Abstract 13171: Long-Term Impact of Untreated Aortic Stenosis at the Time of Coronary Artery Bypass Grafting - Is there a Role for Prophylactic Valve Replacement in the Transcatheter Era?
Background: The late prognostic impact of untreated mild or moderate aortic stenosis (AS) in patients undergoing isolated coronary artery bypass grafting (CABG) is unknown. Equipoise exists regarding the optimal management of this condition, particularly in light of the perceived opportunity for future percutaneous management.
Methods: Among 2,418 consecutive patients with preoperative echocardiography undergoing isolated CABG between 1993 and 2006 at our Institution, 312 patients with mild or moderate AS (aortic valve area [AVA] 1 - 2 cm2) were matched to 312 without AS (AVA > 2 cm2) by age, gender, ejection fraction (EF), number of diseased coronary vessels, number of bypass grafts, use of left internal mammary artery graft, and year of surgery. Multivariable Cox models with aortic valve replacement (AVR) as a time-dependent covariate were internally validated with bootstrap samples.
Results: Mean age was 72 ± 9 yr and 55% (344) were men. Mean follow-up was 8 ± 4.5 yr. Following CABG, there was a significant difference in 10-year survival between patients with moderate (AVA 1 - 1.5 cm2), mild (1.5 - 2 cm2) and no AS (> 2 cm2) (42% vs. 49% vs. 52%; p = 0.007). During follow-up, 33 (11%) patients with mild or moderate AS underwent AVR or balloon valvuloplasty at a mean of 8 ± 3.1 yr. Compared to patients without AS, moderate stenosis independently predicted increased late mortality (HR 2, p < 0.001). More precisely, AVA 1 - 1.25 cm2 and 1.25 - 1.5 cm2 were respectively associated with a 2.5-fold (p < 0.001) and 1.8-fold (p = 0.001) increased mortality risk, compared to those without AS at the time of CABG. Mild AS conferred no additional risk (p = 0.5). Older age (HR 1.3 per 5 yr; p < 0.001), reduced EF (HR 1.1 per 5%; p < 0.001), congestive heart failure (HR 1.5; p = 0.003), preoperative creatinine (HR 1.03 per 0.1 mg/dL; p < 0.001), diabetes mellitus (HR 1.6; p < 0.001), and peripheral vascular disease (HR 2.1, p < 0.001) also predicted increased late mortality (model C statistic = 0.72).
Conclusions: Untreated moderate AS is a significant modifiable determinant of late survival at the time of isolated CABG. Patients with moderate-severe AS (AVA 1.0 - 1.25 cm2) may be at greatest mortality risk and thus may benefit most from prophylactic AVR at index CABG versus delayed valvular intervention.
- © 2012 by American Heart Association, Inc.