Background: Noninvasive molecular imaging of recent ischemia can potentially be used to diagnose acute coronary syndrome (ACS) with high accuracy. Objectives: The authors hypothesized that bedside myocardial contrast echocardiography (MCE) ischemic memory imaging could be achieved with phosphatidylserine microbubbles (MBPS) that are retained in the microcirculation via ischemia-associated endothelial activation. Methods: A dose-finding study was performed in healthy volunteers (n = 17) to establish optimal MBPS dosing. Stable patients with ACS (n = 30) and confirmed antecedent but resolved myocardial ischemia were studied within 2 hours of coronary angiography and percutaneous coronary intervention (PCI) when indicated. MCE molecular imaging was performed 8 minutes after intravenous administration of MBPS. MCE perfusion imaging was used to assess the status of the postischemic microcirculation. Results: Based on dose-finding studies, 0.10 or 0.15 mL of MBPS based on body mass was selected. In patients with ACS, all but 2 underwent primary PCI. MCE molecular imaging signal intensity was greater in the postischemic risk area vs remote territory (median [95% CI]: 56 [33-66] vs 8 [2-17] IU; P < 0.001) with a receiver-operating characteristic curve C-statistic of 0.94 to differentiate post-ischemic from remote territory. Molecular imaging signal in the risk area was not related to type of ACS (unstable angina: 3; non–ST-segment elevation myocardial infarction: 14; ST-segment elevation myocardial infarction: 13), peak troponin, time to PCI, post-PCI myocardial perfusion, GRACE (Global Registry of Acute Coronary Events) score, or HEART score. Conclusions: Molecular imaging with point-of-care echocardiography and MBPS can detect recent but resolved myocardial ischemia. This bedside technique requires only minutes to perform and appears independent of the degree of ischemia.
|Original language||English (US)|
|Number of pages||11|
|Journal||Journal of the American College of Cardiology|
|State||Published - Nov 16 2021|
- molecular imaging
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine