Prognostic utility of myocardial blush grade after PCI in patients with NSTE-ACS: Analysis from the ACUITY trial

Objective: We evaluated the ability of post-procedural myocardial blush grade (MBG) to stratify outcomes of patients undergoing percutaneous coronary intervention (PCI) for non-ST segment elevation acute coronary syndromes (NSTE-ACS). Background: MBG strongly correlates with survival after reperfusion therapy in patients with ST-segment elevation myocardial infarction (STEMI). Methods: Of 13,819 NSTE-ACS patients randomized in the ACUITY trial, 3,115 patients underwent PCI and had MBG analyzed by an independent angiographic core laboratory. We examined net adverse clinical events (NACE; composite ischemia or bleeding), composite ischemia (death, MI or ischemia-driven revascularization) and non-CABG major bleeding according to final MBG. Results: At 30 days, patients with MBG-0/1 had higher rates of NACE (25.1% vs. 13.9%, P = 0.002) and composite ischemia (19.1% vs. 9.4%, P = 0.002) than patients with MBG-2/3. At 1-year follow-up, MBG-0/1 patients had significantly higher rates of composite ischemia compared to other patients (27.8% vs. 19.8%, P = 0.02). By multivariable analysis, MBG-0/1 was an independent predictor of 30-day ischemia-driven revascularization (OR 5.74 [2.63, 12.54], P < 0.0001) in the total population and among patients with normal post-PCI epicardial TIMI-3 flow (OR 6.39 [2.06, 19.78], P = 0.001). However, 1-year outcomes were similar between patients with and without normal myocardial perfusion. Conclusions: In conclusion, MBG is a predictor of 30-day revascularization in the overall population and in patients with normal epicardial flow but fails to stratify 1-year outcomes. Thus, unlike in STEMI patients, the prognostic value of MBG in NSTE-ACS patients appears to be limited to the short-term.