Læknablaðið - 15.01.1998, Blaðsíða 34

32
LÆKNABLAÐIÐ 1998; 84
Framskyggn rannsókn á
blóðþynningarmeðferð á
Landspítalanum
Magnús Haraldsson1’, Páll Torfi Önundarson2’, Brynja R. Guðmundsdóttir21, Kristín Á. Einarsdóttir2),
Árni Kristinsson1’, Kjartan Pálsson1’, Magnús K. Pétursson1>
Haraldsson M, Önundarson PT, Guðmundsdóttir
BR, Einarsdóttir KÁ, Kristinsson Á, Pálsson K, Pét-
ursson MK
A prospective study of oral anticoagulation therapy
nionitorcd with the P&P-test
Læknablaðið 1997; 84: 32-40
Objective: To analyze the outcome of patients on
oral anticoagulation therapy who are monitored
with the prothrombin proconvertin time (P&P-test,
PP).
Material and methods: The prothrombin-procon-
vertin time was used to adjust anticoagulant intensi-
ty in a prospective study of 326 patients treated with
oral anticoagulants for a study period of 121 patient
years. The goal intensity INR was 2.0-3.0 for all
patients. The main indications were: artificial heart
valves 26%, venousthromboembolism 25%, atrial
fibrillation 23%, atherosclerotic disease 14% and
systemic arterial embolism of uncertain etiology
7%.
Results: INR calculated directly from the PP corre-
lated well with INR calculated from the PT. The
mean time adjusted anticoagulant intensity was 2.3
and did not differ significantly according to indica-
tion. Six major bleedings, including one fatal, oc-
curred in five patients during the study period. The
INR was 1.8 in one patient who bled from a duode-
nal ulcer, but 6.8,7.9,8.6,11.6 (died) and 15.5 at five
Frá ''lyflækningadeild Landspítalans, 2)rannsóknastofa í
blóðfræði Landspítalanum. Fyrirspurnir, bréfaskipti: Páll
Torfi Önundarson, rannsóknastofu í blóðfræði, Landspítal-
anum, 101 Reykjavík.
Lykilorð: próþrombín prókonvertin tími, próþrombin timi,
blóðþynning um munn, alþjóðlegt normal hlutfall.
other events. The INR was <4.5 during 97% of the
treatment time of the whole group and 1% of treat-
ment time were at an INR>6.0. The bleeders had a
different pattern with 18% of the treatment time at
INR>6.0. The risk of bleeding was one for every 73
days at that intensity or an almost 600 fold risk
increase compared to an INR<4.5. One patient an-
ticoagulated for systemic embolism had cerebral in-
farction with an event related INR of 2.0. Two pa-
tients with atrial fibrillation died from acute myocar-
dial infarction but event related INR’s were not
available. One patient anticoagulated for venous
thromboembolism died suddenly but was not au-
topsied. No embolic events occurred in patients with
artificial heart valves in spite of the low intensity
anticoagulation.
Conclusion: Despite a relatively low intensity in all
patient groups in this study thromboembolic events
were rare. The risk of bleeding increased markedly
at INR>6.0. The mortality rate of the anticoagulat-
ed population was comparable to the expected age
adjusted Icelandic mortality rate.
Keywords: prothrombin-proconvertin time, prothrombin
time, oral anticoagulation, international normalized ratio.
Ágrip
Tilgangur: Að athuga hvernig sjúklingar á
Landspítalanum eru blóðþynntir og kanna
tíðni meiriháttar áfalla.
Efniviður og aðferðir: Metin var blóðþynn-
ing og safnað upplýsingum um áföll 326 sjúk-
linga á sex mánaða tímabili. Meðaltalsblóð-
þynning einstakra sjúklinga var fundin með því
að margfalda mælingu blóðþynningar með
dagafjölda frá síðustu mælingu, leggja saman
margfeldi tímabila og deila í summuna með
heildarfjölda meðferðardaga. Framkvæmt var
próþrombín - prókonvertínpróf (prothrombin