Clin Res Cardiol 96: Suppl 1 (2007)

P511 - Detection of coronary microembolization by Doppler ultrasound in patients with stable angina pectoris undergoing elective percutaneous coronary interventions
P. Bahrmann1, G. S. Werner2, G. Heusch3, M. Ferrari1, T. Poerner1, A. Voss4, H. R. Figulla1
1Klinik für Innere Medizin I, Universitätsklinikum Jena, Jena; 2Medizinische Klinik I, Klinikum Darmstadt, Darmstadt; 3Zentrum Innere Medizin/Institut für Pathophysiologie, Universitätsklinikum Essen, Essen; 4Abteilung für Medizintechnik, Fachhochschule Jena, Jena;
Background: Intracoronary Doppler guide wires can be used for real time detection and quantification of microembolism during percutaneous coronary interventions (PCI). We investigated whether the frequency of Doppler-detected microembolism is related to the incidence of myonecrosis during elective PCI.
Methods and Results: The study population included 52 consecutive patients (age 64 ± 10 years; 36 men, 16 women) with coronary artery disease who underwent elective PCI of a single vessel stenosis. Using intracoronary Doppler ultrasound, we compared the frequency of microembolism during PCI in 22 patients with periprocedural non ST-elevation myocardial infarctions (pNSTEMI) and 30 patients without pNSTEMI. The two groups were comparable regarding their clinical and procedural characteristics.
In the group with pNSTEMI the total number of coronary microemboli after PCI (27 ± 10 vs. 16 ± 8, P<0.001) was higher than in the group without pNSTEMI (Fig. 1). While high sensitivity C-reactive protein plasma levels were similar before PCI (2.9 ± 2.2 vs. 3.4 ± 1.7 mg/L, P=NS), they were higher in the group with pNSTEMI after PCI (12.6 ± 10.4 vs. 6.1 ± 5.1 mg/L, P<0.05). Microembolic count (Fig. 2) independently correlated to postprocedural cTNI elevation (r=0.565, P<0.001), coronary flow velocity reserve (r=-0.506, P<0.001) and baseline average peak velocity (r=0.499, P<0.001).
Conclusions: Patients with pNSTEMI had a significantly higher frequency of coronary microembolization during PCI and their systemic inflammatory response and microvascular impairment after PCI were more pronounced. Intracoronary Doppler ultrasound provides evidence that pNSTEMI in patients undergoing elective PCI is caused by microembolization during the procedure.


Figure 1. Comparison of microembolic profiles during successive phases of PCI (A: advancement over wire, B: predilation, C: stent deployment, D: postdilation) in both groups (black dots: No pNSTEMI, white dots: pNSTEMI). Vertical lines indicate mean microembolic counts ± SD. The dashed horizontal line indicates the lower threshold limit for microembolic count and a value of cTNI below 0.04 ng/mL. *P<0.05 vs No pNSTEMI.

Figure 2. Relationship between microembolic count during PCI and (A) postprocedural CFVR (r=-0.506, P<0.001), and (B) postprocedural baseline APV (r=0.499, P<0.001).