Predictor of left main coronary artery size: an intravascular ultrasound study in Southeast Asia population

Left main (LM) percutaneous coronary intervention (PCI) has expanded rapidly in the past decade, with up to fourfold increase annually. Recent trials found that intravascular imaging (IVI)-guided LM PCI resulted in lower risks of cardiac death and stent failure due to suboptimal PCI compared to angiography-guided PCI. IVI usage has increased in recent years; however, its utilization remains variable across regions and is still incredibly low in developing countries. Furthermore, to date, there is no data about LM size in the Southeast Asian population. This study aims to determine the mean external elastic membrane (EEM) diameter, cross-sectional area (CSA) of LM, and its predictor. This is a cross-sectional observational study on 100 patients with coronary artery disease (CAD) who underwent IVUS-guided PCI with a pullback to LM in Dr. Hasan Sadikin General Hospital Bandung, Indonesia, from January 2020 until December 2022. Linear regression was used to determine the predictors of LM size. There were 100 segments of LM. LM's mean EEM diameter and CSA were 5.02 ± 0.43 mm and 19.93 ± 3.48 mm². Body surface area (BSA) is an independent predictor of EEM diameter and CSA with a positive linear relationship (p 0.001 and p 0.0001). Hypertension is an independent predictor of EEM diameter with a positive linear relationship (p 0.034). The linear equation to predict EEM diameter and CSA were (2.741 + 1.272BSA(m²) + 0.165 hypertension (yes)) and (2.745 + 9.601BSA(m²)), respectively. The LM coronary artery size of the Southeast Asian population was comparable with the previous studies. BSA and hypertension are independent predictors of EEM diameter, with BSA being stronger than hypertension. Neither sex nor other cardiovascular risk factors affect the LM size. The knowledge of coronary artery size will help the clinician have a reference for intervention, especially when no intravascular imaging is available.