Fused whole-heart coronary and myocardial scar imaging using 3-T CMR. Implications for planning of cardiac resynchronization therapy and coronary revascularization

Abstract

Objectives: The aim of this study was to demonstrate the feasibility of providing spatially matched, 3-dimensional (3D) myocardial scar and coronary imaging for the purpose of fused volumetric image display in patients undergoing cardiac resynchronization therapy (CRT) or coronary artery revascularization (CAR).

Background: Clinical success in coronary vascular-based interventions is mitigated by the presence of scar in related myocardium. Pre-procedural fused volumetric imaging of both myocardial scar and coronary vasculature may benefit pre-procedural planning and patient selection in populations referred for CRT or CAR.

Methods: A total of 55 studies were performed in patients referred for either CRT (n = 42) or CAR (n = 13). Coronary-enhanced and scar-enhanced imaging was performed on a 3-T cardiac magnetic resonance scanner using the same cardiac-gated, 3D, free-breathing cardiac magnetic resonance technique during and 20 minutes following slow gadolinium infusion. Matched image datasets were fused and volume-rendered to simultaneously display coronary anatomy and myocardial scar. Visual scoring of coronary artery, coronary vein, and myocardial scar image quality (score 0 to 4) was performed. The clinical impact of imaging was also scored using a physician survey.

Results: Mean age was 57 ± 14 years. Combined 3D coronary and scar imaging was successful in 49 studies (89%). A quality score ≥ 2 was obtained for 97% of proximal- and mid-coronary artery and vein segments. The mean quality score of 3D scar imaging was 2.8 ± 1.0 and was scored as ≥ 2 in 86% of patients with myocardial scar. All patients with a scar quality score ≥ 2 achieved successful image fusion. Transmural scar was present below ≥ 1 planned target vessel in 9 patients (39%) planned for CRT and 8 patients (62%) planned for CAR. Physician surveys demonstrated incremental clinical impact in 67% of patients.

Conclusions: Three-dimensional myocardial scar and coronary imaging with fused volumetric display is clinically feasible and may be valuable for the planning of vascular-based interventions when regional myocardial scar is pertinent to therapeutic success.