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Corresponding author: Prof. Sergio Coccheri
Università di Bologna
Via Massarenti, 9 - 40138 Bologna
Tel e Fax 051 6364668, E-mail coccheri@med.unibo.it, trombosi@orsola-malpighi.med.unibo.it
It J Practice Cardiol is available at http://www.ancecardio.it
Epidemiological notes
The incidence of confirmed venous
thromboembolism (VTE) in the overall
population, evaluated as Deep Vein
Thrombosis (DVT), ranges between 1
and 2 cases per 1000 subjects per
year (1).
In the hospitalized population asymptomatic
DVT is indeed very frequent(2):
phlebographic investigations have
shown an incidence of "instrumental"
DVT without prophylaxis as high as 40-
60% in patients after orthopedic surgery,
25% after oncological surgery,
20% after general gynecological surgery
etc. Regarding "medical" patients, phlebographic
DVT rates vary from 30% in
patients with stroke or heart failure, to
14-15% in patients with acute medical illnesses.
VTE has a surprisingly high all-cause
mortality rate, amounting to 28% within
the first 30 days and to 36% within one
year (1). Early death is due to fatal pulmonary
embolism in 20% of the lethal
cases. In the remaining cases, mortality
is due to the underlying condition
(other surgical complications, heart or
lung disease, malignancy), as DVT often
occurs in the more seriously ill patients.
Among "ambulatory" patients who refer
to Thrombosis Services for suspected
DVT, about 20% really have DVT.
The main criteria for DVT suspicion are
listed in standard scores among which
the most used are those proposed by
Wells.
Main risk factors
In the recent Olmstedt County study
(1) main risk factors for VTE appeared
to be: hospitalization for surgery or
medical illnesses, trauma, malignancy
with or without chemotherapy, neurologic
disease with extremity paresis,
and prior superficial vein thrombosis.
However, in the female sex, pregnancy,
puerperium and the use of oral contraceptives
are very relevant additional
risk factors (3,4). Regarding more specifically
Pulmonary Embolism (PE), in
the ICOPER study (5), a recent or previous
diagnosis of DVT or PE, an increased
body mass index, surgery within
2 months, bedrest for more than 5
days, cancer, current cigarette smoking,
chronic obstructive pulmonary disease,
trauma, and congestive heart failure
emerged as the main risk predictors. A
known hypercoagulable state was present
in 5% of the cases.
The thrombophilic states
Among primary thrombophilic states a
clear distinction is necessary. A first
group of thrombophilias, namely the
coagulation inhibitor deficiencies as Antithrombin
III, Protein C and Protein S
defects, carry a high risk of VTE. However,
as these defects are very rare in
the general population, their "attributable"
risk in patients with VTE remains
low. On the contrary, the more recently
described thrombophilic mutations of
factors V and II carry only a moderate
to low risk of clinical disease, but their
high prevalence in the general population
(5 to 8%) makes their "attributable"
risk relevant. Furthermore, whilst
in the first group (inhibitor deficiencies)
DVT episodes are of generally early onset
and unprovoked, in the second
group DVT is frequently triggered by
concomitant acquired risk circumstances,
the onset of first episode may be
belated, and family history may be undependable
(6).
Among the acquired, concomitant risk
circumstances, a special role must be
attributed to hormonal oral contraceptives
(OC) (7,8). We also have addres-
S. Coccheri
Venous Thromboembolism
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