Tarek Ahmed bw.indd

Background High thrombotic burden, subsequent distal embolization and myocardial no-refl ow remain a big obstacle which may negate the benefi ts of urgent coronary revascularization in patients with ST-elevation myocardial infarction (STEMI). We aimed at assessing the predictors of (1) thrombus grade in patients undergoing primary percutaneous coronary intervention (PPCI), and (2) infarct size, in order to optimize therapy to reduce thrombus burden. Methods One-hundred and fi fty-three consecutive patients presenting with STEMI and undergoing PPCI were included. Thrombus was evaluated on angiography and scored according to the TIMI study group score. Next, patients were categorized into two groups having either high thrombus grade (HTG; score 4-5) or low thrombus grade (LTG; score 1-3). We evaluated predictors of angiographic thrombus grade among a number of clinical, angiographic and laboratory data. We also assessed infarct size and scintigraphic left ventricular ejection fraction (LVEF) at 3 months in both patient groups. Results Ninety-four patients (58±11 y, 75% males) presented with HTG, whereas 59 patients (58±12 y, 78% males) presented with LTG. Pre-infarction angina (PIA) was more frequently encountered in the LTG group than in the HTG group (25% vs. 10%, p=0.009). Pre-procedural TIMI fl ow was signifi cantly lower in the HTG group (p<0.001), and thrombosuction was more frequently applied in the HTG group (p<0.001). Absence of PIA (OR=0.29, 95% CI=0.11-0.75, p=0.01) and proximal culprit lesion (OR=2.10, 95% CI=1.024.36, p=0.04) were the only independent predictors of HTG. HTG proved an independent predictor of higher peak levels of CK (p<0.001) and troponin-T (p<0.001), as well as lower LVEF (p=0.05) along with male gender and absence of prior statin therapy. Conclusion Absence of PIA and proximal culprit lesions are associated with higher thrombus grade. Higher thrombus grade is associated with larger infarct size and slightly worse LV function. This may have clinical implications in planning strategies, particularly regarding pharmacotherapy, that aim to decrease thrombus burden prior to stent implantation.