physical domain and surgery outside Uganda in the school domain. The only predictor of lower HRQOL score in young adults was surgery outside Uganda in the social domain. Qualitative interviews identified a number of themes that correlated with survey results including abandonment by family, isolation from peers and community, financial hardship and social stigmatization. Conclusion: Health-related quality of life was lower in Ugandan patients after CHD surgery than siblings. Younger patients and those who had surgery outside of Uganda had lower HRQOL. These data have important implications for patients undergoing CHD surgery in LMIC and have potential to inform interventions.

Outcomes of latent rheumatic heart disease: External validation of a simplified score in patients with and without secondary prophylaxis.

BACKGROUND: Secondary antibiotic prophylaxis reduces progression of latent rheumatic heart disease (RHD) but not all children benefit. Improved risk stratification could refine recommendations following positive screening. We aimed to evaluate the performance of a previously developed echocardiographic risk score to predict mid-term outcomes among children with latent RHD. METHODS: We included children who completed the GOAL, a randomized trial of secondary antibiotic prophylaxis among children with latent RHD in Uganda. Outcomes were determined by a 4-member adjudication panel. We applied the point-based score, consisting of 5 variables (mitral valve (MV) anterior leaflet thickening (3 points), MV excessive leaflet tip motion (3 points), MV regurgitation jet length ≥ 2 cm (6 points), aortic valve focal thickening (4 points) and any aortic regurgitation (5 points)), to panel results. Unfavorable outcome was defined as progression of diagnostic category (borderline to definite, mild definite to moderate/severe definite), worsening valve involvement or remaining with mild definite RHD. RESULTS: 799 patients (625 borderline and 174 definite RHD) were included, with median follow-up of 24 months. At total 116 patients (14.5%) had unfavorable outcome per study criteria, 57.8% not under prophylaxis. The score was strongly associated with unfavorable outcome (HR = 1.26, 95% CI 1.16-1.37, p < 0.001). Unfavorable outcome rates in low (≤6 points), intermediate (7-9 points) and high-risk (≥10 points) children at follow-up were 11.8%, 30.4%, and 42.2%, (p < 0.001) respectively (C-statistic = 0.64 (95% CI 0.59-0.69)). CONCLUSIONS: The simple risk score provided an accurate prediction of RHD status at 2-years, showing a good performance in a population with milder RHD phenotypes.

Serum Immune Responses to Group A Streptococcal Antigens following Pharyngeal Acquisitions among Children in Cape Town, South Africa.

There is limited information on the human immune response following infection with group A Streptococcus (Strep A). Animal studies have shown, in addition to the M protein, that shared Strep A antigens elicit protective immunity. This study aimed to investigate the kinetics of antibody responses against a panel of Strep A antigens in a cohort of school-aged children in Cape Town, South Africa. Participants provided serial throat cultures and serum samples at two-monthly follow-up visits. Strep A recovered were emm-typed, and serum samples were analyzed by enzyme-linked immunosorbent assay (ELISA) to assess immune responses to thirty-five Strep A antigens (10-shared and 25-M peptides). Serologic evaluations were performed on serial serum samples from 42 selected participants (from 256 enrolled) based on the number of follow-up visits, the frequency of visits, and throat culture results. Among these, there were 44 Strep A acquisitions, 36 of which were successfully emm-typed. Participants were grouped into three clinical event groups based on culture results and immune responses. A preceding infection was most convincingly represented by a Strep A-positive culture with an immune response to at least one shared antigen and M peptide (11 events) or a Strep A-negative culture with antibody responses to shared antigens and M peptides (9 events). More than a third of participants demonstrated no immune response despite a positive culture. This study provided important information regarding the complexity and variability of human immune responses following pharyngeal acquisition of Strep A, as well as demonstrating the immunogenicity of Strep A antigens currently under consideration as potential vaccine candidates. IMPORTANCE There is currently limited information regarding the human immune response to group A streptococcal throat infection. An understanding of the kinetics and specificity of antibody responses against a panel of Group A Streptococcus (GAS) antigens will serve to refine diagnostic approaches and contribute to vaccine efforts, which together will serve to reduce the burden of rheumatic heart disease, a major source of morbidity and mortality especially in the developing world. This study, utilizing an antibody-specific assay, uncovered three patterns of response profiles following GAS infection, among 256 children presenting with sore throat to local clinics. Overall, the response profiles were complex and variable. Of note, a preceding infection was most convincingly represented by a GAS-positive culture with an immune response to at least one shared antigen and M peptide. Also, more than a third of participants demonstrated no immune response despite a positive culture. All antigens tested were immunogenic, providing guidance for future vaccine development.

Secondary Antibiotic Prophylaxis for Latent Rheumatic Heart Disease.

BACKGROUND: Rheumatic heart disease affects more than 40.5 million people worldwide and results in 306,000 deaths annually. Echocardiographic screening detects rheumatic heart disease at an early, latent stage. Whether secondary antibiotic prophylaxis is effective in preventing progression of latent rheumatic heart disease is unknown. METHODS: We conducted a randomized, controlled trial of secondary antibiotic prophylaxis in Ugandan children and adolescents 5 to 17 years of age with latent rheumatic heart disease. Participants were randomly assigned to receive either injections of penicillin G benzathine (also known as benzathine benzylpenicillin) every 4 weeks for 2 years or no prophylaxis. All the participants underwent echocardiography at baseline and at 2 years after randomization. Changes from baseline were adjudicated by a panel whose members were unaware of the trial-group assignments. The primary outcome was echocardiographic progression of latent rheumatic heart disease at 2 years. RESULTS: Among 102,200 children and adolescents who had screening echocardiograms, 3327 were initially assessed as having latent rheumatic heart disease, and 926 of the 3327 subsequently received a definitive diagnosis on the basis of confirmatory echocardiography and were determined to be eligible for the trial. Consent or assent for participation was provided for 916 persons, and all underwent randomization; 818 participants were included in the modified intention-to-treat analysis, and 799 (97.7%) completed the trial. A total of 3 participants (0.8%) in the prophylaxis group had echocardiographic progression at 2 years, as compared with 33 (8.2%) in the control group (risk difference, -7.5 percentage points; 95% confidence interval, -10.2 to -4.7; P<0.001). Two participants in the prophylaxis group had serious adverse events that were attributable to receipt of prophylaxis, including one episode of a mild anaphylactic reaction (representing <0.1% of all administered doses of prophylaxis). CONCLUSIONS: Among children and adolescents 5 to 17 years of age with latent rheumatic heart disease, secondary antibiotic prophylaxis reduced the risk of disease progression at 2 years. Further research is needed before the implementation of population-level screening can be recommended. (Funded by the Thrasher Research Fund and others; GOAL ClinicalTrials.gov number, NCT03346525.).

Towards automatic diagnosis of rheumatic heart disease on echocardiographic exams through video-based deep learning.

OBJECTIVE: Rheumatic heart disease (RHD) affects an estimated 39 million people worldwide and is the most common acquired heart disease in children and young adults. Echocardiograms are the gold standard for diagnosis of RHD, but there is a shortage of skilled experts to allow widespread screenings for early detection and prevention of the disease progress. We propose an automated RHD diagnosis system that can help bridge this gap. MATERIALS AND METHODS: Experiments were conducted on a dataset with 11 646 echocardiography videos from 912 exams, obtained during screenings in underdeveloped areas of Brazil and Uganda. We address the challenges of RHD identification with a 3D convolutional neural network (C3D), comparing its performance with a 2D convolutional neural network (VGG16) that is commonly used in the echocardiogram literature. We also propose a supervised aggregation technique to combine video predictions into a single exam diagnosis. RESULTS: The proposed approach obtained an accuracy of 72.77% for exam diagnosis. The results for the C3D were significantly better than the ones obtained by the VGG16 network for videos, showing the importance of considering the temporal information during the diagnostic. The proposed aggregation model showed significantly better accuracy than the majority voting strategy and also appears to be capable of capturing underlying biases in the neural network output distribution, balancing them for a more correct diagnosis. CONCLUSION: Automatic diagnosis of echo-detected RHD is feasible and, with further research, has the potential to reduce the workload of experts, enabling the implementation of more widespread screening programs worldwide.

Impact of incorporating echocardiographic screening into a clinical prediction model to optimise utilisation of echocardiography in primary care.

INTRODUCTION: Access to public subspecialty healthcare is limited in underserved areas of Brazil, including echocardiography (echo). Long waiting lines and lack of a prioritisation system lead to diagnostic lag and may contribute to poor outcomes. We developed a prioritisation tool for use in primary care, aimed at improving resource utilisation, by predicting those at highest risk of having an abnormal echo, and thus in highest need of referral. METHODS: All patients in the existing primary care waiting list for echo were invited for participation and underwent a clinical questionnaire, simplified 7-view echo screening by non-physicians with handheld devices, and standard echo by experts. Two derivation models were developed, one including only clinical variables and a second including clinical variables and findings of major heart disease (HD) on echo screening (cut point for high/low-risk). For validation, patients were risk-classified according to the clinical score. High-risk patients and a sample of low-risk underwent standard echo. Intermediate-risk patients first had screening echo, with a standard echo if HD was suspected. Discrimination and calibration of the two models were assessed to predict HD in standard echo. RESULTS: In derivation (N = 603), clinical variables associated with HD were female gender, body mass index, Chagas disease, prior cardiac surgery, coronary disease, valve disease, hypertension and heart failure, and this model was well calibrated with C-statistic = 0.781. Performance was improved with the addition of echo screening, with C-statistic = 0.871 after cross-validation. For validation (N = 1526), 227 (14.9%) patients were classified as low risk, 1082 (70.9%) as intermediate risk and 217 (14.2%) as high risk by the clinical model. The final model with two categories had high sensitivity (99%) and negative predictive value (97%) for HD in standard echo. Model performance was good with C-statistic = 0.720. CONCLUSION: The addition of screening echo to clinical variables significantly improves the performance of a score to predict major HD.

Cardiac changes in pediatric cancer survivors.

Cardiac damage from chemotherapy is a known phenomenon leading to significant morbidity and mortality in the cancer surviving population, and identifying high-risk pediatric patients early is challenging. The purpose of this pilot study was to evaluate whether echo strain, cardiac MRI (CMR), and serum biomarkers are more sensitive methods for detecting cardiac toxicity than standard echo and to examine the relationship between biomarkers in patients without decreased systolic function as determined by standard echo. In this pilot study, we prospectively enrolled pediatric subjects after completion of anthracycline inclusive chemotherapy. Each subject underwent a post-treatment echocardiogram (standard with strain), serum biomarkers (N-terminal brain natriuretic peptide (NT-pro-BNP) and interleukin 1 receptor-like 1 protein (ST2)), and CMR (standard and extracellular volumes (ECVs)). We correlated the markers using Pearson correlation. We enrolled 30 subjects, 11F/19M, aged 8-21 years. Cumulative anthracycline dose (CAD) correlated with BNP (p=0.06), CMR ECV 4-chamber (p=0.05) and sagittal (p=0.01), and mitral valve E/A (p=0.02). BNP correlated with CMR ECV 4-chamber (p=0.001) and sagittal (p=0.001) and with echo average longitudinal strain (ALS) (p=0.05). This study demonstrated a significant correlation of CAD with BNP and CMR ECV. There was also a significant correlation of NT-pro-BNP with CMR ECV and ALS. Combining these parameters with standard echo has the potential to identify high-risk patients early. Further studies are needed for long-term follow-up and management in this vulnerable population.

Task shifting to clinical officer-led echocardiography screening for detecting rheumatic heart disease in Malawi, Africa.

BACKGROUND: Echocardiographic screening for rheumatic heart disease in asymptomatic children may result in early diagnosis and prevent progression. Physician-led screening is not feasible in Malawi. Task shifting to mid-level providers such as clinical officers may enable more widespread screening. Hypothesis With short-course training, clinical officers can accurately screen for rheumatic heart disease using focussed echocardiography. METHODS: A total of eight clinical officers completed three half-days of didactics and 2 days of hands-on echocardiography training. Clinical officers were evaluated by performing screening echocardiograms on 20 children with known rheumatic heart disease status. They indicated whether children should be referred for follow-up. Referral was indicated if mitral regurgitation measured more than 1.5 cm or there was any measurable aortic regurgitation. The κ statistic was calculated to measure referral agreement with a paediatric cardiologist. Sensitivity and specificity were estimated using a generalised linear mixed model, and were calculated on the basis of World Heart Federation diagnostic criteria. RESULTS: The mean κ statistic comparing clinical officer referrals with the paediatric cardiologist was 0.72 (95% confidence interval: 0.62, 0.82). The κ value ranged from a minimum of 0.57 to a maximum of 0.90. For rheumatic heart disease diagnosis, sensitivity was 0.91 (95% confidence interval: 0.86, 0.95) and specificity was 0.65 (95% confidence interval: 0.57, 0.72). CONCLUSION: There was substantial agreement between clinical officers and paediatric cardiologists on whether to refer. Clinical officers had a high sensitivity in detecting rheumatic heart disease. With short-course training, clinical officer-led echo screening for rheumatic heart disease is a viable alternative to physician-led screening in resource-limited settings.

School and Community Screening Shows Malawi, Africa, to Have a High Prevalence of Latent Rheumatic Heart Disease.

Rheumatic heart disease (RHD) is the largest cardiac cause of morbidity and mortality in the world's youth. Early detection of RHD through echocardiographic screening in asymptomatic children may identify an early stage of disease, when secondary prophylaxis has the greatest chance of stopping disease progression. Latent RHD signifies echocardiographic evidence of RHD with no known history of acute rheumatic fever and no clinical symptoms. OBJECTIVE: Determine the prevalence of latent RHD among children ages 5-16 in Lilongwe, Malawi. DESIGN: This is a cross-sectional study in which children ages 5 through 16 were screened for RHD using echocardiography. SETTING: Screening was conducted in 3 schools and surrounding communities in the Lilongwe district of Malawi between February and April 2014. OUTCOME MEASURES: Children were diagnosed as having no, borderline, or definite RHD as defined by World Heart Federation criteria. The primary reader completed offline reads of all studies. A second reader reviewed all of the studies diagnosed as RHD, plus a selection of normal studies. A third reader served as tiebreaker for discordant diagnoses. The distribution of results was compared between gender, location, and age categories using Fisher's exact test. RESULTS: The prevalence of latent RHD was 3.4% (95% CI = 2.45, 4.31), with 0.7% definite RHD and 2.7% borderline RHD. There was no significant differences in prevalence between gender (P = .44), site (P = .6), urban vs. peri-urban (P = .75), or age (P = .79). Of those with definite RHD, all were diagnosed because of pathologic mitral regurgitation (MR) and 2 morphologic features of the mitral valve. Of those with borderline RHD, most met the criteria by having pathological MR (92.3%). CONCLUSION: Malawi has a high rate of latent RHD, which is consistent with other results from sub-Saharan Africa. This study strongly supports the need for a RHD prevention and control program in Malawi.

Risk-stratified postnatal care of newborns with congenital heart disease determined by fetal echocardiography.

BACKGROUND: Advances in fetal echocardiography have improved recognition of congenital heart disease (CHD). Imaging protocols have been developed that predict delivery room (DR) risk and anticipated postnatal level of care (LOC). The aim of this study was to determine the utility of fetal echocardiography in the perinatal management of CHD. METHODS: A retrospective analysis of fetal and postnatal records was conducted. The anticipated LOC was assigned by fetal echocardiography (LOC 1, nursery consult/outpatient follow-up; LOC 2, stable in DR with transfer to cardiac hospital; LOC 3 or 4, DR instability/urgent intervention needed). Prenatal diagnoses and LOC assignment were compared with postnatal diagnoses, treatment, and short-term outcomes. RESULTS: From 2004 to 2012, 8,101 fetuses were evaluated; 7,405 were normal. Of 696 with CHD, 101 terminated, 40 died in utero, and 37 received palliative care. LOC was assigned in the remaining 518. Of 219 LOC 1, 195 (89%) had postnatal follow-up. Only two required transfer for intervention (LOC 1 sensitivity, 0.9; LOC 1 positive predictive value, 0.99). Of 260 assigned LOC 2, 229 (88%) had follow-up. Of these, 200 (87%) were transferred for surgery or intervention. The median time to admission was 195 min. Twenty-two patients (10%) assigned LOC 2 did not require intervention; however, seven (all with D-transposition of the great arteries) required catheter intervention before surgery. Hospital survival was 86% (LOC 2 sensitivity, 0.97; LOC 2 positive predictive value, 0.87). All LOC 3 and 4 patients had follow-up. Thirty-four (87%) needed urgent intervention, with 100% DR and 87% hospital survival (LOC 3 and 4 sensitivity, 0.83; LOC 3 and 4 positive predictive value, 0.87). CONCLUSIONS: Fetal echocardiography enables accurate postnatal risk stratification in CHD, with the exception of D-transposition of the great arteries. LOC 1 assignment facilitated outpatient follow-up; LOC 2 assignment facilitated transfer for intervention. LOC 3 and 4 patients underwent stabilizing intervention or surgery with good short-term outcomes. Given the inability to predict need for intervention in D-transposition of the great arteries, all such patients should be assigned as LOC 3 or 4. Fetal echocardiography with LOC assignment should be used in the planning of postnatal care in CHD.

Three-dimensional printing of intracardiac defects from three-dimensional echocardiographic images: feasibility and relative accuracy.

BACKGROUND: With the advent of three-dimensional (3D) printers and high-resolution cardiac imaging, rapid prototype constructions of congenital cardiac defects are now possible. Typically, source images for these models derive from higher resolution, cross-sectional cardiac imaging, such as cardiac magnetic resonance imaging or computed tomography. These imaging methods may involve intravenous contrast, sedation, and ionizing radiation. New echocardiographic transducers and advanced software and hardware have optimized 3D echocardiographic images for this purpose. Thus, the objectives of this study were to confirm the feasibility of creating cardiac models from 3D echocardiographic data and to assess accuracy by comparing 3D model measurements with conventional two-dimensional (2D) echocardiographic measurements of cardiac defects. METHODS: Nine patients undergoing 3D echocardiography were identified (eight with ventricular septal defects, one with three periprosthetic aortic valve leaks). Raw echocardiographic image data were exported anonymously and converted to Digital Imaging and Communications in Medicine format. The image data were filtered for noise reduction, imported into segmentation software to create a 3D digital model, and printed. Measurements of the defects from the 3D model were compared with defect measurements from conventional 2D echocardiographic data. Meticulous care was taken to ensure identical measurement planes. RESULTS: Long- and short-axis measurements of eight ventricular septal defects and three perivalvar leaks were obtained. Mean ± SD values for the 3D model measurements and conventional 2D echocardiographic measurements were 7.5 ± 6.3 and 7.1 ± 6.2 mm respectively (P = .20), indicating no significant differences between the standard 2D and 3D model measurements. The two groups were highly correlated, with a Pearson correlation coefficient of 0.988. The mean absolute error (2D - 3D) for each measurement was 0.4 ± 0.9 mm, indicating accuracy of the 3D model of <1 mm. CONCLUSIONS: Three-dimensional printed models of echocardiographic data are technically feasible and may accurately reflect ventricular septal defect anatomy. Three-dimensional models derived from 3D echocardiographic data sets represent a new tool in procedural planning for children with congenital heart disease.

Evaluation of a second-generation microtransesophageal echocardiography transducer and software.

BACKGROUND: Transesophageal echocardiographic imaging of small infants has been limited because of equipment size. A newer miniaturized transducer has allowed for the imaging of even the smallest patients but has been limited by intermittent poor image quality because of hardware durability. A second generation of the transducer was developed to address this problem. The aim of this study was to evaluate the performance and durability of the second-generation transducer over multiple uses and to compare the image quality from the modified transducer and new software preset to the original transducer. METHODS: Patients undergoing transesophageal echocardiography (TEE) based on clinical indications with the original or second-generation transducers were included in the study. All studies were reviewed for image quality and unacceptable image degradation, which was defined as imaging quality inadequate for clinical use. Study review was performed by two echocardiographers. RESULTS: Using the original transducer, 37 studies were performed with a mean patient weight of 3.46±0.89 kg (range 2.1-5.7). Using the second-generation transducer, 65 studies were performed with a mean patient weight of 4.87±2.05 kg (range 2.2-13.8). Image quality was clinically inadequate in 8 of the 35 studies with the original transducer and in zero with the second generation (P<.0001). CONCLUSIONS: The second-generation transducer allows for effective use of TEE even in the smallest infants and avoids the mechanical failures associated with the first-generation release.

Impact of telemedicine on hospital transport, length of stay, and medical outcomes in infants with suspected heart disease: a multicenter study.

BACKGROUND: Previous single-center studies have shown that telemedicine improves care in newborns with suspected heart disease. The aim of this study was to test the hypothesis that telemedicine would shorten time to diagnosis, prevent unnecessary transports, reduce length of stay, and decrease exposure to invasive treatments. METHODS: Nine pediatric cardiology centers entered data prospectively on patients aged <6 weeks, matched by gestational age, weight, and diagnosis. Subjects born at hospitals with and without access to telemedicine constituted the study group and control groups, respectively. Data from patients with mild or no heart disease were analyzed. RESULTS: Data were obtained for 337 matched pairs with mild or no heart disease. Transport to a tertiary care center (4% [n = 15] vs 10% [n = 32], P = .01), mean time to diagnosis (100 vs 147 min, P < .001), mean length of stay (1.0 vs 26 days, P = .005) and length of intensive care unit stay (0.96 vs 2.5 days, P = .024) were significantly less in the telemedicine group. Telemedicine patients were significantly farther from tertiary care hospitals than control subjects. The use of inotropic support and indomethacin was significantly less in the telemedicine group. By multivariate analysis, telemedicine patients were less likely to be transported (odds ratio, 0.44; 95% confidence interval, 0.23-0.83) and less likely to be placed on inotropic support (odds ratio, 0.16; 95% confidence interval, 0.10-0.28). CONCLUSIONS: Telemedicine shortened the time to diagnosis and significantly decreased the need for transport of infants with mild or no heart disease. The length of hospitalization and intensive care stay and use of indomethacin and inotropic support were less in telemedicine patients.

Pulmonary artery pressure and iron deficiency in patients with upregulation of hypoxia sensing due to homozygous VHL(R200W) mutation (Chuvash polycythemia).

BACKGROUND: Patients with Chuvash polycythemia, (homozygosity for the R200W mutation in the von Hippel Lindau gene (VHL)), have elevated levels of hypoxia inducible factors HIF-1 and HIF-2, often become iron-deficient secondary to phlebotomy, and have elevated estimated pulmonary artery pressure by echocardiography. The objectives of this study were to provide a comprehensive echocardiographic assessment of cardiovascular physiology and to identify clinical, hematologic and cardiovascular risk factors for elevation of tricuspid regurgitation velocity in children and adults with Chuvash polycythemia. DESIGN AND METHODS: This cross-sectional observational study of 120 adult and pediatric VHL(R200W) homozygotes and 31 controls at outpatient facilities in Chuvashia, Russian Federation included echocardiography assessment of pulmonary artery pressure (tricuspid regurgitation velocity), cardiac volume, and systolic and diastolic function, as well as hematologic and clinical parameters. We determined the prevalence and risk factors for elevation of tricuspid regurgitation velocity in this population and its relationship to phlebotomy. RESULTS: The age-adjusted mean ± SE tricuspid regurgitation velocity was higher in VHL(R200W) homozygotes than controls with normal VHL alleles (2.5±0.03 vs. 2.3±0.05 m/sec, P=0.005). The age-adjusted left ventricular diastolic diameter (4.8±0.05 vs. 4.5±0.09 cm, P=0.005) and left atrial diameter (3.4±0.04 vs. 3.2±0.08 cm, P=0.011) were also greater in the VHL(R200W) homozygotes, consistent with increased blood volume, but the elevation in tricuspid regurgitation velocity persisted after adjustment for these variables. Among VHL(R200W) homozygotes, phlebotomy therapy was associated with lower serum ferritin concentration, and low ferritin independently predicted higher tricuspid regurgitation velocity (standardized beta=0.29; P=0.009). CONCLUSIONS: Children and adults with Chuvash polycythemia have higher estimated right ventricular systolic pressure, even after adjustment for echocardiography estimates of blood volume. Lower ferritin concentration, which is associated with phlebotomy, independently predicts higher tricuspid regurgitation velocity (www.clinicaltrials.gov identifier NCT00495638).