Abstract 14026: Pressure-Wire Based Assessment of Microvascular Resistance Using Calibrated Upstream Balloon Obstruction Predicts Myocardial Viability After PCI for Acute Coronary Syndrome
Aims: The value of Fractional flow reserve(FFR) in infarct myocardium is influenced by the amount of scar tissue in which microvascular reactivity is decreased. We assessed the hypothesis that the ‘microvascular reacitivty of risk area’ can be expressed as a standardized scale with coronary pressure wire if baseline Pd/Pao (Pd : the pressure of distal segment of lesion, Pao : the pressure of aorta) is set to a same certain value in each lesion.
Methods: 29 patients with acute coronary syndrome were enrolled in this study. After successful PCI in culprit lesion of infarct related artery, artificial obstruction with an undersized balloon in stented segment was made in order to set the value of baseline Pd /Pao to 0.8, which was arbitarily determined. And then the drop of the final Pd/Pao from the baseline value (0.8) during maximal hyperemia was defined as ΔFFR0.8(Figure. A). Contrast enhanced cardiac MRI was also performed after PCI (2.8±1.5 days) in all patients. Average transmural extent of infarction (TEI) was defined as “the area of delayed hyperenhancement/the area of myocardial segment involving any thickness of delayed hyperenhancement” in short axis slices of left ventricle(Figure B) . Each ΔFFR0.8 was compared with average TEI.
Results: A significant inverse correlation was found between ΔFFR0.8 and average transmural extent of infarction (TEI) (r2=0.81, p <0.01, Figure C) . The 0.1 cutoff value of ΔFFR0.8 was valid for distinguishing average TEI of 50% with high sensitivity and specificity (100% and 94.4% respectively).
Conclusion: The present data strongly suggest that coronary pressure wire could provide information of both ‘myocardial viability’ and ‘microvascular reactivity’ at risk area. Further studies with larger sample size should be done to verify this result.
- © 2010 by American Heart Association, Inc.