Abbreviated Echocardiographic Screening for Rheumatic Heart Disease by Nonexperts with and without Offsite Expert Review: A Diagnostic Accuracy Study

BACKGROUND

Early detection of rheumatic heart disease (RHD) through echocardiographic screening can facilitate early access to effective treatment, which reduces the risk for progression. Accurate, feasible approaches to echocardiographic screening that can be incorporated into routine health services are needed. The authors hypothesized that offsite expert review could improve the diagnostic accuracy of nonexpert-obtained echocardiographic images.

METHODS

This prospective cross-sectional study was performed to evaluate the diagnostic accuracy of health worker-conducted single parasternal long-axis view with a sweep of the heart using hand-carried ultrasound for the detection of RHD in high-risk populations in Timor-Leste and Australia. In the primary analysis, the presence of any mitral or aortic regurgitation met the criteria for a positive screening result. Sensitivity and specificity were calculated for a screen-and-refer approach based on nonexpert practitioner assessment (approach 1) and for an approach using offsite expert review of nonexpert practitioner-obtained images to decide onward referral (approach 2). Each participant had a reference test performed by an expert echocardiographer on the same day as the index test. Diagnosis of RHD was determined by a panel of three experts, using 2012 World Heart Federation criteria.

RESULTS

The prevalence of borderline or definite RHD among 3,329 participants was 4.0% (95% CI, 3.4%-4.7%). The sensitivity of approach 1 for borderline or definite RHD was 86.5% (95% CI, 79.5%-91.8%), and the specificity was 61.4% (95% CI, 59.7%-63.1%). Approach 2 achieved similar sensitivity (88.4%; 95% CI, 81.5%-93.3%) and improved specificity (77.1%; 95% CI, 75.6%-78.6%).

CONCLUSION

Nonexpert practitioner-obtained single parasternal long-axis view with a sweep of the heart images, reviewed by an offsite expert, can detect borderline and definite RHD on screening with reasonable sensitivity and specificity. Brief training of nonexpert practitioners with ongoing support could be used as an effective strategy for scaling up echocardiographic screening for RHD in high-risk settings.

Single-View Echocardiography by Nonexpert Practitioners to Detect Rheumatic Heart Disease: A Prospective Study of Diagnostic Accuracy

Supplemental Digital Content is available in the text.

Background:

Echocardiographic screening can detect asymptomatic cases of rheumatic heart disease (RHD), facilitating access to treatment. Barriers to implementation of echocardiographic screening include the requirement for expensive equipment and expert practitioners. We aimed to evaluate the diagnostic accuracy of an abbreviated echocardiographic screening protocol (single parasternal-long-axis view with a sweep of the heart) performed by briefly trained, nonexpert practitioners using handheld ultrasound devices.

Methods:

Participants aged 5 to 20 years in Timor-Leste and the Northern Territory of Australia had 2 echocardiograms: one performed by an expert echocardiographer using a GE Vivid I or Vivid Q portable ultrasound device (reference test), and one performed by a nonexpert practitioner using a GE Vscan handheld ultrasound device (index test). The accuracy of the index test, compared with the reference test, for identifying cases with definite or borderline RHD was determined.

Results:

There were 3111 enrolled participants; 2573 had both an index test and reference test. Median age was 12 years (interquartile range, 10–15); 58.2% were female. Proportion with definite or borderline RHD was 5.52% (95% CI, 4.70–6.47); proportion with definite RHD was 3.23% (95% CI, 2.61–3.98).

Compared with the reference test, sensitivity of the index test for definite or borderline RHD was 70.4% (95% CI, 62.2–77.8), specificity was 78.1% (95% CI, 76.4–79.8).

Conclusions:

Nonexpert practitioners can be trained to perform single parasternal-long-axis view with a sweep of the heart echocardiography. However, the specificity and sensitivity are inadequate for echocardiographic screening. Improved training for nonexpert practitioners should be investigated.

P3133Single parasternal long axis echocardiography by briefly trained health workers using handheld devices for detection of rheumatic heart disease: a prospective study of diagnostic accuracy

Introduction

Echocardiographic screening can detect rheumatic heart disease (RHD) in high-risk populations,but is limited by reliance on highly-trained experts and equipment. We sought to determine the diagnostic utility of an ultra-abbreviated single parasternal-long-axis-sweep of the heart (SPLASH) echocardiography protocol to detect RHD, performed by briefly-trained health workers.

Methods

In Timor-Leste and Northern Australia, individuals aged 5–20y were offered school-based echocardiographic screening. Health workers completed online modules followed by one-week of practical training, logging 50 echocardiograms prior to study. The index test was SPLASH, performed and reported by health workers using handheld GE V-scan devices. The index test was abnormal if any mitral or aortic regurgitation was detected. The reference test was a comprehensive echocardiogram, performed by an echocardiographers or cardiologist on a GE Vivid-Q, reported according to World Heart Federation criteria. The diagnostic accuracy of the index test was determined.

Results

2590 subjects underwent index and reference tests. Prevalence of definite RHD was 3.2% (83/2590). Sensitivity and specificity of index test were 0.75 (95% CI 0.64–0.83) and 0.77 (95% CI 0.75–0.78) respectively for detection of any definite RHD, and 0.91 (95% CI 0.74–0.98) and 0.76 (95% CI 0.74–0.78) respectively for detection of moderate or severe RHD.

Conclusion

Health workers using SPLASH detected the vast majority of moderate and severe RHD cases, but lacked sensitivity for detection of mild RHD. Further analysis is underway to evaluate the learning curve and other performance indicators of health workers performing and interpreting echocardiograms. This will allow refinement of SPLASH protocol and augmentation of health worker training to increase detection rates and accuracy for future population screening initiatives.

Acknowledgement/Funding

Heart Foundation Australia Vanguard Grant, Menzies HOT-NORTH pilot project grant, Snow Foundation, Rotary, Bawinanga Aboriginal Corporation, Mala'la