Comparison of Small Blood Vessels Diameter with Intravascular Ultrasound and Coronary Angiography for Guidance of Percutaneous Coronary Intervention

Abstract

Major cardiovascular events (MACE) are a cause of major mortality worldwide. The narrowing and blockage of coronary arteries with atherosclerotic plaques is diagnosed and treated with percutaneous coronary intervention (PCI). During this procedure, coronary angiography (CAG) remains the most widely used guidance modality for the evaluation the affected blood vessel diameter in order to decide if intervention with stent colocation is suitable, where small blood vessels (< 2.75 mm) are majorly left untreated; however, small vessel coronary artery disease (SvCAD) is a significant risk factor for recurrence of MACE, and there are some limitations to the use of CAG that could be improved with the use of newer techniques such as intravascular ultrasound (IVUS), although at higher costs, which might explain their underuse. To address this discrepancy and identify specific cases for its use, we conducted a retrospective study in patients who underwent PCI for MACE with at least one small blood vessel affected. The affected small blood vessels’ diameter was obtained with both CAG and IVUS, additionally we underwent a multivariate analysis to identify risk factors associated with a change in diameter. We included information from 48 patients with mean + SD age of 69.1 + 11.9 years and 34% were masculine gender. We found a significant positive low correlation in diameter measurements of small blood vessels (r=0.1242 p=0.014). Mean diameter with CAG and IVUS was 2.1 mm (95% CI 1.9-2.2), and 2.8 (2.8-3.0) the estimated difference was of 0.8 mm (95 % CI 0.7-0.9). In total 37 (77%) of patients had a reclassification of their blood vessels from a small to medium (2.75-3.00 mm) in 21 cases, or even large (<3.00 mm) in 15 cases, after IVUS; this was important for the decision of intervention and stent collocation. The only variable associated with reclassification of blood vessels after adjusted in a multivariate analysis was DT2 (p=0 0.035). Our findings corroborate that blood vessels might appear smaller with CAG, especially in the diabetes population, therefore at least in these cases the use of IVUS is recommended over CAG.