Abstract 6089: Myocardial Blush Predicts Outcomes in Patients with Acute Coronary Syndromes: An Analysis of the Acute Catheterization and Urgent Intervention Triage strategY (ACUITY) trial
Background: Myocardial blush grade is an angiographic index of myocardial perfusion that correlates with mortality and infarct size following primary PCI in AMI. Whether blush correlates with outcomes following PCI in ACS has not been studied previously.
Methods: The ACUITY trial randomized 13,819 pts with moderate and high risk ACS to unfractionated heparin or enoxaparin + GPI, versus bivalirudin + GPI, vs. bivalirudin alone. The angiographic substudy of ACUITY included the first 7000 consecutive randomized US patients, of which 3115 underwent PCI and had final MBG assessed. All angiograms were reviewed by an independent core laboratory for baseline and final lesion and flow characteristics and outcomes were compared based on MBG.
Results: Myocardial perfusion in the target vessel after PCI was absent in 2.7% (MBG 0/1; N=84), impaired in 11.9% (MBG 2; N=370) and normal in 85.4% (MBG 3; N=2661). Patients with absent myocardial perfusion (MGB 0/1) had lower baseline LVEF (59% vs 66% for MBG 2/3, p<0.005), more prior CABG (28.6% vs 18% for MBG 3), were higher risk (troponin positive or ST/T changes or TIMI risk>5) (89.9% MBG 0/1 vs 68.2% MBG 2 vs 65.5% MBG 3, p<0.0001), with more CPK/troponin elevation (82.1% vs 56.7% MBG 2 vs 56% MBG 3, p<0.0001). Absent MBG correlated with 30 day death, MI and unplanned revasc (Table⇓). However, among pts with normal epicardial flow (TIMI 3, n=3000), absent MBG was uncommon (1%), did not correlate with death or MI, but was associated with unplanned revascularization (p<0.005).
Conclusions: High risk ACS pts undergoing PCI achieve normal myocardial perfusion in approximately 85% of cases. Absent myocardial perfusion (MBG 0/1) is associated with high risk characteristics including reduced LVEF and myocardial enzyme elevation and correlates with adverse ischemic events at 30 days, especially the need for unplanned revascularization procedures.