Comparative clinical and echocardiographic outcomes of coronary artery bypass grafting for nonfilling and filling chronic total occlusion in the left anterior descending artery.

Objective: This study aims to compare the clinical and echocardiographic outcomes of multivessel coronary artery bypass grafting (CABG) for nonfilling vs. filling chronic total occlusion (CTO) in the left anterior descending artery (LAD).

Methods: A retrospective analysis included 257 from 2778 patients undergoing multivessel CABG at Juntendo University between 2002 and 2020. CTO lesions were assessed using coronary angiography, and collateral circulation was graded using the Rentrop classification. Nonfilling CTO was defined as grades 0 and 1 while filling CTO was defined as grades 2 and 3.

Results: LAD revascularization with internal thoracic artery (ITA) grafts showed higher graft dysfunction in nonfilling CTO patients. Transit-time flow measurement revealed lower mean graft flow (23 ± 12 ml/min vs. 36 ± 13 ml/min, P = 0.01) and higher pulsatile index (4.0 ± 1.5 vs. 3.0 ± 1.4, P = 0.02) in nonfilling CTO patients. Postoperative computed tomography in the ITA grafts indicated string signs in 13.7% of nonfilling CTO and 6.1% of filling CTO patients (P = 0.04), with graft occlusion rates of 5.9 and 1.8%, respectively (P = 0.03). Although long-term survival rates showed no significant difference (P = 0.19), filling CTO patients had significant improvements in left ventricular ejection fraction (LVEF) from 39 to 47% (P = 0.01) and wall motion score index (WMSI) from 1.5 to 1.1 (P = 0.02). In contrast, nonfilling CTO patients did not show significant improvements in LVEF (P = 0.76) or WMSI (P = 0.64).

Conclusion: CABG for LAD nonfilling CTO does not significantly impact long-term survival but is associated with lower graft flow, higher occlusion rates, and less improvement in cardiac function compared to filling CTO.