Rheumatic Heart Disease Severity, Progression and Outcomes: A Multi‐State Model

Abstract

BackgroundRheumatic 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 ResultsThe 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.ConclusionsThe 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.

Rheumatic heart disease in North Darfur: an alarmingly high burden and control initiative

“…It was found that the presence of severe disease indicated the need for surgical intervention in up to 50% by 2 years. In the same study, it was shown that 10% of patients with severe RHD were dead within 6 years [7]. This data emphasises that surgery is the only treatment that prevents death in patients with severe RHD.…”

Echocardiographic Screening for Rheumatic Heart Disease in Indigenous Australian Children: A Cost–Utility Analysis

“…A separate analysis was done looking at the potential health effects and economic outcomes of improved adherence to secondary prophylaxis. For modeling purposes, we analyzed the potential effect of increasing adherence to 100%, which, by reducing ARF recurrences, we hypothesized may result in the following improvements in disease progression: Mild RHD remains mild (does not progress to moderate or severe disease). Moderate RHD: (a) A 50% reduction in progression is shown from moderate to severe disease or surgery (in our current practice model, ≈29% currently progress over 10 years since diagnosis, so our improved prophylaxis model allowed 15% to progress, with the other 14% remaining moderate); (b) other transitions from the moderate state remain the same. Severe RHD showed no change to observed disease progression. …”

“…shown from moderate to severe disease or surgery (in our current practice model, %29% currently progress over 10 years since diagnosis, 9 so our improved prophylaxis model allowed 15% to progress, with the other 14% remaining moderate); (b) other transitions from the moderate state remain the same. 3.…”

Screening University Students for Rheumatic Heart Disease

“…Disease severity varies over time, when workers [33] used a multistage model in which surgeries and deaths were evaluated in 591 patients with RHD, one half of cases with severe disease proceeded to valve surgery by 2 years, and 10% were dead within 6 years. Those diagnosed with moderate RHD, had a similar chance of disease regression or progression over time.…”