COMBINED WARFARIN AND ANTIPLATELET THERAPY AFTER ST-JUDE MEDICAL VALVE-REPLACEMENT FOR MITRAL-VALVE DISEASE

Objectives. The clinical effect of combined warfarin and anti- platele t therapy on the incidence of stroke and postoperative complications a fter mitral (plus aortic) valve replacement was studied and compared w ith that observed with warfarin therapy alone. Background. It has been reported that combined warfarin and antiplatelet therapy may be effec tive but may be associated with an increased hemorrhagic risk. Therefo re, definite benefits of the treatment in patients with an implanted p rosthetic valve have not been clearly documented. Methods. Between Jan uary 1980 and December 1992, 195 patients with a St. Jude Medical valv e at the mitral (plus aortic) position were assigned to receive treatm ent with either warfarin alone (125 patients) or warfarin plus antipla telet agents (70 patients), such as dipyridamole (150 or 300 mg daily, 14 patients) or ticlopidine (200 or 400 mg daily, 56 patients). A min imal dose of aspirin (10 to 40 mg) was added (29 patients) if the maxi mal platelet aggregation rate by collagen was not reduced. The target thrombotest level was 10% to 20%. Results. The two treatment groups we re similar with regard to gender and age distribution. The number of p atients with atrial fibrillation, left atrial thrombus, history of pre vious stroke, simultaneous aortic valve operation and previously perfo rmed valve procedures were comparable in the two groups. Actuarial sur vival rate at 10 years was 98.3 +/- 1.7% (mean +/- SD) in the warfarin plus antiplatelet group and 90.3 +/- 3.2% in the warfarin group (p < 0.05 at 1 and 9 to 12 years). The actuarial stroke free rate at 10 yea rs was 95.3 +/- 3.4% and 84.3 +/- 3.8%, respectively (p < 0.05 by the generalized Wilcoxon test). The actuarial complication-free rate at 10 years was 89.4 +/- 4.3% and 67.9 +/- 4.8%, respectively (p < 0.05 by the generalized Wilcoxon test). No hemorrhagic complications were seen in the warfarin plus antiplatelet group. Conclusions. The results str ongly indicate the effectiveness and safety of combined warfarin plus antiplatelet treatment after St. Jude Medical valve replacement for mi tral (plus aortic) valve disease.