Clinical implications of distal embolization during coronary interventional procedures in patients with acute myocardial infarction: quantitative study with Doppler guidewire.

OBJECTIVES: This study sought to investigate the timing and amount of embolic particles generation during the percutaneous coronary intervention (PCI) procedure and studied the relationship between embolic burden and coronary blood flow and myocardial damage.
BACKGROUND: Distal embolization is a major complication of PCI. The Doppler guidewire (DGW) can detect the embolic particles as high-intensity transient signals (HITS) during the PCI procedure.
METHODS: We prospectively studied 37 patients with acute myocardial infarction (MI). Under monitoring with the DGW, we performed first and second balloon angioplasty, followed by stenting and post-high-pressure dilatation. Left ventricular ejection fraction (LVEF) (%) and regional wall motion (RWM) (standard deviation/chord) were measured on days 1 and 22.
RESULTS: The HITS were detected in 35 of 37 patients. The number of HITS was the greatest after stenting (16 +/- 18) followed by first balloon inflation (5 +/- 4). There was a significant correlation between the total number of HITS and the corrected Thrombolysis In Myocardial Infarction frame count (r = 0.52, p = 0.003) and a significant weak inverse correlation between the total number of HITS and changes in LVEF and RWM (r = 0.37, p = 0.03 and r = 0.35, p = 0.04, respectively).
CONCLUSIONS: Distal embolization is common during PCI in patients with acute MI, and the majority of HITS were observed after stenting. An increase in the total number of HITS is associated with reduced coronary blood flow, and is weakly associated with poor recovery of left ventricular function.