Clinical validation of intravascular ultrasound imaging for assessment of coronary stenosis severity: comparison with stress myocardial perfusion imaging.

OBJECTIVES To validate intravascular ultrasound (IVUS) measurements for differentiating functionally significant from nonsignificant coronary stenosis. BACKGROUND To date, there are no validated criteria for the definition of a flow-limiting coronary artery stenosis by IVUS. METHODS Preinterventional IVUS imaging (30-MHz imaging catheter) of 70 de novo coronary lesions was performed. The lesion lumen area and three IVUS-derived stenosis indixes comparing lesion lumen area with the lesion external elastic lamina (EEL) area, the mean reference lumen area and the mean reference EEL area were compared with the results of stress myocardial perfusion imaging. RESULTS The lesion lumen area and three IVUS-derived stenosis indexes showed sensitivities and specificities ranging between 80% and 90% using stress myocardial perfusion imaging as the gold standard. The lesion lumen area < or =4 mm2 is a simple and highly accurate criterion for significant coronary narrowing. CONCLUSIONS Quantitative IVUS indices can be reliably used for identifying significant epicardial coronary artery stenoses.