Venous thromboembolism and the risk of subsequent symptomatic atherosclerosis.
BACKGROUND
Recently, we reported an association between asymptomatic carotid atherosclerosis and venous thromboembolism (VTE) of unknown origin. We hypothesized that patients with VTE of unknown origin would be at a higher risk of developing symptomatic atherosclerosis than patients with VTE induced by known risk factors.


METHODS
To examine this hypothesis, we studied 1,919 consecutive patients followed prospectively after their first VTE episode. The primary outcome was non-fatal and fatal symptomatic atherosclerotic disease in patients with VTE of unknown origin as compared to those with secondary VTE. An independent committee assessed all study outcomes, and adjusted hazard ratios (HR) were calculated using the Cox's proportional hazards model.


RESULTS
After a median follow-up of 48 and 51 months, respectively, at least one symptomatic atherosclerotic complication was detected in 160 of the 1,063 patients (15.1%) with VTE of unknown origin, and in 73 of the 856 (8.5%) with secondary VTE. After adjusting for age and other risk factors of atherosclerosis, the HR for symptomatic atherosclerotic complications in patients with VTE of unknown origin compared to those with secondary VTE was 1.6 (95% confidence intervals; CI: 1.2-2.0). When the analysis was restricted to patients without previous symptomatic atherosclerosis, the HR became 1.7 (95% CI: 1.1-2.4).


CONCLUSIONS
Patients with VTE of unknown origin have a 60% higher risk of developing symptomatic atherosclerotic disease than do patients with secondary venous thrombosis.
Prandoni
P
P
Department of Medical and Surgical Sciences, University Hospital of Padua, Padua, Italy. paoloprandoni@tin.it
Ghirarduzzi
A
A
Prins
M H
MH
Pengo
V
V
Davidson
B L
BL
Sørensen
H
H
Pesavento
R
R
Iotti
M
M
Casiglia
E
E
Iliceto
S
S
Pagnan
A
A
Lensing
A W A
AW
D000368:Aged; D050197:Atherosclerosis / Q000150:complications / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000150:complications* / Q000453:epidemiology / Q000209:etiology; D012306:Risk; D012307:Risk Factors; D020246:Venous Thrombosis / Q000150:complications* / Q000453:epidemiology / Q000209:etiology