ORBID Study Shows OCT Helps Predict Significant Side Branch Ostium Stenosis

May 5, 2016—ORBID, the Optical Coherence Tomography Bifurcation (ORBID) study identified predictors of side branch ostium stenosis (SBOS) after stenting, according to a late-breaking clinical trial presentation at the Society of Cardiovascular Angiographic Interventions (SCAI) 2016 scientific sessions in Orlando, Florida.

SCAI reported that with optical coherence tomography (OCT), investigators found that the maximum lipid arc and the presence of lipid plaque contralateral to the side branch ostium before stenting may contribute to significant SBOS after stenting.

The ORBID study was conducted at the Icahn School of Medicine at Mount Sinai in New York, New York. Annapoorna S. Kini, MD, et al published the findings online ahead of print in Catheterization and Cardiovascular Interventions.

Stenting in the main vessel can result in significant SBOS, making it important for interventional cardiologists to be able to identify "at-risk" patients before they undergo percutaneous coronary intervention (PCI). Significant SBOS is defined as a blockage of 50% or more based on angiography.

The ORBID investigators aimed to identify (using OCT) predictors of significant SBOS before a stent is introduced in the main vessel, which is in the research phase for this application. OCT is more accurate and provides higher-resolution imaging than ultrasound, which is currently the most widely used method in clinical care, noted SCAI.

As summarized by SCAI, the prospective single-center ORBID study analyzed 30 patients who did not have initial blockage in the side branch ostium. Significant SBOS after stenting was observed in 30% of patients. Affected patients were characterized by a higher prevalence of lipids in the blood (100% vs 64%; P = .04) and spotty calcifications (60% vs 0%; P = .005).

A multivariate logistic regression analysis identified maximal lipid arc (odds ratio, 1.014; P = .038) and the presence of lipid plaque contralateral to the side branch ostium (odds ratio, 8.14; P = .046) before stenting as independent predictors of significant SBOS.

In the SCAI announcement, study investigator Samin Sharma, MD, commented, “When inserting a stent into the main vessel of a patient, we have the option of also inserting a wire in the side branch in case SBOS occurs. In our study, OCT proved helpful in identifying predictors of SBOS prior to PCI, which may allow for avoiding inserting a wire in the side branch in select cases.”

He added, “This initial study indicates that OCT is a helpful tool in identifying predictors of significant SBOS in patients before they receive a stent. In the future, this imaging technology could be broadly introduced as a tool to identify at-risk patients, thereby giving interventional cardiologists more information before doing bifurcation stenting.” Dr. Sharma is Director of Clinical Cardiology and Intervention, Dean of International Clinical Affiliations, and President of the Mount Sinai Heart Network at The Mount Sinai Hospital in New York, New York.