Moderate aortic stenosis in coronary artery bypass grafting patients more than 70 years of age: to replace or not to replace?

Abstract

Background: Moderate aortic stenosis in coronary artery bypass graft surgery (CABG) patients more than 70 years old is not unusual. The risk-benefit of performing a concomitant aortic valve replacement (AVR) is often difficult to assess. To stratify the risk-benefit ratio, we reviewed outcomes of CABG patients more than 70 years old with preoperative moderate aortic stenosis (valve area 1.0 to 1.6 cm(2) or indexed valve area 0.6 to 1.0 cm(2)/m(2)).

Methods: Among 263 CABG patients more than 70 years old with moderate aortic stenosis, 167 patients underwent only CABG and 96 had CABG+AVR.

Results: Cross-clamp time (p < 0.0001) and perioperative transient ischemic attack-cerebrovascular accident (p < 0.04) were significantly higher in the CABG+AVR group. In-hospital mortality was comparable among groups (CABG 6.0% versus CABG+AVR 4.2%; p = 0.8). At a mean follow-up of 4.5 ± 3.0 years, 5-year survival (CABG 64.2% ± 4.3% versus CABG+AVR 62.3% ± 5.5%) and freedom from AVR (CABG 97.8% ± 1.2% versus CABG+AVR 98.9% ± 1.1%; p = 0.13) were comparable among both groups. Among patients treated with CABG alone, receiver operating characteristic curve analysis identified 26 mm Hg and 15 mm Hg as maximum and mean aortic valve gradients, respectively, for increased risk of reoperation for late AVR. Multivariate analyses for predictors of operative mortality were preoperative renal failure (odds ratio [OR] 7.64, p < 0.001) and intubation more than 48 hours (OR 11.10, p < 0.0002); for late death, ejection fraction less than 40% (OR 3.35, p < 0.02), New York Heart Association functional class III or IV (OR 2.37, p < 0.002), chronic obstructive pulmonary disease (OR 2.26, p < 0.02), and renal failure (OR 3.03, p < 0.003); for perioperative transient ischemic attack-cerebrovascular accident, cross-clamp time (OR 1.02, p < 0.02) and Parsonnet score (OR 1.09, p < 0.05).

Conclusions: For CABG patients more than 70 years old with minimal comorbidities especially in the presence of aortic gradients of 26/15 mm Hg or greater, concomitant AVR for moderate aortic stenosis should be performed during CABG and may be performed with minimal additional operative risk. Patients with significant comorbidities should be managed with CABG alone, owing to an increased perioperative risk, poor midterm survival, and minimal risk of AVR at 5 years.