Surgery for rheumatic heart disease in the Northern Territory, Australia, 1997–2016: what have we gained?

Abstract

BackgroundBetween 1964 and 1996, the 10-year survival of patients having valve replacement surgery for rheumatic heart disease (RHD) in the Northern Territory, Australia, was 68%. As medical care has evolved since then, this study aimed to determine whether there has been a corresponding improvement in survival.MethodsA retrospective study of Aboriginal patients with RHD in the Northern Territory, Australia, having their first valve surgery between 1997 and 2016. Survival was examined using Kaplan-Meier and Cox regression analysis.FindingsThe cohort included 281 adults and 61 children. The median (IQR) age at first surgery was 31 (18–42) years; 173/342 (51%) had a valve replacement, 113/342 (33%) had a valve repair and 56/342 (16%) had a commissurotomy. There were 93/342 (27%) deaths during a median (IQR) follow-up of 8 (4–12) years. The overall 10-year survival was 70% (95% CI: 64% to 76%). It was 62% (95% CI: 53% to 70%) in those having valve replacement. There were 204/281 (73%) adults with at least 1 preoperative comorbidity. Preoperative comorbidity was associated with earlier death, the risk of death increasing with each comorbidity (HR: 1.3 (95% CI: 1.2 to 1.5), p<0.001). Preoperative chronic kidney disease (HR 6.5 (95% CI: 3.0 to 14.0) p≤0.001)), coronary artery disease (HR 3.3 (95% CI: 1.3 to 8.4) p=0.012) and pulmonary artery systolic pressure>50 mm Hg before surgery (HR 1.9 (95% CI: 1.2 to 3.1) p=0.007) were independently associated with death.InterpretationSurvival after valve replacement for RHD in this region of Australia has not improved. Although the patients were young, many had multiple comorbidities, which influenced long-term outcomes. The increasing prevalence of complex comorbidity in the region is a barrier to achieving optimal health outcomes.

Mechanical valve replacement for patients with rheumatic heart disease: the reality of INR control in Africa and beyond

“…However, for RHD, mechanical valve replacement showed poor results even if the patients underwent surgery in an industrialised country. In Australia's aboriginal population, the 10-year mortality rate after mechanical valve replacement was 38% (27). Similarly, Maori and Pacific Island women returning from mechanical heart valve replacement in New Zealand had a 7-8-fold higher relative risk of death compared with their European counterparts operated at the same institution (17) and more than double the risk of dying compared with those with tissue valves in spite of a 2.8-fold higher risk of re-operation in the latter group.…”

Tertiary prevention and treatment of rheumatic heart disease: a National Heart, Lung, and Blood Institute working group summary

“…Outcomes can also markedly differ depending on the time of presentation (ie, extent of valvular calcification and destruction) and the presence of comorbidities Patients with RHD and preoperative comorbidities have a higher risk of operative mortality, especially when suffering from chronic kidney disease, coronary artery disease and pulmonary artery disease. In the long term, the presence of comorbidities may also negate the survival benefits associated with surgical care for RHD 14…”

“…In the long term, the presence of comorbidities may also negate the survival benefits associated with surgical care for RHD. 14 …”

Australia's rheumatic fever strategy three years on

“…Additional investment from BHP will expand the number of services participating in the program 5 . We also look to the tertiary health system to address its own shortcomings: long term survival of Aboriginal people with RHD valve replacements in the Northern Territory has not improved from 1964 6 …”