Background: Growing evidence suggests that no-reflow reperfusion after direct percutaneous coronary intervention (d-PCI) is associated with an unfavorable clinical outcome. The purpose of this study was to evaluate whether prerevascularization angiographic morphologic features of infarct-related arteries (IRAs) and timely reperfusion could convey information on slow-flow (Thrombolysis In Myocardial Infarction [TIMI] 2 flow) or no-reflow (TIMI grade ≤ 1 flow) reperfusion after d-PCI.
Methods and results: Between May 1993 and September 2000, d-PCI was performed in 794 consecutive patients with acute myocardial infarction. Coronary blood flow failed to normalize in 120 patients (15.1%). The incidence of failure to achieve TIMI 3 flow in the IRAs was significantly higher in patients with vs those without the following distinctive prerevascularization angiographic morphologic features: cutoff pattern of occlusion in the IRA (52.4% vs 10.3%, p < 0.001), accumulated thrombus (> 5 mm) proximal to the occlusion (37.5% vs 3.4%, p < 0.001), presence of floating thrombus (66.7% vs 12.7%, p < 0.001), persistent dye stasis distal to the obstruction (51.9% vs 13.8%, p < 0.001), reference lumen diameter (RLD) of the IRA ≥ 4 mm (46.3% vs 9.6%, p < 0.001), and incomplete obstruction with presence of accumulated thrombus more than three times the RLD of the IRA (51.7% vs 3.9, p < 0.0001). Each of these six angiographic morphologic features indicated “high-burden thrombus formation.” Multiple stepwise logistic regression analysis demonstrated that each of six angiographic morphologic features was an independent predictor of combined slow-flow and no-reflow phenomenon in the IRAs after d-PCI (p < 0.05). In contrast, early reperfusion time (< 240 min, p = 0.0017), prerevascularization TIMI flow grade ≥ 2 (p = 0.0006), and the taper pattern of occlusion in the IRA (p = 0.0284) were independent predictors of freedom from slow-flow or no-reflow phenomenon in the IRAs after d-PCI. The 30-day overall mortality was 8.7% (69 of 794 patients). The 30-day mortality was significantly higher in patients with combined slow-flow and no-reflow phenomenon than in patients with normal coronary blood flow after d-PCI (27.5% vs 5.3%, p < 0.001).
Conclusions: Early reperfusion reduces the incidence of slow-flow or no-reflow phenomenon in the IRA and overall 30-day mortality. The specific angiographic morphologic features in the IRAs can be used as a simple and efficacious method to predict slow-flow or no-reflow phenomenon. These findings provide apparently clinically useful information for the selection of patients who are potential candidates for subsequent prepercutaneous coronary intervention adjunctive therapy.