SAN FRANCISCO — Aortic valve replacement at the time of coronary artery bypass surgery in patients with mild aortic stenosis did not affect operative mortality or long-term survival rates, a retrospective study of 316 patients found.
Among 107 patients who underwent coronary artery bypass graft (CABG) alone and 209 patients who also had a prophylactic aortic valve replacement, 4% died during surgery. Survival rates over a mean 5-year follow-up were similar between groups—about 60%, Dr. Basar Sareyyupoglu and associates reported in a prize-winning poster at the annual meeting of the Society of Thoracic Surgeons.
Although aortic valve replacement is generally favored for CABG patients with moderate aortic valve stenosis, the benefit has been less clear for those with mild aortic valve stenosis, defined as a mean gradient greater than 15 mm Hg and less than 30 mm Hg.
Among patients who underwent CABG alone, the likelihood of needing aortic valve replacement was low (approximately 10%) in the first 5 years but increased to approximately 50% by year 7 and slightly more than 50% by years 8-10.
The decision to intervene on the valve at the time of CABG depends critically on the incremental operative risk imposed by prophylactic aortic valve replacement and on the number of years a patient is expected to live after the surgery, said Dr. Sareyyupoglu of the Mayo Clinic, Rochester, Minn.
Older patients and those whose aortic valves were replaced at the time of CABG were less likely to need a subsequent replacement. Although aortic valve replacement did not affect later mortality rates, multivariate analyses showed that factors such as comorbid illnesses, small body surface area, low ejection fraction, heart failure, and a preoperative permanent pacemaker significantly increased the odds of death during follow-up.
Before surgery, patients in the CABG plus aortic valve replacement group differed significantly from the CABG-only group in several respects. They were less likely to have a history of MI, and more likely to have a bicuspid aortic valve and mild/moderate aortic regurgitation. In addition, they had a higher mean gradient of stenosis, a smaller aortic valve area, and lower ejection fraction, cardiac output, and cardiac index.
Perioperatively, patients in the CABG plus aortic valve replacement group needed significantly longer cross-clamp time and cardiopulmonary bypass time and had a higher risk of retrograde cardioplegia than did their CABG-only counterparts. They received fewer bypass grafts but were more likely to have associated procedures or to need tamponade or blood products.
Average hospital stays were 12 days for the CABG plus aortic valve replacement group and 9 days for the CABG-only group.