Study Design & Methodology

Hypothesis

Intravascular NIRS imaging can identify patients and plaques at risk for NC-MACE during a 24-month period.

Methodology

A total of 1,271 patients were imaged at baseline and followed for 24 months for future NC-MACE.

Endpoints

Nearly 2,500 artery cross-sections were histologically and spectrally analyzed to validate lipid core plaque detection by NIRS. The red and yellow colors on the chemogram help differentiate normal or fibrotic plaque that is presumed to be stable from those that contain lipid core plaques.

*Non-culprit major adverse cardiovascular events (NC-MACE) were independently adjudicated by CEC blinded to NIRS and defined as:

Cardiac death
Cardiac arrest
Non-fatal myocardial infarction
Acute coronary syndrome
Revascularization by CABG or PCI
Re-hospitalization for progressive angina with greater than 20% stenosis progression

Study Co-Primary Endpoints

Vulnerable Patient:

Association between maxLCBI_4mm in all imaged arteries and future patient-level nonculprit MACE*

Vulnerable Plaque:

Association between maxLCBI_4mm in a segment and incidence of future NC-MACE* in same segment

Study Secondary Endpoints

Vulnerable Patient:

A threshold of maxLCBI_4mm>400 will identify patients and plaques at increased risk of a NC-MACE*

*Non-culprit MACE (independently adjudicated by CEC blinded to NIRS)

Statistical Methodology

The co-primary endpoints assessed maxLCBI_4mm as a continuous variable using time-to-event Cox proportional hazard models. The key secondary endpoints were assessed with the maxLCBI_4mm dichotomized at 400.

Ware segments
The analysis unit for both index procedure analysis and event adjudication was defined by paired standardized 30 mm segments (Proximal, Mid, Distal, and Far Distal).

Vulnerable Patient-Level Analysis

MaxLCBI_4mm was computed from all eligible non-culprit scanned area NC-MACE evaluated at a patient level

Vulnerable Plaque-Level Analysis

Evaluation was conditional on the Patient-Level being met
MaxLCBI_4mm was computed in each eligible Ware segments
NC-MACE evaluated only in corresponding segments where imaging occurred