|
|
Is Anticoagulation Necessary in Patients with Bioprosthetic Aortic Valves in Normal Sinus Rhythm?
Andrew W ElBardissi, Daniel J DiBardino, Michael Yamashita, Zain Khalpey, *Lawrence H Cohn
Brigham and Women's Hospital, Boston, MA
Background: Current AHA/ACC guidelines recommend anticoagulation in the first 90 postoperative days in patients who undergo bioprosthetic aortic valve implantation. We sought to determine if immediate postoperative anticoagulation was necessary in patients undergoing isolated bioprosthetic aortic valve replacement and who were discharged in normal sinus rhythm.
Methods: From December 2001 to October 2008 1131 patients underwent bioprosthetic aortic valve implantation. After exclusion of patients who underwent concomitant operations (n=138, 12%), patients who were anticoagulated preoperatively (n=2, 0.20%), and those who experienced postoperative persistent atrial fibrillation requiring anticoagulation at discharge (n=128, 11%), our study base consisted of 861 patients who underwent isolated bioprosthetic valve implantation. Patients were followed for 90 days postoperatively for the incidence of thromboembolism (TE), including stroke, TIA, or peripheral thromboembolic events.
Results: Of the 861 patients in normal sinus rhythm included in this study, 133 (15%) were electively anticoagulated with Warfarin (AC+) postoperatively and 728 (85%) were not given any anticoagulation (AC-). Fifty-four percent (n=387) of AC- patients were discharged on Aspirin 325 mg/day (ASA). Demographic, hemodynamic, and operative characteristics are shown in Table 1. As demonstrated, patients who received postoperative anticoagulation were older, had a higher incidence of hypertension, and were more symptomatic preoperatively. The 90-day incidence of TE after surgery was 7% (n=9) in AC+ and 6% (n=45) in AC- (p=0.35). A multivariate regression model indicated the most significant predictor of TE in the 90 day postoperative period to be preoperative NYHA class III/IV (OR 1.76, 9% vs. 5%, p=0.008) heart failure. Patients in NYHA class III/IV heart failure who were discharged on ASA had a lower incidence of TE than those who were not on ASA (OR 0.34, 10% vs.7% , p=0.06). A similar trend was not appreciated in NYHA III/IV patients who were discharged on Warfarin postoperatively (OR=0.62, 7% vs. 6%, p=0.53).
Conclusions: Immediate postoperative anticoagulation after isolated bioprosthetic aortic valve replacement in patients in normal sinus rhythm does not appear to reduce the risk of TE. Current recommendations should be revisited, as the only subset of patients at high risk of TE are those in NYHA III/IV heart failure; these patients may be best treated with ASA rather than Warfarin. | | | | | AC + (n=133) | AC - (n=728) | p-value | | Age | 74.54 ± 9.1 | 68.95 ± 13.1 | <0.0001 | | Hypertension n (%) | 109 (81%) | 452 (62%) | <0.0001 | | Diabetes n(%) | 24 (18%) | 121 (17%) | 0.68 | | Hyperlipidemia n(%) | 92 (69%) | 440 (60%) | 0.06 | | Peripheral vascular disease n(%) | 19 (14%) | 76 (10%) | 0.19 | | Cerebrovascular disease n(%) | 29 (13%) | 83 (11%) | 0.29 | | NYHA functional status | | | 0.0002 | | I | 20 (15%) | 161 (22%) | | | II | 44 (33%) | 330 (45%) | | | III | 60 (45%) | 214 (29%) | | | IV | 9 (7%) | 23 (3%) | | | Previous surgical interventions | | | | | Previous CABG n(%) | 18 (14%) | 76 (10%) | 0.29 | | | | | | Echocardiographic data | | | | | Ejection Fraction | 54 ± 13 | 58 ± 11 | 0.007 | | Mean PAP | 28 ± 12 | 25 ± 12 | 0.26 | | Aortic Stenosis n(%) | 106 (80%) | 593 (81%) | 0.63 | | Aortic gradient | 44 ± 20 | 48 ± 18 | 0.04 | | Moderate or greater Aortic Regurgitation | 65 (49%) | 343 (47%) | 0.7 | | | | | | Operative characteristics | | | | | CPB time (minutes) | 125 ± 59 | 111 ± 53 | 0.02 | | Cross-clamp time | 80 ± 36 | 75 ± 36 | 0.77 |
Table 1: Demographic, hemoydnamic, and operative patient characteristics.
Back to 2009 Annual Meeting
Back to Main Program
|
