Influence of Chronic Total Occlusions on Coronary Artery Bypass Graft Surgical Outcomes

Abstract

Presence of epicardial coronary artery chronic total occlusion (CTO) predicts higher referral rates for coronary bypass graft surgery (CABG). However, the impact of coronary artery CTO on CABG outcomes has never been systematically studied. We examined one-year outcomes in 605 consecutive Veterans, discharged post-CABG between June 2005 and December 2008. A coronary CTO was present in 256 patients (42%), predominantly (48.3%) in the right coronary artery distribution. Baseline clinical characteristics and medical therapy were similar in patients with and without a coronary CTO. A single CTO was present in 73.8%, and 26.2% patients had multiple CTO. All left anterior descending coronary artery CTO were successfully bypassed, as were >92% in left circumflex and right coronary arteries and 85% CTO in multiple coronary artery distributions. During the mean follow-up of 348.9 ± 4.5 days, incidence of all-cause death and myocardial infarction were similar in both groups (7.1% in CTO group and 7.4% in non-CTO group; p = 0.97). CTO >20 mm in length constituted 74.9% and >40 mm 37.8%. One-year survival post-CABG was significantly lower in patients with CTO lengths >40 mm compared to ≤20 mm (p = 0.04). CTO >40 mm was an independent predictor of post-CABG mortality controlling for age, number of CTO, comorbid diseases, clopidogrel use, severity of coronary artery disease, renal failure, and left ventricular ejection fraction. CABG achieves high success in grafting epicardial coronary vessels with CTO; however, presence of long coronary CTO (>40 mm) is an independent predictor of post-CABG survival.