Safety and efficiency of the HEART-GP strategy with point-of-care high-sensitivity troponin testing for acute chest pain in out-of-hours primary care: a prospective multicentre diagnostic accuracy study

Background: GPs are often the first clinicians to assess acute chest pain in gatekeeper healthcare systems, but usually with limited diagnostic support. They must distinguish conditions that can be managed safely in primary care from those requiring immediate hospital evaluation, particularly acute coronary syndrome (ACS), while avoiding unnecessary over-referral to already pressured emergency departments. We evaluated HEART-GP, a novel GP-led strategy combining structured clinical assessment, fingerstick point-of-care high-sensitivity troponin I testing, and ECG when available. Methods: We performed a prospective, multicentre, paired diagnostic accuracy study in four Dutch out-of-hours primary care centres implementing the HEART-GP strategy. Patients with acute non-traumatic chest pain and possible ACS according to the treating GP were enrolled from March 2023 to August 2025. Before troponin results were available, GPs recorded intended management, allowing paired comparison with unaided clinical judgement. The HEART-GP strategy recommended urgent referral for high clinical suspicion, troponin of >=4 ng/L, or ischaemic ECG. The primary outcome was adjudicated 6-week major adverse cardiovascular events (MACE). The study was registered as ISRCTN11954040. Findings: Of 1104 patients who underwent HEART-GP, 917 were included. MACE occurred in 62 (6.8%) and myocardial infarction in 52 (5.7%). HEART-GP classified 478 (52.1%) as low risk. For MACE, sensitivity was 95.2% (95% CI 86.5-99.0) and negative predictive value was 99.4% (98.1-99.8); three MACE occurred in the low-risk group, with no cardiac deaths. For myocardial infarction, sensitivity was 98.1% (89.7-100) and negative predictive value was 99.8% (98.6-100). Compared with unaided GP judgement, HEART-GP improved sensitivity for MACE (95.2% vs 67.7%; p<0.001) and myocardial infarction (98.1% vs 67.3%; p<0.001), and reduced urgent referrals (439 [47.9%] vs 483 [52.7%]; p=0.042). Interpretation: HEART-GP showed high rule-out safety and may support GP diagnostic certainty and efficient referrals in patients with possible ACS. Implementation requires training, governance, safety-netting, and local pathways.