Radial artery intima-media ratio predicts presence of coronary thin-cap fibroatheroma: A frequency domain-optical coherence tomography study

Abstract

Peripheral arterial disease is a risk factor for cardiac mortality but pathophysiologic mechanisms linking atherosclerosis of peripheral arteries with coronary events in the single patient have not been established. We evaluated by frequency-domain optical coherence tomography (FD-OCT) the possible association between culprit coronary plaque characteristics and proximal radial artery features in a cohort of 51 patients symptomatic coronary artery disease undergoing coronary procedures by transradial route. FD-OCT coronary artery analysis included assessment of TCFA and thrombus. FD-OCT radial artery analysis included intimal thickness index (ITI: intimal area/medial area), intima-media ratio (IMR: the maximum intimal thickness/medial thickness), and percentage of luminal narrowing [%LN: (intimal area+medial area)/external elastic membrane area × 100]. Coronary TCFA and thrombus were detected in 19 (37%) and 7 (14%) patients, respectively. TCFA was significantly associated with higher values of radial artery ITI (0.35 vs. 0.26, p=0.02) and IMR (0.45 vs. 0.32, p=0.03), but not with %LN. In contrast, coronary thrombus was only associated with higher %LN (26.7 vs. 22.8, p=0.02). Multivariate logistic regression analysis identified proximal radial artery IMR (OR 16.3, 95% CI 1.1 to 245.1) as an independent predictor of TCFA. In patients with symptomatic coronary atherosclerosis, vessel wall modifications at the level of the proximal radial artery are associated with adverse coronary features like TCFA and thrombus.