CRT-100.04 Delaying Reperfusion Plus LV Unloading Reduces Infarct Size: A Per-Protocol-Analysis of the STEMI_DTU Pilot Study
Pahuja M, O'Neill W, Karas RH, Moses J, Udelson J, Faraz H, and Kapur NK. CRT-100.04 Delaying Reperfusion Plus LV Unloading Reduces Infarct Size: A Per-Protocol-Analysis of the STEMI_DTU Pilot Study. JACC Cardiovasc Interv 2023; 16(4):S8-S9.
JACC Cardiovasc Interv
Background: Myocardial infarct size (IS) and microvascular obstruction (MVO) are well-established prognostic markers in STEMI. The STEMI-DTU pilot trial was the first exploratory study to identify that LV unloading and delayed reperfusion was feasible. We now report new findings in patients from per-protocol cohort on the basis of magnitude of sum of precordial ST-segment elevation.
Method: In a multicenter, prospective, randomized safety and feasibility trial, 50 patients with anterior STEMI to LV unloading using Impella CP were assigned into two different arms including immediate reperfusion (U-IR) versus delayed reperfusion after 30 minutes of unloading (U-DR). Cardiac magnetic resonance (CMR) imaging assessed infarct size normalized to the area at risk (IS/AAR) 3-5 days after PCI. Patients without CMR at 3-5 days, without PCI of a culprit LAD lesion and without STEMI were not per-protocol and thus excluded from this analysis.
Results: 32 patients meeting all inclusion and exclusion criteria (U-IR,n=15; U-DR,n=17) were included in our analysis. Despite longer symptom-to-balloon times in the U-DR arm, IS/AAR was significantly lower with 30 minutes of delay to reperfusion in the presence of active LV unloading (47±16% vs 60±15%, p=0.02) and remained lower irrespective of the magnitude of precordial ΣSTE (Figure 1). MVO was not significantly different between groups (1.5±2.8% vs 3.5±4.8%,p=0.15), but significantly lower in the U-DR arm among patients with precordial ΣSTE≥8mm (1.5±2.5% vs 5.6±5.3%, p=0.04).
Conclusion: This analysis supports the paradigm-changing concept that when treated per protocol, 30 minutes of delay to reperfusion with active LV unloading may reduce infarct size irrespective of precordial STE magnitude. Ongoing STEMI-DTU Pivotal trial will provide us further information on these findings.