Providing Rapid Out of Hospital Acute Cardiovascular Treatment 4 (PROACT‐4)

BACKGROUND: Whether prehospital point‐of‐care (POC) troponin further accelerates the time to diagnosis in patients with chest pain (CP) is unknown. We conducted a randomized trial of POC‐Troponin testing in the ambulance. METHODS AND RESULTS: Patients with chest pain presenting by ambulance were randomized to usual care (UC) or POC‐Troponin; ST‐elevation myocardial infarction patients or those with noncardiovascular symptoms were excluded. Pre‐hospital high‐sensitivity troponin was analyzed on a POC device and available to the paramedic and emergency department (ED) staff. The final diagnosis was centrally adjudicated. The primary endpoint was time from first medical contact to discharge from ED or admission to hospital. We randomized 601 patients in 19 months; 296 to UC and 305 to POC‐Troponin. After ambulance arrival, the first troponin was available in 38 minutes in POC‐Troponin and 139 minutes in UC. In POC‐Troponin, the troponin was >0.01 ng/mL in 17.4% and >0.03 ng/mL in 9.8%. Patients spent a median of 9.0 hours from first medical contact to final disposition, and 165 (27.4%) were admitted to the hospital. The primary endpoint was shorter in patients randomized to POC‐Troponin (median 8.8 hours [6.2–10.8] compared to UC (median 9.1 hours [6.7–11.2]; P=0.05). There was no difference in the secondary endpoint of repeat ED visits, hospitalizations, or death in the next 30 days. CONCLUSIONS: In this broad population of patients with CP, ambulance POC‐Troponin accelerated the time to final disposition. Enhanced and more cost‐effective early ED discharge of the majority of patients with CP calling 911 is an unrealized opportunity. CLINICAL TRIAL REGISTRATION: URL: https://www.ClinicalTrials.gov/. Unique identifier: NCT01634425.