Kathryn Roberts

Screening for rheumatic heart disease: current approaches and controversies.

Rheumatic heart disease (RHD) is a leading cause of cardiac disease among children in developing nations, and in indigenous populations of some industrialized countries. In endemic areas, RHD has long been a target of screening programmes that, historically, have relied on cardiac auscultation. The evolution of portable echocardiographic equipment has changed the face of screening for RHD over the past 5 years, with greatly improved sensitivity. However, concerns have been raised about the specificity of echocardiography, and the interpretation of minor abnormalities poses new challenges. The natural history of RHD in children with subclinical abnormalities detected by echocardiographic screening remains unknown, and long-term follow-up studies are needed to evaluate the significance of detecting these changes at an early stage. For a disease to be deemed suitable for screening from a public health perspective, it needs to fulfil a number of criteria. RHD meets some, but not all, of these criteria. If screening programmes are to identify additional cases of RHD, parallel improvements in the systems that deliver secondary prophylaxis are essential.

Echocardiographic Screening for Rheumatic Heart Disease in High and Low Risk Australian Children

Background— Echocardiographic screening for rheumatic heart disease (RHD) is becoming more widespread, but screening studies to date have used different echocardiographic definitions. The World Heart Federation has recently published new criteria for the echocardiographic diagnosis of RHD. We aimed to establish the prevalence of RHD in high-risk Indigenous Australian children using these criteria and to compare the findings with a group of Australian children at low risk for RHD. Methods and Results— Portable echocardiography was performed on high-risk Indigenous children aged 5 to15 years living in remote communities of northern Australia. A comparison group of low-risk, non-Indigenous children living in urban centers was also screened. Echocardiograms were reported in a standardized, blinded fashion. Of 3946 high-risk children, 34 met World Heart Federation criteria for definite RHD (prevalence, 8.6 per 1000 [95% confidence interval, 6.0–12.0]) and 66 for borderline RHD (prevalence, 16.7 per 1000 [95% confidence interval, 13.0–21.2]). Of 1053 low-risk children, none met the criteria for definite RHD, and 5 met the criteria for borderline RHD. High-risk children were more likely to have definite or borderline RHD than low-risk children (adjusted odds ratio, 5.7 [95% confidence interval, 2.3–14.1]; P<0.001). Conclusions— The prevalence of definite RHD in high-risk Indigenous Australian children approximates what we expected in our population, and no definite RHD was identified in the low-risk group. This study suggests that definite RHD, as defined by the World Heart Federation criteria, is likely to represent true disease. Borderline RHD was identified in children at both low and high risk, highlighting the need for longitudinal studies to evaluate the clinical significance of this finding.

Long-term outcomes from acute rheumatic fever and rheumatic heart disease: A data-linkage and survival analysis approach

Background: We investigated adverse outcomes for people with acute rheumatic fever (ARF) and rheumatic heart disease (RHD) and the effect of comorbidities and demographic factors on these outcomes. Methods: Using linked data (RHD register, hospital, and mortality data) for residents of the Northern Territory of Australia, we calculated ARF recurrence rates, rates of progression from ARF to RHD to severe RHD, RHD complication rates (heart failure, endocarditis, stroke, and atrial fibrillation), and mortality rates for 572 individuals diagnosed with ARF and 1248 with RHD in 1997 to 2013 (94.9% Indigenous). Results: ARF recurrence was highest (incidence, 3.7 per 100 person-years) in the first year after the initial ARF episode, but low-level risk persisted for >10 years. Progression to RHD was also highest (incidence, 35.9) in the first year, almost 10 times higher than ARF recurrence. The median age at RHD diagnosis in Indigenous people was young, especially among males (17 years). The development of complications was highest in the first year after RHD diagnosis: heart failure incidence rate per 100 person-years, 9.09; atrial fibrillation, 4.70; endocarditis, 1.00; and stroke, 0.58. Mortality was higher among Indigenous than non-Indigenous RHD patients (hazard ratio, 6.55; 95% confidence interval, 2.45–17.51), of which 28% was explained by comorbid renal failure and hazardous alcohol use. RHD complications and mortality rates were higher for urban than for remote residents. Conclusions: This study provides important new prognostic information for ARF/RHD. The residual Indigenous survival disparity in RHD patients, which persisted after accounting for comorbidities, suggests that other factors contribute to mortality, warranting further research.

Rheumatic heart disease severity, progression and outcomes: A multi-state model

Background Rheumatic heart disease (RHD) remains a disease of international importance, yet little has been published about disease progression in a contemporary patient cohort. Multi‐state models provide a well‐established method of estimating rates of transition between disease states, and can be used to evaluate the cost‐effectiveness of potential interventions. We aimed to create a multi‐state model for RHD progression using serial clinical data from a cohort of Australian patients. Methods and Results The Northern Territory RHD register was used to identify all Indigenous residents diagnosed with RHD between the ages of 5 and 24 years in the time period 1999–2012. Disease severity over time, surgeries, and deaths were evaluated for 591 patients. Of 96 (16.2%) patients with severe RHD at diagnosis, 50% had proceeded to valve surgery by 2 years, and 10% were dead within 6 years. Of those diagnosed with moderate RHD, there was a similar chance of disease regression or progression over time. Patients with mild RHD at diagnosis were the most stable, with 64% remaining mild after 10 years; however, 11.4% progressed to severe RHD and half of these required surgery. Conclusions The prognosis of young Indigenous Australians diagnosed with severe RHD is bleak; interventions must focus on earlier detection and treatment if the observed natural history is to be improved. This multi‐state model can be used to predict the effect of different interventions on disease progression and the associated costs.

Long-Term Outcomes From Acute Rheumatic Fever and Rheumatic Heart DiseaseClinical Perspective: A Data-Linkage and Survival Analysis Approach

Background: We investigated adverse outcomes for people with acute rheumatic fever (ARF) and rheumatic heart disease (RHD) and the effect of comorbidities and demographic factors on these outcomes. Methods: Using linked data (RHD register, hospital, and mortality data) for residents of the Northern Territory of Australia, we calculated ARF recurrence rates, rates of progression from ARF to RHD to severe RHD, RHD complication rates (heart failure, endocarditis, stroke, and atrial fibrillation), and mortality rates for 572 individuals diagnosed with ARF and 1248 with RHD in 1997 to 2013 (94.9% Indigenous). Results: ARF recurrence was highest (incidence, 3.7 per 100 person-years) in the first year after the initial ARF episode, but low-level risk persisted for >10 years. Progression to RHD was also highest (incidence, 35.9) in the first year, almost 10 times higher than ARF recurrence. The median age at RHD diagnosis in Indigenous people was young, especially among males (17 years). The development of complications was highest in the first year after RHD diagnosis: heart failure incidence rate per 100 person-years, 9.09; atrial fibrillation, 4.70; endocarditis, 1.00; and stroke, 0.58. Mortality was higher among Indigenous than non-Indigenous RHD patients (hazard ratio, 6.55; 95% confidence interval, 2.45–17.51), of which 28% was explained by comorbid renal failure and hazardous alcohol use. RHD complications and mortality rates were higher for urban than for remote residents. Conclusions: This study provides important new prognostic information for ARF/RHD. The residual Indigenous survival disparity in RHD patients, which persisted after accounting for comorbidities, suggests that other factors contribute to mortality, warranting further research.

Long-Term Outcomes From Acute Rheumatic Fever and Rheumatic Heart Disease

Background: We investigated adverse outcomes for people with acute rheumatic fever (ARF) and rheumatic heart disease (RHD) and the effect of comorbidities and demographic factors on these outcomes. Methods: Using linked data (RHD register, hospital, and mortality data) for residents of the Northern Territory of Australia, we calculated ARF recurrence rates, rates of progression from ARF to RHD to severe RHD, RHD complication rates (heart failure, endocarditis, stroke, and atrial fibrillation), and mortality rates for 572 individuals diagnosed with ARF and 1248 with RHD in 1997 to 2013 (94.9% Indigenous). Results: ARF recurrence was highest (incidence, 3.7 per 100 person-years) in the first year after the initial ARF episode, but low-level risk persisted for >10 years. Progression to RHD was also highest (incidence, 35.9) in the first year, almost 10 times higher than ARF recurrence. The median age at RHD diagnosis in Indigenous people was young, especially among males (17 years). The development of complications was highest in the first year after RHD diagnosis: heart failure incidence rate per 100 person-years, 9.09; atrial fibrillation, 4.70; endocarditis, 1.00; and stroke, 0.58. Mortality was higher among Indigenous than non-Indigenous RHD patients (hazard ratio, 6.55; 95% confidence interval, 2.45–17.51), of which 28% was explained by comorbid renal failure and hazardous alcohol use. RHD complications and mortality rates were higher for urban than for remote residents. Conclusions: This study provides important new prognostic information for ARF/RHD. The residual Indigenous survival disparity in RHD patients, which persisted after accounting for comorbidities, suggests that other factors contribute to mortality, warranting further research.

Long-Term Outcomes From Acute Rheumatic Fever and Rheumatic Heart DiseaseClinical Perspective

Background: We investigated adverse outcomes for people with acute rheumatic fever (ARF) and rheumatic heart disease (RHD) and the effect of comorbidities and demographic factors on these outcomes. Methods: Using linked data (RHD register, hospital, and mortality data) for residents of the Northern Territory of Australia, we calculated ARF recurrence rates, rates of progression from ARF to RHD to severe RHD, RHD complication rates (heart failure, endocarditis, stroke, and atrial fibrillation), and mortality rates for 572 individuals diagnosed with ARF and 1248 with RHD in 1997 to 2013 (94.9% Indigenous). Results: ARF recurrence was highest (incidence, 3.7 per 100 person-years) in the first year after the initial ARF episode, but low-level risk persisted for >10 years. Progression to RHD was also highest (incidence, 35.9) in the first year, almost 10 times higher than ARF recurrence. The median age at RHD diagnosis in Indigenous people was young, especially among males (17 years). The development of complications was highest in the first year after RHD diagnosis: heart failure incidence rate per 100 person-years, 9.09; atrial fibrillation, 4.70; endocarditis, 1.00; and stroke, 0.58. Mortality was higher among Indigenous than non-Indigenous RHD patients (hazard ratio, 6.55; 95% confidence interval, 2.45–17.51), of which 28% was explained by comorbid renal failure and hazardous alcohol use. RHD complications and mortality rates were higher for urban than for remote residents. Conclusions: This study provides important new prognostic information for ARF/RHD. The residual Indigenous survival disparity in RHD patients, which persisted after accounting for comorbidities, suggests that other factors contribute to mortality, warranting further research.