Omar M. Lattouf, Vinod H. Thourani, Patrick D. Kilgo, Kim T. Baio, Robert A. Guyton, John D. Puskas.
Emory University, Atlanta, GA, USA.
OBJECTIVE: Epiaortic ultrasound scanning reliably reveals atherosclerosis of the ascending aorta that may be undetectable by palpation, allowing customized strategies to minimize risk of atherosclerotic embolization during coronary artery bypass grafting (CABG).
METHODS: Patients undergoing primary CABG at an academic center (2004-7) were categorized by extent of ascending aortic atherosclerosis (AAA) with intra-operative epiaortic scanning. Patients were grouped by epiaortic grade (GRADE 1-2 [mild] vs. 3-5 [moderate/severe] AAA) and type of clamp (cross clamp or partial clamp vs none). A propensity score (PS) estimated probability of clamp use based on 44 preoperative risk factors. Multiple logistic regression models measured the association between outcomes - death, stroke, MI and MACE - and the primary variables (epiaortic grade and clamp use), adjusted for PS.
RESULTS: GRADE was available in 4285 patients. Among these, 2558 (59.7 %) had AAA GRADE 1, 1135 (26.5%) GRADE 2, 455 (10.6%) GRADE 3, 85 (2.0%) GRADE 4, and 52 (1.2%) GRADE 5. In 531 (12.4%) cases, intraoperative epiaortic scanning altered the planned surgical strategy. In patients with GRADE 1-2 (n=3686), a cross-clamp ± partial clamp was used in 1314 (35.7%), a partial clamp alone was used in 2011 (54.5%), and no clamp was used in 361 (9.8%) cases. For patients of GRADE 3-5 (n=592), a cross-clamp ± partial clamp was used in 154 (26.0%), a partial clamp alone was used in 115 (19.4%), and no clamp was used in 323 (54.6%) cases. Aortic clamping in patients with GRADE 3-5 AAA increased adjusted risk (AOR) of 30-day mortality 2.86 fold (95%CI 1.13-7.19; p=0.026). GRADE 5 AAA was associated with significantly reduced 1 and 3 year survival.
CONCLUSIONS: Epiaortic ultrasound informs surgical strategy. Patients with GRADE 3-5 AAA are at increased risk of in-hospital mortality, stroke, and MACE compared to patients with GRADE 1-2 AAA. Clamping the aorta (all grades) significantly increases risk for stroke compared to no clamping. Aortic clamping should be avoided whenever feasible in patients with Grade 3-5 AAA.Grade 3-5 AOR (95%CI) p value Clamping AOR (95%CI) p value Interaction Death 3.11 (1.90,5.09) <0.0001 1.74 (0.89,3.41) 0.1083 No p=0.2084 Stroke 2.12 (1.09,4.14) 0.0279 2.76 (1.09,7.00) 0.0321 No p=0.2259 MI 0.85 (0.25,2.87) 0.7971 0.43 (0.14,1.34) 0.1456 No p=0.2006 MACE 2.58 (1.73,3.84) <0.0001 1.60 (0.95,2.68) 0.0751 No p=0.4315
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