A review of outcome following valve surgery for rheumatic heart disease in Australia

Contemporary spectrum, characteristics, and outcomes of adult patients with rheumatic valvular disease in China: Insights from the China-VHD study

Background

Rheumatic valvular disease (RVD) represents a significant health concern in developing countries, yet a scarcity of detailed data exists. This study conducts a comprehensive examination of RVD patients in China, exploring aspects of the disease's spectrum, characteristics, investigation, management, and outcomes.

Methods

The China Valvular Heart Disease (China-VHD) study, a nationwide, multicenter, prospective observational study, enrolled 13,917 adults with moderate-to-severe valvular heart disease from April to June 2018. Among these, 2402 patients with native RVD (19.7% of native VHD patients) were analyzed.

Results

Among the RVD patients, the median age was 57 years (interquartile range 50-65), with 82.5% falling within the 40-70 age range; females were notably predominant (63.9%). Rheumatic etiology prevailed, particularly in southern regions (48.8%). Multivalvular involvement was observed in 47.4% of RVD cases, and atrial fibrillation emerged as the most common comorbidity (43.2%). Severe RVD affected 64.2% of patients. Valvular interventions were undertaken by 66.9% of RVD patients, predominantly involving surgical valve replacement (90.8%). Adverse events, encompassing all-cause mortality and heart failure hospitalization, occurred in 7.3% of patients during the 2-year follow-up. Multivariable analysis identified factors such as age, geographical region, low body mass index, renal insufficiency, left atrial diameter, and left ventricular ejection fraction <50% (all P < 0.05) associated with adverse events, with valvular intervention emerging as a protective factor (HR: 0.201; 95%CI: 0.139 to 0.291; p < 0.001).

Conclusions

This study delivers a comprehensive evaluation of RVD patients in China, shedding light on the spectrum, characteristics, investigation, management, and outcomes of this prevalent condition.

Left ventricular remodelling in rheumatic heart disease - trends over time and implications for follow-up in childhood

BACKGROUND

Rheumatic heart disease (RHD) is the most common form of acquired heart disease worldwide. In RHD, volume loading from mitral regurgitation leads to left ventricular (LV) dilatation, increased wall stress, and ultimately LV dysfunction. Improved understanding of LV dynamics may contribute to refined timing of intervention. We aimed to characterize and compare left ventricular remodelling between rheumatic heart disease (RHD) severity groups by way of serial echocardiographic assessment of volumes and function in children.

METHODS

Children with RHD referred to Perth Children's Hospital (formally Princess Margaret Hospital) (1987-2020) were reviewed. Patients with longitudinal pre-operative echocardiograms at diagnosis, approximately 12 months and at most recent follow-up, were included and stratified into RHD severity groups. Left ventricular (LV) echocardiographic parameters were assessed. Adjusted linear mixed effect models were used to compare interval changes.

RESULTS

146 patients (median age 10 years, IQR 6-14 years) with available longitudinal echocardiograms were analysed. Eighty-five (58.2%) patients had mild, 33 (22.6%) moderate and 28 (19.2%) severe RHD at diagnosis. Mean duration of follow-up was 4.6 years from the initial diagnosis. Severe RHD patients had significantly increased end-systolic volumes (ESV) and end-diastolic volumes (EDV) compared to mild/moderate groups at diagnosis (severe versus mild EDV mean difference 27.05 ml/m2, p < 0.001, severe versus moderate EDV mean difference 14.95 ml/m2, p = 0.006). Mild and moderate groups experienced no significant progression of changes in volume measures. In severe RHD, LV dilatation worsened over time. All groups had preserved cardiac function.

CONCLUSIONS

In mild and moderate RHD, the lack of progression of valvular regurgitation and ventricular dimensions suggest a stable longer-term course. Significant LV remodelling occurred at baseline in severe RHD with progression of LV dilatation over time. LV function was preserved across all groups. Our findings may guide clinicians in deciding the frequency and timing of follow-up and may be of clinical utility during further reiterations of the Australia and New Zealand RHD Guidelines.

Transcatheter heart valve interventions for patients with rheumatic heart disease

Rheumatic heart disease [RHD] is the most prevalent cause of valvular heart disease in the world, outstripping degenerative aortic stenosis numbers fourfold. Despite this, global resources are firmly aimed at improving the management of degenerative disease. Reasons remain complex and include lack of resources, expertise, and overall access to valve interventions in developing nations, where RHD is most prevalent. Is it time to consider less invasive alternatives to conventional valve surgery? Several anatomical and pathological differences exist between degenerative and rheumatic valves, including percutaneous valve landing zones. These are poorly documented and may require dedicated solutions when considering percutaneous intervention. Percutaneous balloon mitral valvuloplasty (PBMV) is the treatment of choice for severe mitral stenosis (MS) but is reserved for patients with suitable valve anatomy without significant mitral regurgitation (MR), the commonest lesion in RHD. Valvuloplasty also rarely offers a durable solution for patients with rheumatic aortic stenosis (AS) or aortic regurgitation (AR). MR and AR pose unique challenges to successful transcatheter valve implantation as landing zone calcification, so central in docking transcatheter aortic valves in degenerative AS, is often lacking. Surgery in young RHD patients requires mechanical prostheses for durability but morbidity and mortality from both thrombotic complications and bleeding on Warfarin remains excessively high. Also, redo surgery rates are high for progression of aortic valve disease in patients with prior mitral valve replacement (MVR). Transcatheter treatments may offer a solution to anticoagulation problems and address reoperation in patients with prior MVR or failing ventricles, but would have to be tailored to the rheumatic environment. The high prevalence of MR and AR, lack of calcification and other unique anatomical challenges remain. Improvements in tissue durability, the development of novel synthetic valve leaflet materials, dedicated delivery systems and docking stations or anchoring systems to securely land the transcatheter devices, would all require attention. We review the epidemiology of RHD and discuss anatomical differences between rheumatic valves and other pathologies with a view to transcatheter solutions. The shortcomings of current RHD management, including current transcatheter treatments, will be discussed and finally we look at future developments in the field.

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

BACKGROUND

Between 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.

METHODS

A 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.

FINDINGS

The 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.

INTERPRETATION

Survival 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.

Long-term outcomes of severe rheumatic mitral stenosis after undergoing percutaneous mitral commissurotomy and mitral valve replacement: A 10-year experience

Introduction: Percutaneous mitral commissurotomy (PTMC) and mitral valve replacement (MVR) are treatments of choice for severe rheumatic mitral stenosis (MS). Data regarding the long-term outcomes of patients who underwent PTMC and MVR are limited.

Methods: A retrospective cohort study was conducted to evaluate the long-term outcomes of patients with severe rheumatic MS who underwent PTMC or MVR between 2010 to 2020. The primary outcome comprised of all-cause death, stroke or systemic embolism, heart failure hospitalization and re-intervention. Cox regression was used to investigate predictors of the primary outcome.

Results: 264 patients were included in analysis, 164 patients (62.1%) in PTMC group and 100 patients in MVR group (37.9%). The majority were females (80.7%) and had atrial fibrillation (68.6%). The mean age was 49.52 (SD: 13.03) years old. MVR group had more age and AF, higher Wilkins’ score with smaller MVA. Primary outcome occurred significantly higher in PTMC group (37.2% vs 22%, P=0.002), as well as, re-intervention (18.3% vs 0%, P<0.001). However, all-cause mortality, stroke or systemic embolism and heart failure hospitalization were not significantly different. In multivariate Cox regression analysis, PTMC (HR 1.94; 95%CI 1.14, 3.32; P=0.015), older age (HR 1.03; 95%CI 1.01, 1.06; P=0.009) and SPAP > 50 mmHg (HR 2.99; 95%CI 1.01, 8.84; P=0.047) were the only predictors of primary outcome.

Conclusion: Primary outcome occurred in PTMC group more than MVR group which was driven by re-intervention. However, all-cause mortality, stroke or systemic embolism and heart failure hospitalization were not significantly different.

Impact of renin-angiotensin system inhibitors on long-term clinical outcomes of patients with rheumatic heart disease

AIMS

Rheumatic heart disease (RHD) remains a major global health problem. Renin-angiotensin-aldosterone system inhibitors (RAASi) are commonly administered in the treatment of cardiovascular disease, but its role in RHD patients is still limited. We performed a retrospective study to determine the effect of RAASi on long-term outcomes for RHD patients.

METHODS AND RESULTS

A 1:1 propensity score matching was implemented to balance baseline characteristics between groups RAASi and non-RAASi. Cox proportional hazards regression model was used to investigate the associations of RAASi with the risks of all-cause mortality, cardiovascular death (CVD), and cerebrovascular death. Binary logistic regression analysis was used to evaluate the associations of RAASi with the risks of 1, 3, and 5 year heart failure (HF) rehospitalization, new-onset atrial fibrillation (AF), and new-onset stroke. A total of 734 RHD patients were enrolled as study participants; nearly half of these participants had combined valve damage (54.4%), worse New York Heart Association functional class status (III and IV, 55.2%), surgical treatment (54.2%), and AF (65.0%). After propensity score matching, 514 RHD patients were finally analysed. RAASi treatment was associated with decreased risks of all-cause mortality [adjusted hazard ratio (HR) = 0.52, 95% confidence interval (CI): 0.37-0.73, P < 0.001], CVD (adjusted HR = 0.48, 95% CI: 0.30-0.76, P = 0.002), and cerebrovascular death (adjusted HR = 0.22, 95% CI: 0.08-0.60, P = 0.003). Further subgroup analysis showed that RAASi treatment was associated with decreased risks of all-cause mortality (adjusted HR = 0.50, 95% CI: 0.31-0.79, P = 0.004), CVD (adjusted HR = 0.48, 95% CI: 0.25-0.91, P = 0.025), and cerebrovascular death (adjusted HR = 0.19, 95% CI: 0.05-0.65, P = 0.008) in RHD patients without surgical treatment, and better effect was observed in RHD patients with surgical treatment on the risks of all-cause mortality (adjusted HR = 0.47, 95% CI: 0.26-0.85, P = 0.012) and CVD (adjusted HR = 0.43, 95% CI: 0.21-0.90, P = 0.024) except cerebrovascular death (adjusted HR = 0.52, 95% CI: 0.08-3.36, P = 0.491). RAASi treatment was associated with decreased HF rehospitalization risk of 1 year [adjusted odds ratio (OR) = 0.38, 95% CI: 0.23-0.61, P < 0.001], 3 year (adjusted OR = 0.43, 95% CI: 0.28-0.68, P < 0.001), and 5 year (adjusted OR = 0.48, 95% CI: 0.30-0.77, P = 0.002) as well as new-onset AF risk (adjusted OR = 0.38, 95% CI: 0.21-0.68, P = 0.001). RAASi treatment had nothing to do with new-onset stroke risk (adjusted OR = 0.80, 95% CI: 0.47-1.38, P = 0.428).

CONCLUSION

Renin-angiotensin-aldosterone system inhibitor treatment was significantly associated with decreased risks of mortality, HF rehospitalization, and new-onset AF in RHD patients in median 5.9 year follow-up.

Postoperative Mortality of Indigenous Populations Compared With Nonindigenous Populations: A Systematic Review

Importance

A range of factors have been identified as possible contributors to racial/ethnic differences in postoperative mortality that are also likely to hold true for indigenous populations. Yet despite its severity as an outcome, death in the period following a surgical procedure is underresearched for indigenous populations.

Objective

To describe postoperative mortality experiences for minority indigenous populations compared with numerically dominant nonindigenous populations and examine the factors that drive any differences observed.

Evidence Review

This review was conducted according to PRIMSA guidelines and registered on PROSPERO. Articles were identified through searches of the Embase, Ovid MEDLINE, Scopus, and Cumulative Index to Nursing and Allied Health Literature databases, with manual review of references and gray literature searches conducted. Eligible articles included those that reported associations between ethnicity/indigeneity and mortality up to 90 days following surgery and published in English between January 1, 1990, and March 26, 2019. Data on the study design, setting, participants (including indigeneity), and results were extracted. A modified Newcastle-Ottawa Quality Assessment Scale was used to determine study quality.

Findings

A total of 442 abstracts were screened, 92 articles were reviewed in full text, and 21 articles (from 20 studies) and 7 reports underwent data extraction. All included studies were cohort studies (3 prospective and the remainder retrospective) investigating a wide range of surgical procedures in the US, Australia, or New Zealand. Seven studies were from single facilities, while the remainder used data from national databases. Sample sizes ranged, with indigenous sample sizes ranging from 20 to 3052 patients and a number of studies reporting less than 10 indigenous deaths. The postoperative mortality experience for minority indigenous populations compared with the nonindigenous populations was mixed. There was evidence from several studies that indigenous populations may be more likely to die following cardiac procedures. However, the available evidence has overall poor study quality, with methods to identify the indigenous populations being a major limitation of most of the studies.

Conclusions and Relevance

Postoperative mortality experiences for indigenous populations should not be interpreted in isolation from the broader context of inequities across the health care pathway and must take into account the quality of data used for indigenous identification.

The use of cardiac valve procedures for rheumatic heart disease in Australia; a cross-sectional study 2002-2017

Background

Australia, although a high income economy, carries a significant burden of rheumatic heart disease (RHD). Acute rheumatic fever (ARF) and RHD are endemic in the Indigenous population. Immigrants from low/lower-income countries (‘non-Indigenous high-risk’) are also at increased risk compared with ‘non-Indigenous low-risk’ Australians. This study describes the utilisation of surgical and percutaneous procedures for RHD-related valve disease among patients aged less than 50 years, from 2002 to 2017.

Methods

A descriptive study using data from the ‘End RHD in Australia: Study of Epidemiology (ERASE) Project’ linking RHD Registers and hospital inpatient data from five states/territories, and two surgical databases. Trends across three-year periods were determined and post-procedural all-cause 30-day mortality calculated.

Results

A total of 3900 valves interventions were undertaken in 3028 procedural episodes among 2487 patients. Over 50% of patients were in the 35–49 years group, and 64% were female. Over 60% of procedures for 3-24 year-olds were for Indigenous patients. There were few significant changes across the study period other than downward trends in the number and proportion of procedures for young Indigenous patients (3–24 years) and ‘non-Indigenous/low risk’ patients aged ≥35 years. Mitral valve procedures predominated, and multi-valve interventions increased, including on the tricuspid valve. The majority of replacement prostheses were mechanical, although bioprosthetic valve use increased overall, being highest among females <35 years and Indigenous Australians. All-cause mortality (n = 42) at 30-days was 1.4% overall (range 1.1–1.7), but 2.0% for Indigenous patients.

Conclusions

The frequency of cardiac valve procedures, and 30-day mortality remained steady across 15 years. Some changes in the distribution of procedures in population groups were evident. Replacement procedures, the use of bioprosthetic valves, and multiple-valve interventions increased. The challenge for Australian public health officials is to reduce the incidence, and improve the early detection and management of ARF/RHD in high-risk populations within Australia.

•

Epidemic RHD in Indigenous Australians drives RHD-related cardiac valve procedures.

•

30-day mortality post-procedural is low in those under 50 years.

•

Bioprosthetic valve replacements higher in young women, and increasing in older patients.

Meta-Analysis of the Incidence, Prevalence, and Correlates of Atrial Fibrillation in Rheumatic Heart Disease

Objective:

To estimate the incidence, prevalence, and correlates of atrial fibrillation (AF) in a global population with rheumatic heart disease (RHD).

Methods:

Bibliographic databases were searched to identify all published studies providing data on AF in patients with RHD. Random-effects meta-analysis method was used to pool estimates.

Results:

Eighty-three studies were included, reporting data from 75,637 participants with RHD in 42 countries. The global prevalence of AF in RHD was 32.8% (range: 4.3%–79.9%). It was higher in severe valvular disease (30.8% vs 20.7%, p = 0.009), in severe mitral valve disease compared to severe aortic disease (30.4% vs 6.3%, p = 0.038). The global cumulative incidence of AF in patients with RHD was 4.8%, 11.4%, 13.2%, and 30.8% at 1, 2, 5, and 10 years of follow-up, respectively. From comparison between patients with and without AF, AF was associated with increased age (mean difference [MD]: 9.5 years; 95% CI: 7.8–1.3), advanced heart failure (odds ratio [OR]: 4.4; 95% CI 2.1–9.3), tricuspid valve involvement (OR: 4.0; 95% CI: 3.0–5.3), history of thromboembolism (OR: 6.2; 95% CI: 3.4–11.4), highly sensitive C-reactive protein (MD: 5.5 mg/dL; 95% CI: 1.2–9.8), systolic pulmonary arterial pressure (MD: 3.6 mmHg; 95% CI: 0.8–6.3), right atrium pressure (MD: 1.5 mmHg; 95% CI: 1.0–2.0), and left atrium diameter (MD: 8.1 mm; 95% CI: 5.5–10.7).

Conclusions:

About one-third of patients with RHD have AF, with an incidence which almost triples every five years after diagnosis. Factors associated with AF include age, advanced heart failure, thromboembolism, and few cardiac hemodynamics parameters.

Adult and Paediatric Cardiac Intervention in Timor-Leste: Disease Burden, Demographics and Clinical Outcomes

BACKGROUND

The East Timor Hearts Fund (ETHF) is a charitable organisation of Australian cardiologists providing outreach screening in Timor-Leste. For patients requiring intervention, ETHF arranges logistics, procedures, and postoperative care. The aim of this project is to evaluate outcomes of patients requiring intervention.

METHODS

The ETHF database of all patients was utilised to identify patients with disease warranting surgical or percutaneous intervention. Both patients who underwent intervention and those who did not proceed to intervention were included in this study. Patients who had intervention arranged by other organisations but have then had follow-up with ETHF were also included. Overall demographics and pre and postoperative factors were assessed, with sub-group analysis of adult and paediatric patients to identify any differences in care.

RESULTS

Of 221 patients requiring intervention, 101 patients underwent intervention, receiving 22 different operations or procedures. Patients were predominantly young (median age 17.5 years) and female (64.7%), with rheumatic heart disease (63.8%). Twenty-four (24) (33.3%) women aged 15-45 years old with cardiac disease warranting intervention were documented as pregnant or breastfeeding at time of clinic assessment. Of patients who did not proceed to intervention, adults were more likely to be lost to follow-up (42.4% vs 18.5%) while paediatric patients were more likely to experience progression of disease (18.5% vs 7.5%, p=0.005). Median waitlist time was 5 months, with no significant difference between adults and children, correlating with a preoperative mortality rate of 5.4%. For patients who underwent intervention, post-procedure mortality was extremely low (0.9%) and attendance of at least one post-procedure review was excellent (99.0%). Eleven (11) (10.9%) patients have required repeat intervention, with no difference in rates between adult and paediatric patients. Length of follow-up extends up to 20 years for some patients.

CONCLUSION

The Timor-Leste interventional cohort was predominantly a young female population with rheumatic and congenital cardiac disease. There were also high rates of pregnancy amongst female patients with severe cardiac disease. Delayed access to intervention may result in preoperative adverse events and mortality, and is a key target for improvement. Patients who undergo intervention have very low post-procedural mortality, good adherence to early medical follow-up and good long-term outcomes.

Outcomes of Redo Valve Surgery in Indigenous Australians

BACKGROUND

Rheumatic heart disease often leads to valve surgery at a young age in our Indigenous population. Anticoagulation can be problematic and therefore repeat surgery to replace degenerated bioprosthetic valves is common. We sought to examine outcomes following redo valve surgery in this population.

METHODS

Data from our institutional database was reviewed from 1992 to 2017. During this period, 82 redo valve surgeries were performed in 73 patients identifying as Aboriginal and Torres Strait Islander. We compared this study group to Indigenous patients undergoing primary valve surgery (n=389) and non-Indigenous patients undergoing redo valve surgery (n=154).

RESULTS

Redo patients had a median age of 29.5 years (IQR 24, 44), 59% were female, and they had significant comorbidities. The 30-day mortality in this cohort was 6% (EuroSCORE II 3.57), and they had significant morbidity. The median time to repeat surgery in those who had previous mitral valve surgery was 6.3 years, with no difference between mitral valve repair or replacement at the index procedure. Compared to non-Indigenous patients undergoing redo valve surgery, the Indigenous patients were significantly younger with higher left ventricular function but a greater proportion of pulmonary hypertension. There were no significant differences in short-term outcomes. Compared to Indigenous patients undergoing primary valve surgery, the Indigenous redo patients were significantly younger with more co-morbidities. There was no difference in 30-day mortality, but the redo patients did have significantly greater resource utilisation (increased hospital and intensive care unit (ICU) lengths of stay, ventilation and blood transfusion) and poorer long-term survival.

CONCLUSIONS

Indigenous patients presenting for redo valve surgery represent a complex and comorbid group of patients, with outcomes worse than expected in a young population, albeit comparable within study groups. Time from original surgery was short at 6 years, and thus a strategy must be in place in terms of planning future surgeries in this cohort of predominantly young rheumatic heart disease patients.

Thoracoscope-Assisted Mitral Valve Replacement with a Small Incision in the Right Chest: A Chinese Single Cardiac Center Experience

BACKGROUND The aim of this study was to investigate the safety, feasibility, and clinical effectiveness of thoracoscopy-assisted mitral valve replacement via thoracic right-anterior minimal incision. MATERIAL AND METHODS A retrospective analysis was conducted of 225 patients with mitral valve lesions who were treated in our hospital from August 2012 to August 2015. Group A included 105 patients undergoing thoracoscopy-assisted mitral valve replacement via a thoracic right-anterior minimal incision, and group B included 120 patients undergoing conventional mitral valve replacement. We collected and analyzed clinical data from both groups. RESULTS The procedures were successful in patients of both groups. No severe complications or mortality were reported. Postoperative mechanical ventilation time (8.6±2.4 h vs. 12.4±3.2 h), duration of intensive care (1.7±1.2 d vs. 2.8±1.3 d), duration of postoperative analgesia use (28.7±8.9 h vs. 36.3±7.5 h), postoperative length of hospital stay (8.2±2.2 d vs. 12.8±2.1 d), pleural fluid drainage (210.5±60.5 ml vs. 425.4±75.6 ml), blood transfusion amount (420.5±80.4 ml vs. 658.3±96.7 ml), and operative incision length (4.7±1.1 cm vs. 22.4±2.5 cm) were significantly shorter (or lower) in group A than in group B. There were different advantages and disadvantages in the 2 kinds of operative procedure in terms of postoperative complications. CONCLUSIONS Thoracoscopy-assisted mitral valve replacement via thoracic right-anterior minimal incision has the same clinical efficacy, safety, and feasibility as conventional mitral valve replacement.

Comparison of outcomes in Australian indigenous and non-indigenous children and adolescents undergoing cardiac surgery

BACKGROUND

Population-based registries report 95% 5-year survival for children undergoing surgery for CHD. This study investigated paediatric cardiac surgical outcomes in the Australian indigenous population.

METHODS

All children who underwent cardiac surgery between May, 2008 and August, 2014 were studied. Demographic information including socio-economic status, diagnoses and co-morbidities, and treatment and outcome data were collected at time of surgery and at last follow-up.

RESULTS

A total of 1528 children with a mean age 3.4±4.6 years were studied. Among them, 123 (8.1%) children were identified as indigenous, and 52.7% (62) of indigenous patients were in the lowest third of the socio-economic index compared with 28.2% (456) of non-indigenous patients (p⩽0.001). The indigenous sample had a significantly higher Comprehensive Aristotle Complexity score (indigenous 9.4±4.2 versus non-indigenous 8.7±3.9, p=0.04). The probability of having long-term follow-up did not differ between groups (indigenous 93.8% versus non-indigenous 95.6%, p=0.17). No difference was noted in 30-day mortality (indigenous 3.2% versus non-indigenous 1.4%, p=0.13). The 6-year survival for the entire cohort was 95.9%. The Cox survival analysis demonstrated higher 6-year mortality in the indigenous group - indigenous 8.1% versus non-indigenous 5.0%; hazard ratio (HR)=2.1; 95% confidence intervals (CI): 1.1, 4.2; p=0.03. Freedom from surgical re-intervention was 79%, and was not significantly associated with the indigenous status (HR=1.4; 95% CI: 0.9, 1.9; p=0.11). When long-term survival was adjusted for the Comprehensive Aristotle Complexity score, no difference in outcomes between the populations was demonstrated (HR=1.6; 95% CI: 0.8, 3.2; p=0.19).

CONCLUSION

The indigenous population experienced higher late mortality. This apparent relationship is explained by increased patient complexity, which may reflect negative social and environmental factors.

Outcomes after mitral valve surgery for rheumatic heart disease

Objective

To further the understanding of the factors influencing outcome following rheumatic heart disease (RHD) related mitral valve surgery, which globally remains an important cause of heart disease and a particular problem in Indigenous Australians.

Methods

The Australian Cardiac Surgery Database was utilised to assess outcomes following mitral valve repair and replacement for RHD and non-RHD valve disease. The association with aetiology, demographics, comorbidities, preoperative status and operative procedure was evaluated.

Results

Mitral valve repairs and replacements undertaken in Australia were analysed from 119 and 1078 RHD surgical procedures and 3279 and 2400 non-RHD procedures, respectively. RHD mitral valve repair, compared with replacement, resulted in a slightly shorter hospital stay and more reoperation for valve dysfunction, but no difference in 30-day survival. In unadjusted survival analysis to 5 years, RHD mitral valve repair and replacement were no different (HR 0.86, 95% CI 0.4 to 1.7), non-RHD repair was superior to replacement (HR 1.7, 95% CI 1.4 to 2.0), RHD and non-RHD repair were no different (HR 0.9, 95% CI 0.5 to 1.7), and RHD replacement was superior to non-RHD (HR 1.5, 95% CI 1.2 to 1.9). None of these differences persisted in adjusted analyses and there was no difference in long-term survival for Indigenous Australians.

Conclusion

In this large prospective cohort study we have demonstrated that adjusted long-term survival following RHD mitral valve repair surgery in Australia is no different to replacement and no different to non-RHD. Interpretation of valve surgery outcome requires careful consideration of patient factors that may also influence survival.

Outcome following valve surgery in Australia: development of an enhanced database module

BACKGROUND

Valvular heart disease, including rheumatic heart disease (RHD), is an important cause of heart disease globally. Management of advanced disease can include surgery and other interventions to repair or replace affected valves. This article summarises the methodology of a study that will incorporate enhanced data collection systems to provide additional insights into treatment choice and outcome for advanced valvular disease including that due to RHD.

METHODS

An enhanced data collection system will be developed linking an existing Australian cardiac surgery registry to more detailed baseline co-morbidity, medication, echocardiographic and hospital separation data to identify predictors of morbidity and mortality outcome following valve surgery.

DISCUSSION

This project aims to collect and incorporate more detailed information regarding pre and postoperative factors and subsequent morbidity. We will use this to provide additional insights into treatment choice and outcome.

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.

Valvular aspects of rheumatic heart disease

Acute rheumatic fever and rheumatic heart disease remain major global health problems. Although strategies for primary and secondary prevention are well established, their worldwide implementation is suboptimum. In patients with advanced valvular heart disease, mechanical approaches (both percutaneous and surgical) are well described and can, for selected patients, greatly improve outcomes; however, access to centres with experienced staff is very restricted in regions that have the highest prevalence of disease. Development of diagnostic strategies that can be locally and regionally provided and improve access to expert centres for more advanced disease are urgent and, as yet, unmet clinical needs. We outline current management strategies for valvular rheumatic heart disease on the basis of either strong evidence or expert consensus, and highlight areas needing future research and development.

Impact of MIF Gene Promoter Variations on Risk of Rheumatic Heart Disease and Its Age of Onset in Saudi Arabian Patients

Although macrophage migration inhibitory factor (MIF) has consistently been shown to be an important immune modulator, data on the association between MIF promoter variations and the risk of developing rheumatic heart disease (RHD) remain inconclusive. RHD is an important complication of streptococcal infections in the Middle East, not least in Saudi Arabia, and identifying risk markers is an important priority. Therefore, we investigated the association between two functional MIF promoter variations and RHD susceptibility and severity in Saudi patients: the MIF-173G > C substitution (rs755622) and the MIF-794 CATT5-8 tetranucleotide repeat (rs5844572). Three hundred twenty-six individuals (124 RHD patients and 202 age-, sex-, and ethnically matched healthy controls) were genotyped using allelic discrimination and fragment analysis. Data were analyzed with respect to disease susceptibility, severity, sex, and age of onset. There was a significantly lower frequency of 173C allele carriage in RHD patients compared to controls [odds ratio (OR) = 0.47; 95% confidence intervals (CIs) = 0.28-0.77; p = 0.003]. Interestingly, the 173C allele was associated with late disease onset (p = 0.001). The 794 5-repeat allele was associated with decreased RHD risk (OR = 0.56; 95% CIs = 0.38-0.82; p = 0.003). In contrast, the 794 6-repeat allele was associated with increased risk of RHD (OR = 1.7; 95% CIs = 1.2-2.5; p = 0.002). MIF promoter variations appear to have a dual role in RHD, with 173C allele non-carriers at higher risk of developing RHD at a younger age. These results require further validation in larger multi-ethnic cohorts, and functional studies are necessary to understand the underlying molecular mechanisms driving the at-risk phenotype.