Abstract Body (Do not enter title and authors here): Introduction: Early prehospital chest pain assessment improves acute coronary syndrome (ACS) outcomes and can reduce unnecessary Emergency Room (ER) visits but requires medical personnel and electrocardiographic (ECG) equipment.

Objective: To evaluate the feasibility of a personal credit-card sized chest pain self-assessment device (HeartBeam, Santa Clara, CA, USA) in diagnosing ACS.

Methods: ACS risk was estimated by serial likelihood ratio analysis of 3 components: pre-existing coronary heart disease (CHD) risk (pre-calculated based on pooled ASCVD equation), chest pain characteristics (interactive proprietary questionnaire), and integrated near-orthogonal 3-lead self-recorded vectorcardiogram (VCG) with optional comparison to baseline using portable handheld HeartBeam recorder. Final ACS risk was graded High/Intermediate/Low by the cloud-based proprietary algorithm. High risk was considered positive for ACS.

Results: 184 ER patients with chest pain (Age 57 +/- 7years, 90 Male, 43 (23%) ACS) comprised learning (n=96) and test (n=88) sets. ACS sensitivity was 28/28 (100%) in learning and 15/16 (94%) in test set with specificity of 43% and 42% respectively. In the subset of patients with pain-free portable VCG recorded 9 months later used as a “reverse baseline” (n=110) sensitivity was 17/17 (100%) and 11/12 (92%), specificity 54% and 58% in learning and test set, respectively (p>0.1 with no baseline). Single patient missed by the analysis had known coronary disease with usual anginal episode resulting in minor troponin leak. In “reverse baseline” analysis 41/110 (37%) patients were classified as Low risk compared to 18/184 (10%) without baseline (p<0.001), all negative for ACS.
Based on the analysis of CHD risk factors, chest pain characteristics, and 12-lead ECG, a consensus of 3-member ER chest pain unit physicians panel had sensitivity/specificity of 94/54% for the whole and 93/48% for the “reverse baseline” groups (p>0.1 with HeartBeam device).

Conclusion: HeartBeam chest pain self-assessment device provides accurate ACS detection comparable to expert ER physicians using 12 lead ECG. The presence of baseline recording reduces the number of false positive results. If confirmed in larger studies, it can be used to facilitate outpatient chest pain assessment and triage by remote physicians and patients themselves.