Background
Disruption of a vulnerable coronary plaque with subsequent thrombosis is currently recognized as the primary mechanism for acute myocardial infarction. Although such plaques are considered to have a thin (less than 65 microns) fibrous cap overlying a lipid pool, imaging modalities in current clinical practice do not have sufficient resolution to identify thin fibrous caps. Optical coherence tomography (OCT) is a new imaging technology capable of obtaining cross-sectional images of coronary vessels. As an optical analog of ultrasound, OCT uses a high-bandwidth infra-red light source instead of an ultrasound-emitting crystal to create high-resolution cross-sectional images of coronary vessels. The resolution of the current OCT system is 10 to 20 microns, which is approximately 10-fold higher than that of intra-vascular ultrasound (IVUS). Furthermore, OCT can visualize stent mal-apposition and tissue protrusion after stenting and neointimal hyperplasia at follow-up.
While there is extensive research on intra-vascular OCT, this new imaging modality has not been adequately assessed. Thus, its clinical value has yet to be established. Stamper et al (2006) stated that the identification of unstable plaque is central in risk-stratifying patients for acute coronary events; and OCT is a modality that has shown considerable promise for the identification of high-risk plaques. They concluded that OCT is a promising technology for the assessment of vulnerable and unstable plaque. The advantages of OCT include its high-resolution and fast data acquisition rate. They stated that future work will focus on improving plaque risk-stratification, especially the identification of reliable markers within the images. Manfrini et al (2007) stated that intra-vascular OCT’s high-resolution (10 to 20 microns) makes it a very interesting method for assessing atherosclerotic plaque microstructure in patients suffering from coronary artery disease (CAD). However, significant limitations still exist, including poor penetration in non-transparent tissue. Kubo and Akasaka (2008) noted that OCT is a specialized research tool that might provide new insights into the diagnosis and treatment of CAD.
Raffel et al (2008) evaluated the in-vivo association between coronary artery remodeling and underlying plaque characteristics identified by OCT. They determined that coronary plaques with positive remodeling exhibit characteristic features of vulnerable plaque. This may explain the link between positive remodeling and unstable clinical presentations. They noted that prospective, longitudinal studies with a larger cohort are needed to confirm these findings and to investigate their clinical significance.
Zafar et al (2014) noted that frequency domain OCT (FD-OCT) provides cross-sectional images of coronary arteries and deployed stents with micron resolution and measures lumen dimensions with good reproducibility.
Yonetsu et al (2013) stated that since its invention in the late 1990s, intra-vascular OCT has been rapidly adopted in clinical research and, more recently, in clinical practice. They determined that although OCT has contributed to cardiovascular research by providing a better understanding of the pathophysiology of CAD, data linking the images and clinical outcomes are lacking.
Indications
Intra-vascular optical coherence tomography (OCT) by any technique for any indication is not safe and effective based on review of available literature using standard strength of evidence guidelines.
Limitations
Cahaba GBA considers intra-vascular optical coherence tomography (OCT) investigational for any indications, including the following because of insufficient evidence of its effectiveness.
Assessment of acute coronary syndrome
Assessment of pulmonary arterial wall fibrosis (as a prognostic marker of pulmonary arterial hypertension)
Assessment of severity of coronary artery lesion (identification and risk stratification of vulnerable plaque)
Guidance of intra-coronary stenting and follow-up evaluation of post-stent placement
Treatment (as an adjunct to percutaneous coronary interventions)
CPT/HCPCS Codes
Group 1 Codes:
0291T Iv oct for proc init vessel
0292T Iv oct for proc addl vessel
ICD-10 CODE DESCRIPTION
XX000 Not Applicable
