Results of bioprosthetic versus mechanical aortic valve replacement performed with concomitant coronary artery bypass grafting

Abstract

Background: Concomitant coronary artery disease with aortic valve disease is an established risk factor for diminished late survival. This study evaluated the results of bioprosthetic (BAVR) or mechanical aortic valve replacement (MAVR) performed with coronary artery bypass grafting (CABG).

Methods: From January 1984 through July 1997, combined AVR + CABG was performed in 750 consecutive patients; 469 received BAVR and 281 received MAVR. BAVR recipients were significantly older (mean age, 75 vs 65 years), and had more nonelective operations, congestive heart failure, peripheral vascular disease, preoperative intraaortic balloons, lower cardiac indices, more severe aortic stenosis, less aortic regurgitation, and more extensive coronary artery disease.

Results: Early complications included operative mortality, 32 patients (4.3% total: 3.8% BAVR and 5.0% MAVR); perioperative infarction, 10 (1.3%); and perioperative stroke, 22 (2.9%). Significant multivariable predictors of early mortality were age, perioperative infarction or stroke, nonelective operation, operative year, ventricular hypertrophy, and need for intraaortic balloon. Ten-year actuarial survival was 41.7% for all patients. Predicted survival for age- and gender-matched cohorts from the general population versus observed survival were BAVR, 45% versus 36%; MAVR, 71% versus 48% (survival differences BAVR 9% vs MAVR 23%, p < 0.007). Significant multivariable predictors of late mortality included age, congestive failure, perioperative stroke, extent of coronary disease, peripheral vascular disease, and diabetes. Valve type was not significant. Ten-year actuarial freedom from valve-related complications were (BAVR vs MAVR) structural deterioration, 95% versus 100%, p = NS; thromboembolism, 86% versus 84%, p = NS; anticoagulant bleeding, 93% versus 88%, p < 0.005; reoperation, 98% versus 98%, p = NS.

Conclusions: AVR + CABG has diminished late survival despite the type of prosthesis inserted. Although valve type did not predict late mortality, mechanical AVR was associated with worse survival compared with predicted and more valve-related complications due to anticoagulation requirements.