Reducing heart failure patient hospitalisation numbers using remote heart alert system

Every year approximately 500,000 patients attending UK Emergency Departments have a suspected diagnosis of heart attack (acute myocardial infarction, or AMI), though only five per cent have AMI.

AMI can be diagnosed through a blood test for a protein called cardiac troponin (cTn), which is released into the blood when heart muscle is damaged. Previously, it took up to 12 hours before cTn rose to levels detectable by traditional blood tests, meaning patients with suspected AMI were admitted for an average two-day hospital stay before AMI could be safely ruled-out. This highlighted the need to reduce unnecessary hospital admissions and provide early reassurance for patients.

To address this problem, Manchester researchers, supported by Manchester University NHS Foundation Trust’s (MFT) Diagnostics and Technology Accelerator (DiTA), designed and tested new high-sensitivity troponin blood tests in three stages. First, to test if AMI could be ruled-out with a single blood test in the Emergency Department.

In three studies supported by Roche, results showed that this approach is very effective, allowing one third of patients to receive immediate and safe reassurance without hospital admission. Next, for patients who could not be diagnosed with one test, researchers validated an approach to reduce the interval between samples from six hours to one hour.

In a 14-centre study with Roche, results found that sampling after one hour would allow another third of patients to be safely reassured without hospital admission. Finally, researchers developed a decision aid called ‘T-MACS’ which combines a high-sensitivity troponin test with other information (electrocardiogram, symptoms and signs) to calculate the probability of AMI for individual patients.

Researchers validated the model under collaborative agreements using assays from Roche, Siemens, Abbott, Singulex and Alere. T-MACS can safely rule-out AMI for around 45 per cent of patients after one blood test. T-MACS also accurately rules-in AMI for the highest-risk patients, allowing them to receive early treatment.

T-MACS has been implemented across Greater Manchester and guided the care of over 30,000 patients; two-thirds of whom avoided unnecessary hospitalisation.

MFT research is now focused on developing T-MACS using machine learning; using TMACS to guide shared decision-making with patients and evaluating new high-sensitivity troponin tests at the point of care in hospitals and ambulances in partnership with Roche, Abbott, LumiraDx and Siemens.

The HealthTech Research Centre in Emergency and Acute Care will build on the success of MFT’s DiTA to ensure that state-of-the-art technologies and innovations are assisting our clinicians to diagnose diseases earlier and ensure appropriate treatments are provided sooner to our patients from Greater Manchester and beyond.