QRS score: A simple marker to quantify the extent of myocardial scarring in patients with chronic total arterial occlusion

BACKGROUND: Chronic total occlusion (CTO) is a critical and unique subgroup of coronary lesions. This study aimed to investigate the correlation between the Selvester QRS score and late gadolinium enhancement cardiac magnetic resonance imaging (LGE‐CMRI) in quantifying myocardial scarring to provide a simple and feasible method for treating CTO. METHODS: The medical records of 134 patients with absolute CTO who underwent coronary angiography between May 1, 2014 and December 30, 2017 were retrospectively reviewed. All patients were grouped according to the CTO location (right coronary artery [RCA] CTO, left artery descending [LAD] CTO, left circumflex [LCX] CTO, and multivessel CTO groups). The degree of myocardial scarring was determined according to the Selvester QRS score and using the LGE‐CMRI. All patients were followed up for at least 12 months. RESULTS: Among the 62 CTO patients, 55 had occlusion of a single vessel and seven had occlusion of multiple vessels, of which 27 (43.55%) were in the RCA CTO group, 16 (25.81%) in the LAD CTO group, 12 (19.35%) in the LCX CTO group, and 7 (11.29%) in the multivessel CTO group. The area under the receiver operating characteristic curve for the QRS score that was used to determine the degree of myocardial scarring was 0.806, with a sensitivity and specificity of 94.7% and 42.1%, respectively. The Selvester QRS score and LGE‐CMRI measures of scar size were correlated in the RCA CTO, LCX CTO, and multivessel CTO groups (r = 0.466, 0.593, and 0.775, respectively). CONCLUSION: The Selvester QRS score was feasible for detecting myocardial scarring in patients with CTO.