Intravascular ultrasound-derived morphological predictors of myocardial ischemia assessed by stress myocardial...

Although ischemia-guided revascularization improves clinical outcomes, morphological determinants of clinically relevant myocardial ischemia have not been studied. To identify intravascular ultrasound (IVUS)-derived anatomical parameters for predicting myocardial perfusion defect and its extent.

A total of 103 patients (88 stable and 15 unstable angina) with 153 lesions (angiographic diameter stenosis of 30-80%) underwent stress myocardial perfusion computed tomography (CT) and IVUS pre-procedure. The volume of CT perfusion defect and %CT perfusion defect in the target vessel territories were measured.

The CT perfusion defect was seen in 76 (50%) lesions. The independent determinants for the presence of CT perfusion defect were IVUS-minimal lumen area (MLA) (adjusted OR = 0.56, 95% CI = 0.38-0.82), plaque burden (adjusted OR = 1.07, 95% CI = 1.02-1.11) and involvement of left main or left anterior descending artery (adjusted OR = 4.13, 95% CI = 1.75-9.78, all P < 0.05). The CT perfusion defect was predicted by IVUS-MLA <2.28mm² (sensitivity 74%, specificity 82%) and plaque burden >77% (sensitivity 79%, specificity 78%) as thresholds. The independent determinants for the volume of CT perfusion defect were the involvement of left main or left anterior descending artery (β = 16.43, standard errors = 4.387, P = 0.020) and a greater plaque burden (β = 0.56, standard errors = 0.163, P = 0.026).

IVUS-derived morphological parameters were useful to predict the presence of CT perfusion defect and the size of myocardial ischemia that were primarily determined by lesion severity and subtended myocardial territory. © 2016 Wiley Periodicals, Inc.