Bioprostheses with atrial fibrillation and mechanical prostheses in aortic valve replacement

Clinical performance of bioprostheses (BP) with presence of atrial fibrillation and/or paced rhythm and mechanical prostheses (MP) in aortic valve replacement was considered a study of importance.

Aortic valve replacement (AVR) was performed in 163 replacements with porcine bioprostheses (Carpentier-Edwards supra-annular) with atrial fibrillation/paced rhythm identified at latest follow-up. Mechanical population was 886 procedures (St. Jude Medical = 436; CarboMedics = 450). Concomitant coronary artery bypass (CAB) was conducted in 40.5 % (66) of BP; 27.0 % (239) of MP. MP patients were all (100 %) on Coumadin and BP patients 35.6 % on acetylsalicylic acid (ASA), 37.4 % Coumadin, 7.4 % Coumadin + ASA, and 19.6 % on no therapy.

Major thromboembolism (TE) and hemorrhage (ATH) occurred in 2.4 %/pt-yr (32) for BP and 5.3 %/pt-yr (157) for MP ( p < 0.0001); (TE major 1.6 %/pt-yr [21] for BP and 2.1 %/pt-yr [62] for MP [ p = 0.24]; ATH = 0.8 %/pt-yr [11] for BP and 3.2 %/pt-yr [95] for MP) ( p < 0.0001). There were no predictors of overall TE, TE major, ATH, overall TE + ATH, and TE major + ATH. Age and CAB were predictors of survival. Overall BP survival at 8 years was 97.5 +/- 1.5 %; and for MP 66.4 +/- 4.8 % ( p < 0.01). Actuarial freedom from overall thromboembolism and hemorrhage was 54.5 +/- 10.8 % for MP; 85.9 +/- 3.1 % for BP ( p = 0.0000). For major thromboembolism and hemorrhage, actuarial freedom was 63.4 +/- 11.8 % for MP; 91.4 +/- 2.5 % for BP ( p = 0.0003).

Patients with atrial fibrillation/paced rhythm having AVR with bioprostheses with 45 % on Coumadin have greater freedom from thromboembolism and hemorrhage than after AVR with mechanical prostheses on Coumadin.