Aim: Current guidelines (AHA, 1998) recommend 3 months of anticoagulation with coumadin after bioprosthetic aortic valve replacement. In the rapidly expanding population of elderly patients referred for AVR, the risk / benefit ratio of this treatment may be questionable. The aim of this study is to assess the impact of a strategy “a priori” avoiding coumadin in terms of valve related complications and survival.
Patients and Method: Between 2003 and 2006 a registry series of 102 patients (Pt) (age ≥ 70 y and annular dimension ≤ 21 mm on TEE) was prospectively studied after AVR with the Mitroflow® bioprosthesis. Post op antithrombotic treatment consisted in aspirin (160 mg) and prophylactic LMW heparin (enoxaparin 40 mg/d sc for 15 days) unless there was an indication for coumadin treatment. Preop. characteristics, Euroscore risk estimation, post-op evaluation (neurological, EKG, TT echo and 24h holter recording) and discharge treatment were analysed. Complete follow-up was obtained in every patient at 6-8 weeks postop and then yearly. Valvular morbidity and mortality is reported according to Edmunds et al (JTCVS, 1996).
Results: Among the 102 Pt there were 80.4 % M and 19.6 % F. Mean patient age was 79 ± 5 y . Mean Euroscore was 8 ± 2. A previous history of atrial fibrillation was noted in 18. 6% of the Pt, 13.7% had a previous cerebro-vascular accident and 11.8 % were on coumadin before surgery. 84 % had severe AS, 4% AI and 12 % mixed lesions. There were 13.7 % redo. The size of the prostheses were predominantly 21 (44%) and 23 (36%) . Associated CABG was performed in 31.4 % and mitral or tricuspid surgery in 4.9%. The operative mortality (30d) was 6,9%. There were 2 peroperative strokes and one late thromboembolic femoral occlusion. No postop, minor or major stroke was reported, either in coumadin or aspirin patients. There was no valve thrombosis or valve dysfunction .No bleeding complication was recorded. 49% of the patients received coumadin at discharge mainly for persisting A- Fib (33.3%). Actuarial survival is 86% at 20 months.
Conclusions: A low thromboembolic complication rate and valve related complications were observed in this study despite avoidance of coumadin in 51 % of the patients. Antiagregation with aspirin seems safe and is convenient for this elderly population.This assumption is only valid for the studied bioprosthesis in the aortic position. Further studies are warranted to validate these preliminary data to other bioprosthesis and in a randomized manner.