Data collection on: demographics, rule-out diagnostic protocol (instant cardiac troponin+Copeptin, instant at Limit of Detection, 0-1h, 0-3 h, 0-6 hour, other; time of second sample from admission; turnaround time for first and consecutive sample(s); rates of echo, computed tomography (CT) coronary or CT pulmonary artery, CT chest or CT triple rule-out, chest X-ray, stress test performed or recommended within 3 working days; length of stay in ED, length of stay in hospital including initial referral; rates of admission, discharge or referral; rates of in-hospital percutaneous coronary Intervention (PCI) or coronary artery Bypass graft (CABG), coronary angiography findings based on a definition of obstructive coronary artery disease (CAD) ≥ 50% stenosis.