TY - JOUR
T1 - Trial of combined warfarin plus dipyridamole or aspirin therapy in prosthetic heart valve replacement
T2 - Danger of aspirin compared with dipyridamole
AU - Chesebro, James H.
AU - Fuster, Valentin
AU - Elveback, Lila R.
AU - McGoon, Dwight C.
AU - Pluth, James R.
AU - Puga, Francisco J.
AU - Wallace, Robert B.
AU - Danielson, Gordon K.
AU - Orszulak, Thomas A.
AU - Piehler, Jeffrey M.
AU - Schaff, Hartzell V.
PY - 1983/5/15
Y1 - 1983/5/15
N2 - Despite the use of oral anticoagulation in patients with prosthetic heart valves, persistent thromboembolism over time warrants a search for improved methods of prevention. Thus, patients receiving 1 or more mechanical prosthetic heart valves were randomized to therapy with warfarin plus dipyridamole (400 mg/day) or warfarin plus aspirin (500 mg/day) on the basis of location and type of valve and surgeon, and followed up with a concurrent, nonrandomized control group taking warfarin alone. In 534 patients followed up 1,319 patient-years, excessive bleeding (necessitating blood transfusion or hospitalization) was noted in the warfarin plus aspirin group (23 of 170 [14%], or 6.0 100 patient-years) compared with warfarin plus dipyridamole (7 of 181 [4%], or 1.6 100 patient-years, p <0.001), or warfarin alone (9 of 183 [5%], or 1.8 100 patient-years, p <0.001). A trend was evident toward a reduction in thromboembolism in the warfarin plus dipyridamole group (2 of 181 [1%], or 0.5 100 patient-years) as compared with warfarin plus aspirin (7 of 170 [4%], or 1.8 100 patient-years), or warfarin alone (6 of 183 [4%], or 1.2 100 patient-years). Adequacy of anticoagulation (based on 12,720 prothrombin time determinations) was similar in all 3 groups with 65% of prothrombin times in the therapeutic range (1.5 ≤prothrombin time/control ≤2.5), 30% too low, and 5% too high. Warfarin plus aspirin therapy resulted in excessive bleeding and is contraindicated. Longer follow-up study is needed to determine whether further separation of the incidence of thromboembolism can be detected.
AB - Despite the use of oral anticoagulation in patients with prosthetic heart valves, persistent thromboembolism over time warrants a search for improved methods of prevention. Thus, patients receiving 1 or more mechanical prosthetic heart valves were randomized to therapy with warfarin plus dipyridamole (400 mg/day) or warfarin plus aspirin (500 mg/day) on the basis of location and type of valve and surgeon, and followed up with a concurrent, nonrandomized control group taking warfarin alone. In 534 patients followed up 1,319 patient-years, excessive bleeding (necessitating blood transfusion or hospitalization) was noted in the warfarin plus aspirin group (23 of 170 [14%], or 6.0 100 patient-years) compared with warfarin plus dipyridamole (7 of 181 [4%], or 1.6 100 patient-years, p <0.001), or warfarin alone (9 of 183 [5%], or 1.8 100 patient-years, p <0.001). A trend was evident toward a reduction in thromboembolism in the warfarin plus dipyridamole group (2 of 181 [1%], or 0.5 100 patient-years) as compared with warfarin plus aspirin (7 of 170 [4%], or 1.8 100 patient-years), or warfarin alone (6 of 183 [4%], or 1.2 100 patient-years). Adequacy of anticoagulation (based on 12,720 prothrombin time determinations) was similar in all 3 groups with 65% of prothrombin times in the therapeutic range (1.5 ≤prothrombin time/control ≤2.5), 30% too low, and 5% too high. Warfarin plus aspirin therapy resulted in excessive bleeding and is contraindicated. Longer follow-up study is needed to determine whether further separation of the incidence of thromboembolism can be detected.
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U2 - 10.1016/0002-9149(83)90673-2
DO - 10.1016/0002-9149(83)90673-2
M3 - Article
C2 - 6342354
AN - SCOPUS:0021104088
SN - 0002-9149
VL - 51
SP - 1537
EP - 1541
JO - The American journal of cardiology
JF - The American journal of cardiology
IS - 9
ER -