The impact of diffuseness of coronary artery disease on the outcomes of patients undergoing primary and reoperative coronary artery bypass grafting

Objective: Diffuse coronary artery disease jeopardizes myocardium, increasing surgical mortality in primary coronary artery bypass grafting (CABG). We sought to determine the impact of diffuseness on pre- and post-discharge outcomes for both primary and reoperative CABG (REOP). Methods: Using a validated system for measuring diffuseness of coronary disease, preoperative angiograms were scored for primary CABG (n = 792) and REOP cases (n = 268) performed 1997-2004. A diffuseness score (DS) > 18 was defined as elevated. In-hospital mortality, intermediate-term survival, and in-hospital composite outcome (COMP) (one or more of: mortality, stroke, MI, deep sternal infection, sepsis, IABP insertion, or return to OR) were examined. Results: In-hospital mortality and COMP for patients with DS > 18 were significantly higher (7.9% vs 2.4%, p < 0.0001), (17.8% vs 9.2%, p < 0.0001). DS (mean ± SD) was higher in REOP cases than primary CABG (18.9 ± 7.1 vs 14.4 ± 6.0, p < 0.0001). By multivariate analysis, DS > 18 (OR 2.00, 95%CI, 1.20-3.32, p = 0.008) and REOP (OR 2.40, 95%CI, 1.53-3.77, p < 0.0001) were independently associated with COMP. Using propensity scores 82% of cases with DS > 18 (n = 289) were matched 1:1 to cases with DS ≤ 18. In-hospital mortality and COMP were significantly higher for cases with DS > 18 (6.9% vs 2.8%, p = 0.02), (16.6% vs 10.4%, p = 0.03). Comparing cases with DS ≤ 18 versus DS > 18 and primary CABG versus REOP, survival at 2 years was 92.1% versus 84.5% (p = 0.001) and 92.7% versus 82.7% (p < 0.0001), respectively. Conclusions: Diffuse coronary artery disease is an important predictor of morbidity and mortality in primary and REOP CABG patients, and should be considered in both individual patient assessment and risk adjustment.