Abstract 2465: Association of Myocardial Perfusion Grade After Late Infarct Reperfusion with Baseline Indices of Global LV Function; Analysis from the Total Occlusion Study of Canada-2
Background: Acute MI reperfusion studies employing analyses of radiographic contrast blush (myocardial perfusion grade, MPG) have shown a relationship between MPG, infarct size, and LV function. MPG has thereby been proposed as a marker of microvascular integrity. The relationships between MPG and indices of LV function in pts undergoing late MI reperfusion have not been explored. TOSCA-2 provides this opportunity.
Aim: to explore the relation of MPG to pre-PCI indices of global and regional LV function in the setting of late infarct reperfusion.
Methods: TOSCA-2 is a NHLBI-funded angiographic ancillary study of the Occluded Artery Trial (OAT), an international randomized trial of PCI for occluded IRA’s detected 3–28 days post-MI. The present analysis was based upon 157 TOSCA-2 pts assigned PCI in whom MPG was evaluable. We employed the TIMI MPG scheme (0- no blush, 1-stain, 2- slow entry/exit, 3-normal). Clinical parameters were reported by study sites. Angiographic parameters, including MPG, were evaluated in a core angiographic lab.
Results: Preserved blush (MPG 2/3) was associated with higher LV ejection fraction (EF), lower end-systolic volume (ESV) and lower end-diastolic volume (EDV) (Table⇓). The association with end systolic volume remained significant in a multivariate model (OR1.032, 95% CI 1.008 –1.057; p=0.009). On ANOVA there was an association between regional wall motion and MPG grades 0,1,2,3 (p=0.03) (N=146).
Conclusion: Myocardial perfusion grade is associated with both global and segmental indices of LV function. These observations extend prior analyses undertaken in acute MI settings indicating that MPG represents preserved microvascular integrity and myocardial viability. The capacity for MPG to predict global and regional functional recovery following late reperfusion warrants further study.