30-Oct-2001
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Arch Hellen Med, 2000, 17(Supplement):110-114
ORIGINAL PAPER
Experience of monitoring patients in the anticoagulant therapy
Ê. MARAGKOS, ̀. BELLIA, Å. DIGENOPOULOU, V. TSEVRENIS,
G. THEODOSIADIS, N. VGONTZA, A. GAFOU, E. NOMIKOU, A. LAGIANDREOU,
I. GEORGOPOULOS, A. KOUSOULAKOU, E. KONTOPOULOU-GRIVA
1st Blood Transfusion Center, Hippokration
General Hospital of Athens, Greece
OBJECTIVE It is generally assumed
that oral anticoagulant therapy requires frequent laboratory controls to assure
therapeutic efficacy and to prevent life threatening adverse events. We performed
this study in order to evaluate the therapeutic efficacy and the adverse events
of our Anticoagulant Therapy Outpatient Clinic.
METHOD Our outpatient clinic began its activity
in 1984 when we were treating 30 patients and we are now monitoring 850 of them.
In 1998 we treated 578 outpatients with anticoagulant therapy. From those 371
patients had mechanical heart valves, 93 atrial fibrillation, 24 mitral or aortic
valvular disease, 59 thrombosis, 11 congenital thrombophilia, 15 acquired thrombophilia
and 5 pregnancy in high risk. Their follow up constituted of the history of
their disease, laboratory testing with different thromboplastins (ISI: 1.0–1.03)
and monitoring of the anticoagulant therapy. A special card of attendance was
given to each one, as well as a book with instructions and precautions with
a special report to food and drug interactions as well as to precautions during
surgical and dental interventions or pregnancy. The therapeutic target INR for
the patients with mechanical heart valves was 2.5–3.5, for those with arteriovenous
bypass, atrial fibrillation, myocardial infraction, pulmonary embolism, and
deep vein thrombosis (DVT) was 2–3 and for prevention of DVT 2–2.5. The prescribed
anticoagulants were acenocoumarol or warfarin with or without aspirin and low
molecular weight heparins in specific situations.
RESULTS The mean frequency of laboratory testing
and monitoring of patients was three weeks with range 1–5 of weeks. The target
INR was achieved in approximately 68–71% of our patients. In 1998 eight thrombotic
events occured at INR lower than the therapeutic one, 14 bleeding events at
INR higher and two severe bleeding episodes because of oral anticoagulants plus
aspirin administration. Our results are in agreement with large clinical trials
in the current literature.
CONCLUSIONS The efficacy of anticoagulant therapy
necessitates a close control of the actual intensity of anticoagulation that
requires both patient’s obedience and close monitoring by a specifically educated
doctor in order to prevent life threatening adverse events. All of these are
achieved in specialized anticoagulant therapy outpatient clinics, that must
be organized at certain hospitals all over the country.
Key words: Adverse events, Anticoagulant therapy, Outpatient clinic.