Infective Endocarditis and Rheumatic Heart Disease in the North of Australia

The aetiology and incidence of infective endocarditis in people living with rheumatic heart disease in tropical Australia

PURPOSE

To define the incidence and microbiological aetiology of infective endocarditis (IE) in patients with rheumatic heart disease (RHD) in tropical Australia.

METHODS

A retrospective study that examined all episodes of IE between January 1998 and June 2021 among individuals on the RHD register in Far North Queensland, Australia.

RESULTS

There were 1135 individuals with a diagnosis of RHD on the register during the study period, representing 10962 patient-years at risk. Overall, there were 18 episodes of definite IE occurring in 16 individuals, although only 7 episodes occurred in native valves (11 occurred in prosthetic valves) equating to 0.7 episodes of native valve IE/1000 patient-years. No patient with mild RHD - and only one child with RHD - developed IE during the study period. Despite the study's tropical location, the causative organism was usually typical skin or oral flora. Among individuals with an indication for benzathine penicillin G (BPG) prophylaxis, only 1/6 episodes of IE due to a penicillin-susceptible organism received BPG in the month before presentation.

CONCLUSION

Although RHD predisposes individuals to IE, the absolute risk of IE in native valve disease in tropical Australia is low and might be reduced further by improved adherence to secondary BPG prophylaxis.

Medical Treatment for Rheumatic Heart Disease: A Narrative Review

BACKGROUND

Acute rheumatic fever (ARF) and rheumatic heart disease (RHD) are rare in high-income countries; however, in Aotearoa New Zealand ARF and RHD disproportionately affect Indigenous Māori and Pacific Peoples. This narrative review explores the evidence regarding non-surgical management of patients with clinically significant valve disease or heart failure due to RHD.

METHODS

Medline, EMBASE and Scopus databases were searched, and additional publications were identified through cross-referencing. Included were 28 publications from 1980 onwards.

RESULTS

Of the available interventions, improved anticoagulation management and a national RHD register could improve RHD outcomes in New Zealand. Where community pharmacy anticoagulant management services (CPAMS) are available good anticoagulation control can be achieved with a time in the therapeutic range (TTR) of more than 70%, which is above the internationally recommended level of 60%. The use of pharmacists in anticoagulation control is cost-effective, acceptable to patients, pharmacists, and primary care practitioners. There is a lack of local data available to fully assess other interventions; including optimal therapy for heart failure, equitable access to specialist RHD care, prevention, and management of endocarditis.

CONCLUSION

As RHD continues to disproportionately affect Indigenous and minority groups, pro-equity tertiary prevention interventions should be fully evaluated to ensure they are reducing disease burden and improving outcomes in patients with RHD.

Adapted from: Prevention of Viridans Group Streptococcal Infective Endocarditis: A Scientific Statement From the American Heart Association

BACKGROUND

In 2007, the American Heart Association published updated evidence-based guidelines on the recommended use of antibiotic prophylaxis to prevent viridans group streptococcal (VGS) infective endocarditis (IE) in cardiac patients undergoing invasive procedures. The 2007 guidelines significantly scaled back the underlying conditions for which antibiotic prophylaxis was recommended, leaving only 4 categories thought to confer the highest risk of adverse outcome. The purpose of this update is to examine interval evidence of the acceptance and impact of the 2007 recommendations on VGS IE and, if needed, to make revisions based on this evidence.

METHODS AND RESULTS

A writing group was formed consisting of experts in prevention and treatment of infective endocarditis including members of the American Dental Association, the Infectious Diseases Society of America, and the American Academy of Pediatrics, in addition to the American Heart Association. MEDLINE database searches were done for English language articles on compliance with the recommendations in the 2007 guidelines and the frequency of and morbidity or mortality from VGS IE after publication of the 2007 guidelines. Overall, there was good general awareness of the 2007 guidelines but variable compliance with recommendations. There was no convincing evidence that VGS IE frequency, morbidity, or mortality has increased since 2007.

CONCLUSIONS

On the basis of a review of the available evidence, there are no recommended changes to the 2007 VGS IE prevention guidelines. We continue to recommend VGS IE prophylaxis only for categories of patients at highest risk for adverse outcome while emphasizing the critical role of good oral health and regular access to dental care for all. Randomized controlled studies to determine whether antibiotic prophylaxis is effective against VGS IE are needed to further refine recommendations.

Prevention of Viridans Group Streptococcal Infective Endocarditis: A Scientific Statement From the American Heart Association

BACKGROUND

In 2007, the American Heart Association published updated evidence-based guidelines on the recommended use of antibiotic prophylaxis to prevent viridans group streptococcal (VGS) infective endocarditis (IE) in cardiac patients undergoing invasive procedures. The 2007 guidelines significantly scaled back the underlying conditions for which antibiotic prophylaxis was recommended, leaving only 4 categories thought to confer the highest risk of adverse outcome. The purpose of this update is to examine interval evidence of the acceptance and impact of the 2007 recommendations on VGS IE and, if needed, to make revisions based on this evidence.

METHODS AND RESULTS

A writing group was formed consisting of experts in prevention and treatment of infective endocarditis including members of the American Dental Association, the Infectious Diseases Society of America, and the American Academy of Pediatrics, in addition to the American Heart Association. MEDLINE database searches were done for English language articles on compliance with the recommendations in the 2007 guidelines and the frequency of and morbidity or mortality from VGS IE after publication of the 2007 guidelines. Overall, there was good general awareness of the 2007 guidelines but variable compliance with recommendations. There was no convincing evidence that VGS IE frequency, morbidity, or mortality has increased since 2007.

CONCLUSIONS

On the basis of a review of the available evidence, there are no recommended changes to the 2007 VGS IE prevention guidelines. We continue to recommend VGS IE prophylaxis only for categories of patients at highest risk for adverse outcome while emphasizing the critical role of good oral health and regular access to dental care for all. Randomized controlled studies to determine whether antibiotic prophylaxis is effective against VGS IE are needed to further refine recommendations.

Predictors of early left ventricular dysfunction after mitral valve replacement for rheumatic valvular disease

OBJECTIVE

The purpose of this study was to determine the predictors of early left ventricular (LV) dysfunction in patients with rheumatic heart disease (RHD) after mitral valve replacement (MVR). We examined echocardiographic and nonechocardiographic predictors.

METHODS

This study included 571 patients receiving MVR for RHD from 2012 to 2017. Their baseline characters, preoperative examination, operation data, and postoperative echocardiography were collected retrospectively. Univariate and multivariate logistic regression were used to evaluate the predictors of early LV dysfunction after MVR. The LV dysfunction was defined as left ventricular end-ejection fraction (LVEF) <50%. The interaction model was further performed to calculate interaction effects between predictors selected by logistic regression.

RESULTS

In the 571 patients, 164 (28.7%) had early LV dysfunction after the operation, but only 94 (16.5%) had a preoperative LVEF <50%. Significant differences between two groups (LVEF ≥50% or LVEF <50%) were finally revealed in LV end-diastolic dimension, preoperative atrial fibrillation (AF), preoperative LVEF <50%, and the white blood cell (WBC) count measured after admission (>10 × 10⁹ L ^-1 ) in the multivariate logistic regression. Corresponding odds ratios (ORs) were 1.06, 1.82, 3.63, and 2.64, respectively. Diabetes, lesion type, LV end-systolic dimension, aspartate transaminase, alanine transaminase, and serum creatinine were statistically significant (P < .05) in univariate logistic regression, with matched ORs 2.45, 1.66/0.65, 1.07, 2.50, 1.83, and 2.90, respectively. However, these variables were not significant anymore in the multivariate logistic model. Besides, the OR of early postoperative LV dysfunction increased to 7.00 when preoperative AF, preoperative LVEF <50%, and WBC >10 × 10⁹ L^-1 were all present.

CONCLUSIONS

The preoperative LV dysfunction, a large LV volume, AF and over-normal WBC could independently predict postoperative LV dysfunction.

Patient autonomy and doctor's concern - a case of intravenous drug abuser

Intravenous substance abuse is often associated with physical and psychological harm, and often requires urgent medical attention. We report a case of a young male who presented with life-threatening complications of intravenous drug abuse, but refused to give details or agree to the proposed treatment, raising concerns for the team of doctors. A compos mentis patient has a right to decide what should be done to his body. Medical management or surgical interventions cannot be initiated without the patient's consent even if these are lifesaving procedures, or a procedure meant to benefit the patient. Medical practitioner can be liable for assault (criminal law), medical negligence (law of tort), damages (civil action) and even human rights issues may be raised if a patient's autonomy is not respected.

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.

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.

Epidemiologic features and long-term outcome of dialysis patients with infective endocarditis in Taiwan

BACKGROUND

The incidence of infective endocarditis (IE) is high in dialysis patients. Limited data are available on the risk factors for IE and long-term outcome after IE in dialysis patients, especially in Asian populations.

METHODS

We used Taiwan National Health Insurance Research Database to design a longitudinal cohort study. 68,426 ESRD patients who began dialysis between 1999 and 2007 were included. The follow-up period was from the start of dialysis to death, end of dialysis, or end of 2008. Cox proportional hazards models were used to identify the risk factors for IE.

RESULTS

IE was diagnosed in 502 patients during follow-up (201.4 per 100,000 person-years). Diabetes mellitus (DM), congestive heart failure (CHF), cerebro-vascular accident (CVA), and rheumatic heart disease (RHD) (HR: 3.07, 95% CI: 1.99-4.75) were associated with an increasing risk of development of IE. The cumulative incidence rate of IE in patients with RHD was 1.4, 2.2, and 3.9% at 1, 3, and 5 years. In-hospital mortality was 23.5%. Cumulative survival rates post-IE were 54.3% at 1 year and only 35.3% at 5 years.

CONCLUSION

Dialysis patients had a higher risk of IE. Those who were older and had DM, CHF, CVA, or especially RHD were at a greater risk. Dialysis patients with IE also had high mortality.

A review of valve surgery for rheumatic heart disease in Australia

BACKGROUND

Globally, rheumatic heart disease (RHD) remains an important cause of heart disease. In Australia it particularly affects older non-Indigenous Australians and Aboriginal Australians and/or Torres Strait Islander peoples. Factors associated with the choice of treatment for advanced RHD remain variable and poorly understood.

METHODS

The Australian and New Zealand Society of Cardiac and Thoracic Surgeons Cardiac Surgery Database was analysed. Demographics, co-morbidities, pre-operative status and valve(s) affected were collated and associations with management assessed.

RESULTS

Surgical management of 1384 RHD and 15843 non-RHD valve procedures was analysed. RHD patients were younger, more likely to be female and Indigenous Australian, to have atrial fibrillation (AF) and previous percutaneous balloon valvuloplasty (PBV). Surgery was performed on one valve in 64.5%, two valves in 30.0% and three valves in 5.5%. Factors associated with receipt of mechanical valves in RHD were AF (OR 2.69) and previous PBV (OR 1.98) and valve surgery (OR 3.12). Predictors of valve repair included being Indigenous (OR 3.84) and having fewer valves requiring surgery (OR 0.10). Overall there was a significant increase in the use of mitral bioprosthetic valves over time.

CONCLUSIONS

RHD valve surgery is more common in young, female and Indigenous patients. The use of bioprosthetic valves in RHD is increasing. Given many patients are female and younger, the choice of valve surgery and need for anticoagulation has implications for future management of RHD and related morbidity, pregnancy and lifestyle plans.

Screening for rheumatic heart disease in Aboriginal and Torres Strait Islander children

Rheumatic heart disease is preventable but causes significant morbidity and mortality in Aboriginal Australian and Torres Strait Islander populations. Screening echocardiography has the potential to detect early rheumatic heart disease thereby enabling timely commencement of treatment (secondary prophylaxis) to halt disease progression. However, a number of issues prevent echocardiographic screening for rheumatic heart disease satisfying the Australian criteria for acceptable screening programs. Primarily, it is unclear what criteria should be used to define a positive screening result as questions remain regarding the significance, natural history and potential treatment of early and subclinical rheumatic heart disease. Furthermore, at present the delivery of secondary prophylaxis in Australia remains suboptimal such that the potential benefits of screening would be limited. Finally, the impact of echocardiographic screening for rheumatic heart disease on local health services and the psychosocial health of patients and families are yet to be ascertained.

Rheumatic Fever Follow-Up Study (RhFFUS) protocol: a cohort study investigating the significance of minor echocardiographic abnormalities in Aboriginal Australian and Torres Strait Islander children

Background

In Australia, rheumatic heart disease (RHD) is almost exclusively restricted to Aboriginal Australian and Torres Strait Islander people with children being at highest risk. International criteria for echocardiographic diagnosis of RHD have been developed but the significance of minor heart valve abnormalities which do not reach these criteria remains unclear. The Rheumatic Fever Follow-Up Study (RhFFUS) aims to clarify this question in children and adolescents at high risk of RHD.

Methods/design

RhFFUS is a cohort study of Aboriginal and/or Torres Strait Islander children and adolescents aged 8–17 years residing in 32 remote Australian communities. Cases are people with non-specific heart valve abnormalities detected on prior screening echocardiography. Controls (two per case) are age, gender, community and ethnicity-matched to cases and had a prior normal screening echocardiogram. Participants will have echocardiography about 3 years after initial screening echocardiogram and enhanced surveillance for any history suggestive of acute rheumatic fever (ARF). It will then be determined if cases are at higher risk of (1) ARF or (2) developing progressive echocardiography-detected valve changes consistent with RHD.

The occurrence and timing of episodes of ARF will be assessed retrospectively for 5 years from the time of the RhFFUS echocardiogram. Episodes of ARF will be identified through regional surveillance and notification databases, carer/subject interviews, primary healthcare history reviews, and hospital separation diagnoses.

Progression of valvular abnormalities will be assessed prospectively using transthoracic echocardiography and standardized operating and reporting procedures. Progression of valve lesions will be determined by specialist cardiologist readers who will assess the initial screening and subsequent RhFFUS screening echocardiogram for each participant. The readers will be blinded to the initial assessment and temporal order of the two echocardiograms.

Discussion

RhFFUS will determine if subtle changes on echocardiography represent the earliest changes of RHD or mere variations of normal heart anatomy. In turn it will inform criteria to be used in determining whether secondary antibiotic prophylaxis should be utilized in individuals with no clear history of ARF and minor abnormalities on echocardiography. RhFFUS will also inform the ongoing debate regarding the potential role of screening echocardiography for the detection of RHD in this setting.