LumiraDx participates in the Healthy Heart Bus Initiative with innovative, fingerstick blood NT-proBNP test

Purpose

Across 2 days in February 2023, LumiraDx participated in a communitybased initiative to improve knowledge of heart health and encourage people to #starttalkingaboutyourheart. The collaboration was between several community-based heart health and heart failure charities, providers of health services and commercial organisations who all came together to drive awareness in heart health and potential ways to improve current pathways. This was an ideal opportunity for LumiraDx to explore how our innovative, direct fingerstick point of care NT-proBNP test, when used in a community setting, can assist in identifying this missing cohort of unidentified/undiagnosed people. This is the first step in understanding where change in current pathways can bring benefits that support both patients, and healthcare professionals to transform community-based healthcare.

Methods

The community testing service was advertised across social media in the days preceding the walk-in clinic to increase awareness in the local surrounding area of the presence of the Community Heart Health Check service. Members of the public were able to access the Heart Health service in a centrally located community space, where healthcare professionals (HCPs) and members of the heart charities were on hand to provide information and support. People who attended the service were offered advice on heart health, there was an opportunity to have a heart rhythm check, and a stethoscope check (heart auscultation) which can detect heart valve disease. A questionnaire, designed by Heart Valve Voice (www.heartvalvevoice.com) was used to ascertain which people would benefit from a fingerstick NT-proBNP test, by asking questions around the signs and symptoms usually associated with heart conditions like heart failure.

The answers given to the questionnaire were reviewed by the HCP and the heart auscultation and pulse check were completed. The HCP then identified if an NT-proBNP test was required by ticking a box on the questionnaire form and adding any necessary comments.

Individual presents at community heart health-check service

The NT-proBNP test

Those members of the public who were identified as positive for signs and symptoms of potential heart failure, had an NT-proBNP test performed by a HCP using the LumiraDx direct fingerstick NT-proBNP test3. The cut-off used for NT-proBNP was 400pg/mL (ng/L)* as outlined in the Westcliffe Cardiology Services: Managing of Heart Failure: detection and diagnosis (April 2021)

Fig.2. Cut-off for NT-proBNP adapted from Westcliffe Cardiology Services (April 2021)

Results

Day 1 of the service provision, 85 people attended the bus at Site 1, and, following a positive symptom questionnaire, 37 of those went on to have their NT-proBNP measured by direct fingerstick using the LumiraDx NT-proBNP test. 4 of the 37 people had an NT-proBNP result that was >400pg/mL (ng/L).

On Day 2, 181 people attended the bus at Site 2 and 60 went on to have an NT-proBNP test, with 2 people having a result >400pg/mL (ng/L).

In total, 266 people engaged with the Heart Health Community service over the 2 days, 97 of those went on to have their NT-proBNP measured using the LumiraDx NT-proBNP fingerstick test, with 6 of those being above the 400pg/mL (ng/L) cut-off outlined in Westcliffe Cardiology Services (Fig. 2). All 6 people were signposted to further investigation, and the member of the public with NT-proBNP >2001pg/mL (ng/L) was fast tracked to the Heart Failure clinic.

Table 1: Summary of results, by site, that were above the established cut-off 400pg/mL (ng/L)

Conclusion

The aim of the Healthy Heart Bus Initiative is to raise public awareness of a range of potential heart conditions, and to also provide education. The opportunity for LumiraDx to join this worthwhile initiative fits entirely with the vision of transforming healthcare, and our direct fingerstick NT-proBNP test opens up this possibility. The bus empowered members of the public to seek advice, who perhaps were having difficulty in accessing healthcare professionals via their primary care services, or did not realise that the symptoms they were experiencing warranted further investigation.

For this initiative, the 400pg/mL (ng/L) cut-off for NT-proBNP was applied according to local guidelines. The European Society of Cardiology (ESC) clinical practice guidelines for Heart Failure outline the use of Natriuretic Peptides (NP) in a diagnostic algorithm along with signs and symptoms⁴ .

The upper limits of normal in the non-acute setting are 125pg/mL (ng/L) for NT-proBNP, where <125pg/mL (ng/L) the probability of having heart failure is extremely low. If the ESC cut-off is applied to the Healthy Heart Bus population, the number of individuals who would warrant further investigation would increase from 6 people (6.2%) to 23 people (23.7%) (Table 2). This demonstrates that use of the ESC cut-off would result in almost 4x the number of people potentially requiring follow up and referral for further investigations.

The Healthy Heart Bus Initiative can enable and potentially drive improvements in understanding of heart conditions, and signpost members of the public for how to access information, provision of point of care testing and importantly reach those people who may not be able to easily talk to their Doctor.

Table 2: Summary of results when applying ESC NT-proBNP cut-off at ≥125pg/mL (ng/L)

*Unit of measurement - The LumiraDx NT-proBNP test is able to display results in both pg/mL and ng/L

References:

1. “Heart Failure – A Blueprint for Change” www.BHF.org.uk [accessed March 2023]

2. Atrial Fibrillation – Find the missing 300,000” https://www.bhf.org.uk/forprofessionals/healthcare-professionals/blog/2019/rushed-to-hospital-whenheart-failure-isnt-diagnosed-early-enough [accessed March 2023]

3. LumiraDx NT-proBNP test www.lumiradx.com/uk-en 4. ESC Guidelines Aug 2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure (escardio.org)