Left Ventricular Remodeling After Anterior-STEMI PCI: Imaging Observations in the Door-to-Unload (DTU) Pilot Trial
William W O'Neill, Dee Dee Wang1, Samantha Polak
1Henry Ford Hospital, 2799 West Grand Blvd, CFP 439, Detroit, MI 48202 USA. dwang2@hfhs.org.
Objectives:
To determine the predictive value of cardiac magnetic resonance (CMR) and echocardiographic parameters on left ventricular (LV) remodeling in ST-segment elevation myocardial infarction (STEMI) patients without cardiogenic shock and treated with mechanical LV unloading followed by immediate or delayed percutaneous coronary intervention (PCI)-mediated reperfusion.
Background:
In STEMI, infarct size (IS) directly correlates with major cardiovascular outcomes. Preclinical models demonstrate mechanical LV unloading before reperfusion reduces IS. The door-to-unload (DTU)-STEMI pilot trial evaluated the safety and feasibility of LV unloading and delayed reperfusion in patients with STEMI.
Methods:
This multicenter, prospective, randomized, safety and feasibility trial evaluated patients with anterior STEMI randomized 1:1 to LV unloading with the Impella CP (Abiomed) followed by immediate reperfusion vs delayed reperfusion after 30 minutes of unloading. Patients were assessed by CMR at 3-5 days and 30 days post PCI. Echocardiographic evaluations were performed at 3-5 and 90 days post PCI. At 3-5 days post PCI, patients were compared based on IS as percentage of LV mass (group 1 ≤25%, group 2 >25%). Selection of IS threshold was performed post hoc.
Results:
Fifty patients were enrolled from April 2017 to May 2018. At 90 days, group 1 (IS ≤25%) exhibited improved LV ejection fraction (from 53.1% to 58.9%; P=.001) and group 2 (IS >25%) demonstrated no improvement (from 37.6% to 39.1%; P=.55). LV end-diastolic volume and end-systolic volume were unchanged in group 1 and worsened in group 2. There was correlation between 3-5 day and 30-day CMR measurements of IS and 90-day echocardiography-derived LV ejection fraction.
Conclusions:
Immediate 3-5 day post-therapy IS by CMR correlates with 90-day echocardiographic LVEF and indices of remodeling. Patients with post-therapy IS >25% demonstrated evidence of adverse remodeling. Larger studies are needed to corroborate these findings with implications on patient management and prognosis.
