Optical Coherence Tomography Superior to Intravascular Ultrasound in Lesion Assessment

Optical coherence tomography (OCT) is superior to intravascular ultrasound (IVUS) in detecting flow-limiting non-left main coronary lesions, according to a study published in the International Journal of Cardiology.

In this meta-analysis, researchers performed a systematic review of the PubMed, Medline, and Cochrane databases to identify studies examining the diagnostic accuracy of IVUS and OCT in detecting significant stenoses compared with fractional flow reserve (FFR), which is considered the gold standard for physiological assessment (33 studies with 6919 patients). The study included randomized controlled clinical trials or observational studies with prospective or retrospective data evaluating the accuracy of IVUS (24 studies with 6095 patients and 6532 lesions) and OCT (7 studies with 582 patients and 741 lesions) in predicting hemodynamically significant lesions. The researchers also included 2 studies reporting both IVUS and OCT with 242 patients and 264 lesions in their final analysis.

Both IVUS- and OCT-derived minimum lumen area (MLA) had similar sensitivity in predicting hemodynamically significant lesions (IVUS-MLA: 0.747 vs OCT-MLA 0.732; P =.519). OCT-MLA had higher specificity (0.763 vs 0.665; P <.001) and significantly more diagnostic accuracy in detecting flow-limiting stenoses than IVUS-MLA (AUC, 0.810 vs 0.754, P =.045). Studies with the clinically significant FFR cut-off value of 0.80 showed similar results that OCT-MLA has better accuracy than IVUS-MLA in detecting hemodynamically significant stenoses (AUC 0.809 vs 0.750; P =.037).

This study was limited by factors inherent in meta-analyses. For example, the researchers did not have access to individual patient data and instead relied on published summary statistics. Most of the studies included patients with an acute coronary syndrome where the FFR value for guiding revascularization was questionable. There were also significant differences in study inclusion criteria, patient ethnicity, incidence of coronary arteries studied, and location of the studied lesions. A large-scale prospective study is needed to confirm the superiority of OCT over IVUS.

“We found that 1) IVUS- and OCT-derived MLA have the best diagnostic accuracy for detecting flow limiting lesions, that 2) IVUS-MLA and OCT-MLA had a similar sensitivity but OCT-MLA had superior specificity and overall diagnostic accuracy in identifying significant stenoses and that 3) the superiority of OCT-MLA over IVUS-MLA in detecting flow limiting lesions was not affected by vessel size,” concluded the researchers. “Therefore, OCT should be preferred to IVUS when an interventional cardiologist wishes to use a single intravascular modality to assess lesion morphology, its hemodynamic significance, and plan treatment.”

Reference

Ramasamy A, Chen Y, Zanchin T, et al. Optical coherence tomography enables more accurate detection of functionally significant intermediate non-left main coronary artery stenoses than intravascular ultrasound: A meta-analysis of 6919 patients and 7537 lesions* [published online October 9, 2019]. Int J Cardiol. doi:10.1016/j.ijcard.2019.09.067