PCI Complications: "No-Reflow"

Definition and Incidence
The reduced flow during percutaneous coronary intervention (PCI) is defined as the reduction in anterograde despite a patent lumen at the site of PCI, and occurs during 1-5% of PCIs. No reflow is an important predictor of mortality after PCI (1). No reflow is a common (15%) finding during primary angioplasty for acute MI(2).

No-reflow is likely due to distal embolization of atheromatous and thrombotic debris dislodged by balloon inflation or stent implantation. Predictors of no reflow include a higher plaque burden, thrombus, lipid pools by IVUS, higher lesion elastic membrane cross-sectional area, pre-infarction angina, and TIMI flow grade 0 on the initial coronary angiogram, among other factors (3-5). Compared to aspirates obtained from patients without no reflow, analysis of aspirates obtained from patients who developed no reflow contained more atheromatous plaque and significantly more platelet and fibrin complex, macrophages, and cholesterol crystals (6). The 30-day mortality was significantly higher (27.5%) in patients with combined slow-flow and no-reflow phenomenon than in patients with normal coronary blood flow after PCI (5.3%, P < 0.001) (2).

Intracoronary Pharmacotherapy
Intracoronary or intragraft nitroprusside (7), adenosine (8), verapamil (9), nicardipine (10), GP IIb/IIIa inhibitors, fibrinolytic therapy and aspiration of atherosclerotic debris are some of the treatment strategies that have been used to correct the episodes of no-reflow.