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—Utilising 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 complications (heart failure, endocarditis, stroke and atrial fibrillation) and mortality rates for 572 individuals diagnosed with ARF and 1248 with RHD in 1997-2013 (94.9% Indigenous).
Results—ARF recurrence was highest (incidence 3.7 per 100 person-years) in the first year after initial ARF episode but low-level risk persisted for more than 10 years. Progression to RHD was also highest (incidence 35.9) in the first year, almost ten times higher than ARF recurrence. The median age at RHD diagnosis in Indigenous people was young, especially amongst males (17yrs). 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; stroke: 0.58. Mortality was higher among Indigenous than non-Indigenous RHD patients (hazard ratio 6.55, 2.45-17.51), of which 28% was explained by comorbid renal failure and hazardous alcohol use. RHD complications and mortality were higher for urban than 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 other factors contribute to mortality, warranting further research.
- rheumatic fever
- rheumatic heart disease
- comorbidities heart failure
- survival analysis
- Received December 16, 2015.
- Revision received April 23, 2016.
- Accepted May 27, 2016.
Circulation is published on behalf of the American Heart Association, Inc., by Wolters Kluwer. This is an open access article under the terms of the Creative Commons Attribution Non-Commercial-NoDervis License (http://creativecommons.org/licenses/by-nc-nd/3.0/), which permits use, distribution, and reproduction in any medium, provided that the original work is properly cited, the use is noncommercial, and no modifications or adaptations are made.