Assessment of the coronary calcification by optical coherence tomography

Aims: Optical coherence tomography (OCT) can delineate calcified plaque without artefacts. The aim of this study was to evaluate the ability of OCT to quantify calcified plaque in ex vivo human coronary arteries. Methods and results: Ninety-one coronary segments from 33 consecutive human cadavers were examined. By intravascular ultrasound (IVUS), 32 superficial calcified plaques, defined as the leading edge of the acoustic shadowing appears within the most shallow 50% of the plaque plus media thickness, were selected and compared with corresponding OCT and histological examinations. The area of calcification was measured by planimetry. IVUS significantly underestimated the area of calcification compared with histological examination (y=0.39x+0.14, r=0.78, p<0.001). Although OCT slightly underestimated the area of calcification (y=0.67x+0.53, r=0.84, p<0.001), it showed a better correlation with histological examination than IVUS. Conclusions: Both OCT and IVUS underestimated the area of calcification, but OCT estimates of the area of calcification were more accurate than those estimated by IVUS. Thus, OCT may be a more useful clinical tool to quantify calcified plaque.