AREVA: multicenter randomized comparison of low-dose versus standard-dose anticoagulation in patients with mechanical prosthetic heart valves.
BACKGROUND
Moderate anticoagulation may be proposed to reduce the risk of hemorrhage for certain patients with a mechanical prosthesis, but the consequences for risk of thromboembolism are debated.


RESULTS
The purpose of the AREVA trial was to compare moderate oral anticoagulation (international normalized ratio [INR] of 2.0 to 3.0) with the usual regimen (INR of 3.0 to 4.5) after a single-valve replacement with a mechanical prosthesis, either Omnicarbon or St Jude. Patients included were between 18 and 75 years old, in sinus rhythm, and with a left atrial diameter < or = 50 mm on the time-motion echocardiogram. Patients were randomized for INR after surgery. From 1991 to 1994, 433 patients underwent valve replacement (aortic, 414; mitral, 19) with 353 St Jude and 80 Omnicarbon prostheses; 380 patients were randomized for INR: 188 for INR 2.0 to 3.0 and 192 for INR 3.0 to 4.5. Mean follow-up was 2.2 years (1 to 4 years). Analysis of 18001 INR samples showed that the mean of the median of INR was 2.74 +/- 0.35 in the 2.0 to 3.0 group and 3.21 +/- 0.33 in the 3.0 to 4.5 group (P < .0001). Thromboembolic events, as assessed from clinical data and CT brain scans, occurred in 10 patients in the 2.0 to 3.0 INR group and 9 patients in the 3.0 to 4.5 INR group (P = .78). Hemorrhagic events occurred in 34 patients in the 2.0 to 3.0 INR group and 56 patients in the 3.0 to 4.5 INR group (P < .01), with 13 and 19 major hemorrhagic events, respectively (P = .29).


CONCLUSIONS
In selected patients with mechanical prostheses, moderate anticoagulation prevents thromboembolic events as effectively as conventional anticoagulation and reduces the incidence of hemorrhagic events.
Acar
J
J
Hôpital Tenon, Paris, France.
Iung
B
B
Boissel
J P
JP
Samama
M M
MM
Michel
P L
PL
Teppe
J P
JP
Pony
J C
JC
Breton
H L
HL
Thomas
D
D
Isnard
R
R
de Gevigney
G
G
Viguier
E
E
Sfihi
A
A
Hanania
G
G
Ghannem
M
M
Mirode
A
A
Nemoz
C
C
D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage*; D001760:Bleeding Time; D004305:Dose-Response Relationship, Drug; D005260:Female; D006350:Heart Valve Prosthesis; D006470:Hemorrhage / Q000139:chemically induced / Q000401:mortality; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016019:Survival Analysis; D013923:Thromboembolism / Q000188:drug therapy / Q000401:mortality / Q000517:prevention & control; D013997:Time Factors; D016896:Treatment Outcome
D000925:Anticoagulants