Near-infrared spectroscopy predicts cardiovascular outcome in patients with coronary artery disease

Purpose: Intra-coronary near-infrared spectroscopy (NIRS) is capable of identifying lipid core-containing plaques, which can subsequently be quantified as a lipid core burden index (LCBI). Currently, no data are available on the long-term prognostic value of NIRS in patients with coronary artery disease (CAD). Methods: In this prospective, observational study, NIRS imaging was performed in a non-culprit coronary artery in 203 patients referred for angiography due to stable angina pectoris (SAP) or acute coronary syndrome (ACS). Results: The one-year cumulative incidence of the primary endpoint (the composite of all-cause mortality, non-fatal ACS, stroke and unplanned coronary revascularization) was 10.4%. Cumulative one-year rates in patients with an LCBI equal to and above the median (43.0) versus those with LCBI values below the median, were 16.7% versus 4.0% (P=0.003) (adjusted hazard ratio, 4.04; 95% confidence interval, 1.33-12). The relation between LCBI and the primary endpoint was similar in SAP and ACS patients (p-value for heterogeneity=0.14). Similar results were observed for the secondary endpoints of all-cause mortality or non-fatal ACS (8.8% vs. 1.0%, P=0.010), all-cause mortality, non-fatal ACS or stroke (11.8% vs. 1.0%, P=0.002) and all-cause mortality, non-fatal ACS or unplanned coronary revascularization (13.7% vs. 4.0%, P=0.014). KM curves for the primary endpoint Conclusion: CAD patients with a LCBI equal to or above the median of 43.0, as assessed by NIRS in a non-culprit coronary artery, had a four-fold risk of adverse cardiovascular events during one-year follow-up. Apparently, the LCBI as assessed in a non-culprit vessel, reflects vascular vulnerability of the larger coronary tree. Our results should be (externally) validated in a larger sample.