Hypverventilation Strain CMR Imaging in Patients With Acute Chest Pain

Background In patients with suspected acute coronary syndrome (ACS) high-sensitivity cardiac tropnonin T (hscTnT) is used for rapid patient triage. Fast-strain encoded (fSENC) CMR imaging with breathing maneuvers may accelerate diagnostic work-up and identify patients suffering from ACS. Methods Patients presenting with ACS (hscTnT level 5-52ng/L) were prospectively enrolled. fSENC imaging was performed within the 1-hour timeframe (0h/1h algorithm) prior to 2nd hscTnT lab results. Images were acquired at rest as well as after 1-minute of hyperventilation followed by a short breath-hold. Results In 108 patients (58 male; mean age: 57±17y) the mean study time was 17 ± 3 minutes. An abnormal strain response after the breathing maneuver correctly identified all 17 patients with a hscTnT dynamic (0h/1h algorithm) and explanatory significant coronary lesions, while in 86 patients without serologic or angiographic evidence for severe coronary artery disease the strain response was normal (sensitivity 100%, specificity 94.5%; 5 false positive results). The number of dysfunctional segments (strain>-10) proved to be a quantifiable marker for identifying patients with ACS. Conclusions In patients with suspected ACS and inconclusive initial hscTnT, fSENC imaging with a breathing maneuver may safely and rapidly identify patients with ACS, without the use of stress or contrast agents/ medication.