A novel cardiac output response to stress test developed to improve diagnosis and monitoring of heart failure in primary care

BackgroundWe developed a simple non-invasive Cardiac Output Response to Stress (CORS) Test to improve diagnosis and monitoring of heart failure in primary care.AimThe aim of the present study was to assess test-retest reproducibility of the CORS test.MethodThirty-two healthy volunteers (age, 64±10, female n=18) were recruited. Cardiac output was measured continuously using bioreactance method in supine and standing position, and during a two 3-min stages of a step-exercise protocol (10 and 15 steps per minute) using a 15-cm height bench. The CORS test was performed twice i.e. Test 1 and Test 2.ResultsCardiac output and stroke volume were not significantly different between the two tests at supine (6.2±1.4 versus 6.3±1.7 L/min, P = 0.84; 102±24 versus 108±32 ml/beat, P = 0.36), standing (5.7±2.1 versus 5.7±1.9 L/min, P = 0.99; 82±32 versus 83±29 ml/beat, P = 0.93), stage one step-exercise (8.5± 1.8 versus 8.2±1.9 L/min, P = 0.56; 104±26 versus 104±27 ml/beat, P = 0.99) and stage two step-exercise (9.9±1.7 versus 9.6±2.0 L/min, P = 0.51; 109±29 versus 111±26 ml/beat, P = 0.76). There was a significant positive relationship between Test 1 and Test 2 cardiac outputs (r=0.92, P<0.01 with coefficient of variation of 7.1%). The mean difference in cardiac output (with upper and lower limits of agreement) between Test 1 and Test 2 was 0.1 (−1.9 to 2.1) L/min, combining rest and exercise data.ConclusionThe CORS test demonstrates acceptable reproducibility and can potentially be used in primary care to identify and monitor heart failure.

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Opportunities and challenges of a novel cardiac output response to stress (CORS) test to enhance diagnosis of heart failure in primary care: a qualitative study

British Journal of General Practice ◽

10.3399/bjgp19x703421 ◽

2019 ◽

Vol 69 (suppl 1) ◽

pp. bjgp19X703421

Author(s):

Sarah Charman ◽

Nduka Okwose ◽

Gregory Maniatopoulos ◽

Sara Graziadio ◽

Luke Vale ◽

...

Keyword(s):

Heart Failure ◽

Primary Care ◽

Cardiac Output ◽

Qualitative Study ◽

Secondary Care ◽

Primary Care Physicians ◽

Diagnostic Testing ◽

Clinical Test ◽

Output Response ◽

Response To Stress

BackgroundPrimary care physicians lack access to an objective cardiac function test during diagnostic testing for suspected heart failure.AimTo determine the role of the novel Cardiac Output Response to Stress (CORS) test in the current diagnostic pathway for heart failure and the opportunities and challenges to potential implementation in primary care.MethodQualitative study using semi-structured in-depth interviews which were audiorecorded and transcribed verbatim. Data from the interviews were analysed thematically using an inductive approach. Fourteen healthcare professionals (six males, eight females) from primary (GPs, nurses, healthcare assistants, and practice managers) and secondary care (consultant cardiologists) participated.ResultsFour themes relating to opportunities and challenges surrounding the implementation of the new diagnostic technology were identified. These reflected that adoption of CORS test would be an advantage to primary care but the test had barriers to implementation which include establishment of clinical utility, suitability for immobile patients, and cost implication to GP practices.ConclusionThe development of a simple non-invasive clinical test to accelerate the diagnosis of heart failure in primary care maybe helpful to reduce unnecessary referrals to secondary care. The CORS test has the potential to serve this purpose however, factors such as cost-effectiveness, diagnostic accuracy, and seamless implementation in primary care have to be fully explored.

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Opportunities and challenges of a novel cardiac output response to stress (CORS) test to enhance diagnosis of heart failure in primary care: qualitative study

BMJ Open ◽

10.1136/bmjopen-2018-028122 ◽

2019 ◽

Vol 9 (4) ◽

pp. e028122

Author(s):

Sarah Charman ◽

Nduka Okwose ◽

Gregory Maniatopoulos ◽

Sara Graziadio ◽

Tamara Metzler ◽

...

Keyword(s):

Heart Failure ◽

Primary Care ◽

Cardiac Output ◽

Qualitative Study ◽

Secondary Care ◽

Clinical Test ◽

Output Response ◽

Diagnostic Technology ◽

Response To Stress ◽

Barriers To Implementation

ObjectiveTo explore the role of the novel cardiac output response to stress (CORS), test in the current diagnostic pathway for heart failure and the opportunities and challenges to potential implementation in primary care.DesignQualitative study using semistructured in-depth interviews which were audio recorded and transcribed verbatim. Data from the interviews were analysed thematically using an inductive approach.SettingNewcastle upon Tyne, UK.ParticipantsFourteen healthcare professionals (six males, eight females) from primary (general practitioners (GPs), nurses, healthcare assistant, practice managers) and secondary care (consultant cardiologists).ResultsFour themes relating to opportunities and challenges surrounding the implementation of the new diagnostic technology were identified. These reflected that the adoption of CORS test would be an advantage to primary care but the test had barriers to implementation which include: establishment of clinical utility, suitability for immobile patients and cost implication to GP practices.ConclusionThe development of a simple non-invasive clinical test to accelerate the diagnosis of heart failure in primary care maybe helpful to reduce unnecessary referrals to secondary care. The CORS test has the potential to serve this purpose; however, factors such as cost effectiveness, diagnostic accuracy and seamless implementation in primary care have to be fully explored.

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