Interscallop separations of the posterior mitral valve leaflet: a solution to the 'borderline RHD' conundrum?

Echocardiographic Screening of Rheumatic Heart Disease: Current Concepts and Challenges

The incidence of acute rheumatic fever (ARF), which most commonly affects children aged 5-15 years after group A Streptococcus (GAS) infection, ranges from 8 to 51 per 100 000 people worldwide. Rheumatic heart disease (RHD), which occurs when patients with ARF are inappropriately treated or not given regular prophylaxis, is the most common cause of non-congenital heart disease in children and young adults in low-income countries. Timely treatment of GAS infection can prevent ARF, and penicillin prophylaxis can prevent recurrence of ARF. Secondary prophylaxis with benzathine penicillin G has been shown to decrease the incidence of RHD and is a key aspect of RHD control. The most important factor determining the prognosis of RHD is the severity of cardiac involvement. Although approximately 70% of patients with carditis in the acute phase of the disease recover without sequelae, carditis is important because it is the only complication of ARF that causes sequelae. One-third of patients with ARF are asymptomatic. Patients with mild symptoms of recurrent ARF and silent RHD will develop severe morbidities within 5-10 years if they do not receive secondary preventive treatments. A new screening program should be established to prevent cardiac morbidities of ARF in moderate- and highrisk populations. In the present study, we examined the applicability of echocardiographic screening programs for RHD. Cite this article as: Topçu S, Uçar T. Echocardiographic screening of rheumatic heart disease: Current concepts and challenges. Turk Arch Pediatr. 2024;59(1):3-12.

Detection and management of latent rheumatic heart disease: a narrative review

Rheumatic heart disease (RHD) is a public health concern in many developing nations around the world. Early detection of latent or subclinical RHD can help in reversing mild lesions, retarding disease progression, reducing morbidity and mortality, and improving the quality of life of patients. Echocardiography is the gold-standard method for screening and confirming latent RHD cases. The rates and determinants of progression of latent RHD cases as assessed by echocardiography have been found to be variable through studies. Even though latent RHD has a slow rate of progression, the rate of progression of its subtype, 'definite' RHD, is substantial. A brief training of nonexpert operators on the use of handheld echocardiography with a simplified protocol is an important strategy to scale up the screening program to detect latent cases. Newer advancements in screening, such as deep-learning digital stethoscopes and telehealth services, have provided an opportunity to expand screening programs even in resource-constrained settings. Newer studies have established the efficacy and safety profile of secondary antibiotic prophylaxis in latent RHD. The concerned authorities in endemic regions of the world should work on improving the availability and accessibility of antibiotic prophylaxis.

Morpho-mechanistic screening criteria for the echocardiographic detection of rheumatic heart disease

INTRODUCTION

Screening echocardiography, guided by the current World Heart Federation (WHF) criteria, has important limitations that impede the establishment of large-scale rheumatic heart disease (RHD) control programmes in endemic regions. The criteria misclassify a significant number of normal cases as borderline RHD. Prior attempts to simplify them are limited by incorporation bias due to the lack of an externally validated, accurate diagnostic test for RHD. We set out to assess novel screening criteria designed to avoid incorporation bias and to compare this against the performance of the current WHF criteria.

METHODS

The performance of the WHF and the morpho-mechanistic (MM) RHD screening criteria (a novel set of screening criteria that evaluate leaflet morphology, motion and mechanism of regurgitation) as well as a simplified RHD MM 'rule-out' test (based on identifying a predefined sign of anterior mitral valve leaflet restriction for the mitral valve and any aortic regurgitation for the aortic valve) were assessed in two contrasting cohorts: first, a low-risk RHD cohort consisting of children with a very low-risk RHD profile. and second, a composite reference standard (CRS) RHD-positive cohort that was created using a composite of two criteria to ensure a cohort with the highest possible likelihood of RHD. Subjects included in this group required (1) proven, prior acute rheumatic fever and (2) current evidence of predefined valvular regurgitation on echocardiography.

RESULTS

In the low-risk RHD cohort (n=364), the screening specificities for detecting RHD of the MM and WHF criteria were 99.7% and 95.9%, respectively (p=0.0002). The MM rule-out test excluded 359/364 cases (98.6%). In the CRS RHD-positive cohort (n=65), the screening sensitivities for the detection of definite RHD by MM and WHF criteria were 92.4% and 89.2%, respectively (p=0.2231). The MM RHD rule-out test did not exclude any cases from the CRS RHD-positive cohort.

CONCLUSION

Our proposed MM approach showed an equal sensitivity to the WHF criteria but with significantly improved specificity. The MM RHD rule-out test excluded RHD-negative cases while identifying all cases within the CRS RHD-positive cohort. This holds promise for the development of a two-step RHD screening algorithm to enable task shifting in RHD endemic regions.

Early surgery determines prognosis in patients with infective endocarditis: outcome in patients managed by an Endocarditis Team-a prospective cohort study

Background

Infective endocarditis (IE) in South Africa is associated with significant morbidity and mortality, despite occurring in younger patients with fewer co-morbidities. Possible contributors include the high rates of blood culture negative endocarditis, high rates of mechanical valve replacement and the lack of inter-disciplinary coordination during management.

Methods

The Tygerberg Endocarditis Cohort (TEC) study prospectively enrolled patients with IE between November 2019 and April 2021. All patients were managed by an Endocarditis Team with a set protocol for organism detection and a strategy of early surgery limiting the use of prosthetic material.

Results

Seventy-two consecutive patients with IE were included, with a causative organism identified in 86.1% of patients. The majority of patients had a guideline indication for surgery (n=58; 80.6%). The in-hospital mortality rate was 18%, with a 6-month mortality rate of 25.7%. Surgery was performed in 42 patients (58.3%), with prosthetic valve (PVE) replacement in 32 (76.2%), conventional repair surgery in 8 (19.1%) and mitral valve reconstruction in 2 (4.8%) of patients. Patients who underwent surgery had a significantly lower in-hospital (4.8% vs. 56.3%; P<0.01) and 6-month (4.9% vs. 75.0%; P<0.01) mortality rate as compared with patients with an indication for surgery who did not undergo surgery.

Conclusions

We have observed a reduction in the 6-month mortality rate in patients with IE following the establishment of an Endocarditis Team, adhering to a set protocol for organism detection and favouring early repair or reconstruction surgery. Patients who underwent surgery had a significantly lower mortality rate than patients with an indication for surgery who did not undergo surgery. Preventable residual mortality was driven by surgical delay.

Modified Duke/European Society of Cardiology 2015 clinical criteria for infective endocarditis: time for an update?

BACKGROUND

The diagnosis of infective endocarditis (IE) is based on the modified Duke/European Society of Cardiology (ESC) 2015 clinical criteria. The sensitivity of the criteria is unknown in South Africa, but high rates of blood culture negative endocarditis (BCNIE), coupled with a change in the clinical features of IE, may limit the sensitivity.

METHODS

The Tygerberg Endocarditis Cohort study prospectively enrolled patients with IE between November 2019 and June 2021. A standardised protocol for organism detection, with management of patients by an Endocarditis Team, was employed. Patients with definite IE by pathological criteria were analysed to determine the sensitivity of the current clinical criteria.

RESULTS

Eighty consecutive patients with IE were included of which 45 (56.3%) had definite IE by pathological criteria. In patients with definite IE by pathological criteria, 26/45 (57.8%) of patients were classified as definite IE by clinical criteria. BCNIE was present in 25/45 (55.6%) of patients and less than three minor clinical criteria were present in 32/45 (75.6%) of patients. The elevation of Bartonella serology to a major microbiological criterion of the modified Duke/ESC 2015 clinical criteria would increase the sensitivity (57.8% vs 77.8%; p=0.07).

CONCLUSION

The sensitivity of the modified Duke/ESC 2015 clinical criteria is lower than expected in patients with IE in South Africa, primarily due to the high rates of Bartonella-associated BCNIE. The elevation of Bartonella serology to a major microbiological criterion, similar to the status of Coxiella burnetii in the current criteria, would increase the sensitivity. The majority of patients with definite IE by pathological criteria had less than three minor criteria present.

Screening for subclinical rheumatic heart disease: addressing borderline disease in a real-world setting

Aims

The World Heart Federation (WHF) criteria identify a large borderline rheumatic heart disease (RHD) category that has hampered the implementation of population-based screening. Inter-scallop separations (ISS) of the posterior mitral valve leaflet, a recently described normal variant of the mitral valve, appears to be an important cause of mild mitral regurgitation (MR) leading to misclassification of cases as WHF ‘borderline RHD’. This study aims to report the findings of the Echo in Africa project, a large-scale RHD screening project in South Africa and determine what proportion of borderline cases would be re-classified as normal if there were a systematic identification of ISS-related MR.

Methods and results

A prospective cross-sectional study of underserved secondary schools in the Western Cape was conducted. Participants underwent a screening study with a handheld (HH) ultrasound device. Children with an abnormal HH study were re-evaluated with a portable laptop echocardiography machine. A mechanistic evaluation was applied in cases with isolated WHF ‘pathological’ MR (WHF ‘borderline RHD’). A total of 5255 participants (mean age 15± years) were screened. A total of 3439 (65.8%) were female. Forty-nine cases of WHF ‘definite RHD’ [9.1 cases/1000 (95% confidence interval, CI, 6.8–12.1 cases/1000)] and 104 cases of WHF ‘borderline RHD’ [19.5 cases/1000 (95% CI, 16.0–23.7 cases/1000)] were identified. Inter-scallop separations-related MR was the underlying mechanism of MR in 48/68 cases classified as WHF ‘borderline RHD’ with isolated WHF ‘pathological’ MR (70.5%).

Conclusion

In a real-world, large-scale screening project, the adoption of a mechanistic evaluation based on the systematic identification of ISS-related MR markedly reduced the number of WHF ‘screen-positive’ cases misclassified as WHF ‘borderline RHD’. Implementing strategies that reduce this misclassification could reduce the cost- and labour burden on large-scale RHD screening programmes.